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Sample records for adirondack class basalts

  1. Calcium Sulfate in Atacama Desert Basalt: A Possible Analog for Bright Material in Adirondack Basalt, Gusev Crater

    NASA Technical Reports Server (NTRS)

    Sutter, B.; Golden, D. C.; Amundson, R.; Chong-Diaz, G.; Ming, D. W.

    2007-01-01

    The Atacama Desert in northern Chile is one of the driest deserts on Earth (< 2mm/y). The hyper-arid conditions allow extraordinary accumulations of sulfates, chlorides, and nitrates in Atacama soils. Examining salt accumulations in the Atacama may assist understanding salt accumulations on Mars. Recent work examining sulfate soils on basalt parent material observed white material in the interior vesicles of surface basalt. This is strikingly similar to the bright-white material present in veins and vesicles of the Adirondack basalt rocks at Gusev Crater which are presumed to consist of S, Cl, and/or Br. The abundance of soil gypsum/anhydrite in the area of the Atacama basalt suggested that the white material consisted of calcium sulfate (Ca-SO4) which was later confirmed by SEM/EDS analysis. This work examines the Ca-SO4 of Atacama basalt in an effort to provide insight into the possible nature of the bright material in the Adirondack basalt of Gusev Crater. The objectives of this work are to (i) discuss variations in Ca-SO4 crystal morphology in the vesicles and (ii) examine the Ca-SO4 interaction(s) with the basalt interior.

  2. Alteration Mineralogy of Adirondack-class Rocks in Gusev Crater, Mars

    NASA Astrophysics Data System (ADS)

    Hamilton, V. E.; Ruff, S. W.

    2009-12-01

    The rock Adirondack is the type example of a class of basaltic rocks analyzed by the Mars Exploration Rover Spirit in Gusev crater. Thermal infrared spectra of Adirondack-class rocks acquired by the Mini-TES instrument are distinguishable from spectra of other rock classes by the presence of an emissivity peak at 430 cm-1 and a minimum near 510 cm-1, which are characteristic of olivine. This is the primary spectral class on the plains of Gusev, but spectra of rocks exhibiting similar low wavenumber spectral character have been acquired along the rover traverse in the Columbia Hills, and we have confirmed that these also are Adirondack-class. Linear mixture modeling of their infrared spectra (enabled by applying a correction for dust on the Mini-TES optics) suggests that they are mafic with sulfate minerals present as alteration phases (up to 25%) in the majority of these rocks, broadly consistent with APXS-measured chemistry. The RAT-brushed surface of an unusual plains rock referred to as Mazatzal exhibits a spectral shape and modeled mineralogy consistent with the absence of olivine and the presence of amorphous phases low in silica, and is a coating unlike any other observed on Mars. We have also used a previously-demonstrated factor analysis and target transformation (FATT) technique with Adirondack-class rock spectra to retrieve the spectral shapes of independently-varying components within the data set. Using this approach, we have identified four shapes attributable to two distinct surface components, fine particulate surface dust, and a second dust component similar to downwelling sky radiance and/or dust on the Mini-TES optics. The two surface shapes do not resemble those of the two canonical surface types measured from orbit. One of the surface shapes is very similar to that of the lherzolitic Shergottite ALH A77005. Preliminary linear mixture analysis of this shape shows that it is dominated by olivine (~57%, ~Fo45) and pyroxene (~28%), with minor

  3. Geochemical affinities of a Late Precambrian basaltic dike, Adirondack Lowlands, Northern New York

    SciTech Connect

    Badger, R.L. . Dept. of Geology)

    1993-03-01

    Late Precambrian rifting and the opening of the Iapetus Ocean basin have produced a series of NE-trending basaltic dikes in the Adirondack Lowlands of New York. Twelve samples were taken from the largest of these dikes, a 14 km long body, in order to study the chemical variability along and across strike and to characterize the source region. The dike consists of an assemblage of plagioclase, Ti-rich clinopyroxene, magnetite/ilmenite and a hydrated phase that was probably olivine. All analyzed samples contain normative olivine, and most contain normative nepheline, indicative of alkalic affinities. Chemical variations are relatively minor, with generally as much variation occurring across strike (max. width 10m) as along strike. SiO[sub 2] varies from 43.9--45.0 wt%; TiO[sub 2]: 4.8--5.1 wt%; P[sub 2]O[sub 5]: 0.8--1.1 wt%; Ni: 55--79 ppm; Sr:P 300--600 ppm; Rb: 35--66 ppm; Y/Nb = 1.1; Zr/Nb = 8. Chondrite normalized REE patterns show strong LREE enrichment. Tectonic discrimination plots (Zr--Ti/100--Y[star]) are indicative of within plate magmatism, and plots of Y/nb vs. Zr/Nb suggest an enriched, OIB-type mantle plume source. Trace element characteristics suggest a genetic correlation with Late Precambrian, rift related magmas of the Ottawa Graben and of the eastern Adirondack Mountains and western Vermont.

  4. Formation of Fe/mg Smectite Under Acidic Conditions from Synthetic Adirondack Basaltic Glass: an Analog to Fe/mg Smectite Formation on Mars

    NASA Technical Reports Server (NTRS)

    Sutter, B.; Peretyazhko, T.; Morris, R. V.; Ming, D. W.

    2014-01-01

    Smectite has been detected as layered material hundreds of meters thick, in intracrater depositional fans, in plains sediments, and deposits at depth on Mars. If early Mars hosted a dense CO2 atmosphere, then extensive carbonate should have formed in the neutral/alkaline conditions expected for smectite formation. However, large carbonate deposits on Mars have not been discovered. Instead of neutral to moderately alkaline conditions, early Mars may have experienced mildly acidic conditions that allowed for Fe/Mg smectite formation but prevented widespread carbonate formation. The objective of this work is to demonstrate that Fe(II)/Mg saponite and nontronite can form in mildly acidic solutions (e.g., pH 4). Synthetic basaltic glass (< 53 microns) of Adirondack rock class composition was exposed to pH 4 (acetic acid buffer) and N2 purged (anoxic) solutions amended with 0 and 10 mM Mg or Fe(II). Basaltic glass in these solutions was heated to 200 C in batch reactors for 1, 7, and 14 days. X-ray diffraction analysis of reacted materials detected the presence of phyllosilicates as indicated by a approx. 15.03-15.23Angstroms (001) peak. Smectite was confirmed as the phyllosilicate after treatments with glycerol and KCl and heating to 550 C. Trioctahedral saponite was confirmed by the presence of a 4.58 to 4.63 Angstroms (02l) and 1.54Angstroms (060) peaks. Saponite concentration was highest, as indicated by XRD peak intensity, in the 10 mM Mg treatment followed by the 0 mM and then 10 mM Fe(II) treatments. This order of sapontite concentration suggests that Fe(II) additions may have a role in slowing the kinetics of saponite formation relative to the other treatments. Nontronite synthesis was attempted by exposing Adirondack basaltic glass to pH 4 oxic solutions (without N2 purge) at 200 C for 14 days. X-ray diffraction analysis indicated that mixtures of trioctahedral (saponite) and dioctahedral (nontronite) may have formed in these experiments based on the 02l and 060

  5. Formation of Fe/Mg Smectite under acidic conditions from synthetic Adirondack Basaltic Glass: An Analog to Fe/Mg Smectite Formation on Mars.

    NASA Astrophysics Data System (ADS)

    Sutter, B.; Peretyazhko, T.; Morris, R. V.; Ming, D. W.

    2014-12-01

    Smectite has been detected as layered material hundreds of meters thick, in intracrater depositional fans, in plains sediments, and deposits at depth on Mars. If early Mars hosted a dense CO2 atmosphere, then extensive carbonate should have formed in the neutral/alkaline conditions expected for smectite formation. However, large carbonate deposits on Mars have not been discovered. Instead of neutral to moderately alkaline conditions, early Mars may have experienced mildly acidic conditions that allowed for Fe/Mg smectite formation but prevented widespread carbonate formation. The objective of this work is to demonstrate that Fe(II)/Mg-saponite and nontronite can form in mildly acidic solutions (e.g., pH 4). Synthetic basaltic glass (< 53 μm) of Adirondack rock class composition was exposed to pH 4 (acetic acid buffer) and N2 purged (anoxic) solutions amended with 0 and 10 mM Mg or Fe(II). Basaltic glass in these solutions was heated to 200ºC in batch reactors for 1, 7, and 14 days. X-ray diffraction analysis of reacted materials detected the presence of phyllosilicates as indicated by a ~15.03-15.23Ǻ (001) peak. Smectite was confirmed as the phyllosilicate after treatments with glycerol and KCl and heating to 550°C. Trioctahedral saponite was confirmed by the presence of a 4.58 to 4.63 Ǻ (02l) and 1.54Ǻ (060) peaks. Saponite concentration was highest, as indicated by XRD peak intensity, in the 10 mM Mg treatment followed by the 0 mM and then 10 mM Fe(II) treatments. This order of sapontite concentration suggests that Fe(II) additions may have a role in slowing the kinetics of saponite formation relative to the other treatments. Nontronite synthesis was attempted by exposing Adirondack basaltic glass to pH 4 oxic solutions (without N2 purge) at 200ºC for 14 days. X-ray diffraction analysis indicated that mixtures of trioctahedral (saponite) and dioctahedral (nontronite) may have formed in these experiments based on the 02l and 060 peaks. Mössbauer analysis

  6. Adirondack's Inner Self

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This spectrum - the first taken of a rock on another planet - reveals the different iron-containing minerals that makeup the martian rock dubbed Adirondack. It shows that Adirondack is a type of volcanic rock known as basalt. Specifically, the rock is what is called olivine basalt because in addition to magnetite and pyroxene, two key ingredients of basalt, it contains a mineral called olivine. This data was acquired by Spirit's Moessbauer spectrometer before the rover developed communication problems with Earth on the 18th martian day, or sol, of its mission.

  7. Basaltic Soil of Gale Crater: Crystalline Component Compared to Martian Basalts and Meteorites

    NASA Technical Reports Server (NTRS)

    Treiman, A. H.; Bish, D. L.; Ming, D. W.; Morris, R. V.; Schmidt, M.; Downs, R. T.; Stolper, E. M.; Blake, D. F.; Vaniman, D. T.; Achilles, C. N.; Chipera, S. J.; Bristow, T. F.; Crisp, J. A.; Farmer, J. A.; Morookian, J. M.; Morrison, S. M.; Rampe, E. B.; Sarrazin, P.; Yen, A. S.; Anderosn, R. C.; DesMarais, D. J.; Spanovich, N.

    2013-01-01

    A significant portion of the soil of the Rocknest dune is crystalline and is consistent with derivation from unweathered basalt. Minerals and their compositions are identified by X-ray diffraction (XRD) data from the CheMin instrument on MSL Curiosity. Basalt minerals in the soil include plagioclase, olivine, low- and high-calcium pyroxenes, magnetite, ilmenite, and quartz. The only minerals unlikely to have formed in an unaltered basalt are hematite and anhydrite. The mineral proportions and compositions of the Rocknest soil are nearly identical to those of the Adirondack-class basalts of Gusev Crater, Mars, inferred from their bulk composition as analyzed by the MER Spirit rover.

  8. Magnetite in Martian Meteorite Mil 03346 and Gusev Adirondack Class Basalt: Mossbauer Evidence for Variability in the Oxidation State of Adirondack Lavas

    NASA Technical Reports Server (NTRS)

    Morris, R. V.; McKay, G. A.; Ming, D. W.; Klingelhoefer, G.; Schroeder, C.; Rodionov, D.; Yen, A.

    2006-01-01

    The Moessbauer spectrometers on the Mars Exploration Rovers Spirit (Gusev crater) and Opportunity (Meridiani Planum) have returned information on the oxidation state of iron, the mineralogical composition of Fe-bearing phases, and the distribution of Fe among oxidation states and phases [1,2,3]. To date, approx.100 and approx.85 surface targets have been analyzed by the Spirit and Opportunity spectrometers, respectively. Twelve component subspectra (8 doublets and 4 sextets) have been identified and most have been assigned to mineralogical compositions [4]. Two sextet subspectra result from the opaque and strongly magnetic mineral magnetite (Fe3O4 for the stoichiometric composition), one each for the crystallographic sites occupied by tetrahedrally-coordinated Fe3+ and by octahedrally-coordinated Fe3+ and Fe2+. At Gusev crater, the percentage of total Fe associated with magnetite for rocks ranges from 0 to approx. 35% (Fig. 1) [3]. The range for soils (approx.5 to approx.12% of total Fe from Mt, with one exception) is narrower. The ubiquitous presence of Mt in soil firmly establishes the phase as the strongly magnetic component in martian soil [4,5].

  9. Magnetite in Martian Meteorite Mil 03346 and Gusev Adirondack Class Basalt: Moessbauer Evidence for Variability in the Oxidation State of Adirondack Lavas

    NASA Technical Reports Server (NTRS)

    Morris, R. V.; McKay, G. A.; Ming, D. W.; Klingelhoefer, G.; Schroeder, C.; Rodionov, D.; Yen, A.

    2006-01-01

    The Moessbauer spectrometers on the Mars Exploration Rovers Spirit (Gusev crater) and Opportunity (Meridiani Planum) have returned information on the oxidation state of iron, the mineralogical composition of Fe-bearing phases, and the distribution of Fe among oxidation states and phases [1,2,3]. To date, 100 and 85 surface targets have been analyzed by the Spirit and Opportunity spectrometers, respectively. Twelve component subspectra (8 doublets and 4 sextets) have been identified and most have been assigned to mineralogical compositions [4]. Two sextet subspectra result from the opaque and strongly magnetic mineral magnetite (Fe3O4 for the stoichiometric composition), one each for the crystallographic sites occupied by tetrahedrally-coordinated Fe3+ and by octahedrally-coordinated Fe3+ and Fe2+. At Gusev crater, the percentage of total Fe associated with magnetite for rocks ranges from 0 to 35% (Fig. 1) [3]. The range for soils (5 to 12% of total Fe from Mt, with one exception) is narrower. The ubiquitous presence of Mt in soil firmly establishes the phase as the strongly magnetic component in martian soil

  10. The effects of weathering on the strength and chemistry of Columbia River Basalts and their implications for Mars Exploration Rover Rock Abrasion Tool (RAT) results

    NASA Astrophysics Data System (ADS)

    Thomson, B. J.; Hurowitz, J. A.; Baker, L. L.; Bridges, N. T.; Lennon, A. M.; Paulsen, G.; Zacny, K.

    2014-08-01

    Basalt physical properties such as compressive strength and density are directly linked to their chemistry and constitution; as weathering progresses, basalts gradually become weaker and transition from intact rock to saprolite and ultimately, to soil. Here we quantify the degree of weathering experienced by the Adirondack-class basalts at the Mars Exploration Rover Spirit site by performing comparative analyses on the strength and chemistry of a series of progressively weathered Columbia River Basalt (CRB) from western Idaho and eastern Washington. CRB samples were subjected to compressive strength tests, Rock Abrasion Tool grinds, neutron activation analysis, and inductively coupled plasma optical emission spectroscopy. Analyses of terrestrial basalts indicate linked strength-chemical changes, as expected. Weathering sufficient to induce the loss of more than 50% of some cations (including >50% of MgO and MnO as well as ∼38% of Fe2O3 and 34% of CaO) was observed to weaken these samples by as much as 50% of their original strength. In comparison with the terrestrial samples, Adirondack-class basalts are most similar to the weakest basalt samples measured in terms of compressive strength, yet they do not exhibit a commensurate amount of chemical alteration. Since fluvial and lacustrine activity in Gusev crater appears to have been limited after the emplacement of flood basalt lavas, the observed weakness is likely attributable to thin-film weathering on exposed, displaced rocks in the Gusev plains (in addition to some likely shock effects). The results indicate that Adirondack-class basalts may possess a several mm-thick weak outer rind encasing an interior that is more pristine than otherwise indicated, and also suggest that long rock residence times may be the norm.

  11. Adirondack Under the Microscope

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This image was taken by the Mars Exploration Rover Spirit front hazard-identification camera after the rover's first post-egress drive on Mars Sunday, Jan. 15, 2004. Engineers drove the rover approximately 3 meters (10 feet) from the Columbia Memorial Station toward the first rock target, seen in the foreground. The football-sized rock was dubbed Adirondack because of its mountain-shaped appearance. Scientists have begun using the microscopic imager instrument at the end of the rover's robotic arm to examine the rock and understand how it formed.

  12. Adirondack Under the Microscope-2

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This overhead look at the martian rock dubbed Adirondack was captured by the Mars Exploration Rover Spirit's panoramic camera. It shows the approximate region where the rover's microscopic imager began its first close-up inspection.

  13. Smectite Formation from Basaltic Glass Under Acidic Conditions on Mars

    NASA Technical Reports Server (NTRS)

    Peretyazhko, T. S.; Sutter, B.; Morris, R. V.; Agresti, D. G.; Le, L.; Ming, D. W.

    2015-01-01

    Massive deposits of phyllosilicates of the smectite group, including Mg/Fe-smectite, have been identified in Mars's ancient Noachian terrain. The observed smectite is hypothesized to form through aqueous alteration of basaltic crust under neutral to alkaline pH conditions. These pH conditions and the presence of a CO2-rich atmosphere suggested for ancient Mars were favorable for the formation of large carbonate deposits. However, the detection of large-scale carbonate deposits is limited on Mars. We hypothesized that smectite deposits may have formed under acidic conditions that prevented carbonate precipitation. In this work we investigated formation of saponite at a pH of approximately 4 from Mars-analogue synthetic Adirondack basaltic glass of composition similar to Adirondack class rocks located at Gusev crater. Hydrothermal (200º Centigrade) 14 day experiments were performed with and without 10 millimoles Fe(II) or Mg under anoxic condition [hereafter denoted as anoxic_Fe, anoxic_Mg and anoxic (no addition of Fe(II) or Mg)] and under oxic condition [hereafter denoted as oxic (no addition of Fe(II) or Mg)]. Characterization and formation conditions of the synthesized saponite provided insight into the possible geochemical conditions required for saponite formation on Mars.

  14. Basalt-Trachybasalt Fractionation in Gale Crater, Mars

    NASA Astrophysics Data System (ADS)

    Bridges, J. C.; Edwards, P. H.; Filiberto, J.; Schwenzer, S. P.; Gasda, P.; Wiens, R.

    2016-08-01

    A set of igneous float rocks in Gale Crater have been analysed by ChemCam. They are basalt-trachybasalts, 47 to 53 ± 5 wt% SiO2 and formed by ol-dominated crystal fractionation from an Adirondack type basalt, in magmatism with tholeiitic affinities.

  15. Adirondack tourism: perceived consequences of acid rain

    SciTech Connect

    Metz, W.C.

    1984-03-01

    This report seeks to place in perspective the perceived effects of acid precipitation on the tourist industry in the Adirondacks. The 9375-square mile park is host to almost nine million tourists annually, not including seasonal residents. Since the park was established almost 100 years ago, there have been many changes in tourist characteristics, available recreational facilities, kinds of activities, accessibility of the area, and land use and resource management policies. The tourist industry has been influenced by both controllable and uncontrollable factors. At present the overwhelming majority of recreational opportunities and natural resources important to the Adirondack tourist industry are relatively unaffected by acid precipitation. Fishing, a significant component of the tourist industry, is the most vulnerable, but any presumed adverse economic effect has to be weighed against the location of the impacted waters, total Adirondack fishing habitat, substitution available, habitat usage, fisherman characteristics, resource management, and the declining importance of fishing as an Adirondack recreational attraction. Concern is expressed as to whether present minimal acidification impacts are the precursor of major future impacts on Adirondack terrestrial and aquatic environments, and ultimately tourism. Tourism in the Adirondacks is increasing, while many other regional employment sectors are declining. It is becoming a more stable multiseason industry. Its future growth and character will be affected by government, private organization, business community, and resident controversies regarding land use and resource management attitudes, policies, budgets, and regulations. The acid precipitation issue is only one of many related controversies. 65 references, 2 figures.

  16. Nitrate deposition and impact on Adirondack streams

    SciTech Connect

    Simonin, H.A.; Kretser, W.A.

    1997-12-31

    Acidic deposition has a great impact on water chemistry and fish populations in the Adirondack region. Although the Clean Air Act Amendments of 1990 have resulted in some reductions of sulfate deposition, nitrate deposition has not yet been well controlled, and continues to impact aquatic resources. As part of the USEPA funded Episodic Response Project four Adirondack headwater streams were intensively monitored over an 18 month period. Atmospheric deposition was also monitored at a centrally located station. The quantity of nitrate being deposited on the study watersheds was calculated based on monthly net deposition data which ranged from 0.6 kg/ha/month to 3.6 kg/ha/month. These data were then compared to the monthly export of nitrate from the watershed in these streams. Nitrate concentrations were highest in the streamwater during the spring snowmelt period prior to the time when forest vegetation actively utilizes nitrate. On an annual basis the amount of nitrate which left the watershed via stream water exceeded the amount which fell as nitrate deposition. These data are important in documenting the impact of nitrate in the acidification of Adirondack streams during the spring, which coincides with brook trout hatching. Control programs for nitrous oxide emissions are presently aimed at reducing ozone levels during the May-September period. These emissions control programs need to be expanded to also reduce nitrate deposition in the sensitive Adirondack region during the winter and spring periods when nitrate deposition has its greatest impact on aquatic resources.

  17. Adirondack Post-Drill (3-D)

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This is a 3-D anaglyph showing a microscopic image taken of an area measuring 3 centimeters (1.2 inches) across on the rock called Adirondack. The image was taken at Gusev Crater on the 33rd day of the Mars Exploration Rover Spirit's journey (Feb. 5, 2004), after the rover used its rock abrasion tool to drill into the rock. Debris from the use of the tool is visible to the left of the hole.

  18. Fluid-absent metamorphism in the Adirondacks

    NASA Technical Reports Server (NTRS)

    Valley, J. W.

    1986-01-01

    Results on late Proterozoic metamorphism of granulite in the Adirondacks are presented. There more than 20,000 sq km of rock are at granulite facies. Low water fugacites are implied by orthopyroxene bearing assemblages and by stability of k'spar-plag-quartz assemblages. After mentioning the popular concept of infiltration of carbon dioxide into Precambrian rocks and attendent generation of granulite facies assemblages, several features of Adirondack rocks pertinent to carbon dioxide and water during their metamorphism are summarized: wollastonite occurs in the western lowlands; contact metamorphism by anorthosite preceeding granulite metamorphism is indicated by oxygen isotopes. Oxygen fugacity lies below that of the QFM buffer; total P sub water + P sub carbon dioxide determined from monticellite bearing assemblages are much less than P sub total (7 to 7.6 kb). These and other features indicate close spatial association of high- and low-P sub carbon dioxide assemblages and that a vapor phase was not present during metamorphism. Thus Adirondack rocks were not infiltrated by carbon dioxide vapor. Their metamorphism, at 625 to 775 C, occurred either when the protoliths were relatively dry or after dessication occurred by removal of a partial melt phase.

  19. The primary fO2 of basalts examined by the Spirit rover in Gusev Crater, Mars: Evidence for multiple redox states in the martian interior

    NASA Astrophysics Data System (ADS)

    Schmidt, Mariek E.; Schrader, Christian M.; McCoy, Timothy J.

    2013-12-01

    The primary oxygen fugacity (fO2) of basaltic melts reflects the mantle source oxidation state, dictates the crystallizing assemblage, and determines how the magma will evolve. Basalts examined by the Spirit Mars Exploration Rover in Gusev Crater range from the K-poor Adirondack class (0.02 wt% K2O) to K-rich Backstay class (up to 1.2 wt% K2O) and exhibit substantially more variation than observed in martian basaltic meteorites. The ratios of ferric to total iron (Fe3+/FeT) measured by the Mössbauer spectrometer are high (equivalent to -0.76 to +2.98ΔQFM; quartz-fayalite-magnetite buffer as defined by Wones and Gilbert, 1969), reflecting secondary Fe3+ phases. By combining the Fe3+/FeT of the igneous minerals (olivine, pyroxene, and magnetite) determined by Mössbauer spectrometer, we estimate primary fO2 for the Gusev basalts to be -3.6 to 0.5ΔQFM. Estimating the fO2 as a function of the dependence of the CIPW normative fayalite/magnetite ratios on Fe3+/FeT yields a slightly smaller range of -2.58 to +0.57ΔQFM. General similarity between the fO2 estimated for the Gusev basalts and ranges in fO2 for the shergottitic meteorites (-3.8 to 0.2ΔQFM; Herd, 2003; Goodrich et al., 2003) suggests that the overall range of fO2 for the martian igneous rocks and mantle is relatively restricted. Like the shergottites (Herd, 2003), estimated fO2 of three Gusev classes (Adirondack, Barnhill and Irvine) correlates with a proxy for LREE enrichment (K2O/TiO2). This suggests mixing between melts or fluids derived from reservoirs with contrasting fO2 and REE characteristics. Oxygen fugacity estimates for the martian interior suggest that tectonic processes have not led to sufficient recycling of oxidized surface material into the martian interior to entirely affect the overall oxidation state of the mantle.

  20. Spirit Takes a Turn for Adirondack

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This rear hazard-identification camera image looks back at the circular tracks made in the martian soil when the Mars Exploration Rover Spirit drove about 3 meters (10 feet) toward the mountain-shaped rock called Adirondack, Spirit's first rock target. Spirit made a series of arcing turns totaling approximately 1 meter (3 feet). It then turned in place and made a series of short, straightforward movements totaling approximately 2 meters (6.5 feet). The drive took about 30 minutes to complete, including time stopped to take images. The two rocks in the upper left corner of the image are called 'Sashimi' and 'Sushi.' In the upper right corner is a portion of the lander, now known as the Columbia Memorial Station.

  1. Factors affecting acid neutralizing capacity in the Adirondack region of New York: a solute mass balance approach.

    PubMed

    Ito, Mari; Mitchell, Myron J; Driscoll, Charles T; Roy, Karen M

    2005-06-01

    High rates of acidic deposition in the Adirondack region of New York have accelerated acidification of soils and surface waters. Annual input-output budgets for major solutes and acid-neutralizing capacity (ANC) were estimated for 43 drainage lake-watersheds in the Adirondacks from 1998 to 2000. Sulfate was the predominant anion on an equivalent basis in both precipitation and drainage export. Calcium ion had the largest cation drainage export, followed by Mg2+. While these watersheds showed net nitrogen (N) retention, the drainage losses of SO4(2-), Cl-, base cations, and ANC exceeded their respective inputs from precipitation. Land cover (forest type and wetlands) affected the export of SO4(2-), N solutes, and dissolved organic carbon (DOC). The relationships of solute export with elevation (negative for base cations and Cl-, positive for NO3- and H+) suggest the importance of the concomitant changes of biotic and abiotic watershed characteristics associated with elevational gradients. The surface water ANC increased with the sum of base cations and was greatest in the lakes with watersheds characterized by thick deposits of glacial till. The surface water ANC was also higher in the lake-watersheds with lower DOC export. Some variation in lake ANC was associated with variability in acidic deposition. Using a classification system previously developed for Adirondack lakes on the basis primarily of surficial geology, lake-watersheds were grouped into five classes. The calculated ANC fluxes based on the major sinks and sources of ANC were comparable with measured ANC for the thick-till (I) and the medium-till lake-watersheds with low DOC (II). The calculated ANC was overestimated for the medium-till with high DOC (III) and the thin-till with high DOC (V) lake-watersheds, suggesting the importance of naturally occurring organic acids as an ANC sink, which was not included in the calculations. The lower calculated estimates than the measured ANC for the thin-till lake

  2. Acid Rain Effects on Adirondack Streams - Results from the 2003-05 Western Adirondack Stream Survey (the WASS Project)

    USGS Publications Warehouse

    Lawrence, Gregory B.; Roy, Karen M.; Baldigo, Barry P.; Simonin, Howard A.; Passy, Sophia I.; Bode, Robert W.; Capone, Susan B.

    2009-01-01

    Traditionally lakes have been the focus of acid rain assessments in the Adirondack region of New York. However, there is a growing recognition of the importance of streams as environmental indicators. Streams, like lakes, also provide important aquatic habitat, but streams more closely reflect acid rain effects on soils and forests and are more prone to acidification than lakes. Therefore, a large-scale assessment of streams was undertaken in the drainage basins of the Oswegatchie and Black Rivers; an area of 4,585 km2 in the western Adirondack region where acid rain levels tend to be highest in New York State.

  3. Condition of Education in the Adirondack Blue Line.

    ERIC Educational Resources Information Center

    New York State Education Dept., Albany.

    This document profiles education in the Adirondack Park area of upstate New York. The introduction describes the Adironack Blue Line area, its school districts, and its revenues for school funding. Elementary and secondary education are described in terms of attendance rates, pupil-teacher ratio, teacher turnover rate, and median teacher salaries…

  4. VALUATION OF NATURAL RESOURCE IMPROVEMENTS IN THE ADIRONDACKS

    EPA Science Inventory

    The benefits of improving natural resources in the Adirondacks are estimated to be between $336 million and $1.1 billion per year (2003$), according to a new study by Resources for the Future. The five-year study, supported by an EPA grant, estimates New Yorkers willingness-to-...

  5. A comparison of the temporally integrated monitoring of ecosystems and Adirondack Long Term-Monitoring programs in the Adirondack Mountain region of New Yrok

    EPA Science Inventory

    This paper compares lake chemistry in the Adirondack region of New York measured by the Temporally Integrated Monitoring of Ecosystems (TIME) and Adirondack Long-Term Monitoring (ALTM) programs by examining the data from six lakes common to both programs. Both programs were initi...

  6. Granite emplacement during tectonic exhumation: The Adirondack example

    NASA Astrophysics Data System (ADS)

    Selleck, Bruce W.; McLelland, James M.; Bickford, M. E.

    2005-10-01

    Sensitive high-resolution ion microprobe U-Pb zircon ages for late to posttectonic leucogranites fix the timing of extensional collapse of a portion of the Mesoproterozoic Grenville orogen of eastern North America. Plutons of Lyon Mountain Granite (LMG) were emplaced within the Carthage Colton shear zone synchronously with formation of extensional mylonite at 1045 1037 Ma. Leucogranite melts were generated in the hot granulite facies core of the Adirondack Highlands Central Granulite terrane that served as the lower plate for down-to-the-northwest extension. The LMG suite is associated with high-temperature hydrothermal magnetite deposits in the Adirondack Highlands, and widespread Cl + CO2 hydrothermal alteration of upper-plate rocks is localized along the Carthage Colton shear zone where LMG granites are present. The relationships between melt generation, granite intrusion, high strain rates, extensional collapse, and high- temperature hydrothermal activity provide a framework for understanding midcrustal processes in modern and ancient orogenic belts.

  7. Shock metamorphism of lunar and terrestrial basalts

    NASA Technical Reports Server (NTRS)

    Schaal, R. B.; Hoerz, F.

    1977-01-01

    Lonar Crater (India) basalt and lunar basalt 75035 were shock loaded under controlled laboratory conditions up to 1000 kbar, generally in a CO/CO2 (1:1) environment evacuated to 10 to the minus seventh power torr. The Kieffer et al. (1976) classification scheme of progressive shock metamorphism is found to apply to lunar basalts. The major shock features of the five classes that span the range 0 to 1000 kbar are described. Only three out of 152 basalt specimens show shock effects in their natural state as severe as Class 2 features. The scarcity of shocked basalt hand samples in contrast to the abundance of shock-produced agglutinates and homogeneous glass spheres in the lunar regolith indicates the dominant role of micrometeorite impact in the evolution of the lunar regolith. The overall glass content in asteroidal and Mercurian regoliths is considered.

  8. Acidification in the Adirondacks: defining the biota in trophic levels of 30 chemically diverse acid-impacted lakes.

    PubMed

    Nierzwicki-Bauer, Sandra A; Boylen, Charles W; Eichler, Lawrence W; Harrison, James P; Sutherland, James W; Shaw, William; Daniels, Robert A; Charles, Donald F; Acker, Frank W; Sullivan, Timothy J; Momen, Bahram; Bukaveckas, Paul

    2010-08-01

    The Adirondack Mountains in New York State have a varied surficial geology and chemically diverse surface waters that are among the most impacted by acid deposition in the U.S. No single Adirondack investigation has been comprehensive in defining the effects of acidification on species diversity, from bacteria through fish, essential for understanding the full impact of acidification on biota. Baseline midsummer chemistry and community composition are presented for a group of chemically diverse Adirondack lakes. Species richness of all trophic levels except bacteria is significantly correlated with lake acid-base chemistry. The loss of taxa observed per unit pH was similar: bacterial genera (2.50), bacterial classes (1.43), phytoplankton (3.97), rotifers (3.56), crustaceans (1.75), macrophytes (3.96), and fish (3.72). Specific pH criteria were applied to the communities to define and identify acid-tolerant (pH<5.0), acid-resistant (pH 5.0-5.6), and acid-sensitive (pH>5.6) species which could serve as indicators. Acid-tolerant and acid-sensitive categories are at end-points along the pH scale, significantly different at P<0.05; the acid-resistant category is the range of pH between these end-points, where community changes continually occur as the ecosystem moves in one direction or another. The biota acid tolerance classification (batc) system described herein provides a clear distinction between the taxonomic groups identified in these subcategories and can be used to evaluate the impact of acid deposition on different trophic levels of biological communities.

  9. Diatom diversity in chronically versus episodically acidified adirondack streams

    USGS Publications Warehouse

    Passy, S.I.; Ciugulea, I.; Lawrence, G.B.

    2006-01-01

    The relationship between algal species richness and diversity, and pH is controversial. Furthermore, it is still unknown how episodic stream acidification following atmospheric deposition affects species richness and diversity. Here we analyzed water chemistry and diatom epiphyton dynamics and showed their contrasting behavior in chronically vs. episodically acidic streams in the Adirondack region. Species richness and diversity were significantly higher in the chronically acidic brown water stream, where organic acidity was significantly higher and the ratio of inorganic to organic monomeric aluminum significantly lower. Conversely, in the episodically acidic clear water stream, the inorganic acidity and pH were significantly higher and the diatom communities were very species-poor. This suggests that episodic acidification in the Adirondacks may be more stressful for stream biota than chronic acidity. Strong negative linear relationships between species diversity, Eunotia exigua, and dissolved organic carbon against pH were revealed after the influence of non-linear temporal trends was partialled out using a novel way of temporal modeling. ?? 2006 WILEY-VCH Verlag GmbH & Co. KGaA.

  10. Decline of red spruce in the Adirondacks, New York

    SciTech Connect

    Scott, J.T.; Siccama, T.G.; Johnson, A.H.; Breisch, A.R.

    1984-01-01

    Thirty-two stands in the spruce-fir forests of Whiteface Mountain in the Adirondacks, originally sampled from 1964-66, were resurveyed in 1982. From 10-25 Bitterlich points were used in each stand in 1982 to obtain an estimate of basal area per hectare. Data were summarized for low elevation (<900m) and high elevation (> or = 900m) forests. Red spruce declined by 40-60% in basal area for the low elevation forests and by 60-70% above 900m. Balsam fir decreased by 35% at high elevations, due to natural disturbance in several of the stands, but was unchanged when only undisturbed stands were considered. The decline of red spruce accounted for about three quarters of the total decrease in basal area for both the high- and low-elevation forests. Spruce seedling frequency for the high-elevation sample decreased by 80%, but was unchanged below 900m. The pattern of spruce decline in the Adirondacks is similar to findings for New England. The cause of the decline is speculative at the time.

  11. Continental Flood Basalts

    NASA Astrophysics Data System (ADS)

    Continental flood basalts have been receiving considerable scientific attention lately. Recent publications have focused on several particular flood-basalt provinces (Brito-Arctic, Karoo, Parana', Deccan, and Columbia Plateau), and much attention has been given to the proposed connection between flood-basalt volcanism, bolide impacts, and mass extinctions. The editor of Continental Flood Basalts, J. D. Macdougall, conceived the book to assemble in a single volume, from a vast and scattered literature, an overview of each major post-Cambrian flood-basalt province.Continental Flood Basalts has 10 chapters; nine treat individual flood-basalt provinces, and a summary chapter compares and contrasts continental flood-basalts and mid-oceanic ridge basalts. Specifically, the chapters address the Columbia River basalt, the northwest United States including the Columbia River basalt, the Ethiopian Province, the North Atlantic Tertiary Province, the Deccan Traps, the Parana' Basin, the Karoo Province, the Siberian Platform, and Cenozoic basaltic rocks in eastern China. Each chapter is written by one or more individuals with an extensive background in the province.

  12. Adirondack lakes survey: An interpretive analysis of fish communities and water chemistry, 1984--1987

    SciTech Connect

    Baker, J.P. , Raleigh, NC ); Gherini, S.A.; Munson, R.K. ); Christensen, S.W. ); Driscoll, C.T. ); Gallagher, J. ); Newton, R.M. ); Reckhow, K.H. ); Schofield, C.L. (Co

    1990-01-01

    The Adirondack Lakes Survey Corporation (ALSC) was formed as a cooperative effort of the New York State Department of Environmental Conservation and the Empire State Electric Energy Research Corporation to better characterize the chemical and biological status of Adirondack lakes. Between 1984 and 1987, the ALSC surveyed 1469 lakes within the Adirondack ecological zone. As a follow-up to the survey, the ALSC sponsored a series of interpretive analyses of the ALSC data base. The primary objectives of these analyses were as follows: Evaluate the influence of mineral acids (from acidic deposition) and nonmineral acids (natural organic acids) on lake pH levels; classify Adirondack lakes according to lake and watershed features expected to influence their responsiveness to changes in acidic deposition; evaluate the sensitivity of Adirondack lakes to changes in environmental conditions, such as changes in mineral acids or dissolved organic carbon concentrations; identify lake characteristics important in explaining the observed present-day status of fish communities in Adirondack lakes, in particular the relative importance of lake acidity; evaluate changes that have occurred over time in Adirondack fish communities and probable causes for these trends by using the available historical data on fish communities in the Adirondacks and the ALSC data base; and determine the degree to which the existing fish resource might be at risk from continued acidic deposition, or might recover if acidity levels were reduced. The basic approach examined relationships observed in the ALSC data base among watershed characteristics, lake chemistry, and fish status. Individual reports are processed separately for the data bases.

  13. Oxygen isotope evidence for shallow emplacement of Adirondack anorthosite

    USGS Publications Warehouse

    Valley, J.W.; O'Neil, J.R.

    1982-01-01

    Oxygen isotopic analysis of wollastonites from the Willsboro Mine, Adirondack Mountains, New York reveals a 400-ft wide zone of 18O depletion at anorthosite contacts. Values of ??18O vary more sharply with distance and are lower (to -1.3) than any yet reported for a granulite fades terrain. Exchange with circulating hot meteoric water best explains these results and implies that the anorthosite was emplaced at relatively shallow depths, <10 km, in marked contrast to the depth of granulite fades metamorphism (23 km). These 18O depletions offer the first strong evidence for shallow emplacement of anorthosite within the Grenville Province and suggest that regional metamorphism was a later and tectonically distinct event. ?? 1982 Nature Publishing Group.

  14. Post-granulite facies fluid infiltration in the Adirondack Mountains

    SciTech Connect

    Morrison, J.; Valley, J.W.

    1988-06-01

    Granulite facies lithologies from the Adirondack Mountains of New York contain alteration assemblages composed dominantly of calcite +/- chlorite +/- sericite. These assemblages document fluid infiltration at middle to upper crustal levels. Cathodoluminescence of samples from the Marcy anorthosite massif indicates that the late fluid infiltration is more widespread than initially indicated by transmitted-light petrography alone. Samples that appear unaltered in transmitted light show extensive anastomosing veins of calcite (< 0.05 mm wide) along grain boundaries, in crosscutting fractures, and along mineral cleavages. The presence of the retrograde calcite documents paleopermeability in crystalline rocks and is related to the formation of high-density CO/sub 2/-rich fluid inclusions. Recognition of this process has important implications for studies of granulite genesis and the geophysical properties of the crust.

  15. Non-primary layering in some Adirondack orthogneisses

    SciTech Connect

    Levy, R.; McLelland, J.; Ritter, A. . Geology Dept.)

    1993-03-01

    Metamorphic, as opposed to primary, layering has been shown to be important in many tectonites. Within orthogneisses additional types of non-primary layering are common and have important genetic implications. Here the authors cite three Adirondack examples. (1) Hyde School Gneiss of the Adirondack Lowlands contains semi-continuous layers of foliated amphibolite arranged parallel to contacts and early foliation and disrupted by pegmatitic, alaskitic, and tonalitic host rock. Layering appears to be the result of penetration of amphibolite by granitoid magma first along extensional fractures and then parallel to foliation. Intrusion is envisaged to take place in active shear zones initially occupied by foliated amphibolite that is subsequently penetrated parallel to foliation by granitoids. (2) South of Elizabethtown foliated, isoclinally folded gabbroic anorthosite is well layered with garnetiferous amphibolite, quartz-feldspar gneiss, and calcsilicate. Because of rock composition, the layering cannot be due to metavolcanic sequences nor can disruption be attributed to partial melting. A satisfactory interpretation is that gabbroic anorthosite intruded mafic and carbonate-rich rocks in lit-par-lit fashion. (3) North of Speculator a garnetiferous amphibolite/gabbro has been intruded by granite now containing xenoliths, some with ophitic opx. Much of the layering in the granite consists of clots of plagioclase, garnet, pyroxene (chloritized) arranged in parallel. These are interpreted as small xenoliths of garnetiferous amphibolite/gabbro entrained into the granitic magma and strung out in the direction of flow. These examples provide further evidence that layering can develop during magmatic emplacement and need not represent primary stratification. Assignment of a primary origin to such layering necessarily results in misinterpretation of geologic history.

  16. Geochemical studies of mafic and other low silica, Precambrian intrusive rocks in the Adirondack lowlands, New York

    SciTech Connect

    Antibus, J.; Carl, J.D. . Dept. of Geology)

    1993-03-01

    Mafic metaigneous rocks in the Adirondack Lowlands include gabbros, amphibolites and diorites that are associated with, and hard to distinguish from, a host of dark colored, low-silica, alkali feldspar-bearing rocks that include syenogabbros, syenites and monzonites. All rocks intrude metasedimentary and metavolcanic host rocks and occur as isolated, pre- to syn-metamorphic bodies, generally with elongate, sheet-like form. Some occur within or marginal to deformation zones. Lacking are the massive igneous complexes of the Highlands where anorthosites, charnockites and mangerites comprise a common field association. Amphibolites vary from mappable sheets that are hundreds of meters thick to thin (<1 m) layers within the host gneisses. Gabbros and diorites vary from circular to oval-shaped bodies, generally <2 km across, that may be infolded with the host rocks. Pervasive shear in Lowland granitic rocks (Hyde School Gneiss) that resulted in major sheath folds, as proposed by Tewksbury, extends into the mafic bodies whose margins show strong gneissic textures and grain size reduction, but the cores are less deformed. The Balmat gabbro varies inwardly and systematically from monzonitic to gabbroic composition in decreasing Si, Na, K, Rb, Zr and Ba, and in increasing Ca, Mg, Fe, Ti, P, Sr, Cr, V and Ni content. Y/Nb ratios remain constant at 3-4. Among explanations of assimilation and metasomatism, the authors tentatively prefer an hypothesis of exclusion of alkali material during crystallization of mafic magma. Calc alkali and low potassium tholeiites are indicated in plots of the Balmat and other mafic bodies on Ti/100-Zr-Yx3 and Ti-Zr discrimination diagrams, although there is much scatter of data. Within-plate basalts are lacking, and ocean floor basalts are indicated for some amphibolites.

  17. Melting of the primitive martian mantle at 0.5-2.2 GPa and the origin of basalts and alkaline rocks on Mars

    NASA Astrophysics Data System (ADS)

    Collinet, Max; Médard, Etienne; Charlier, Bernard; Vander Auwera, Jacqueline; Grove, Timothy L.

    2015-10-01

    We have performed piston-cylinder experiments on a primitive martian mantle composition between 0.5 and 2.2 GPa and 1160 to 1550 °C. The composition of melts and residual minerals constrain the possible melting processes on Mars at 50 to 200 km depth under nominally anhydrous conditions. Silicate melts produced by low degrees of melting (<10 wt.%) were analyzed in layers of vitreous carbon spheres or in micro-cracks inside the graphite capsule. The total range of melt fractions investigated extends from 5 to 50 wt.%, and the liquids produced display variable SiO2 (43.7-59.0 wt.%), MgO (5.3-18.6 wt.%) and Na2O + K2O (1.0-6.5 wt.%) contents. We provide a new equation to estimate the solidus temperature of the martian mantle: T (°C) = 1033 + 168.1 P (GPa) - 14.22P2 (GPa), which places the solidus 50 °C below that of fertile terrestrial peridotites. Low- and high-degree melts are compared to martian alkaline rocks and basalts, respectively. We suggest that the parental melt of Adirondack-class basalts was produced by ∼25 wt.% melting of the primitive martian mantle at 1.5 GPa (∼135 km) and ∼1400 °C. Despite its brecciated nature, NWA 7034/7533 might be composed of material that initially crystallized from a primary melt produced by ∼10-30 wt.% melting at the same pressure. Other igneous rocks from Mars require mantle reservoirs with different CaO/Al2O3 and FeO/MgO ratios or the action of fractional crystallization. Alkaline rocks can be derived from mantle sources with alkali contents (∼0.5 wt.%) similar to the primitive mantle.

  18. Acidification in the Adirondacks: Defining the Biota in trophic Levels of 30 Chemically Diverse Acid-Impacted Lakes

    EPA Science Inventory

    The Adirondack Mountains in New York State have a varied surficial geology and chemically diverse surface waters that are among the most impacted by acid deposition in the U.S. No single Adirondack investigation has been comprehensive in defining the effects of acidification on ...

  19. Distribution of epipelic algal communities in an oligotrophic Adirondack lake

    SciTech Connect

    Roberts, D.A.

    1987-01-01

    The biovolume and species composition of algae on the sediment along depth gradients were determined before and after artificial neutralization of an oligotrophic lake in the Adirondack Park in New York State. The epipelic algal community of Woods Lake (Herkimer Co., NY) was dominated by diatoms and cyanobacteria prior to and following liming. Distinct depth-zonation patterns of community composition were evident and unaffected by the base (CaCO/sub 3/) addition. Prior to liming, there was an increase in total algal biovolume with depth, due to the presence of a dense cyanobacterial community on the sediments in deeper water (5 m to 8 m). This mat was dominated by a single species of cyanobacteria, Hapalosiphon pumilus, which accounted for the late summer maximum in total biovolume at 7 m. The shallower (1 m-4 m) epipelic communities were dominated by diatoms, which showed a spring maximum in total biovolume. Woods Lake, one of the sites of the Lake Acidification Mitigation Project (LAMP), was treated with CaCO/sub 3/ on May 31, 1985. Among other physical and chemical changes, the base treatment increased the pH from 5.0 to above 9.0, ANC from 0 to > 400 ..mu..eq/L. Water clarity was reduced immediately after liming and cleared gradually over an eight-week period.

  20. Wolf restoration to the Adirondacks: the advantages and disadvantages of public participation in the decision

    USGS Publications Warehouse

    Mech, L. David; Sharpe, V.A.; Norton, B.; Donnelley, S.

    2000-01-01

    The first time I ever saw a wolf in New York State's Adirondack Mountains was in 1956. It was a brush wolf, or coyote (Canis latrans), not a real wolf, but to an eager young wildlife student this distinction meant little. The presence of this large deer-killing canid let my fresh imagination view the Adirondacks as a real northern wilderness. Since then I have spent the last 40 years studying the real wolf: the gray wolf (Canis lupus). Although inhabiting nearby Quebec and Ontario, the gray wolf still has not made its way back to the Adirondacks as it has to Wisconsin, Michigan, and Montana. Those three states had the critical advantages of a nearby reservoir population of wolves and wilderness corridors through which dispersers from the reservoirs could immigrate. The Adirondacks, on the other hand, are geographically more similar to the greater Yellowstone area in that they are separated from any wolf reservoir by long distances and intensively human-developed areas aversive to wolves from the reservoir populations. If wolves are to return to the Adirondacks, they almost certainly will have to be reintroduced, as they were to Yellowstone National Park. Wolf reintroduction, as distinct from natural recovery, is an especially contentious issue, for it entails dramatic, deliberate action that must be open to public scrutiny, thorough discussion and review, and highly polarized debate. This is as it should be because once a wolf population is reintroduced to an area, it must be managed forever. There is no turning back. The wolf was once eradicated not just from the Adirondacks but from almost all of the 48 contiguous states. That feat was accomplished by a primarily pioneering society that applied itself endlessly to the task, armed with poison. We can never return to those days, so once the wolf is reintroduced successfully, it will almost certainly be here to stay.

  1. Modeling and mapping of atmospheric mercury deposition in adirondack park, new york.

    PubMed

    Yu, Xue; Driscoll, Charles T; Huang, Jiaoyan; Holsen, Thomas M; Blackwell, Bradley D

    2013-01-01

    The Adirondacks of New York State, USA is a region that is sensitive to atmospheric mercury (Hg) deposition. In this study, we estimated atmospheric Hg deposition to the Adirondacks using a new scheme that combined numerical modeling and limited experimental data. The majority of the land cover in the Adirondacks is forested with 47% of the total area deciduous, 20% coniferous and 10% mixed. We used litterfall plus throughfall deposition as the total atmospheric Hg deposition to coniferous and deciduous forests during the leaf-on period, and wet Hg deposition plus modeled atmospheric dry Hg deposition as the total Hg deposition to the deciduous forest during the leaf-off period and for the non-forested areas year-around. To estimate atmospheric dry Hg deposition we used the Big Leaf model. The average atmospheric Hg deposition to the Adirondacks was estimated as 17.4 [Formula: see text]g m[Formula: see text] yr[Formula: see text] with a range of -3.7-46.0 [Formula: see text]g m[Formula: see text] yr[Formula: see text]. Atmospheric Hg dry deposition (370 kg yr[Formula: see text]) was found to be more important than wet deposition (210 kg yr[Formula: see text]) to the entire Adirondacks (2.4 million ha). The spatial pattern showed a large variation in atmospheric Hg deposition with scattered areas in the eastern Adirondacks having total Hg deposition greater than 30 μg m(-2) yr(-1), while the southwestern and the northern areas received Hg deposition ranging from 25-30 μg m(-2) yr(-1).

  2. U-Pb zircon geochronology of the Adirondack Mountains and implications for their geologic evolution

    SciTech Connect

    McLelland, J. ); Chiarenzelli, J. ); Whitney, P.; Ischsen, Y. )

    1988-10-01

    U-Pb zircon studies of metamorphosed igneous rocks in the Adirondack Mountains have yielded preliminary ages within the range 1420-990 Ma. Several geochronologically and geochemically distinct episodes of igneous intrusion and at least one pre-granulite facies dynamothermal metamorphic event are documented. This information is consistent with recent field and geochronological studies throughout the Grenville province and suggests that a complex sequence of events occurred in the Adirondack Mountains prior to the widespread deformation and metamorphism commonly attributed to the {approximately} 1100-1000 Ma Ottawan phase of the Grenvillian orogenic cycle.

  3. Mafic rocks of the Adirondack Highlands: One suite or many

    SciTech Connect

    Whitney, P.R. . New York State Museum)

    1993-03-01

    Mafic rocks in the granulite facies terrane of the Adirondack Highlands form at least 3 and possibly as many as 6 groups, based on field, petrographic, and geochemical criteria. Most abundant is the olivine metagabbro-amphibolite group (OMA), equivalent to the mafic suite'' of Olson (J. Petrol. 33:471, 1992). OMA occurs in irregular to tabular bodies, locally with intrusive relations, in all major rock types in the E and central Highlands. OMA is strongly olivine normative and forms a continuous differentiation series (Olson, 1992). Plagioclase-two pyroxene-garnet granulites (PGG) form dikes up to several m wide, in anorthositic host rocks. PGG are ferrogabbroic or ferrodioritic and approximately silica saturated. Two subgroups differ sharply in Mg, P, and trace elements. Ferrodiorite and monzodiorite gneisses (FMG), quartz normative and commonly migmatitic, occur in several large bodies in the NE Highlands and as extensive thin sheets in the W and SE Highlands, in association with anorthositic rocks. Three subgroups are distinguishable using Mg/Fe ratios and trace elements. Major element least-squares modeling suggests that both PGG and FMG could be derived by fractionation of gabbroic anorthosite liquids. A differentiation series is not evident, however, and both trace element (Ba, Rb, Sr, Zr and REE) data and normative plagioclase (An [>=] plag. in anorthosite) indicate a more complex origin. One subgroup of FMG may be early cumulates of the mangerite-charnockite suite. The chemistry of OMA, PGG, and FMG reflects their evolved nature and cannot be readily interpreted in terms of magma sources.

  4. Wetland vegetation responses to liming an Adirondack watershed

    SciTech Connect

    Mackun, I.R.

    1993-01-01

    Watershed liming as a long-term mitigation strategy to neutralize lake acidity, from increasing acid deposition, was initiated in North America at Woods Lake in the west central Adirondack region of New York. In October 1989, a dose of 10 MT lime (83.5% CaCO[sub 3]) ha[sup [minus]1] was aerially applied to 48% of the watershed. The wetlands adjacent to Woods Lake showed two distinct community types: one dominated by Chamaedaphne calyculata, and one dominated by graminoids and other herbaceous species. Within two years, liming did not alter the structure of either community type, and changed the cover or frequency of only 6 of 64 individual taxa. Most of these changes occurred in the herbaceous community type. The only strong positive response to liming was a nearly threefold increase in cover of the rhizomatous sedge Cladium mariscoides. The cover of Carex interior and Sphagnum spp. benefited from lime addition, while cover of Drosera intermedia and Muhlenbergia uniflora, and frequency of Hypericum canadense responded negatively to lime. Liming influenced the competitive release of only three taxa, all forbs with small growth forms. The tissue chemistry of foliage and twigs of Myrica gale, Chamaedaphne calyculata, and Carex stricta in the Chamaedaphne calyculata community type clearly illustrated species-specific patterns of nutrient accumulation and allocation both before and after liming. Concentrations of 17 of 20 elements responded to liming, although the responses varied among species and plant parts. Carex foliage was least responsive to liming, and Chamaedaphne twigs were most responsive. Elemental changes in plant tissues will be reflected in litter and many influence long-term nutrient dynamics in the wetland community.

  5. Detailed studies of selected, well-exposed fracture zones in the Adirondack Mountains dome, New York

    SciTech Connect

    Wiener, R.W.; Isachsen, Y.W.

    1987-01-01

    The Adirondack Mountains constitute a relatively young (Mesozoic, Cenozoic) dome on the craton. The dome is undergoing contemporary uplift, based on geodetic releveling, and is seismically active. The breached dome provides a very large window through Paleozoic cover and thus permits ground study of the fracture systems that characterize the seismogenic basement and influence the patterns of brittle deformation that are found in overlying Paleozoic rocks of the platform. The predominant fracture zones are linear valleys that trend NNE to NE, parallel to the long axis of the dome. The 36 field studies of the lineament segments discussed in this report suggest that the prominent NE to NNE fracture systems in the eastern Adirondacks are dominantly high angle faults down-stepped to the east, whereas those in the central Adirondacks are dominantly zero-displacement crackle zones. The origin of these features is related to the rapid uplift of the Adirondack dome. Similar features can be expected to be found in other areas of domal uplift or rapid regional uplift.

  6. Nitrate trends in the Adirondack Mountains, Northeastern US, 1993-2007

    EPA Science Inventory

    The Adirondack Mountains in New York State receive some of the highest rates of nitrogen deposition in the Northeastern U.S. Between 1993 and 2007, nitrogen deposition loads did not significantly change and average annual wet inorganic nitrogen deposition was 6 kg/ha (Figure 1)....

  7. Chemical response of lakes in the Adirondack Region of New York to declines in acidic deposition.

    PubMed

    Driscoll, Charles T; Driscoll, Kimberley M; Roy, Karen M; Mitchell, Myron J

    2003-05-15

    Long-term changes in the chemistry of wet deposition and lake water were investigated in the Adirondack Region of New York. Marked decreases in concentrations of SO4(2-) and H+ in wet deposition have occurred at two sites since the late 1970s. These decreases are consistent with long-term declines in emissions of sulfur dioxide (SO2) in the eastern United States. Changes in wet NO3- deposition and nitrogen oxides (NOx) emissions have been minor over the same interval. Virtually all Adirondack Lakes have shown marked decreases in concentrations of SO4(2-), which coincide with decreases in atmospheric S deposition. Concentrations of NO3- have also decreased in several Adirondack lakes. As atmospheric N deposition has not changed over this period, the mechanism contributing to this apparent increase in lake/watershed N retention is not evident. Decreases in concentrations of SO4(2-) + NO3- have resulted in increases in acid-neutralizing capacity (ANC) and pH and resulted in a shift in the speciation of monomeric Al from toxic inorganic species toward less toxic organic forms in some lakes. Nevertheless, many lakes continue to exhibit pH values and concentrations of inorganic monomeric Al that are critical to aquatic biota. Extrapolation of rates of ANC increase suggests that the time frame of chemical recovery of Adirondack Lakes will be several decades if current decreases in acidic deposition are maintained.

  8. Influence of natural acidity and fisheries management activities upon the status of Adirondack fish populations

    SciTech Connect

    Retzsch, W.C.; Everett, A.G.

    1981-01-01

    Acidification and the disappearance of fish from some Adirondack waters does not appear to be caused solely by acid rain. Acidification is a natural process under certain conditions and precipitation acidified by industrial emissions appears to be only one of many possible causes of pond, lake and stream acidification. Factors other than acid precipitation can cause acidification or reduce fish stocks. As a result of glaciation, northern New York State has hundreds of glacial ponds and lakes, most of which are dystrophic or oligotrophic. Many such waters are located in the western and central portions of the Adirondacks, an area frequently cited as exhibiting the most pronounced effects of acid rain. It is widely recognized that natural unpolluted bogs and peat deposits result in low pH environments. Seasonal and weather conditions also appear to have a substantial effect upon the acidity of peat-bog outflows. An evaluation of recent survey data on critically acidified Adirondack waters indicates that of 192 waters with values less than pH 5.0, approximately 61 percent appear to be directly influenced by natural bog conditions and an additional 14 percent are probably influenced. A review of historical and recent survey data suggest that significant factors, such as natural causes of acidification, low oxygen concentrations, high CO/sub 2/ and H/sub 2/S concentrations, and extreme temperatures may have been ignored or underestimated in evaluating the cause of acidification and fish disappearances in some Adirondack waters. Another factor responsible for the current status of fish stocks in the Adirondacks involves past and present fishery resource management activities.

  9. Nitrogen biogeochemistry in the Adirondack Mountains of New York: hardwood ecosystems and associated surface waters.

    PubMed

    Mitchell, Myron J; Driscoll, Charles T; Inamdar, Shreeram; McGee, Greg G; Mbila, Monday O; Raynal, Dudley J

    2003-01-01

    Studies on the nitrogen (N) biogeochemistry in Adirondack northern hardwood ecosystems were summarized. Specific focus was placed on results at the Huntington Forest (HFS), Pancake-Hall Creek (PHC), Woods Lake (WL), Ampersand (AMO), Catlin Lake (CLO) and Hennessy Mountain (HM). Nitrogen deposition generally decreased from west to east in the Adirondacks, and there have been no marked temporal changes in N deposition from 1978 through 1998. Second-growth western sites (WL, PHC) had higher soil solution NO(3-) concentrations and fluxes than the HFS site in the central Adirondacks. Of the two old-growth sites (AMO and CLO), AMO had substantially higher NO(3-) concentrations due to the relative dominance of sugar maple that produced litter with high N mineralization and nitrification rates. The importance of vegetation in affecting N losses was also shown for N-fixing alders in wetlands. The Adirondack Manipulation and Modeling Project (AMMP) included separate experimental N additions of (NH4)2SO4 at WL, PHC and HFS and HNO3 at WL and HFS. Patterns of N loss varied with site and form of N addition and most of the N input was retained. For 16 lake/watersheds no consistent changes in NO(3-) concentrations were found from 1982 to 1997. Simulations suggested that marked NO(3-) loss will only be manifested over extended periods. Studies at the Arbutus Watershed provided information on the role of biogeochemical and hydrological factors in affecting the spatial and temporal patterns of NO(3-) concentrations. The heterogeneous topography in the Adirondacks has generated diverse landscape features and patterns of connectivity that are especially important in regulating the temporal and spatial patterns of NO(3-) concentrations in surface waters.

  10. Basaltic island sand provenance

    SciTech Connect

    Marsaglia, K.M. . Dept. of Geological Sciences)

    1992-01-01

    The Hawaiian Islands are an ideal location to study basaltic sand provenance in that they are a series of progressively older basaltic shield volcanoes with arid to humid microclimates. Sixty-two sand samples were collected from beaches on the islands of Hawaii, Maui, Oahu and Kauai and petrographically analyzed. The major sand components are calcareous bioclasts, volcanic lithic fragments, and monomineralic grains of dense minerals and plagioclase. Proportions of these components vary from island to island, with bioclastic end members being more prevalent on older islands exhibiting well-developed fringing reef systems and volcanic end members more prevalent on younger, volcanically active islands. Climatic variations across the island of Hawaii are reflected in the percentage of weathered detritus, which is greater on the wetter, northern side of the island. The groundmass of glassy, basaltic lithics is predominantly black tachylite, with lesser brown sideromelane; microlitic and lathwork textures are more common than holohyaline vitric textures. Other common basaltic volcanic lithic fragments are holocrystalline aggregates of silt-sized pyroxene or olivine, opaque minerals and plagioclase. Sands derived from alkalic lavas are texturally and compositionally indistinguishable from sands derived from tholeiitic lavas. Although Hawaiian basaltic sands overlap in composition with magmatic arc-derived sands in terms of their relative QFL, QmPK and LmLvLs percentages, they are dissimilar in that they lack felsic components and are more enriched in lathwork volcanic lithic fragments, holocrystalline volcanic lithic fragments, and dense minerals.

  11. Continental Basaltic Rocks

    NASA Astrophysics Data System (ADS)

    Farmer, G. L.

    2003-12-01

    During the past few decades, geochemical studies of continental basaltic rocks and their petrologic kin have become mainstays of studies of the continental lithosphere. These igneous rocks have taken on such an important role largely because the chemical and isotopic composition of continental basaltic rocks and their mantle (see Chapter 2.05) and crustal xenoliths (see Chapter 3.01) provide the best proxy record available to earth scientists for the chemical and physical evolution of the deep continental lithosphere and underlying mantle, areas that are otherwise resistant to direct study. Keeping this in mind, the primary goal of this chapter is to illustrate how geochemical data can be used both to assess the origin of these rocks and to study the evolution of the continental lithosphere.A complete overview of continental basaltic rocks will not be attempted here, because continental "basalts" come in too wide a range of compositions, and because of the sheer volume of geochemical data available for such rocks worldwide. The scope of the chapter is limited to a discussion of a select group of ultramafic to mafic composition "intraplate" continental igneous rocks consisting primarily of kimberlites, potassic and sodic alkali basalts, and continental flood basalts. Igneous rocks forming at active continental margins, such as convergent or transform plate margins, are important examples of continental magmatism but are not directly discussed here (convergent margin magmas are discussed in Chapters 2.11, 3.11, and 3.18). The geochemistry of intraplate igneous rocks of the ocean basins are covered in Chapters 2.04 and 3.16. Although basaltic magmatism has occurred throughout the Earths history, the majority of the examples presented here are from Mesozoic and Cenozoic volcanic fields due to the more complete preservation of younger continental mafic igneous rocks. While considerable effort has been expended in studying the chemical differentiation of mafic magmas

  12. Long-term recovery of lakes in the Adirondack region of New York to decreases in acidic deposition

    NASA Astrophysics Data System (ADS)

    Waller, Kristin; Driscoll, Charles; Lynch, Jason; Newcomb, Dani; Roy, Karen

    2012-01-01

    After years of adverse impacts to the acid-sensitive ecosystems of the eastern United States, the Acid Rain Program and Nitrogen Budget Program were developed to control sulfur dioxide (SO 2) and nitrogen oxide (NO x) emissions through market-based cap and trade systems. We used data from the National Atmospheric Deposition Program's National Trends Network (NTN) and the U.S. EPA Temporally Integrated Monitoring of Ecosystems (TIME) program to evaluate the response of lake-watersheds in the Adirondack region of New York to changes in emissions of sulfur dioxide and nitrogen oxides resulting from the Acid Rain Program and the Nitrogen Budget Program. TIME is a long-term monitoring program designed to sample statistically selected subpopulations of lakes and streams across the eastern U.S. to quantify regional trends in surface water chemistry due to changes in atmospheric deposition. Decreases in wet sulfate deposition for the TIME lake-watersheds from 1991 to 2007 (-1.04 meq m -2-yr) generally corresponded with decreases in estimated lake sulfate flux (-1.46 ± 0.72 meq m -2-yr), suggesting declines in lake sulfate were largely driven by decreases in atmospheric deposition. Decreases in lake sulfate and to a lesser extent nitrate have generally coincided with increases in acid neutralizing capacity (ANC) resulting in shifts in lakes among ANC sensitivity classes. The percentage of acidic Adirondack lakes (ANC <0 μeq L -1) decreased from 15.5% (284 lakes) to 8.3% (152 lakes) since the implementation of the Acid Rain Program and the Nitrogen Budget Program. Two measures of ANC were considered in our analysis: ANC determined directly by Gran plot analysis (ANC G) and ANC calculated by major ion chemistry (ANC calc = CB - CA). While these two metrics should theoretically show similar responses, ANC calc (+2.03 μeq L -1-yr) increased at more than twice the rate as ANC G (+0.76 μeq L -1-yr). This discrepancy has important implications for assessments of lake recovery

  13. LANDSAT applications by the Adirondack Park Agency for land cover analyses and forest cover change

    NASA Technical Reports Server (NTRS)

    Banta, J. S.; Curran, R. P.

    1981-01-01

    The New York State Adirondack Park Agency is using LANDSAT imagery to provide current, consistent parkwide data on forest cover, forest change and other land cover characteristics for the Adirondack Park, an area of 9,375 sq. miles (24,280 sq km). Boundaries of the study area were digitized and the data were enhanced and geographically rectified. A classification scheme was devised which emphasized the basic land cover types of the Park: hardwoods, spruce-fir, pine, wet conifer, brushland, grassland, agricultural areas, exposed earth, urban areas, and water bodies. Cover type classifications for disturbed forest land were also chosen: cut hardwoods, regenerating hardwoods, and cut spruce fir. Field verification of 1978 classification revealed an accurate differentiation of forest types within types and between nonforested/forested areas. The classification accurately detects forest land disturbances; however, it is not always descriptive of the level of disturbance.

  14. Deep crustal deformation by sheath folding in the Adirondack Mountains, USA

    NASA Technical Reports Server (NTRS)

    Mclelland, J. M.

    1988-01-01

    As described by McLelland and Isachsen, the southern half of the Adirondacks are underlain by major isoclinal (F sub 1) and open-upright (F sub 2) folds whose axes are parallel, trend approximately E-W, and plunge gently about the horizontal. These large structures are themselves folded by open upright folds trending NNE (F sub 3). It is pointed out that elongation lineations in these rocks are parallel to X of the finite strain ellipsoid developed during progressive rotational strain. The parallelism between F sub 1 and F sub 2 fold axes and elongation lineations led to the hypothesis that progressive rotational strain, with a west-directed tectonic transport, rotated earlier F sub 1-folds into parallelism with the evolving elongation lineation. Rotation is accomplished by ductile, passive flow of F sub 1-axes into extremely arcuate, E-W hinges. In order to test these hypotheses a number of large folds were mapped in the eastern Adirondacks. Other evidence supporting the existence of sheath folds in the Adirondacks is the presence, on a map scale, of synforms whose limbs pass through the vertical and into antiforms. This type of outcrop pattern is best explained by intersecting a horizontal plane with the double curvature of sheath folds. It is proposed that sheath folding is a common response of hot, ductile rocks to rotational strain at deep crustal levels. The recognition of sheath folds in the Adirondacks reconciles the E-W orientation of fold axes with an E-W elongation lineation.

  15. U-Pb age of the Diana Complex and Adirondack granulite petrogenesis

    USGS Publications Warehouse

    Basu, A.R.; Premo, W.R.

    2001-01-01

    U-Pb isotopic analyses of eight single and multi-grain zircon fractions separated from a syenite of the Diana Complex of the Adirondack Mountains do not define a single linear array, but a scatter along a chord that intersects the Concordia curve at 1145 ?? 29 and 285 ?? 204 Ma. For the most concordant analyses, the 207Pb/206Pb ages range between 1115 and 1150 Ma. Detailed petrographic studies revealed that most grains contained at least two phases of zircon growth, either primary magmatic cores enclosed by variable thickness of metamorphic overgrowths or magmatic portions enclosing presumably older xenocrystic zircon cores. The magmatic portions are characterized by typical dipyramidal prismatic zoning and numerous black inclusions that make them quite distinct from adjacent overgrowths or cores when observed in polarizing light microscopy and in back-scattered electron micrographs. Careful handpicking and analysis of the "best" magmatic grains, devoid of visible overgrowth of core material, produced two nearly concordant points that along with two of the multi-grain analyses yielded an upper-intercept age of 1118 ?? 2.8 Ma and a lower-intercept age of 251 ?? 13 Ma. The older age is interpreted as the crystallization age of the syenite and the younger one is consistent with late stage uplift of the Appalachian region. The 1118 Ma age for the Diana Complex, some 35 Ma younger than previously believed, is now approximately synchronous with the main Adirondack anorthosite intrusion, implying a cogenetic relationship among the various meta-igneous rocks of the Adirondacks. The retention of a high-temperature contact metamorphic aureole around Diana convincingly places the timing of Adirondack regional metamorphism as early as 1118 Ma. This result also implies that the sources of anomalous high-temperature during granulite metamorphism are the syn-metamorphic intrusions, such as the Diana Complex.

  16. Post-metamorphic fluid infiltration into granulites from the Adirondack Mountains, USA

    NASA Technical Reports Server (NTRS)

    Morrison, J.; Valley, John W.

    1988-01-01

    Post-metamorphic effects in the anorthosites of the Adirondacks, New York were described. Calcite-chlorite-sericite assemblages occur as veins, in disseminated form and as clots, and document retrograde fluid infiltration. These features are associated with late-state CO2-rich fluid inclusions. Stable isotope analyses of calcites indicates that the retrograde fluids interacted with meta-igneous and supracrustal lithologies, but the precise timing of the retrogression is as yet unknown.

  17. Fluid heterogeneity during granulite facies metamorphism in the Adirondacks: stable isotope evidence

    USGS Publications Warehouse

    Valley, J.W.; O'Neil, J.R.

    1984-01-01

    The preservation of premetamorphic, whole-rock oxygen isotope ratios in Adirondack metasediments shows that neither these rocks nor adjacent anorthosites and gneisses have been penetrated by large amounts of externally derived, hot CO2-H2O fluids during granulite facies metamorphism. This conclusion is supported by calculations of the effect of fluid volatilization and exchange and is also independently supported by petrologic and phase equilibria considerations. The data suggest that these rocks were not an open system during metamorphism; that fluid/rock ratios were in many instances between 0.0 and 0.1; that externally derived fluids, as well as fluids derived by metamorphic volatilization, rose along localized channels and were not pervasive; and thus that no single generalization can be applied to metamorphic fluid conditions in the Adirondacks. Analyses of 3 to 4 coexisting minerals from Adirondack marbles show that isotopic equilibrium was attained at the peak of granulite and upper amphibolite facies metamorphism. Thus the isotopic compositions of metamorphic fluids can be inferred from analyses of carbonates and fluid budgets can be constructed. Carbonates from the granulite facies are on average, isotopically similar to those from lower grade or unmetamorphosed limestones of the same age showing that no large isotopic shifts accompanied high grade metamorphism. Equilibrium calculations indicate that small decreases in ??18O, averaging 1 permil, result from volatilization reactions for Adirondack rock compositions. Additional small differences between amphibolite and granulite facies marbles are due to systematic lithologie differences. The range of Adirondack carbonate ??18O values (12.3 to 27.2) can be explained by the highly variable isotopic compositions of unmetamorphosed limestones in conjunction with minor 18O and 13C depletions caused by metamorphic volatilization suggesting that many (and possibly most) marbles have closely preserved their

  18. Fish population losses from Adirondack Lakes: The role of surface water acidity and acidification

    NASA Astrophysics Data System (ADS)

    Baker, Joan P.; Warren-Hicks, William J.; Gallagher, James; Christensen, Sigurd W.

    1993-04-01

    Changes over time in the species composition of fish communities in Adirondack lakes were assessed to determine (1) the approximate numbers offish populations that have been lost and (2) the degree to which fish population losses may have resulted from surface water acidification and acidic deposition. Information on the present-day status offish communities was obtained by the Adirondack Lakes Survey Corporation, which surveyed 1469 Adirondack lakes in 1984-1987 (53% of the total ponded waters in the Adirondack ecological zone). Two hundred and ninety-five of these lakes had been surveyed in 1929-1934 during the first statewide biological survey; 720 had been surveyed in one or more years prior to 1970. Sixteen to 19% of the lakes with adequate historical data appeared to have lost one or more fish populations as a result of acidification. Brook trout and acid-sensitive minnow species had experienced the most widespread effects. Populations of brook trout and acid-sensitive minnows had been lost apparently as a result of acidification from 11% and 19%, respectively, of the lakes with confirmed historical occurrence of these taxa. By contrast, fish species that tend to occur primarily in lower elevation and larger lakes, such as largemouth and smallmouth bass and brown trout, have experienced little to no documented adverse effects. Lakes that were judged to have lost fish populations as a result of acidification had significantly lower; pH and, in most cases, also had higher estimated concentrations of inorganic aluminum and occurred at higher elevations than did lakes with the fish species still present. No other lake characteristics were consistently associated with fish population losses attributed to acidification. The exact numbers and proportions of fish populations affected could not be determined because of limitations on the quantity and quality of historical data. Lakes for which we had adequate historical data to assess long-term trends in fish

  19. Alteration of Basaltic Glass to Mg/Fe-Smectite under Acidic Conditions: A Potential Smectite Formation Mechanism on Mars

    NASA Technical Reports Server (NTRS)

    Peretyazhko, Tanya; Sutter, Brad; Ming, Douglas W.

    2014-01-01

    Phyllosilicates of the smectite group including Mg- and Fe-saponite and Fe(III)-rich nontronite have been identified on Mars. Smectites are believed to be formed under neutral to alkaline conditions that prevailed on early Mars. This hypothesis is supported by the observation of smectite and carbonate deposits in Noachian terrain on Mars. However, smectite may have formed under mildly acidic conditions. Abundant smectite formations have been detected as layered deposits hundreds of meters thick in intracrater depositional fans and plains sediments, while no large deposits of carbonates are found. Development of mildly acidic conditions at early Mars might allow formation of smectite but inhibit widespread carbonate precipitation. Little is known regarding the mechanisms of smectite formation from basaltic glass under acidic conditions. The objective of this study was to test a hypothesis that Mars-analogue basaltic glass alters to smectite minerals under acidic conditions (pH 4). The effects of Mg and Fe concentrations and temperature on smectite formation from basaltic glass were evaluated. Phyllosilicate synthesis was performed in batch reactors (Parr acid digestion vessel) under reducing hydrothermal conditions at 200 C and 100 C. Synthetic basaltic glass with a composition similar to that of the Gusev crater rock Adirondack (Ground surface APXS measurement) was used in these experiments. Basaltic glass was prepared by melting and quenching procedures. X-ray diffraction (XRD) analysis indicated that the synthesized glass was composed of olivine, magnetite and X-ray amorphous phase. Samples were prepared by mixing 250 mg Adirondack with 0.1 M acetic acid (final pH 4). In order to study influence of Mg concentration on smectite formation, experiments were performed with addition of 0, 1 and 10 mM MgCl2. After 1, 7 and 14 day incubations the solution composition was analyzed by Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and the altered glass and formed

  20. Very high potassium (VHK) basalt - Complications in mare basalt petrogenesis

    NASA Technical Reports Server (NTRS)

    Shervais, J. W.; Taylor, L. A.; Laul, J. C.; Shih, C.-Y.; Nyquist, L. E.

    1985-01-01

    The first comprehensive report on the petrology and geochemistry of Apollo 14 VHK (Very High Potassium) basalts and their implications for lunar evolution is presented. The reported data are most consistent with the hypothesis that VHK basalts formed through the partial assimilation of granite by a normal low-Ti, high-Al mare basalt magma. Assimilation was preceded by the diffusion-controlled exchange of alkalis and Ba between basalt magma and the low-temperature melt fraction of the granite. Hypotheses involving volatile/nonvolatile fractionations or long-term enrichment of the source regions in K are inconsistent with the suprachondritic Ba/La ratios and low initial Sr-87/Sr-86 ratios of VHK basalt. An important implication of this conclusion is that granite should be a significant component of the lunar crust at the Apollo 14 site.

  1. The Grenville Orogenic Cycle (ca. 1350-1000 Ma): an Adirondack perspective

    NASA Astrophysics Data System (ADS)

    McLelland, James; Daly, J. Stephen; McLelland, Jonathan M.

    1996-11-01

    The Adirondack Mountains are characterized by three major events that took place during the interval ca. 1350-1000 Ma. The earliest of these is the arc-related Elzevirian Orogeny (ca. 1350-1185 Ma) during which substantial volumes of juvenile calc-alkaline crust were added to the Adirondacks as well as to the northwest segment of the Central Metasedimentary Belt. Data from the southwestern United States as well as from Ireland and Baltica indicate that Elzevirian magmatism and orogeny were of global dimensions. Within the southwestern sector of the Grenville Province, the Elzevirian Orogeny culminated at ca. 1185 Ma when accretion of all outboard terranes was completed. Compressional orogeny related to this convergence resulted in overthickened crust and lithosphere which subsequently delaminated giving rise to orogen collapse and AMCG magmatism that swept southeastward from the Frontenac Terrane into the Adirondack Highlands during the interval ca. 1180-1130 Ma. Localized compressional events within neighboring parts of the Grenville Province emphasize the continued existence of contraction during this interval, although crustal extension caused local in sedimentary basins in which were deposited the Flinton and the St. Boniface Groups. The Adirondacks have not yet provided any record of events within the interval ca. 1125-1100 Ma, although there is evidence of contraction elsewhere in the southwestern Grenville Province at that time. At 1100-1090 Ma the northern Adirondack Highlands were invaded by mildly A-type hornblende granites (Hawkeye suite) that are interpreted to be the result of local crustal thinning contemporaneous with rifting and mafic magmatism taking place in the Midcontinent rift. Immediately following, at ca. 1090 Ma, the global-scale continental collision of the Ottawan Orogeny was initiated. Strong convergence, deformation, and metamorphism continued to at least ca. 1070 Ma, and rocks older than this are profoundly affected by this event

  2. VNIR spectral classes of rocks in the Columbia Hills, Gusev Crater, Mars as observed by the Mars Exploration Rover Spirit's Pancam

    NASA Astrophysics Data System (ADS)

    Farrand, W. H.; Bell, J. F.; Johnson, J. R.

    2005-12-01

    The Mars Exploration Rover Spirit has been examining the Columbia Hills in Gusev Crater for over 400 martian sols and has observed a number of texturally, chemically, mineralogically and spectrally distinct rocks- both in situ and out of place. This paper reports on the discrimination of these rocks into spectral classes using the rover's Panoramic Camera or Pancam. The Pancam has 11 spectrally unique channels in the Visible and Near Infrared (VNIR) (400 to 1010 nm) spectral range. Six spectral classes were determined as of sol 419 of the mission and these include plains basalts typified by the rock Adirondack, lower West Spur rocks, a larger number of rocks higher on the West Spur (Clovis-class), rocks on the northwest flank of Husband Hill (Wishstone-class and Peace-class), rocks near the crest of Husband Hill (Watchtower-class). Among the Cumberland Ridge rocks examined after sol 419, the Larry's Lookout outcrop includes Watchtower-class rocks, the Jibsheet outcrop has rocks with similar spectral characteristics to the Watchtower class, and the Methuselah outcrop is similar in spectral character to the Wishstone and Lower West Spur classes. Higher on Husband Hill, low albedo rocks, some with specular reflecting surfaces and some with a clast and matrix texture were observed in the Voltaire region, and the clasts and matrix materials are spectrally distinct from each other. Diagnostic NIR features of these classes include a shallow long wavelength band center at, or longer than, 1000 nm in the Clovis-class, a deeper absorption centered at 930 nm in Lower West Spur and Wishstone-class rocks, and an absorption centered at 900 nm with a steep increase in reflectance going out to the 1000 nm band in the Watchtower class. There is also a correspondence between Mössbauer measurements of Fe3+/FeTotal and Pancam measurements of 535 nm band depth. Tentative assignments can be made of minerals/materials responsible for these spectral features. The West Spur/Clovis-class

  3. Age and petrogenesis of the Diana Complex, Adirondack Mountains, New York

    SciTech Connect

    Grant, N.; Yang, Yingping . Dept. of Geology); Cliff, R. . Dept. of Earth Sciences)

    1992-01-01

    U-Pb zircon data show that the Diana Complex was emplaced 1152[plus minus]12 Ma ago along the Carthage-Colton Mylonite Zone (CCMZ), that marks the boundary between the Adirondack Highlands and the Lowlands. The tectonic setting of the Complex is uncertain because granitoid plutons of the same age were emplaced under syntectonic conditions in the Lowlands, while in the Highlands the same plutons have been viewed as anorogenic. Deformation focused on the CCMZ is reflected in whole-rock Rb-Sr isochron age of 1038[plus minus]97 Ma for the Complex. This resetting is typical of granitoid plutons within a 10 km-wide zone across the CCMZ, but is absent outside this zone elsewhere in the Lowlands. Although the chemical continuity of the Complex with Adirondack mafic rocks of the same presumed age demonstrates that crystal fractionation from a basic parent was a likely origin for the Complex, it is probable the magmas were modified by crustal assimilation. For example, the initial [sup 87]Sr/[sup 86]Sr[sub 1152] values for the Complex (0.7042[plus minus]3) are higher than the same ratios for Adirondack mafic rocks (0.7033[plus minus]6), and one zircon fraction lies to the right of the discordia defined by the other four analyzed fractions. The nature and age of the assimilant may be constrained by a metasedimentary xenolith with a whole-rock Rb-Sr isochron age of 1318[plus minus]15 Ma. Changes in TiO[sub 2] and P[sub 2]O[sub 5] abundances and La/Yb values indicate that the crystallization of both accessory (e.g., Fe-Ti oxides, apatite and zircon) and silicate phases were important in the fractionation of the Diana Complex syenites.

  4. Chronic and episodic acidification of Adirondack streams from acid rain in 2003-2005

    USGS Publications Warehouse

    Lawrence, G.B.; Roy, K.M.; Baldigo, Barry P.; Simonin, H.A.; Capone, S.B.; Sutherland, J.W.; Nierzwicki-Bauer, S. A.; Boylen, C.W.

    2008-01-01

    Limited information is available on streams in the Adirondack region of New York, although streams are more prone to acidification than the more studied Adirondack lakes. A stream assessment was therefore undertaken in the Oswegatchie and Black River drainages; an area of 4585 km2 in the western part of the Adirondack region. Acidification was evaluated with the newly developed base-cation surplus (BCS) and the conventional acid-neutralizing capacity by Gran titration (ANCG). During the survey when stream water was most acidic (March 2004), 105 of 188 streams (56%) were acidified based on the criterion of BCS < 0 ??eq L-1, whereas 29% were acidified based on an ANCG value < 0 ??eq L-1. During the survey when stream water was least acidic (August 2003), 15 of 129 streams (12%) were acidified based on the criterion of BCS < 0 ??eq L-1, whereas 5% were acidified based on ANCG value < 0 ??eq L -1. The contribution of acidic deposition to stream acidification was greater than that of strongly acidic organic acids in each of the surveys by factors ranging from approximately 2 to 5, but was greatest during spring snowmelt and least during elevated base flow in August. During snowmelt, the percentage attributable to acidic deposition was 81%, whereas during the October 2003 survey, when dissolved organic carbon (DOC) concentrations were highest, this percentage was 66%. The total length of stream reaches estimated to be prone to acidification was 718 km out of a total of 1237 km of stream reaches that were assessed. Copyright ?? 2008 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.

  5. Characterization of an organic acid analog model in Adirondack, New York, surface waters

    NASA Astrophysics Data System (ADS)

    Fakhraei, H.; Driscoll, C. T.

    2013-12-01

    Natural waters include a variety of organic matter that differs in composition and functional groups. Dissolved organic matter is important but difficult to characterize acidic and metal binding (e.g., Al) functional groups in chemical equilibrium models. In this study data from Adirondack Lake Survey were used to calibrate an organic acid analog model in order to quantify the influence of organic acids on surface water chemistry. The study sites in the Adirondack region of New York have diverse levels of dissolved organic carbon (DOC), used as a surrogate for organic acids. DOC in 55 Adirondack surface waters varies from 180 μmol C/l (in Little Echo Pond) to 1263 μmol C/l (in Sunday Pond). To reduce the variability inherited in the large raw data set, suite of mean observations was constructed by grouping and averaging measured data into pH intervals of 0.05 pH units from pH 4.15 to 7.3. A chemical equilibrium model, which includes major solutes in natural waters, was linked to an optimization algorithm (genetic algorithm) to calibrate a triprotic organic analog model which includes proton and aluminum binding by adjusting the dissociation constants and site density of DOC. The object of fitting procedure was to simultaneously minimize the discrepancy between observed and simulated pH, acid neutralizing capacity (ANC), organic monomeric aluminum and inorganic monomeric aluminum. A sensitivity analysis on calibrated values indicate that the speciation of the modeled solutes are most responsive to the dissociation constant of AlOrg= Al3+ + Org3- reaction (Org3- represents organic anion), the site density of DOC and the second H+ dissociation constant of the triprotic organic analog (i.e. H2Org- = 2H+ + Org3- reaction).

  6. Chronic and episodic acidification of Adirondack streams from acid rain in 2003-2005.

    PubMed

    Lawrence, Gregory B; Roy, Karen M; Baldigo, Barry P; Simonin, Howard A; Capone, Susan B; Sutherland, James W; Nierzwicki-Bauer, Sandra A; Boylen, Charles W

    2008-01-01

    Limited information is available on streams in the Adirondack region of New York, although streams are more prone to acidification than the more studied Adirondack lakes. A stream assessment was therefore undertaken in the Oswegatchie and Black River drainages; an area of 4585 km(2) in the western part of the Adirondack region. Acidification was evaluated with the newly developed base-cation surplus (BCS) and the conventional acid-neutralizing capacity by Gran titration (ANC(G)). During the survey when stream water was most acidic (March 2004), 105 of 188 streams (56%) were acidified based on the criterion of BCS < 0 microeq L(-1), whereas 29% were acidified based on an ANC(G) value < 0 microeq L(-1). During the survey when stream water was least acidic (August 2003), 15 of 129 streams (12%) were acidified based on the criterion of BCS < 0 microeq L(-1), whereas 5% were acidified based on ANC(G) value < 0 microeq L(-1). The contribution of acidic deposition to stream acidification was greater than that of strongly acidic organic acids in each of the surveys by factors ranging from approximately 2 to 5, but was greatest during spring snowmelt and least during elevated base flow in August. During snowmelt, the percentage attributable to acidic deposition was 81%, whereas during the October 2003 survey, when dissolved organic carbon (DOC) concentrations were highest, this percentage was 66%. The total length of stream reaches estimated to be prone to acidification was 718 km out of a total of 1237 km of stream reaches that were assessed.

  7. Chronic and episodic acidification of Adirondack streams from acid rain in 2003-2005.

    PubMed

    Lawrence, Gregory B; Roy, Karen M; Baldigo, Barry P; Simonin, Howard A; Capone, Susan B; Sutherland, James W; Nierzwicki-Bauer, Sandra A; Boylen, Charles W

    2008-01-01

    Limited information is available on streams in the Adirondack region of New York, although streams are more prone to acidification than the more studied Adirondack lakes. A stream assessment was therefore undertaken in the Oswegatchie and Black River drainages; an area of 4585 km(2) in the western part of the Adirondack region. Acidification was evaluated with the newly developed base-cation surplus (BCS) and the conventional acid-neutralizing capacity by Gran titration (ANC(G)). During the survey when stream water was most acidic (March 2004), 105 of 188 streams (56%) were acidified based on the criterion of BCS < 0 microeq L(-1), whereas 29% were acidified based on an ANC(G) value < 0 microeq L(-1). During the survey when stream water was least acidic (August 2003), 15 of 129 streams (12%) were acidified based on the criterion of BCS < 0 microeq L(-1), whereas 5% were acidified based on ANC(G) value < 0 microeq L(-1). The contribution of acidic deposition to stream acidification was greater than that of strongly acidic organic acids in each of the surveys by factors ranging from approximately 2 to 5, but was greatest during spring snowmelt and least during elevated base flow in August. During snowmelt, the percentage attributable to acidic deposition was 81%, whereas during the October 2003 survey, when dissolved organic carbon (DOC) concentrations were highest, this percentage was 66%. The total length of stream reaches estimated to be prone to acidification was 718 km out of a total of 1237 km of stream reaches that were assessed. PMID:18948480

  8. Sulfide Stability of Planetary Basalts

    NASA Technical Reports Server (NTRS)

    Caiazza, C. M.; Righter, K.; Gibson, E. K., Jr.; Chesley, J. T.; Ruiz, J.

    2004-01-01

    The isotopic system, 187Re 187Os, can be used to determine the role of crust and mantle in magma genesis. In order to apply the system to natural samples, we must understand variations in Re/Os concentrations. It is thought that low [Os] and [Re] in basalts can be attributed to sulfide (FeS) saturation, as Re behaves incompatibly to high degrees of evolution until sulfide saturation occurs [1]. Previous work has shown that lunar basalts are sulfide under-saturated, and mid-ocean ridge, ocean-island and Martian (shergottites) basalts are saturated [2,3]. However, little is known about arc basalts. In this study, basaltic rocks were analyzed across the Trans-Mexican Volcanic Belt.

  9. Effect of acidification damages on the economic value of the Adirondack fishery to New York anglers

    SciTech Connect

    Mullen, J.K.; Menz, F.C.

    1985-02-01

    A travel cost model is used to estimate losses in the net economic value of the Adirondack recreational fishery resulting from damages caused by acidic deposition. Annual losses to New York resident anglers are estimated to be approximately $1 million per year in 1976 dollars. Although there are many reasons why these damages understate the full extent of losses to both current users and others, this research represents one of the initial attempts to quantify one type of cost associated with the acidic deposition problem.

  10. Empirical Relationships Between Watershed Attributes and Headwater Lake Chemistry in the Adirondack Region

    SciTech Connect

    Hunsaker, C.T.

    1987-01-01

    Surface water acidification may be caused or influenced by both natural watershed processes and anthropogenic actions. Empirical models and observational data can be useful for identifying watershed attributes or processes that require further research or that should be considered in the development of process models. This study focuses on the Adirondack region of New York and has two purposes: to (1) develop empirical models that can be used to assess the chemical status of lakes for which no chemistry data exist and (2) determine on a regional scale watershed attributes that account for variability in lake pH and acid-neutralizing capacity (ANC). Headwater lakes, rather than lakes linked to upstream lakes, were selected for initial analysis. The Adirondacks Watershed Data Base (AWDB), part of the Acid Deposition Data Network maintained at Oak Ridge National Laboratory (ORNL), integrates data on physiography, bedrock, soils, land cover, wetlands, disturbances, beaver activity, land use, and atmospheric deposition with the water chemistry and morphology for the watersheds of 463 headwater lakes. The AWD8 facilitates both geographic display and statistical analysis of the data. The report, An Adirondack Watershed Data Base: Attribute and Mapping Information for Regional Acidic Deposition Studies (ORNL/TM--10144), describes the AWDB. Both bivariate (correlations and Wilcoxon and Kruskal-Wallis tests) and multivariate analyses were performed. Fifty-seven watershed attributes were selected as input variables to multiple linear regression and discriminant analysis. For model development -200 lakes for which pH and ANC data exist were randomly subdivided into a specification and a verification data set. Several indices were used to select models for predicting lake pH (31 variables) and ANC (27 variables). Twenty-five variables are common to the pH and ANC models: four lake morphology, nine soil/geology, eight land cover, three disturbance, and one watershed aspect. An

  11. Episodic acidification and associated fish and benthic invertebrate responses of four adirondack headwater streams. Methods report

    SciTech Connect

    Kretser, W.A.; Simonin, H.A.; Bath, D.W.; Gallagher, J.; Olson, M.L.

    1993-10-01

    Four low order Adirondack streams were investigated from September 1988 through June 1990 to examine the effects of hydrologic events in relation to stream chemistry and associated biological communities. The four streams were monitored continuously for pH, specific conductivity, temperatures, flow and water quality using a variety of instrumentation and procedures. During base flow and hydrologic events, weekly water samples were collected manually. Assessment of the biological communities in response to changes in water chemistry involved a number of standard fisheries techniques including electroshocking for population estimates, in situ bioassay experiments and radio tagging experiments.

  12. Why Hexagonal Basalt Columns?

    PubMed

    Hofmann, Martin; Anderssohn, Robert; Bahr, Hans-Achim; Weiß, Hans-Jürgen; Nellesen, Jens

    2015-10-01

    Basalt columns with their preferably hexagonal cross sections are a fascinating example of pattern formation by crack propagation. Junctions of three propagating crack faces rearrange such that the initial right angles between them tend to approach 120°, which enables the cracks to form a pattern of regular hexagons. To promote understanding of the path on which the ideal configuration can be reached, two periodically repeatable models are presented here involving linear elastic fracture mechanics and applying the principle of maximum energy release rate. They describe the evolution of the crack pattern as a transition from rectangular start configuration to the hexagonal pattern. This is done analytically and by means of three-dimensional finite element simulation. The latter technique reproduces the curved crack path involved in this transition.

  13. Why Hexagonal Basalt Columns?

    PubMed

    Hofmann, Martin; Anderssohn, Robert; Bahr, Hans-Achim; Weiß, Hans-Jürgen; Nellesen, Jens

    2015-10-01

    Basalt columns with their preferably hexagonal cross sections are a fascinating example of pattern formation by crack propagation. Junctions of three propagating crack faces rearrange such that the initial right angles between them tend to approach 120°, which enables the cracks to form a pattern of regular hexagons. To promote understanding of the path on which the ideal configuration can be reached, two periodically repeatable models are presented here involving linear elastic fracture mechanics and applying the principle of maximum energy release rate. They describe the evolution of the crack pattern as a transition from rectangular start configuration to the hexagonal pattern. This is done analytically and by means of three-dimensional finite element simulation. The latter technique reproduces the curved crack path involved in this transition. PMID:26550724

  14. Changes in the chemistry of acidified Adirondack streams from the early 1980s to 2008

    USGS Publications Warehouse

    Lawrence, G.B.; Simonin, H.A.; Baldigo, Barry P.; Roy, K.M.; Capone, S.B.

    2011-01-01

    Lakes in the Adirondack region of New York have partially recovered in response to declining deposition, but information on stream recovery is limited. Here we report results of Adirondack stream monitoring from the early 1980s to 2008. Despite a 50% reduction in atmospheric deposition of sulfur, overall increases in pH of only 0.28 and ANC of 13 μeq L-1 were observed in 12 streams over 23 years, although greater changes did occur in streams with lower initial ANC, as expected. In the North Tributary of Buck Creek with high dissolved organic carbon (DOC) concentrations, SO(4)(2-) concentrations decreased from 1999 to 2008 at a rate of 2.0 μmol L-1 y-1, whereas in the neighboring South Tributary with low DOC concentrations, the decrease was only 0.73 μmol L-1 y-1. Ca2+ leaching decreased in the North Tributary due to the SO(4)(2-) decrease, but this was partially offset by an increase in Ca2+ leaching from increased DOC concentrations.

  15. Eskers as an aid to the understanding of deglaciation in the Northern Adirondacks

    SciTech Connect

    King, G.S. . Geology Dept.)

    1993-03-01

    Eskers in the Northern Adirondack Mountains of New York State have been examined in order to gain a better understanding of their origin, their relationship to other glacial landforms, and to determine the relative timing of their formation. Ultimately, it is hoped that eskers can be used to construct a model of the former ice sheet for the region. Cross sections and longitudinal profiles were constructed to give a better understanding of esker form. Subsequent fieldwork was designed to confirm and compliment these morphometric analyses. The sedimentology of an esker and adjacent fan was logged and interpreted. The spatial relations between the eskers, fans, and delta complexes were identified. Results indicate that the eskers of the Northern Adirondack Mountains formed at different stages in the retreat of the ice sheet and are not related to an integrated subglacial drainage system. The presence of a lacustrine fan at the south end of the St. Regis Esker indicates that a glacial lake was present at the ice sheet margin and delimits an ice marginal position. The morphology and distribution of eskers may be useful as an indicator in the timing of continental deglaciation of northern New York State. Research for this project was funded by a University of Dayton Research Council Grant to D. Pair.

  16. The origin of garnet in the anorthosite-charnockite suite of the Adirondacks

    USGS Publications Warehouse

    McLelland, J.M.; Whitney, P.R.

    1977-01-01

    Detailed analysis of textural and chemical criteria in rocks of the anorthosite-charnockite suite of the Adirondack Highlands suggests that development of garnet in silica-saturated rocks of the suite occurs according to the reaction: {Mathematical expression}, where ?? is a function of the distribution of Fe and Mg between the several coexisting ferromagnesian phases. Depending upon the relative amounts of Fe and Mg present, quartz may be either a reactant or a product. Using an aluminum-fixed reference frame, this reaction can be restated in terms of a set of balanced partial reactions describing the processes occurring in spatially separated domains within the rock. The fact that garnet invariably replaces plagioclase as opposed to the other reactant phases indicates that the aluminum-fixed model is valid as a first approximation. This reaction is univariant and produces unzoned garnet. It differs from a similar equation proposed by de Waard (1965) for the origin of garnet in Adirondack metabasic rocks, i.e. 6 Orthopyroxene+2 Anorthite = Clinopyroxene+Garnet+2 Quartz, the principle difference being that iron oxides (ilmenite and/or magnetite) are essential reactant phases in the present reactions. The product assemblage (garnet+clinopyroxene+plagioclase ?? orthopyroxene ?? quartz) is characteristic of the clinopyroxene-almandine subfacies of the granulite facies. ?? 1977 Springer-Verlag.

  17. Changes in the chemistry of acidified Adirondack streams from the early 1980s to 2008.

    PubMed

    Lawrence, G B; Simonin, H A; Baldigo, B P; Roy, K M; Capone, S B

    2011-10-01

    Lakes in the Adirondack region of New York have partially recovered in response to declining deposition, but information on stream recovery is limited. Here we report results of Adirondack stream monitoring from the early 1980s to 2008. Despite a 50% reduction in atmospheric deposition of sulfur, overall increases in pH of only 0.28 and ANC of 13 μeq L(-1) were observed in 12 streams over 23 years, although greater changes did occur in streams with lower initial ANC, as expected. In the North Tributary of Buck Creek with high dissolved organic carbon (DOC) concentrations, SO(4)(2-) concentrations decreased from 1999 to 2008 at a rate of 2.0 μmol L(-1) y(-1), whereas in the neighboring South Tributary with low DOC concentrations, the decrease was only 0.73 μmol L(-1) y(-1). Ca(2+) leaching decreased in the North Tributary due to the SO(4)(2-) decrease, but this was partially offset by an increase in Ca(2+) leaching from increased DOC concentrations.

  18. Interpretation of gravity anomalies in the northwest Adirondack lowlands, northern New York

    SciTech Connect

    Revetta, F.A.; O'Brian, B. . Geology Dept.)

    1993-03-01

    Twelve hundred gravity measurements were made in the Adirondack Highlands and northwest Adirondack Lowlands, New York between 44[degree]15 minutes and 44[degree]30 minutes N. Latitude and 75[degree]00 minutes W. Longitude. A Bouguer gravity map constructed from the gravity measurements includes the Carthage-Colton Mylonite Zone, a major structural boundary between the highlands and lowlands. The gravity map indicates the gravity contours trend parallel to the CCMZ along most of its length however in some areas the contours cross the boundary. No clear-cut relationships exists between the CCMZ and gravity contours. The Bouguer gravity map shows several prominent gravity anomalies which correlate with the geology seismicity and mineral deposits in the area. Gravity lows of 20 to 30 g.u. are centered over the Gouverneur, Hyde and Payne Lake Alaskite gneiss bodies. A gravity high of 20 g.u. occurs over the Pleasant Lake gabbro pluton. Gravity highs of 35 and 100 g.u. occur over the Sylvia Lake Zinc District and marble just north of the district. A gravity high at Russell, N.Y. coincides with a cluster of nine earthquake epicenters. Finally a steep gravity gradient separates high density rocks from lower density rocks along the Black Lake fault. Two-dimensional computer modeling of the geologic features is underway and quantitative models of the structures will be presented.

  19. Use of stream chemistry for monitoring acidic deposition effects in the Adirondack region of New York

    USGS Publications Warehouse

    Lawrence, G.B.; Momen, B.; Roy, K.M.

    2004-01-01

    Acid-neutralizing capacity (ANC) and pH were measured weekly from October 1991 through September 2001 in three streams in the western Adirondack Mountain region of New York to identify trends in stream chemistry that might be related to changes in acidic deposition. A decreasing trend in atmospheric deposition of SO42- was observed within the region over the 10-yr period, although most of the decrease occurred between 1991 and 1995. Both ANC and pH were inversely related to flow in all streams; therefore, a trend analysis was conducted on (i) the measured values of ANC and pH and (ii) the residuals of the concentration-discharge relations. In Buck Creek, ANC increased significantly (p 0.10). In Bald Mountain Brook, ANC and residuals of ANC increased significantly (p < 0.01), although the trend was diatonic-a distinct decrease from 1991 to 1996 was followed by a distinct increase from 1996 to 2001. In Fly Pond outlet, ANC and residuals of ANC increased over the study period (p < 0.01), although the trend of the residuals resulted largely from an abrupt increase in 1997. In general, the trends observed in the three streams are similar to results presented for Adirondack lakes in a previous study, and are consistent with the declining trend in atmospheric deposition for this region, although the observed trends in ANC and pH in streams could not be directly attributed to the trends in acidic deposition.

  20. Using Satellite Imagery to Assess Large-Scale Habitat Characteristics of Adirondack Park, New York, USA

    NASA Astrophysics Data System (ADS)

    McClain, Bobbi J.; Porter, William F.

    2000-11-01

    Satellite imagery is a useful tool for large-scale habitat analysis; however, its limitations need to be tested. We tested these limitations by varying the methods of a habitat evaluation for white-tailed deer ( Odocoileus virginianus) in the Adirondack Park, New York, USA, utilizing harvest data to create and validate the assessment models. We used two classified images, one with a large minimum mapping unit but high accuracy and one with no minimum mapping unit but slightly lower accuracy, to test the sensitivity of the evaluation to these differences. We tested the utility of two methods of assessment, habitat suitability index modeling, and pattern recognition modeling. We varied the scale at which the models were applied by using five separate sizes of analysis windows. Results showed that the presence of a large minimum mapping unit eliminates important details of the habitat. Window size is relatively unimportant if the data are averaged to a large resolution (i.e., township), but if the data are used at the smaller resolution, then the window size is an important consideration. In the Adirondacks, the proportion of hardwood and softwood in an area is most important to the spatial dynamics of deer populations. The low occurrence of open area in all parts of the park either limits the effect of this cover type on the population or limits our ability to detect the effect. The arrangement and interspersion of cover types were not significant to deer populations.

  1. Changes in the chemistry of acidified Adirondack streams from the early 1980s to 2008.

    PubMed

    Lawrence, G B; Simonin, H A; Baldigo, B P; Roy, K M; Capone, S B

    2011-10-01

    Lakes in the Adirondack region of New York have partially recovered in response to declining deposition, but information on stream recovery is limited. Here we report results of Adirondack stream monitoring from the early 1980s to 2008. Despite a 50% reduction in atmospheric deposition of sulfur, overall increases in pH of only 0.28 and ANC of 13 μeq L(-1) were observed in 12 streams over 23 years, although greater changes did occur in streams with lower initial ANC, as expected. In the North Tributary of Buck Creek with high dissolved organic carbon (DOC) concentrations, SO(4)(2-) concentrations decreased from 1999 to 2008 at a rate of 2.0 μmol L(-1) y(-1), whereas in the neighboring South Tributary with low DOC concentrations, the decrease was only 0.73 μmol L(-1) y(-1). Ca(2+) leaching decreased in the North Tributary due to the SO(4)(2-) decrease, but this was partially offset by an increase in Ca(2+) leaching from increased DOC concentrations. PMID:21741140

  2. Microbiological survey of Adirondack lakes with various pH values

    SciTech Connect

    Boylen, C.W.; Shick, M.O.; Roberts, D.A.

    1983-05-01

    Many of the lakes in the Adirondack region of New York State are particularly sensitive to high H/sup +/ inputs from acidic deposition. Nine high-altitude oligotrophic Adirondack lakes having water of pH 4.3 to 7.0 were surveyed for total bacterial numbers and possible adaptation of the microbial communities to environmental pH. The number of heterotrophic bacteria from water samples recoverable on standard plate count agar were low (10 to 1000 per ml) for most of the lakes. Sediment aerobic heterotrophs recovered on standard plate count agar ranged from 14,000 to 1,300,000 per g of sediment. Low density values were consistent with the oligotrophic nature of all the lakes surveyed. There were no apparent differences in numbers of bacteria originally isolated at pH 5.0 and pH 7.0 between circumneutral lakes (pH 6.0) and acidic lakes (pH 5.0). A chi-square contingency test clearly showed (P 0.005) that two distinct heterotrophic populations had been originally isolated at pH 5.0 and pH 7.0, although there is undoubtedly some overlap between the two populations. 35 references, 5 figures, 3 tables.

  3. PIXE Analysis of Aerosol and Soil Samples Collected in the Adirondack Mountains

    NASA Astrophysics Data System (ADS)

    Yoskowitz, Joshua; Ali, Salina; Nadareski, Benjamin; Labrake, Scott; Vineyard, Michael

    2014-09-01

    We have performed an elemental analysis of aerosol and soil samples collected at Piseco Lake in Upstate New York using proton induced X-ray emission spectroscopy (PIXE). This work is part of a systematic study of airborne pollution in the Adirondack Mountains. Of particular interest is the sulfur content that can contribute to acid rain, a well-documented problem in the Adirondacks. We used a nine-stage cascade impactor to collect the aerosol samples near Piseco Lake and distribute the particulate matter onto Kapton foils by particle size. The soil samples were also collected at Piseco Lake and pressed into cylindrical pellets for experimentation. PIXE analysis of the aerosol and soil samples were performed with 2.2-MeV proton beams from the 1.1-MV Pelletron accelerator in the Union College Ion-Beam Analysis Laboratory. There are higher concentrations of sulfur at smaller particle sizes (0.25-1 μm), suggesting that it could be suspended in the air for days and originate from sources very far away. Other elements with significant concentrations peak at larger particle sizes (1-4 μm) and are found in the soil samples, suggesting that these elements could originate in the soil. The PIXE analysis will be described and the resulting data will be presented.

  4. Hanford basalt flow mineralogy

    SciTech Connect

    Ames, L.L.

    1980-09-01

    Mineralogy of the core samples from five core wells was examined in some detail. The primary mineralogy study included an optical examination of polished mounts, photomicrographs, chemical analyses of feldspars, pyroxenes, metallic oxides and microcrystalline groundmasses and determination from the chemical analyses of the varieties of feldspars, pyroxenes and metallic oxides. From the primary mineralogy data, a firm understanding of the average Hanford basalt flow primary mineralogy emerged. The average primary feldspar was a laboradorite, the average pyroxene was an augite and the average metallic oxide was a solid solution of ilmenite and magnetite. Secondary mineralization consisted of vug filling and joint coating, chiefly with a nontronite-beidellite clay, several zeolites, quartz, calcite, and opal. Specific flow units also were examined to determine the possibility of using the mineralogy to trace flows between core wells. These included units of the Pomona, the Umatilla and a high chromium flow just below the Huntzinger. In the Umatilla, or high barium flow, the compositional variation of the feldspars was unique in range. The pyroxenes in the Pomona were relatively highly zoned and accumulated chromium. The high chromium flow contained chromium spinels that graded in chromium content into simple magnetites very low in chromium content. A study of the statistical relationships of flow unit chemical constituents showed that flow unit constituents could be roughly correlated between wells. The probable cause of the correlation was on-going physical-chemical changes in the source magma.

  5. Flood basalts and mass extinctions

    NASA Technical Reports Server (NTRS)

    Morgan, W. Jason

    1988-01-01

    There appears to be a correlation between the times of flood basalts and mass-extinction events. There is a correlation of flood basalts and hotspot tracks--flood basalts appear to mark the beginning of a new hotspot. Perhaps there is an initial instability in the mantle that bursts forth as a flood basalt but then becomes a steady trickle that persists for many tens of millions of years. Suppose that flood basalts and not impacts cause the environmental changes that lead to mass-extinctions. This is a very testable hypothesis: it predicts that the ages of the flows should agree exactly with the times of extinctions. The Deccan and K-T ages agree with this hypothesis; An iridium anomaly at extinction boundaries apparently can be explained by a scaled-up eruption of the Hawaiian type; the occurrence of shocked-quartz is more of a problem. However if the flood basalts are all well dated and their ages indeed agree with extinction times, then surely some mechanism to appropriately produce shocked-quartz will be found.

  6. Nickel in high-alumina basalts

    USGS Publications Warehouse

    Hedge, C.E.

    1971-01-01

    New analyses of high-alumina basalts reveal an average nickel content higher than previously indicated. Ni in high-alumina basalts correlates with magnesium in the same way as it does in other basalt types. There is therefore no reason, based on Ni contents, to hypothesize a special origin for high-alumina basalts and it is permissible (based on Ni contents) to form andesites by fractional crystallization from high-alumina basalts. ?? 1971.

  7. Basaltic Lava Channels

    NASA Astrophysics Data System (ADS)

    Cashman, K. V.; Griffiths, R. W.; Kerr, R. C.

    2004-12-01

    or channel bends that exposes more core lava to cooling than simply that of the shear zones. Thus the channel geometry plays a major role in the thermal history of a flow. As lava flows rarely flow through pre-existing channels of prescribed geometry, we have performed an additional set of analog laboratory experiments to determine the relationship between flow rate, slope, and channel formation in solidifying flows. All flows develop stable uniform channels within solidified levees except when the flow rate is sufficiently low to permit flow front solidification, inflation, and tube formation. On constant slopes, increasing flow rates result in increases in both the rate of flow advance rate and the channel width, and a decrease in levee width. At constant flow rates, both channel width and levee width decrease with increasing slope while flow advance rate increases. Limited data on the geometry of basaltic lava channels indicate that experimental data are consistent with field observations, however, both additional field data and scaling relationships are required to fully utilize the laboratory experiments to predict channel development in basaltic lava flows.

  8. Origin of coronas in metagabbros of the Adirondack mts., N. Y

    USGS Publications Warehouse

    Whitney, P.R.; McLelland, J.M.

    1973-01-01

    Metagabbros from two widely separated areas in the Adirondacks show development of coronas. In the Southern Adirondacks, these are cored by olivine which is enclosed in a shell of orthopyroxene that is partially, or completely, rimmed by symplectites consisting of clinopyroxene and spinel. Compositions of the corona phases have been determined by electron probe and are consistent with a mechanism involving three partial reactions, thus: (a) Olivine=Orthopyroxene+(Mg, Fe)++. (b) Plagioclase+(Mg, Fe)+++Ca++=Clinopyroxene+Spinel+Na+. (c) Plagioclase+(Mg, Fe)+++Na+=Spinel+more sodic plagioclase+Ca++. Reaction (a) occurs in the inner shell of the corona adjacent to olivine; reaction (b) in the outer shell; and (c) in the surrounding plagioclase, giving rise to the spinel clouding which is characteristic of the plagioclase in these rocks. Alumina and silica remain relatively immobile. These reactions, when balanced, can be generalized to account for the aluminous nature of the pyroxenes and for changing plagioclase composition. Summed together, the partial reactions are equivalent to: (d) Olivine + Anorthite = Aluminous orthopyroxene + Aluminous Clinopyroxene + Spinel (Kushiro and Yoder, 1966). In the Adirondack Highlands, coronas between olivine and plagioclase commonly have an outer shell of garnet replacing the clinopyroxene/spinel shell. The origin of the garnet can also be explained in terms of three partial reactions: (e) Orthopyroxene+Ca++=Clinopyroxene+(Mg, Fe)++. (f) Clinopyroxene+Spinel+Plagioclase+(Mg, Fe)++=Garnet+Ca+++Na+. (g) Plagioclase+(Mg, Fe)+++Na+=Spinel + more sodic plagioclase+Ca++. These occur in the inner and outer corona shell and the surrounding plagioclase, respectively, and involve the products of reactions (a)-(d). Alumina and silica are again relatively immobile. Balanced, and generalized to account for aluminous pyroxenes and variable An content of plagioclase, they are equivalent to: (h) Orthopyroxene+Anorthite+Spinel=Garnet (Green and

  9. The Influence of Speckled Alder on Nitrogen Accumulation in Adirondack Wetlands

    NASA Astrophysics Data System (ADS)

    Kiernan, B. D.; Hurd, T. M.; Raynal, D. J.

    2001-05-01

    Shrub-dominated wetlands of the Adirondacks typically support vigorous populations of nitrogen-fixing speckled alder Alnus incana (L.) Moench var. americana Regel), and are the second most abundant wetland type in the Adirondack region. In symbiotic association with an actinomycete of the genus Frankia, this shrub fixes 37-43 kg N/ha/yr in monotypic stands. This study was undertaken to quantify the abundance of alder in wetlands typed as "Scrub-shrub 1" (SS1; known as alder/willow wetlands) in the National Wetlands Inventory, and to determine the accumulation of nitrate and ammonium in alder wetland substrates. Twenty wetlands from the Oswegatchie-Black (OB) and Upper Hudson (UH) watersheds were randomly selected using the Adirondack Park Agency's GIS data base which includes wetland cover types assigned using remotely sensed data. Wetlands designated as "SS1" (scrub-shrub vegetation) and "SS1/EM1" (scrub-shrub with emergent herbaceous vegetation) were included in the sample. Six wetlands varying in alder abundance were chosen to estimate N accumulation in the substrate, with measurement of dissolved inorganic N in groundwater and ion exchange resin extracts. In the OB watershed, A. incana averaged 30 % of total shrub density in SS1 wetlands and 36 % in SS1/EM1 wetlands. Alder accounted for 49 % of all stems in UH SS1 wetlands, 28 % in the SS1/EM1 wetlands and in total accounted for 35 % of all stems in this study. Nitrate in IER extracts and groundwater was significantly higher in high-density alder wetlands (p < 0.05). Eight of the 20 wetlands included in this study were estimated to have less than 3,000 alder stems/ha, and five were estimated to have greater than 10,000 stems/ha. The other seven wetlands averaged 6,000 stems/ha. At nine sites, foliar N equaled or exceeded estimated atmospheric deposition (~10 kg/ha/yr), and was likely derived from N fixation. We conclude that 50 % of the SS1/EM1 wetlands and at least 75 % of the SS1 wetlands in these watersheds

  10. Simulation of growth of Adirondack conifers in relation to global climate change

    SciTech Connect

    Pan, Y.; Raynal, D.J. )

    1993-06-01

    Several conifer species grown in plantations in the southeastern Adirondack mountains of New York were chosen to model tree growth. In the models, annual xylem growth was decomposed into several components that reflect various intrinsic or extrinsic factors. Growth signals indicative of climatic effects were used to construct response functions using both multivariate analysis and Kalman filter methods. Two models were used to simulate tree growth response to future CO[sub 2]-induced climate change projected by GCMs. The comparable results of both models indicate that different conifer species have individualistic growth responses to future climatic change. The response behaviors of trees are affected greatly by local stand conditions. The results suggest possible changes in future growth and distributions of naturally occurring conifers in this region.

  11. Bubble Growth in Lunar Basalts

    NASA Astrophysics Data System (ADS)

    Zhang, Y.

    2009-05-01

    Although Moon is usually said to be volatile-"free", lunar basalts are often vesicular with mm-size bubbles. The vesicular nature of the lunar basalts suggests that they contained some initial gas concentration. A recent publication estimated volatile concentrations in lunar basalts (Saal et al. 2008). This report investigates bubble growth on Moon and compares with that on Earth. Under conditions relevant to lunar basalts, bubble growth in a finite melt shell (i.e., growth of multiple regularly-spaced bubbles) is calculated following Proussevitch and Sahagian (1998) and Liu and Zhang (2000). Initial H2O content of 700 ppm (Saal et al. 2008) or lower is used and the effect of other volatiles (such as carbon dioxide, halogens, and sulfur) is ignored. H2O solubility at low pressures (Liu et al. 2005), concentration-dependent diffusivity in basalt (Zhang and Stolper 1991), and lunar basalt viscosity (Murase and McBirney 1970) are used. Because lunar atmospheric pressure is essentially zero, the confining pressure on bubbles is completely supplied by the overlying magma. Due to low H2O content in lunar basaltic melt (700 ppm H2O corresponds to a saturation pressure of 75 kPa), H2O bubbles only grow in the upper 16 m of a basalt flow or lake. A depth of 20 mm corresponds to a confining pressure of 100 Pa. Hence, vesicular lunar rocks come from very shallow depth. Some findings from the modeling are as follows. (a) Due to low confining pressure as well as low viscosity, even though volatile concentration is very low, bubble growth rate is extremely high, much higher than typical bubble growth rates in terrestrial melts. Hence, mm-size bubbles in lunar basalts are not strange. (b) Because the pertinent pressures are so low, bubble pressure due to surface tension plays a main role in lunar bubble growth, contrary to terrestrial cases. (c) Time scale to reach equilibrium bubble size increases as the confining pressure increases. References: (1) Liu Y, Zhang YX (2000) Earth

  12. A generalized garnet-forming reaction for metaigneous rocks in the Adirondacks

    USGS Publications Warehouse

    McLelland, J.M.; Whitney, P.R.

    1980-01-01

    A generalized reaction is presented to account for garnet formation in a variety of Adirondack metaigneous rocks. This reaction, which is the sum of five partial reactions written in aluminum-fixed frames of reference, is given by: 4(y+1+w)Anorthite+4 k(y+1+2 w)Olivine +4(1-k)(y+1+2 w)Fe-oxide+(8(y+1) -4 k(y+1+2 w))Orthopyroxene = 2(y+1)Garnet +2(y+1+2 w)Clinopyroxene+4 wSpinel where y is a function of plagioclase composition, k refers to the relative amounts of olivine and Fe-oxide participating in the reaction, and w is a measure of silicon mobility. When mass balanced for Mg and Fe, this reaction is found to be consistent with analyzed mineral compositions in a wide range of Adirondack metaigneous rocks. The reaction applies equally well whether the garnets were formed directly from the rectants given above or went through an intermadiate stage involving the formation of spinel, orthopyroxene, and clinopyroxene. The actual reactions which have produced garnet in both undersaturated and quartz-bearing rocks are special cases of the above general reaction. The most important special cases appear to be those in which the reactants include either olivine alone (k=1) or Fe-oxide alone (k=0). Silicon is relatively immobile (w =2) in olivine bearing, magnesium-rich rocks (k???1), and this correlates with the increased intensity in spinel clouding of plagioclase in these rocks. Silicon mobility apparently increases in the more iron-rich rocks, which also tend to contain clear or lightly clouded plagioclase. In all the rocks studied the most common composition of metamorphic plagioclase is close to An33 (i.e., y=1). Plagioclase of lower anorthite content may be too sodic to participate in garnet formation at the P-T conditions involved. ?? 1980 Springer-Verlag.

  13. Use of stream chemistry for monitoring acidic deposition effects in the Adirondack region of New York.

    PubMed

    Lawrence, Gregory B; Momen, Bahram; Roy, Karen M

    2004-01-01

    Acid-neutralizing capacity (ANC) and pH were measured weekly from October 1991 through September 2001 in three streams in the western Adirondack Mountain region of New York to identify trends in stream chemistry that might be related to changes in acidic deposition. A decreasing trend in atmospheric deposition of SO4/2- was observed within the region over the 10-yr period, although most of the decrease occurred between 1991 and 1995. Both ANC and pH were inversely related to flow in all streams; therefore, a trend analysis was conducted on (i) the measured values of ANC and pH and (ii) the residuals of the concentration-discharge relations. In Buck Creek, ANC increased significantly (p < 0.05) over the 10 yr, but the residuals of ANC showed no trend (p > 0.10). In Bald Mountain Brook, ANC and residuals of ANC increased significantly (p < 0.01), although the trend was diatonic-a distinct decrease from 1991 to 1996 was followed by a distinct increase from 1996 to 2001. In Fly Pond outlet, ANC and residuals of ANC increased over the study period (p < 0.01), although the trend of the residuals resulted largely from an abrupt increase in 1997. In general, the trends observed in the three streams are similar to results presented for Adirondack lakes in a previous study, and are consistent with the declining trend in atmospheric deposition for this region, although the observed trends in ANC and pH in streams could not be directly attributed to the trends in acidic deposition.

  14. Persistent mortality of brook trout in episodically acidified streams of the Southwestern Adirondack Mountains, New York

    USGS Publications Warehouse

    Baldigo, Barry P.; Lawrence, G.; Simonin, H.

    2007-01-01

    Water chemistry, discharge, and mortality of caged brook trout Salvelinus fontinalis were characterized in six headwater streams in the southwestern Adirondack Mountains of New York during spring 2001-2003. Results were compared with mortality recorded during similar tests during 1984-1985, 1988-1990, and 1997 to assess contemporary relations between stream acidification and brook trout mortality, the effects of exposure duration on mortality, and the effects of decreased rates of acidic deposition on water quality and fish mortality. Water quality and mortality of caged, young-of-the-year brook trout were evaluated during 30-d exposure periods from mid-April to late May during the most recent tests. In 2001-2003, mortality ranged from 0% to 100% and varied among streams and years, depending on the timing of toxicity tests in relation to the annual snowmelt and on the ability of each watershed to neutralize acids and prevent acutely toxic concentrations of inorganic monomeric aluminum (Alim) during high-flow events. Mortality rates in 2001-2003 tests were highly variable but similar to those observed during earlier tests. This similarity suggests that stream water quality in the southwestern Adirondack Mountains has not changed appreciably over the past 20 years. Concentrations of Alim greater than 2.0 and 4.0 ??mol/L were closely correlated with low and high mortality rates, respectively, and accounted for 83% of the variation in mortality. Two to four days of exposure to Alim concentrations greater than 4.0 ??mol/L resulted in 50-100% mortality. The extended periods (as long as 6 months) during which Alim concentrations exceeded 2.0 and 4.0 ??mol/L in one or more streams, combined with the low tolerance of many other fish species to acid and elevated Al concentrations, indicate a high potential for damage to fish communities in these and other poorly buffered streams of the Northeast. ?? Copyright by the American Fisheries Society 2007.

  15. Use of stream chemistry for monitoring acidic deposition effects in the Adirondack region of New York.

    PubMed

    Lawrence, Gregory B; Momen, Bahram; Roy, Karen M

    2004-01-01

    Acid-neutralizing capacity (ANC) and pH were measured weekly from October 1991 through September 2001 in three streams in the western Adirondack Mountain region of New York to identify trends in stream chemistry that might be related to changes in acidic deposition. A decreasing trend in atmospheric deposition of SO4/2- was observed within the region over the 10-yr period, although most of the decrease occurred between 1991 and 1995. Both ANC and pH were inversely related to flow in all streams; therefore, a trend analysis was conducted on (i) the measured values of ANC and pH and (ii) the residuals of the concentration-discharge relations. In Buck Creek, ANC increased significantly (p < 0.05) over the 10 yr, but the residuals of ANC showed no trend (p > 0.10). In Bald Mountain Brook, ANC and residuals of ANC increased significantly (p < 0.01), although the trend was diatonic-a distinct decrease from 1991 to 1996 was followed by a distinct increase from 1996 to 2001. In Fly Pond outlet, ANC and residuals of ANC increased over the study period (p < 0.01), although the trend of the residuals resulted largely from an abrupt increase in 1997. In general, the trends observed in the three streams are similar to results presented for Adirondack lakes in a previous study, and are consistent with the declining trend in atmospheric deposition for this region, although the observed trends in ANC and pH in streams could not be directly attributed to the trends in acidic deposition. PMID:15224937

  16. Impacts of acidification on macroinvertebrate communities in streams of the western Adirondack Mountains, New York, USA

    USGS Publications Warehouse

    Baldigo, Barry P.; Lawrence, G.B.; Bode, R.W.; Simonin, H.A.; Roy, K.M.; Smith, A.J.

    2009-01-01

    Limited stream chemistry and macroinvertebrate data indicate that acidic deposition has adversely affected benthic macroinvertebrate assemblages in numerous headwater streams of the western Adirondack Mountains of New York. No studies, however, have quantified the effects that acidic deposition and acidification may have had on resident fish and macroinvertebrate communities in streams of the region. As part of the Western Adirondack Stream Survey, water chemistry from 200 streams was sampled five times and macroinvertebrate communities were surveyed once from a subset of 36 streams in the Oswegatchie and Black River Basins during 2003-2005 and evaluated to: (a) document the effects that chronic and episodic acidification have on macroinvertebrate communities across the region, (b) define the relations between acidification and the health of affected species assemblages, and (c) assess indicators and thresholds of biological effects. Concentrations of inorganic Al in 66% of the 200 streams periodically reached concentrations toxic to acid-tolerant biota. A new acid biological assessment profile (acidBAP) index for macroinvertebrates, derived from percent mayfly richness and percent acid-tolerant taxa, was strongly correlated (R2 values range from 0.58 to 0.76) with concentrations of inorganic Al, pH, ANC, and base cation surplus (BCS). The BCS and acidBAP index helped remove confounding influences of natural organic acidity and to redefine acidification-effect thresholds and biological-impact categories. AcidBAP scores indicated that macroinvertebrate communities were moderately or severely impacted by acidification in 44-56% of 36 study streams, however, additional data from randomly selected streams is needed to accurately estimate the true percentage of streams in which macroinvertebrate communities are adversely affected in this, or other, regions. As biologically relevant measures of impacts caused by acidification, both BCS and acidBAP may be useful

  17. The basalts of Mare Frigoris

    NASA Astrophysics Data System (ADS)

    Kramer, G. Y.; Jaiswal, B.; Hawke, B. R.; Öhman, T.; Giguere, T. A.; Johnson, K.

    2015-10-01

    This paper discusses the methodology and results of a detailed investigation of Mare Frigoris using remote sensing data from Clementine, Lunar Prospector, and Lunar Reconnaissance Orbiter, with the objective of mapping and characterizing the compositions and eruptive history of its volcanic units. With the exception of two units in the west, Mare Frigoris and Lacus Mortis are filled with basalts having low-TiO2 to very low TiO2, low-FeO, and high-Al2O3 abundances. These compositions indicate that most of the basalts in Frigoris are high-Al basalts—a potentially undersampled, yet important group in the lunar sample collection for its clues about the heterogeneity of the lunar mantle. Thorium abundances of most of the mare basalts in Frigoris are also low, although much of the mare surface appears elevated due to contamination from impact gardening with the surrounding high-Th Imbrium ejecta. There are, however, a few regional thorium anomalies that are coincident with cryptomare units in the east, the two youngest mare basalt units, and some of the scattered pyroclastic deposits and volcanic constructs. In addition, Mare Frigoris lies directly over the northern extent of the major conduit for a magma plumbing system that fed many of the basalts that filled Oceanus Procellarum, as interpreted by Andrews-Hanna et al. (2014) using data from the Gravity Recovery and Interior Laboratory mission. The relationship between this deep-reaching magma conduit and the largest extent of high-Al basalts on the Moon makes Mare Frigoris an intriguing location for further investigation of the lunar mantle.

  18. Chemical Weathering Kinetics of Basalt on Venus

    NASA Technical Reports Server (NTRS)

    Fegley, Bruce, Jr.

    1997-01-01

    The purpose of this project was to experimentally measure the kinetics for chemical weathering reactions involving basalt on Venus. The thermochemical reactions being studied are important for the CO2 atmosphere-lithosphere cycle on Venus and for the atmosphere-surface reactions controlling the oxidation state of the surface of Venus. These reactions include the formation of carbonate and scapolite minerals, and the oxidation of Fe-bearing minerals. These experiments and calculations are important for interpreting results from the Pioneer Venus, Magellan, Galileo flyby, Venera, and Vega missions to Venus, for interpreting results from Earth-based telescopic observations, and for the design of new Discovery class (e.g., VESAT) and New Millennium missions to Venus such as geochemical landers making in situ elemental and mineralogical analyses, and orbiters, probes and balloons making spectroscopic observations of the sub-cloud atmosphere of Venus.

  19. Total Mercury and Methylmercury Dynamics; stream export in an upland forested watershed in the Adirondack region of New York State

    NASA Astrophysics Data System (ADS)

    Carleton, W.; Vidon, P.; Mitchell, M. J.

    2012-12-01

    Although levels of mercury and acid rain deposition have greatly declined in recent years due to legislation controls on industry emissions, their legacy has had a lasting effect on the Adirondack region of New York State. This historical mercury deposition is of concern because of the high chance for methylmercury production and export to occur. The impact of forested uplands on methylmercury export remains poorly understood in relation to other ecosystems. Research indicates that sulfate dynamics play a large role in regulating the production of methylmercury in the presence of inorganic mercury; however the relationship between methylmercury production and nitrate availability at various times of the year is less understood, yet, hypothesized to potentially impact sulfate reduction and ultimately methylmercury production in a variety of ecosystems. In this study, mercury and water quality (including sulfate and nitrate) will be monitored in spring, summer and fall of 2012 at 7 locations in Arbutus Watershed, Adirondacks, NY. Proxies (UV absorbance, Fluorescence indices) for total mercury and methylmercury will be utilized to predict export. The main objectives of this research are to determine the relevance of forested uplands in methylmercury export, as well as gain further understanding of mercury dynamics and associated proxies in relation to nitrate and sulfate availability. Photo courtesy of the Adirondack Ecological Center

  20. Effects of acidic deposition and soil acidification on sugar maple trees in the Adirondack Mountains, New York

    USGS Publications Warehouse

    Sullivan, Timothy J.; Lawrence, Gregory B.; Bailey, Scott W.; McDonnell, Todd C.; Beier, Colin M.; Weathers, K.C.; McPherson, G.T.; Bishop, Daniel A.

    2013-01-01

    We documented the effects of acidic atmospheric deposition and soil acidification on the canopy health, basal area increment, and regeneration of sugar maple (SM) trees across the Adirondack region of New York State, in the northeastern United States, where SM are plentiful but not well studied and where widespread depletion of soil calcium (Ca) has been documented. Sugar maple is a dominant canopy species in the Adirondack Mountain ecoregion, and it has a high demand for Ca. Trees in this region growing on soils with poor acid–base chemistry (low exchangeable Ca and % base saturation [BS]) that receive relatively high levels of atmospheric sulfur and nitrogen deposition exhibited a near absence of SM seedling regeneration and lower crown vigor compared with study plots with relatively high exchangeable Ca and BS and lower levels of acidic deposition. Basal area increment averaged over the 20th century was correlated (p < 0.1) with acid–base chemistry of the Oa, A, and upper B soil horizons. A lack of Adirondack SM regeneration, reduced canopy condition, and possibly decreased basal area growth over recent decades are associated with low concentrations of nutrient base cations in this region that has undergone soil Ca depletion from acidic deposition.

  1. Effects of acidic deposition and soil acidification on sugar maple trees in the Adirondack Mountains, New York.

    PubMed

    Sullivan, T J; Lawrence, G B; Bailey, S W; McDonnell, T C; Beier, C M; Weathers, K C; McPherson, G T; Bishop, D A

    2013-11-19

    We documented the effects of acidic atmospheric deposition and soil acidification on the canopy health, basal area increment, and regeneration of sugar maple (SM) trees across the Adirondack region of New York State, in the northeastern United States, where SM are plentiful but not well studied and where widespread depletion of soil calcium (Ca) has been documented. Sugar maple is a dominant canopy species in the Adirondack Mountain ecoregion, and it has a high demand for Ca. Trees in this region growing on soils with poor acid-base chemistry (low exchangeable Ca and % base saturation [BS]) that receive relatively high levels of atmospheric sulfur and nitrogen deposition exhibited a near absence of SM seedling regeneration and lower crown vigor compared with study plots with relatively high exchangeable Ca and BS and lower levels of acidic deposition. Basal area increment averaged over the 20th century was correlated (p < 0.1) with acid-base chemistry of the Oa, A, and upper B soil horizons. A lack of Adirondack SM regeneration, reduced canopy condition, and possibly decreased basal area growth over recent decades are associated with low concentrations of nutrient base cations in this region that has undergone soil Ca depletion from acidic deposition.

  2. Effects of acidic deposition and soil acidification on sugar maple trees in the Adirondack Mountains, New York.

    PubMed

    Sullivan, T J; Lawrence, G B; Bailey, S W; McDonnell, T C; Beier, C M; Weathers, K C; McPherson, G T; Bishop, D A

    2013-11-19

    We documented the effects of acidic atmospheric deposition and soil acidification on the canopy health, basal area increment, and regeneration of sugar maple (SM) trees across the Adirondack region of New York State, in the northeastern United States, where SM are plentiful but not well studied and where widespread depletion of soil calcium (Ca) has been documented. Sugar maple is a dominant canopy species in the Adirondack Mountain ecoregion, and it has a high demand for Ca. Trees in this region growing on soils with poor acid-base chemistry (low exchangeable Ca and % base saturation [BS]) that receive relatively high levels of atmospheric sulfur and nitrogen deposition exhibited a near absence of SM seedling regeneration and lower crown vigor compared with study plots with relatively high exchangeable Ca and BS and lower levels of acidic deposition. Basal area increment averaged over the 20th century was correlated (p < 0.1) with acid-base chemistry of the Oa, A, and upper B soil horizons. A lack of Adirondack SM regeneration, reduced canopy condition, and possibly decreased basal area growth over recent decades are associated with low concentrations of nutrient base cations in this region that has undergone soil Ca depletion from acidic deposition. PMID:24102084

  3. Radiation shielding concrete made of Basalt aggregates.

    PubMed

    Alhajali, S; Yousef, S; Kanbour, M; Naoum, B

    2013-04-01

    In spite of the fact that Basalt is a widespread type of rock, there is very little available information on using it as aggregates for concrete radiation shielding. This paper investigates the possibility of using Basalt for the aforementioned purpose. The results have shown that Basalt could be used successfully for preparing radiation shielding concrete, but some attention should be paid to the choice of the suitable types of Basalt and for the neutron activation problem that could arise in the concrete shield.

  4. Temperature dependence of basalt weathering

    NASA Astrophysics Data System (ADS)

    Li, Gaojun; Hartmann, Jens; Derry, Louis A.; West, A. Joshua; You, Chen-Feng; Long, Xiaoyong; Zhan, Tao; Li, Laifeng; Li, Gen; Qiu, Wenhong; Li, Tao; Liu, Lianwen; Chen, Yang; Ji, Junfeng; Zhao, Liang; Chen, Jun

    2016-06-01

    The homeostatic balance of Earth's long-term carbon cycle and the equable state of Earth's climate are maintained by negative feedbacks between the levels of atmospheric CO2 and the chemical weathering rate of silicate rocks. Though clearly demonstrated by well-controlled laboratory dissolution experiments, the temperature dependence of silicate weathering rates, hypothesized to play a central role in these weathering feedbacks, has been difficult to quantify clearly in natural settings at landscape scale. By compiling data from basaltic catchments worldwide and considering only inactive volcanic fields (IVFs), here we show that the rate of CO2 consumption associated with the weathering of basaltic rocks is strongly correlated with mean annual temperature (MAT) as predicted by chemical kinetics. Relations between temperature and CO2 consumption rate for active volcanic fields (AVFs) are complicated by other factors such as eruption age, hydrothermal activity, and hydrological complexities. On the basis of this updated data compilation we are not able to distinguish whether or not there is a significant runoff control on basalt weathering rates. Nonetheless, the simple temperature control as observed in this global dataset implies that basalt weathering could be an effective mechanism for Earth to modulate long-term carbon cycle perturbations.

  5. Basalt here, basalt there: Constraining the basaltic nature of eight Vp-type asteroids in the inner and outer main asteroid belt

    NASA Astrophysics Data System (ADS)

    Hardersen, Paul Scott; Reddy, Vishnu

    2016-10-01

    The distribution and abundance of basaltic material in the main asteroid belt has multiple implications that impact our understanding of the physical and thermal conditions that existed in the inner solar system during the formation epoch about 4.6 Gyr ago. Subjects impacted by a more accurate basaltic asteroid inventory include the efficacy of current inner solar system heating model predictions (Al-26 and T Tauri induction heating), the existence of differentiated parent bodies other than (4) Vesta, the dispersion efficiency of Vestoids by YORP forces, and the predictive ability of the V-taxonomy in predicting a basaltic surface composition. This work reports on a continuation of an effort to better constrain the basaltic asteroid population in the main asteroid belt with the goal of observing about 650 Vp-type asteroids. This work focuses on two populations: a) those Vp-classified asteroids (Carvano et al., 2010) in the spatial vicinity of (4) Vesta (candidate Vestoids) in the inner main belt, and b) Vp-classified asteroids in the outer main belt beyond 2.5 AU. Thus far, 23 Vp-type asteroids and candidate Vestoids have been observed and analyzed, which are all strongly suggestive of a basaltic surface composition (Hardersen et al., 2014, 2015, 2016 (in preparation)). However, unpublished work is beginning to show that the Vp taxonomic class is less accurate in its ability to identify basaltic surface compositions in outer-belt Vp-type asteroids. We report here on an additional set of Vp-type asteroids that were observed at the NASA Infrared Telescope Facility (IRTF) in December 2015 and January 2016. All observations were obtained with the SpeX spectrograph in prism mode with spectral range from 0.7 to 2.5 microns. They include (4900) Maymelou, (7302) 1993 CQ, (9064) Johndavies, (9531) Jean-Luc, (11341) Babbage, (17480) 1991 PE10, (20171) 1996 WC2, and (25849) 2000 ET107. We present average near-infrared (NIR) reflectance spectra of each asteroid, determine the

  6. Trace elements in ocean ridge basalts

    NASA Technical Reports Server (NTRS)

    Kay, R. W.; Hubbard, N. J.

    1978-01-01

    A study is made of the trace elements found in ocean ridge basalts. General assumptions regarding melting behavior, trace element fractionation, and alteration effects are presented. Data on the trace elements are grouped according to refractory lithophile elements, refractory siderophile elements, and volatile metals. Variations in ocean ridge basalt chemistry are noted both for regional and temporal characteristics. Ocean ridge basalts are compared to other terrestrial basalts, such as those having La/Yb ratios greater than those of chondrites, and those having La/Yb ratios less than those of chondrites. It is found that (1) as compared to solar or chondrite ratios, ocean ridge basalts have low ratios of large, highly-charged elements to smaller less highly-charged elements, (2) ocean ridge basalts exhibit low ratios of volatile to nonvolatile elements, and (3) the transition metals Cr through Zn in ocean ridge basalts are not fractionated more than a factor of 2 or 3 from the chondritic abundance ratios.

  7. Alkali metasomatism in the major gneiss, northwest Adirondacks, New York: open system or closed?

    NASA Astrophysics Data System (ADS)

    Carl, James D.

    1981-09-01

    The thickest clastic unit in the northwest Adirondacks. New York, undergoes gradual transition from amphibolite to granulite facies over a distance of 55 km from Emeryville to Colton. This Precambrian quartz-biotite-oligoclase-K-feldspar gneiss with migmatite characteristics has long been cited as having undergone progressive loss of K, Si, Fe2+, Ba and H2O toward Colton and granulite facies conditions (ENGEL and ENGEL, 1958, 1960a. b). Chemical data obtained from new samples, however, cast doubt upon the interpretation of open system alkali metasomatism. Outcrop to outcrop chemical variation is shown to be of similar magnitude to the chemical variation recorded across the entire gneiss belt. Chemical differences between Emeryville and Colton are not those expected from progressive degranitization by loss of alkali-bearing fluid. Ratios of {K}/{Rb} and Ca-Na K suggest that metamorphism was isochemical on the scale of outcrop. These new data were obtained from mixtures of leucosome and fine-grained paragneiss at each of 7 outcrops. The sampling technique contrasts with that of A.E.J. and C. Engel who analyzed leucosome separately from fine grained (‘least altered’) gneiss.

  8. Development of LANDSAT Derived Forest Cover Information for Integration into Adirondack Park GIS

    NASA Technical Reports Server (NTRS)

    Curran, R. P.; Banta, J. S.

    1982-01-01

    Based upon observed changes in timber harvest practices partially attributable to forest biomass removable for energy supply purposes, the Adirondack Park Agency began in 1979 a multi-year project to implement a digital geographic information system (GIS). An initial developmental task was an inventory of forest cover information and analysis of forest resource change and availability. While developing the GIS, a pilot project was undertaken to evaluate the usefulness of LANDSAT derived land cover information for this purpose, and to explore the integration of LANDSAT data into the GIS. The prototype LANDSAT analysis project involved: (1) the use of both recent and historic data to derive land cover information for two dates; and (2) comparison of land cover over time to determine quantitative and geographic changes. The "recent data," 1978 full foliage data over portions of four LANDSAT scenes, was classified, using ground truth derived training samples in various forested and non-forested categories. Forested categories include the following: northern hardwoods, pine, spruce-fir, and pine plantation, while nonforested categories include wet-conifer, pasture, grassland, urban, exposed soil, agriculture, and water.

  9. Increased Calcium Availability Leads to Greater Forest Floor Accumulation in an Adirondack Forest

    NASA Astrophysics Data System (ADS)

    Melvin, A.; Goodale, C. L.

    2010-12-01

    Nutrient availability in Northeastern US forests has been dramatically altered by anthropogenic activities. Acid deposition has not only increased nitrogen (N) availability, but has also been linked to soil acidification and a loss of base cations, largely calcium (Ca). We are studying the long-term effects of a Ca addition on carbon (C) and N cycling in a forested catchment in the Adirondack Park, New York. In 1989, calcium carbonate (lime) was added to two subcatchments within the Woods Lake Watershed to ameliorate the effects of soil Ca depletion. Two additional subcatchments were left as controls. Eighteen years after the Ca application, both soil pH and exchangeable Ca concentrations remain elevated in the organic horizons and upper mineral soils of the treated subcatchments. The forest floor mass in this watershed is very large and measurements show that the organic layer in the limed subcatchments is significantly larger than in the controls (212 t/ha vs. 116 t/ha), resulting in greater C and N stocks in the Ca-amended soils. This finding suggests that Ca may stabilize soil organic matter (SOM), resulting in greater C storage under high soil Ca conditions. We are investigating potential drivers of this SOM accumulation in the limed subcatchments, including rates of leaf litter production and the decomposition rate of forest floor material. This work will provide important insights into how long-term changes in soil Ca availability influence SOM stabilization, retention and nutrient cycling.

  10. Increases in dissolved organic carbon accelerate loss of toxic Al in Adirondack lakes recovering from acidification

    USGS Publications Warehouse

    Lawrence, Gregory B.; Dukett, James E; Houck, Nathan; Snyder, Phillip; Capone, Susan B.

    2013-01-01

    Increasing pH and decreasing Al in surface waters recovering from acidification have been accompanied by increasing concentrations of dissolved organic carbon (DOC) and associated organic acids that partially offset pH increases and complicate assessments of recovery from acidification. To better understand the processes of recovery, monthly chemistry from 42 lakes in the Adirondack region, NY, collected from 1994 to 2011, were used to (1) evaluate long-term changes in DOC and associated strongly acidic organic acids and (2) use the base-cation surplus (BCS) as a chemical index to assess the effects of increasing DOC concentrations on the Al chemistry of these lakes. Over the study period, the BCS increased (p < 0.01) and concentrations of toxic inorganic monomeric Al (IMAl) decreased (p < 0.01). The decreases in IMAl were greater than expected from the increases in the BCS. Higher DOC concentrations that increased organic complexation of Al resulted in a decrease in the IMAl fraction of total monomeric Al from 57% in 1994 to 23% in 2011. Increasing DOC concentrations have accelerated recovery in terms of decreasing toxic Al beyond that directly accomplished by reducing atmospheric deposition of strong mineral acids.

  11. Late Quaternary history of the southwestern St. Lawrence Lowlands and adjacent Adirondack Highlands

    SciTech Connect

    Pair, D.L. . Dept. of Geology)

    1993-03-01

    The reconstruction of Late Wisconsinan ice retreat, proglacial lakes, and Champlain Sea history from the northwest Adirondack slope and adjacent St. Lawrence Lowlands is critical to the synthesis of a regional picture of deglacial events in the eastern Great Lakes region. Unfortunately, these same areas are well known for their limited exposures, landforms covered by thick forest, large tracts of land inaccessible to detailed field mapping, and the overall paucity of glacial materials preserved on upland surfaces. Despite these limitations, a model which utilizes multiple and field-truthed evidence has been used to designate areas where ice border deposits indicate a substantial recessional position. It employs the following criteria in this analysis: sedimentology and morphostratigraphy of morainal landform segments and related sediments; orientation and continuity of ice border drainage channels; and the relationship of ice borders and drainage systems to well documented local and regional water bodies which accompanied ice retreat. The results of this approach have provided a unique regional picture of deglaciation. Despite the inherent limitations of working in upland areas to reconstruct glacial events, detailed morphostratigraphic correlations based on multiple lines of evidence can yield important information. The positions of five former ice borders have been reconstructed from the available data. These ice margins correspond closely with those documented previously by others adjoining areas. This type of study, utilizing multiple and field-truthed lines of evidence, constitutes a tangible step towards understanding the nature and history of ice retreat along this portion of the Laurentide Ice Sheet.

  12. Chemistry and transport of soluble humic substances in forested watersheds of the Adirondack Park, New York

    NASA Astrophysics Data System (ADS)

    Cronan, Christopher S.; Aiken, George R.

    1985-08-01

    Studies were conducted in conjunction with the Integrated Lake-Watershed Acidification Study (ILWAS) to examine the chemistry and leaching patterns of soluble humic substances in forested watersheds of the Adirondack region. During the summer growing season, mean dissolved organic carbon (DOC) concentrations in the ILWAS watersheds ranged from 21-32 mg C l-1 in O/A horizon leachates, from 5-7 mg C l-1 in B horizon leachates, from 2-4 mg C l-1 in groundwater solutions, from 6-8 mg C l-1 in first order streams, from 3-8 mg C l-1 in lake inlets, and from 2-7 mg C l-1 in lake outlets. During the winter, mean DOC concentrations dropped significantly in the upper soil profile. Soil solutions from mixed and coniferous stands contained as much as twice the DOC concentration of lysimeter samples from hardwood stands. Results of DOC fractionation analysis showed that hydrophobia and hydrophilic acids dominate the organic solute composition of natural waters in these watersheds. Charge balance and titration results indicated that the general acid-base characteristics of the dissolved humic mixture in these natural waters can be accounted for by a model organic acid having an averagepKa of 3.85, an average charge density of 4-5 μeq mg-1 C at ambient pH, and a total of 6-7 meq COOH per gram carbon.

  13. Phytoplankton limitation by phosphorus and zooplankton grazing in an acidic Adirondack lake

    SciTech Connect

    Singer, R.; Evans, G.L.; Pratt, N.C.

    1984-08-01

    Lakes which are believed to have been acidified by atmospheric deposition of anthropogenic substances are known for their unusually high water clarity and low nutrient concentrations. Some evidence indicates that alterations in predator/prey relationships, an indirect effect of acidification, bring about the increase in water clarity. Enclosures were used to study the effects of phosphorus addition and zooplankton removal on the phytoplankton of an acidic lake in the Adirondack Mountains of New York. Fertilized enclosures had significantly lower alkalinities and contained significantly more dissolved oxygen after the incubation period than did unfertilized enclosures. The P concentration remained at or near the limit of detection in the unfertilized enclosures. The phytoplankton population bloomed after the addition of 80 micro g/liter of phosphate as KH/sub 2/PO/sub 4/. The response was measured by cell counts of the dominant phytoplankton. Chlamydomonas, and by changes in chlorophyll a concentration. About half the number of algal cells were present after the two week incubation when zooplankton were not removed, indicating that zooplankton herbivory can influence, but not totally control, the algal production. 46 references.

  14. Chemistry and transport of soluble humic substances in forested watersheds of the Adirondack Park, New York

    USGS Publications Warehouse

    Cronan, C.S.; Aiken, G.R.

    1985-01-01

    Studies were conducted in conjunction with the Integrated Lake-Watershed Acidification Study (ILWAS) to examine the chemistry and leaching patterns of soluble humic substances in forested watersheds of the Adirondack region. During the summer growing season, mean dissolved organic carbon (DOC) concentrations in the ILWAS watersheds ranged from 21-32 mg C l-1 in O/A horizon leachates, from 5-7 mg C l-1 in B horizon leachates, from 2-4 mg C l-1 in groundwater solutions, from 6-8 mg C l-1 in first order streams, from 3-8 mg C l-1 in lake inlets, and from 2-7 mg C l-1 in lake outlets. During the winter, mean DOC concentrations dropped significantly in the upper soil profile. Soil solutions from mixed and coniferous stands contained as much as twice the DOC concentration of lysimeter samples from hardwood stands. Results of DOC fractionation analysis showed that hydrophobia and hydrophilic acids dominate the organic solute composition of natural waters in these watersheds. Charge balance and titration results indicated that the general acid-base characteristics of the dissolved humic mixture in these natural waters can be accounted for by a model organic acid having an averagepKa of 3.85, an average charge density of 4-5 ??eq mg-1 C at ambient pH, and a total of 6-7 meq COOH per gram carbon. ?? 1985.

  15. U-Pb zircon geochronology and evolution of some Adirondack meta-igneous rocks

    NASA Technical Reports Server (NTRS)

    Mclelland, J. M.

    1988-01-01

    An update was presented of the recent U-Pb isotope geochronology and models for evolution of some of the meta-igneous rocks of the Adirondacks, New York. Uranium-lead zircon data from charnockites and mangerites and on baddeleyite from anorthosite suggest that the emplacement of these rocks into a stable crust took place in the range 1160 to 1130 Ma. Granulite facies metamorphism was approximately 1050 Ma as indicated by metamorphic zircon and sphene ages of the anorthosite and by development of magmatitic alaskitic gneiss. The concentric isotherms that are observed in this area are due to later doming. However, an older contact metamorphic aureole associated with anorthosite intrusion is observed where wollastonite develops in metacarbonates. Zenoliths found in the anorthosite indicate a metamorphic event prior to anorthosite emplacement. The most probable mechanism for anorthosite genesis is thought to be ponding of gabbroic magmas at the Moho. The emplacement of the anorogenic anorthosite-mangerite-charnockite suite was apparently bracketed by compressional orogenies.

  16. Long-term pCO2 trends in Adirondack Lakes

    NASA Astrophysics Data System (ADS)

    Seekell, David A.; Gudasz, Cristian

    2016-05-01

    Lakes are globally significant sources of CO2 to the atmosphere. However, there are few temporally resolved records of lake CO2 concentrations and long-term patterns are poorly characterized. We evaluated annual trends in the partial pressure of CO2 (pCO2) based on chemical measurements from 31 Adirondack Lakes taken monthly over an 18 year period. All lakes were supersaturated with CO2 and were sources of CO2 to the atmosphere. There were significant pCO2 trends in 29% of lakes. The median magnitude of significant positive trends was 32.1 µatm yr-1. Overall, 52% of lakes had pCO2 trends greater than those reported for the atmosphere and ocean. Significant trends in lake pCO2 were attributable to regional recovery from acid deposition and changing patterns of ice cover. These results illustrate that lake pCO2 can respond rapidly to environmental change, but the lack of significant trend in 71% of lakes indicates substantial lake-to-lake variation in magnitude of response.

  17. Evidence for multiple metamorphic events in the Adirondack Mountains, N. Y

    SciTech Connect

    McLelland, J.; Lochhead, A.; Vyhnal, C.

    1988-05-01

    Field evidence consisting of: (1) rotated, foliated xenoliths, (2) country rock foliation truncated by isoclinally folded igneous intrusions bearing granulite facies assemblages document one, or more, early dynamothermal event(s) of regional scale and high grade. Early metamorphism resulted in pronounced linear and planar fabric throughout the Adirondacks and preceded the emplacement of the anorthosite-mangerite-charnockite-granite-alaskite (AMCA) suite which contains xenoliths of the metamorphosed rocks. Olivine metagabbros, believed to be approximately contemporaneous with the AMCA-suite, also crosscut and contain xenoliths of, strongly foliated metasediments. These intrusive rocks caused contact metamorphism in the metasediments which locally exhibit both anatectite and restite assemblages. Subsequently, this already complex framework underwent three phases of folding, including an early recumbent isoclinical event, and was metamorphosed to granulite facies P,T conditions. The age of the early metamorphism cannot yet be narrowly constrained, but isotopic results suggest that it may be as young as approx. 1200 Ma or older than approx. 1420 Ma. U-Pb zircon ages indicate emplacement of the AMCA-(metagabbro)-suite in the interval 1160-1130 Ma and place the peak of granulite facies metamorphism between 1070-1025 Ma. The anorogenic character of the AMCA-suite, and the occurrence of metadiabase dike swarms within it, are further evidence of the separate nature of the metamorphic events that precede and postdate AMCA emplacement.

  18. Juvenile Middle Proterozoic crust in the Adirondack Highlands, Grenville province, northeastern North America

    SciTech Connect

    Daly, J.S. ); McLelland, J.M. )

    1991-02-01

    Nd isotope data indicate that minimal amounts of significantly older crust have contributed to the genesis of the oldest (ca. 1.3-13.5 Ga) plutons in the Adirondack Highlands. These are magmatic arc tonalites with positive initial {epsilon}{sub Nd} values and Sm-Nd depleted mantle model ages (t{sub DM}) that are within 70 m.y. of the time of their crystallization. Granitoids of the anorthosite-mangerite-charnockite-granite suite, dated at 1,156-1,134 Ma, as well as the 1,100-1,050 Ma plutons, associated with the Ottawan phase of the Grenvillian orogenic cycle, also have positive initial {epsilon}{sub Nd} values and t{sub DM} ages similar to the tonalites. Derivation of both groups of granitoids by crustal melting of the magmatic arc is consistent with the available isotopic and geochemical data. Juvenile late Middle Proterozoic crust that formed during or just prior to the Grenville cycle appears to dominate the southwestern Grenville province as well as the Grenville inliers to the south. In contrast, most of the contiguous Grenville province in Canada comprises largely reworked older crust.

  19. Sedimentology of basal Potsdam sandstone in Adirondack border region, New York, southeastern Ontario, and southwestern Quebec

    SciTech Connect

    McRae, L.E.; Johnson, G.D.

    1986-05-01

    Field evidence supports the relatively widespread presence of nonmarine facies within the basal Potsdam formation of the Adirondack border areas of northern New York, southeastern Ontario, and southwestern Quebec. Detailed observations of areal extent, analysis of sedimentary structures and paleocurrent directions, and petrographic studies have been combined with the paleomagnetic determination of the temporal relationships of these strata to establish depositional patterns and facies trends within basal Potsdam units. Four distinct nonmarine lithofacies have been identified: massive matrix-supported conglomerate, stratified framework-supported conglomerate, conglomerate-arkose, and pebble conglomerate-arkose fining-upward sequences, interpreted to represent debris flows, proximal gravelly braided-stream deposits, intermediate to distal gravelly braided-stream deposits, and proximal sandy braided-stream deposits, respectively. Facies of eolian or possibly tidal, and shallow marine origin have also been identified at the base of the Potsdam sequence. Most basal Potsdam sediments are compositionally and texturally immature, derived directly from the crystalline detritus of the extensively weathered Precambrian surface and regoliths that may have locally developed on the craton. The desert-like environment of the Precambrian surface allowed for rapid transport and deposition of relatively unweathered sediments and the subsequent construction of a braided alluvial plain system. Field relations and evidence derived from consideration of the paleomagnetic properties in five localities of fine-grained alluvium suggest that terrestrial Potsdam deposition in the Early and Middle Cambrian largely preceded the marine transgression that deposited the thick, shallow marine units typifying most of the Potsdam sequence.

  20. Increases in dissolved organic carbon accelerate loss of toxic Al in Adirondack lakes recovering from acidification.

    PubMed

    Lawrence, Gregory B; Dukett, James E; Houck, Nathan; Snyder, Phil; Capone, Sue

    2013-07-01

    Increasing pH and decreasing Al in surface waters recovering from acidification have been accompanied by increasing concentrations of dissolved organic carbon (DOC) and associated organic acids that partially offset pH increases and complicate assessments of recovery from acidification. To better understand the processes of recovery, monthly chemistry from 42 lakes in the Adirondack region, NY, collected from 1994 to 2011, were used to (1) evaluate long-term changes in DOC and associated strongly acidic organic acids and (2) use the base-cation surplus (BCS) as a chemical index to assess the effects of increasing DOC concentrations on the Al chemistry of these lakes. Over the study period, the BCS increased (p < 0.01) and concentrations of toxic inorganic monomeric Al (IMAl) decreased (p < 0.01). The decreases in IMAl were greater than expected from the increases in the BCS. Higher DOC concentrations that increased organic complexation of Al resulted in a decrease in the IMAl fraction of total monomeric Al from 57% in 1994 to 23% in 2011. Increasing DOC concentrations have accelerated recovery in terms of decreasing toxic Al beyond that directly accomplished by reducing atmospheric deposition of strong mineral acids.

  1. Chemical variations within a metagabbro, N. W. Adirondack lowlands, N. Y

    SciTech Connect

    Von Derau, G.D. Jr.; Van Brocklin, M.F. . Geology Dept.)

    1993-03-01

    A metagabbro located in the N.W. Adirondack lowlands has been examined in order to study the chemical changes that occur from the edge of the body into the core. Samples were collected from within a mine adit starting near the contact of the country rock and going into the metagabbro for a distance of 65 feet. The country rock contains an assemblage of alkali feldspar, plagioclase, quartz, biotite, apatite and magnetite. The metagabbro contains an assemblage of plagioclase, hornblende, clinopyroxene, biotite, quartz, sphene, apatite and opaques. Chemical data show a decrease of SiO[sub 2] and K[sub 2]O from the edge of the metagabbro towards the center, and an increase in CaO, Fe[sub 2]O[sub 3], MgO, TiO[sub 2], P[sub 2]O[sub 5], Ni, V, and Cr[sub 2]O[sub 3]. The Al[sub 2]O[sub 3], and Na[sub 2]O content remain nearly constant. Hand samples stained with sodium cobaltinitrite also reflect decreasing K[sub 2]O towards the core of the body. These chemical gradations may be due to metasomatism, assimilation of country rock or true compositional zoning during crystallization of an alkali-rich gabbro.

  2. Increases in dissolved organic carbon accelerate loss of toxic Al in Adirondack lakes recovering from acidification.

    PubMed

    Lawrence, Gregory B; Dukett, James E; Houck, Nathan; Snyder, Phil; Capone, Sue

    2013-07-01

    Increasing pH and decreasing Al in surface waters recovering from acidification have been accompanied by increasing concentrations of dissolved organic carbon (DOC) and associated organic acids that partially offset pH increases and complicate assessments of recovery from acidification. To better understand the processes of recovery, monthly chemistry from 42 lakes in the Adirondack region, NY, collected from 1994 to 2011, were used to (1) evaluate long-term changes in DOC and associated strongly acidic organic acids and (2) use the base-cation surplus (BCS) as a chemical index to assess the effects of increasing DOC concentrations on the Al chemistry of these lakes. Over the study period, the BCS increased (p < 0.01) and concentrations of toxic inorganic monomeric Al (IMAl) decreased (p < 0.01). The decreases in IMAl were greater than expected from the increases in the BCS. Higher DOC concentrations that increased organic complexation of Al resulted in a decrease in the IMAl fraction of total monomeric Al from 57% in 1994 to 23% in 2011. Increasing DOC concentrations have accelerated recovery in terms of decreasing toxic Al beyond that directly accomplished by reducing atmospheric deposition of strong mineral acids. PMID:23751119

  3. Hydraulic and biochemical gradients limit wetland mercury supply to an Adirondack stream

    USGS Publications Warehouse

    Bradley, Paul M.; Burns, Douglas A.; Harvey, Judson; Journey, Celeste A.; Brigham, Mark E.; Murray, Karen

    2016-01-01

    Net fluxes (change between upstream and downstream margins) for water, methylmercury (MeHg), total mercury (THg), dissolved organic carbon (DOC), and chloride (Cl) were assessed twice in an Adirondack stream reach (Sixmile Brook, USA), to test the hypothesized importance of wetland-stream hydraulic and chemical gradients as fundamental controls on fluvial mercury (Hg) supply. The 500 m study reach represented less than 4% of total upstream basin area. During a snowmelt high-flow event in May 2009 surface water, DOC, and chloride fluxes increased by 7.1±1.3%, 8.0±1.3%, and 9.0±1.3%, respectively, within the reach, demonstrating that the adjacent wetlands are important sources of water and solutes to the stream. However, shallow groundwater Hg concentrations lower than in the surface water limited groundwater-surface water Hg exchange and no significant changes in Hg (filtered MeHg and THg) fluxes were observed within the reach despite the favorable hydraulic gradient. In August 2009, the lack of significant wetland-stream hydraulic gradient resulted in no net flux of water or solutes (MeHg, THg, DOC, or Cl) within the reach. The results are consistent with the wetland-Hg-source hypothesis and indicate that hydraulic and chemical gradient (direction and magnitude) interactions are fundamental controls on the supply of wetland Hg to the stream.

  4. Acid precipitation effects on algal productivity and biomass in Adirondack Mountain lakes

    SciTech Connect

    Hendrey, G.R.

    1982-12-01

    Relationships between phytoplankton communities and lake acidity in three Adirondack Mountain lakes were studied at Woods Lake (pH ca. 4.9), Sagamore Lake (pH ca. 5.5), and Panther Lake (pH ca. 7.0). Species numbers decrease with increasing acidity. Patterns of increasing biomass and productivity in Woods Lake may be atypical of similar oligotrophic lakes in that they develop rather slowly to maxima six weeks after ice-out, instead of occurring very close to ice-out. Contributions of netplankton, nannoplankton and ultraplankton to productivity per m/sup 2/ show that the smaller plankton are relatively more important in the more acid lakes. This pattern could be determined by nutrient availability (lake acidification is suspected of leading to decreased availability of phosphorus). This was consistent with a hypothesis that microbial heterotrophic activity is reduced with increasing acidity, but the smaller phytoplankton may be more leaky at low pH. 11 references, 2 tables.

  5. Relationships between surface sediment diatom assemblages and lakewater characteristics in Adirondack Lakes

    SciTech Connect

    Charles, D.F.

    1985-06-01

    Relationships between surface sediment diatom assemblages and lakewater characteristics were studied in 38 lakes in the Adirondack Mountains of northern New York. Most of the lakes are dilute, poorly buffered, and oligotrophic to mesotrophic. The diatom flora typical for circumneutral to acidic lakes. The purposes of this study were to identify the environmental factors most strongly related to the distributions of diatom taxa and the overall composition of diatom assemblages, and to derive equations to infer lakewater pH from diatom assemblage data. Relationships between diatom assemblages and environmental gradients were analyzed using reciprocal averaging ordination (RA). Correlations between Ra axis 1 and pH-related factors were strong. Correlations were weaker (but still statistically significant) with elevation, epilimnion temperature, and concentrations of SO/sub 4/, Cl, and Si. Total P, chlorophyll a, water color, and mean depth were not important in explaining differences among assemblages. Predictive equations were derived for inferring lakewater pH from diatom assemblage data. Agreement between predicted and measured pH was very good. These predictive relationships can be used to interpret stratigraphic diatom assemblages to reconstruct lake pH histories.

  6. Thermoluminescence dating of Hawaiian basalt

    USGS Publications Warehouse

    May, Rodd James

    1979-01-01

    The thermoluminescence (TL) properties of plagioclase separates from 11 independently dated alkalic basalts 4,500 years to 3.3 million years old and 17 tholeiitic basalts 16 years to 450,000 years old from the Hawaiian Islands were investigated for the purpose of developing a TL dating method for young volcanic rocks. Ratios of natural to artificial TL intensity, when normalized for natural radiation dose rates, were used to quantify the thermoluminescence response of individual samples for age-determination purposes. The TL ratios for the alkalic basalt plagioclase were found to increase with age at a predictable exponential rate that permits the use of the equation for the best-fit line through a plot of the TL ratios relative to known age as a TL age equation. The equation is applicable to rocks ranging in composition from basaltic andesite to trachyte over the age range from about 2,000 to at least 250,000 years before present (B.P.). The TL ages for samples older than 50,000 years have a calculated precision of less than :t 10 percent and a potential estimated accuracy relative to potassium-argon ages of approximately :t 10 percent. An attempt to develop a similar dating curve for the tholeiitic basalts was not as successful, primarily because the dose rates are on the average lower than those for the alkalic basalts by a factor of 6, resulting in lower TL intensities in the tholeiitic basalts for samples of equivalent age, and also because the age distribution of dated material is inadequate. The basic TL properties of the plagioclase from the two rock types are similar, however, and TL dating of tholeiitic basalts should eventually be feasible over the age range 10,000 to at least 200,000 years B.P. The average composition of the plagioclase separates from the alkalic basalts ranges from oligoclase to andesine; compositional variations within this range have no apparent effect on the TL ratios. The average composition of the plagioclase from the tholeiitic

  7. Flood basalts and extinction events

    NASA Technical Reports Server (NTRS)

    Stothers, Richard B.

    1993-01-01

    The largest known effusive eruptions during the Cenozoic and Mesozoic Eras, the voluminous flood basalts, have long been suspected as being associated with major extinctions of biotic species. Despite the possible errors attached to the dates in both time series of events, the significance level of the suspected correlation is found here to be 1 percent to 4 percent. Statistically, extinctions lag eruptions by a mean time interval that is indistinguishable from zero, being much less than the average residual derived from the correlation analysis. Oceanic flood basalts, however, must have had a different biological impact, which is still uncertain owing to the small number of known examples and differing physical factors. Although not all continental flood basalts can have produced major extinction events, the noncorrelating eruptions may have led to smaller marine extinction events that terminated at least some of the less catastrophically ending geologic stages. Consequently, the 26 Myr quasi-periodicity seen in major marine extinctions may be only a sampling effect, rather than a manifestation of underlying periodicity.

  8. Flood Basalts and Neoproterozoic Glaciation

    NASA Astrophysics Data System (ADS)

    Halverson, G. P.; Cox, G. M.; Kunzmann, M.; Strauss, J. V.; Macdonald, F. A.

    2014-12-01

    Large igneous provinces (LIPs), which are commonly associated with supercontinental break-up, are the product of the emplacement of >106 km3 of mafic rocks in less than a few million years. LIP magmatism, in particular continental flood basalt (CFB) volcanism, perturbs global climate on shorter time scales through the radiative effects of degassed SO2 and CO2. On longer time scales, CFBs alter climate through the effect of the high weatherabilty of mafic rocks (5-10 times greater than average continental crust) on global silicate weathering. A link between flood basalt weathering, Rodinia break-up, and Neoproterozoic snowball glaciation has been postulated. Here we present a new compilation of Nd isotope data on Neoproterozoic mudstones from Laurentia, Australia, and South China along with a new seawater strontium isotope record from well preserved carbonates that support this hypothesis. These datasets are consistent with an outsized role of basalt weathering on the global silicate weathering budget during the second half of the Tonian period (~850 to 725 Ma). Along with Os isotope data, they also suggest that an additional pulse of basalt weathering at the end of the Tonian may have initiated the Sturtian snowball glaciation. CFBs have relatively high concentrations of phosphorous. Hence, the drawdown in atmospheric CO2 required to trigger the Sturtian snowball Earth was likely accomplished through a combination of increased silicate weathering rates and enhanced biological productivity driven by greater nutrient supply to the oceans. CFBs were also the likely source of the iron in Neoproterozoic iron formation (IF), all significant occurrences of which are restricted to Sturtian-aged glacial successions. Dramatic declines in ɛNd following the Cryogenian snowball glaciations are mirrored by stepwise increases in 87Sr/86Sr, reflecting the scouring of the continents by global ice sheets. This continental resurfacing removed the extensive basalt carapace as well as

  9. REE patterns versus the origin of the basaltic achondrites

    NASA Technical Reports Server (NTRS)

    Consolmagno, G. J.

    1979-01-01

    The spectral uniqueness of asteroid 4 Vesta has led to suggestions that it is the eucrite parent body. However, there exist other basaltic achondrite types besides eucrites; either they also came from Vesta or else there exist other achondrite parent bodies. Howardites appear to be mixtures of eucrites and diogenites, and mesosiderites mixtures of eucrites or howardites and iron; thus one may infer that all four classes come from the same parent body. The REE patterns of eucrites and diogenites are modeled in order to test this hypothesis; eucrites can be made easily, but the patterns of diogenites are more difficult to match. The other basaltic achondrites are so rare that one cannot argue from statistics of abundances against a disrupted parent body for their origin. Pallasites and most irons likely had an origin separate from eucrites, again in parent bodies since disrupted.

  10. Petrogenesis of Luna 16 aluminous mare basalts

    NASA Technical Reports Server (NTRS)

    Ma, M.-S.; Schmitt, R. A.; Nielsen, R. L.; Taylor, G. J.; Warner, R. D.; Keil, K.

    1979-01-01

    Bulk compositions, petrology and mineralogy of Luna 16 aluminous mare basalt particles of less than 0.5 mm are described. The data rule out any close genetic relationships between Luna 16 and other major types of lunar mare basalts. Compared to high-Ti mare basalts, the Luna 16 basalts contain lower TiO2 and Ta and higher Al2O3 and REE abundances, suggesting that the Luna 16 source rocks crystallized later than (i.e. stratigraphically above) the ilmenite-bearing high-Ti basalt cumulate source rocks. The REE pattern for the Luna 16 basalts requires that the source material from which they were derived crystallized from a light REE enriched magma.

  11. Basaltic volcanism - The importance of planet size

    NASA Technical Reports Server (NTRS)

    Walker, D.; Stolper, E. M.; Hays, J. F.

    1979-01-01

    The volumetrically abundant basalts on the earth, its moon, and the eucrite parent planet all have chemical compositions that are controlled to a large extent by dry, low-pressure, crystal-liquid equilibria. Since this generalization is valid for these three planetary bodies, we infer that it may also apply to the other unsampled terrestrial planets. Other characteristics of basaltic volcanism show variations which appear to be related to planet size: the eruption temperatures, degrees of fractionation, and chemical variety of basalts and the endurance of basaltic volcanism all increase with planet size. Although the processes responsible for chemical differences between basalt suites are known, no simple systematization of the chemical differences between basalts from planet to planet has emerged.

  12. Moessbauer Mineralogy of Rock, Soil, and Dust at Gusev Crater, Mars: Spirit's Journey through Weakly Altered Olivine Basalt on the Plains and Pervasively Altered Basalt in the Columbia Hills

    NASA Technical Reports Server (NTRS)

    Morris, R. V.; Klingelhoefer, G.; Schroeder, C.; Rodionov, D. S.; Yen, A.; Ming, D. W.; deSouza, P. A., Jr.; Fleischer, I.; Wdowiak, T.; Gellert, R.; Bernhardt, B.; Evlanov, E. N.; Zubkov, B.; Foh, J.; Bonnes, U.; Kankeleit, E.; Guetlich, P.; Renz, F.; Squyres, S. W.; Arvidson, R. E.

    2006-01-01

    The Moessbauer spectrometer on Spirit measured the oxidation state of Fe, identified Fe-bearing phases, and measured relative abundances of Fe among those phases for surface materials on the plains and in the Columbia Hills of Gusev crater. Eight Fe-bearing phases were identified: olivine, pyroxene, ilmenite, magnetite, nanophase ferric oxide (npOx), hematite, goethite, and a Fe(3+)-sulfate. Adirondack basaltic rocks on the plains are nearly unaltered (Fe(3+)/Fe(sub T)<0.2) with Fe from olivine, pyroxene (Ol>Px), and minor npOx and magnetite. Columbia Hills basaltic rocks are nearly unaltered (Peace and Backstay), moderately altered (WoolyPatch, Wishstone, and Keystone), and pervasively altered (e.g., Clovis, Uchben, Watchtower, Keel, and Paros with Fe(3+)/Fe(sub T) approx.0.6-0.9). Fe from pyroxene is greater than Fe from olivine (Ol sometimes absent), and Fe(2+) from Ol+Px is 40-49% and 9-24% for moderately and pervasively altered materials, respectively. Ilmenite (Fe from Ilm approx.3-6%) is present in Backstay, Wishstone, Keystone, and related rocks along with magnetite (Fe from Mt approx. 10-15%). Remaining Fe is present as npOx, hematite, and goethite in variable proportions. Clovis has the highest goethite content (Fe from Gt=40%). Goethite (alpha-FeOOH) is mineralogical evidence for aqueous processes because it has structural hydroxide and is formed under aqueous conditions. Relatively unaltered basaltic soils (Fe(3+)/Fe(sub T) approx. 0.3) occur throughout Gusev crater (approx. 60-80% Fe from Ol+Px, approx. 10-30% from npOx, and approx. 10% from Mt). PasoRobles soil in the Columbia Hills has a unique occurrence of high concentrations of Fe(3+)-sulfate (approx. 65% of Fe). Magnetite is identified as a strongly magnetic phase in Martian soil and dust.

  13. Characterization of reference Umtanum and Cohassett basalt

    SciTech Connect

    Allen, C.C.; Johnston, R.G.; Strope, M.B.

    1985-02-01

    The Basalt Waste Isolation Project (BWIP) Materials Testing Group (MTG) provides large quantities of reference basalt for testing waste package materials under repository conditions, site sorption characteristics and other experimental purposes. This document describes the reference rock materials currently used in testing, namely entablature and colonnade basalt from the Umtanum and Cohassett flows. The data include sampling locations, bulk chemical composition, modal percentages of major phases, and the chemical and mineralogical compositions of these phases. 8 refs., 17 figs., 15 tabs.

  14. The Use of Basalt, Basalt Fibers and Modified Graphite for Nuclear Waste Repository - 12150

    SciTech Connect

    Gulik, V.I.; Biland, A.B.

    2012-07-01

    New materials enhancing the isolation of radioactive waste and spent nuclear fuel are continuously being developed.. Our research suggests that basalt-based materials, including basalt roving chopped basalt fiber strands, basalt composite rebar and materials based on modified graphite, could be used for enhancing radioactive waste isolation during the storage and disposal phases and maintaining it during a significant portion of the post-closure phase. The basalt vitrification process of nuclear waste is a viable alternative to glass vitrification. Basalt roving, chopped basalt fiber strands and basalt composite rebars can significantly increase the strength and safety characteristics of nuclear waste and spent nuclear fuel storages. Materials based on MG are optimal waterproofing materials for nuclear waste containers. (authors)

  15. Characterization of atmospheric aerosols in the Adirondack Mountains using PIXE, SEM/EDX, and Micro-Raman spectroscopies

    NASA Astrophysics Data System (ADS)

    Vineyard, M. F.; LaBrake, S. M.; Ali, S. F.; Nadareski, B. J.; Safiq, A. D.; Smith, J. W.; Yoskowitz, J. T.

    2015-05-01

    We are making detailed measurements of the composition of atmospheric aerosols collected in the Adirondack Mountains as a function of particle size using proton-induced X-ray emission, scanning electron microscopy with energy-dispersive X-ray spectroscopy, and Micro-Raman spectroscopy. These measurements provide valuable data to help identify the sources and understand the transport, transformation, and effects of airborne pollutants in upstate New York. Preliminary results indicate significant concentrations of sulfur in small particles that can travel great distances, and that this sulfur may be in the form of oxides that can contribute to acid rain.

  16. Mare basalt magma source region and mare basalt magma genesis

    SciTech Connect

    Binder, A.B.

    1982-11-15

    Given the available data, we find that the wide range of mare basaltic material characteristics can be explained by a model in which: (1) The mare basalt magma source region lies between the crust-mantle boundary and a maximum depth of 200 km and consists of a relatively uniform peridotite containing 73--80% olivine, 11--14% pyroxene, 4--8% plagioclase, 0.2--9% ilmenite and 1--1.5% chromite. (2) The source region consists of two or more density-graded rhythmic bands, whose compositions grade from that of the very low TiO/sub 2/ magma source regions (0.2% ilmenite) to that of the very high TiO/sub 2/ magma source regions (9% ilmenite). These density-graded bands are proposed to have formed as co-crystallizing olivine, pyroxene, plagioclase, ilmenite, and chromite settled out of a convecting magma (which was also parental to the crust) in which these crystals were suspended. Since the settling rates of the different minerals were governed by Stoke's law, the heavier minerals settled out more rapidly and therefore earlier than the lighter minerals. Thus the crystal assemblages deposited nearest the descending side of each convection cell were enriched in heavy ilmenite and chromite with respect to lighter olivine and pyroxene and very much lighter plagioclase. The reverse being the case for those units deposited near the ascending sides of the convection cells.

  17. Subseafloor basalts as fungal habitats

    NASA Astrophysics Data System (ADS)

    Ivarsson, M.; Bengtson, S.

    2013-12-01

    The oceanic crust makes up the largest potential habitat for life on Earth, yet next to nothing is known about the abundance, diversity and ecology of its biosphere. Our understanding of the deep biosphere of subseafloor crust is, with a few exceptions, based on a fossil record. Surprisingly, a majority of the fossilized microorganisms have been interpreted or recently re-interpreted as remnants of fungi rather than prokaryotes. Even though this might be due to a bias in fossilization the presence of fungi in these settings can not be neglected. We have examined fossilized microorganisms in drilled basalt samples collected at the Emperor Seamounts in the Pacific Ocean. Synchrotron-radiation X-ray tomography microscopy (SRXTM) studies has revealed a complex morphology and internal structure that corresponds to characteristic fungal morphology. Chitin was detected in the fossilized hyphae, which is another strong argument in favour of a fungal interpretation. Chitin is absent in prokaryotes but a substantial constituent in fungal cell walls. The fungal colonies consist of both hyphae and yeast-like growth states as well as resting structures and possible fruit bodies, thus, the fungi exist in vital colonies in subseafloor basalts. The fungi have also been involved in extensive weathering of secondary mineralisations. In terrestrial environments fungi are known as an important geobiological agent that promotes mineral weathering and decomposition of organic matter, and they occur in vital symbiosis with other microorganisms. It is probable to assume that fungi would play a similar role in subseafloor basalts and have great impact on the ecology and on biogeochemical cycles in such environments.

  18. Origin of the Grande Ronde Basalts, Columbia River Basalt Group

    NASA Astrophysics Data System (ADS)

    Durand, S. R.; Sen, G.; Reidel, S. P.

    2005-12-01

    The Columbia River basalts are generally thought to have formed by plume melting. Takahashi et al. (1998) suggested that the near-aphyric Grande Ronde Basalts (GR), which comprise ~63% of the CRBG, are essentially primary melts formed by nearly complete fusion of eclogite source rock in the plume and that such melting took place ~2.0 GPa. Durand and Sen (2002) examined phenocrysts and whole rock analyses and concluded that all the basalts are non-primary and, more importantly, that they underwent significant "processing" in shallow crustal magma chambers which erased their higher pressure geochemical signal, thus casting doubt on the validity of the eclogitic plume melting model. Here we report the results of our efforts to simulate the higher pressure histories of GR basalts using COMAGMAT and MELTS software. Our intent was to evaluate (1) whether such melts could be derived from primary melts formed by partial melting of a peridotite source as an alternative to the eclogite model, or if bulk melting of eclogite is required; and (2) at what pressure such primary melts could have been in equilibrium with the mantle. We carried out both forward and inverse modeling. In the forward models we chose different starting melt compositions, all produced in laboratory experiments, from peridotite vs. eclogitic sources. Our starting melts were produced by 6-17% partial melting of the peridotite KLB-1 (Hirose and Kushiro, 1993) and 18-40% melting of eclogites (77SL-582; CRB72-31; Keshav et al., 2004; Takahashi et al., 1998) at 1-3.0 GPa. In a second model, our starting melt composition was the most primitive GR lava with 6.5 wt. % MgO. We extrapolated a linear regression through the GR data to 8 wt. % MgO. We then assumed that such a melt was only olivine-equilibrated, and incrementally added olivine while maintaining equilibrium between olivine and melt using a Kd of 0.3, until a melt in equilibrium with the mantle olivine (Fo89) was found. This composition was fractionated

  19. A New Twist on the Seasonality of Nitrate Retention and Release in Adirondack Watersheds

    NASA Astrophysics Data System (ADS)

    Lawrence, G. B.; Ross, D. S.; Sutherland, J. W.; Nierzwicki-Bauer, S.; Boylen, C.

    2004-12-01

    Release of nitrate to surface waters in the Northeast has a distinct seasonality that is generally explained by high retention from plant uptake during the growing season, and low retention during the non-growing season, when biological demand is low and soil- water flux is elevated in the absence of transpiration. In the Adirondack region of New York, the highest rates of release, which consistently occur during spring snowmelt, are considered to be the result of nitrate accumulation in the soil and snowpack over the winter. This explanation implies that plants out compete nitrifying bacteria for available ammonium during the growing season. Biweekly and automated high-flow sampling over five years in two tributaries of Buck Creek, in the western Adirondacks, however, has revealed inconsistencies with the conventional view of nitrate retention and release. Although low concentrations of nitrate were measured in stream water during the growing season, concentrations were lowest each year in mid October (near the completion of leaf drop) in the North tributary, and were either the lowest or second lowest each year in mid October in the South tributary. Furthermore, concentrations of nitrate in both watersheds remained elevated throughout the snowmelt periods despite sustained high flows. For example, the concentration in the South tributary on April 9th, 2001, (the initial stage of snowmelt) was 76 micromoles per liter, and on April 24th (following two of the three largest flow events over the 5 years of sampling), was 82 micromoles per liter. Flushing of nitrate stored in the soil over the winter would result in a peak concentration in the stream that would be followed by a rapid decrease. To explain these results we hypothesize a three-way competition that includes heterotrophic non-nitrifying bacteria, as well as plants and autotrophic nitrifying bacteria. Leaf drop in the fall provides a large input of labile carbon with a high C to N ratio (>20) that favors

  20. Geologic controls on the sources of water to Lake George, Southeastern Adirondack Mountains of New York

    SciTech Connect

    Shuster, E.L.; LaFleur, R.G.; McCaffrey, R. . Dept. of Earth and Environmental Sciences); Boylen, C.W. . Rensselaer Fresh Water Inst.)

    1993-03-01

    Lake George is a long, deep, fault-bounded lake in the Adirondack Mountains, with relatively undeformed Paleozoic sediments in its valley floor and fractured high-grade meta-igneous and meta-sedimentary Proterozoic rocks in the drainage basins's upland. Overlying these rocks is a thin mantle of glacial deposits, consisting of sandy tills, kamic sands and glacio-lacustrine clays. Stratified ice-contact deposits and glacio-lacustrine deposits are generally restricted to the basins's lower elevations. The configuration of fractured bedrock and glacial overburden deposits of varying hydraulic conductivities suggests a variety of potential hydrogeologic flow routes, which can be generally categorized as reflect near-surface and deep groundwater flow systems. A hydrologic survey of the lake suggests that groundwater contributes approximately 20% to Lake George's annual hydrologic budget, with precipitation directly onto the lake's surface and tributary streamflow comprising the remaining 25% and 55%, respectively. Separating streamflow responses to precipitation by formal inversion into quick-, intermediate-, and slow-recession curves (originating from soils, unconsolidated surficial deposits, and fractured bedrock, respectively) suggests that as much as 40 to 50% of the tributary streamflow during the summer of 1988 originated from the slowest return route, a similar percentage has followed the intermediate route, and less than 10% of the streamflow originated as soil water ( runoff''). The flow-partitioning calculations typically suggest decay constants for these exponential recession curves on the order of 1, 10, and 100 days for the quick-, intermediate-, and slow-flow components to tributary streamflow, respectively.

  1. An empirical approach to modeling methylmercury concentrations in an Adirondack stream watershed

    USGS Publications Warehouse

    Burns, Douglas A.; Nystrom, Elizabeth A.; Wolock, David M.; Bradley, Paul M.; Riva-Murray, Karen

    2014-01-01

    Inverse empirical models can inform and improve more complex process-based models by quantifying the principal factors that control water quality variation. Here we developed a multiple regression model that explains 81% of the variation in filtered methylmercury (FMeHg) concentrations in Fishing Brook, a fourth-order stream in the Adirondack Mountains, New York, a known “hot spot” of Hg bioaccumulation. This model builds on previous observations that wetland-dominated riparian areas are the principal source of MeHg to this stream and were based on 43 samples collected during a 33 month period in 2007–2009. Explanatory variables include those that represent the effects of water temperature, streamflow, and modeled riparian water table depth on seasonal and annual patterns of FMeHg concentrations. An additional variable represents the effects of an upstream pond on decreasing FMeHg concentrations. Model results suggest that temperature-driven effects on net Hg methylation rates are the principal control on annual FMeHg concentration patterns. Additionally, streamflow dilutes FMeHg concentrations during the cold dormant season. The model further indicates that depth and persistence of the riparian water table as simulated by TOPMODEL are dominant controls on FMeHg concentration patterns during the warm growing season, especially evident when concentrations during the dry summer of 2007 were less than half of those in the wetter summers of 2008 and 2009. This modeling approach may help identify the principal factors that control variation in surface water FMeHg concentrations in other settings, which can guide the appropriate application of process-based models.

  2. An empirical approach to modeling methylmercury concentrations in an Adirondack stream watershed

    NASA Astrophysics Data System (ADS)

    Burns, Douglas A.; Nystrom, Elizabeth A.; Wolock, David M.; Bradley, Paul M.; Riva-Murray, Karen

    2014-10-01

    Inverse empirical models can inform and improve more complex process-based models by quantifying the principal factors that control water quality variation. Here we developed a multiple regression model that explains 81% of the variation in filtered methylmercury (FMeHg) concentrations in Fishing Brook, a fourth-order stream in the Adirondack Mountains, New York, a known "hot spot" of Hg bioaccumulation. This model builds on previous observations that wetland-dominated riparian areas are the principal source of MeHg to this stream and were based on 43 samples collected during a 33 month period in 2007-2009. Explanatory variables include those that represent the effects of water temperature, streamflow, and modeled riparian water table depth on seasonal and annual patterns of FMeHg concentrations. An additional variable represents the effects of an upstream pond on decreasing FMeHg concentrations. Model results suggest that temperature-driven effects on net Hg methylation rates are the principal control on annual FMeHg concentration patterns. Additionally, streamflow dilutes FMeHg concentrations during the cold dormant season. The model further indicates that depth and persistence of the riparian water table as simulated by TOPMODEL are dominant controls on FMeHg concentration patterns during the warm growing season, especially evident when concentrations during the dry summer of 2007 were less than half of those in the wetter summers of 2008 and 2009. This modeling approach may help identify the principal factors that control variation in surface water FMeHg concentrations in other settings, which can guide the appropriate application of process-based models.

  3. Homogeneous /sup 18/O enrichment of the Marcy Anorthosite Massif, Adirondack Mountains, New York

    SciTech Connect

    Morrison, J.; Valley, J.W.

    1985-01-01

    The Marcy Anorthosite Massif in the Adirondack Mountains, New York, is a composite intrusion that was metamorphosed to granulite facies at approx. 1.1 Ga. The massif is dominantly anorthosite but ranges from anorthosite (1-10% mafics) to oxide-rich pyroxenite layers (up to 98% mafics). In the St Regis Quad (SRQ) systematic variations in the percentage of mafics (POM) roughly parallel the foliation and increase toward the contacts (Davis, 1971). In 47 SRQ samples studied the POM varies from 2-25%; garnet ranges from 0-11%, pyroxene from <1-16% and oxides from <1-8%. Percent phenocrysts varies between 1-80. The Port Kent-Westport Unit (PKW) and an associated hybrid unit show significantly greater textural variability. The POM Varies from 1-50%; garnet ranges from 0-18%, pyroxene from 0-15%, oxides from 0-3% and phenocrysts vary from 0-80%. A total of 28 unaltered plagioclase phenocrysts have been analyzed for delta/sup 18/O: in 13 SRQ samples delta/sup 18/O = 9.0-9.8 (x=9.4. sigma=0.2) and in 15 samples from the PKW and hybrid units values of delta/sup 18/O=8.5-10.5 (x=9.5.sigma0.5). No correlations exist between the modal parameters and delta/sup 18/O. The results from SRQ demonstrate an extreme homogeneity suggesting for the first time a pristine magmatic character which is supported by the virtual absence of metasedimentary inclusions. This contrasts with PKW where inclusions are common and delta/sup 18/O values are more heterogeneous. Further analyses will evaluate the possibility of an anomalous source region as a cause of the /sup 18/O enrichment in the anorthosite.

  4. Atmospheric Science Research at the Whiteface Mountain Adirondack High Peaks Observatory

    NASA Astrophysics Data System (ADS)

    Schwab, J. J.; Brandt, R. E.; Casson, P.; Demerjian, K. L.; Crandall, B. A.

    2014-12-01

    The Atmospheric Sciences Research Center established an atmospheric observatory at Whiteface Mountain in the Adirondacks in 1961. The current mountain top observatory building was built by the University at Albany in 1969-70 and the New York State Department of Environmental Conservation (DEC) began ozone measurements at this summit location in 1973. Those measurements continue to this day and constitute a valuable long term data record for tropospheric ozone in the northeastern U.S. The elevation of the summit is 1483 m above sea level, and is roughly 90 m above the tree line in this location. With a mean cloud base height of less than 1100 m at the summit, it is a prime location for cloud research. The research station headquarters, laboratories, offices, and a second measurement site are located at the Marble Mountain Lodge, perched on a shoulder northeast of the massif at an elevation of 604 m above sea level. Parameters measured at the site include meteorological variables, trace gases, precipitation chemistry, aerosol mass and components, and more. Precipitation and cloud chemistry has a long history at the lodge and summit locations, respectively, and continues to this day. Some data from the 40-year record will be shown in the presentation. In the late 1980's the summit site was outfitted with instrumentation to measure oxides of nitrogen and other ozone precursors. Measurements of many of these same parameters were added at the lodge site and continue to this day. In this poster we will give an overview of the Whiteface Mountain Observatory and its two measurement locations. We will highlight the parameters currently being measured at our sites, and indicate those measured by ASRC, as well as those measured by other organizations. We will also recap some of the historical activities and measurement programs that have taken place at the site, as alluded to above. Also included will be examples of the rich archive of trends data for gas phase species

  5. Charnockites and granites of the western Adirondacks, New York, USA: a differentiated A-type suite

    USGS Publications Warehouse

    Whitney, P.R.

    1992-01-01

    Granitic rocks in the west-central Adirondack Highlands of New York State include both relatively homogeneous charnockitic and hornblende granitic gneisses (CG), that occur in thick stratiform bodies and elliptical domes, and heterogeneous leucogneisses (LG), that commonly are interlayered with metasedimentary rocks. Major- and trace-element geochemical analyses were obtained for 115 samples, including both types of granitoids. Data for CG fail to show the presence of more than one distinct group based on composition. Most of the variance within the CG sample population is consistent with magmatic differentiation combined with incomplete separation of early crystals of alkali feldspar, plagioclase, and pyroxenes or amphibole from the residual liquid. Ti, Fe, Mg, Ca, P, Sr, Ba, and Zr decrease with increasing silica, while Rb and K increase. Within CG, the distinction between charnockitic (orthopyroxene-bearing) and granitic gneisses is correlated with bulk chemistry. The charnockites are consistently more mafic than the hornblende granitic gneisses, although forming a continuum with them. The leucogneisses, while generally more felsic than the charnockites and granitic gneisses, are otherwise geochemically similar to them. The data are consistent with the LG suite being an evolved extrusive equivalent of the intrusive CG suite. Both CG and LG suites are metaluminous to mildly peraluminous and display an A-type geochemical signature, enriched in Fe, K, Ce, Y, Nb, Zr, and Ga and depleted in Ca, Mg, and Sr relative to I- and S-type granites. Rare earth element patterns show moderate LREE enrichment and a negative Eu anomaly throughout the suite. The geochemical data suggest an origin by partial melting of biotite- and plagioclase-rich crustal rocks. Emplacement occurred in an anorogenic or post-collisional tectonic setting, probably at relatively shallow depths. Deformation and granulite-facies metamorphism with some partial melting followed during the Ottawan phase

  6. Hydrogeologic controls of surface-water chemistry in the Adirondack region of New York State

    USGS Publications Warehouse

    Peters, N.E.; Driscoll, C.T.

    1987-01-01

    Relationships between surface-water discharge, water chemistry, and watershed geology were investigated to evaluate factors affecting the sensitivity of drainage waters in the Adirondack region of New York to acidification by atmospheric deposition. Instantaneous discharge per unit area was derived from relationships between flow and staff-gage readings at 10 drainage basins throughout the region. The average chemical composition of the waters was assessed from monthly samples collected from July 1982 through July 1984. The ratio of flow at the 50-percent exceedence level to the flow at the 95-percent exceedence level of flow duration was negatively correlated with mean values of alkalinity or acid-neutralizing capacity (ANC), sum of basic cations (SBC), and dissolved silica, for basins containing predominantly aluminosilicate minerals and little or no carbonate-bearing minerals. Low ratios are indicative of systems in which flow is predominately derived from surface- and ground-water storage, whereas high ratios are characteristic of watersheds with variable flow that is largely derived from surface runoff. In an evaluation of two representative surface-water sites, concentrations of ANC, SBC, and dissolved silica, derived primarily from soil mineral weathering reactions. decreased with increasing flow. Furthermore, the ANC was highest at low flow when the percentage of streamflow derived from ground water was maximum. As flow increased, the ANC decreased because the contribution of dilute surface runoff and lateral flow through the shallow acidic soil horizons to total flow increased. Basins having relatively high ground-water contributions to total flow, in general, have large deposits of thick till or stratified drift. A major factor controlling the sensitivity of these streams and lakes to acidification is the relative contribution of ground water to total discharge. ?? 1987 Martinus Nijhoff/Dr W. Junk Publishers.

  7. Short-term responses of wetland vegetation after liming of an Adirondack watershed

    SciTech Connect

    Mackun, I.R.; Leopold, D.J.; Raynal, D.J. )

    1994-08-01

    Watershed liming has been suggested as a long-term mitigation strategy for lake acidity, particularly in areas subject to high levels of acidic deposition. However, virtually no information has been available on the impacts of liming on wetland vegetation. In 1989, 1100 Mg of limestone (83.5% CaCO[sub 3]) were aerially applied to 48% (100 ha) of the Woods Lake watershed in the west-central Adirondack region of New York as part of the first comprehensive watershed liming study in North America. We inventoried wetland vegetation in 1.0-m[sup 2] plots before liming and during the subsequent 2 yr. Within this period liming influenced the cover, frequency, or importance values of only 6 of 64 wetland taxa. The cover of Sphagnum spp. and of the cespitose sedge Carex interior decreased in control relative to limed plots, and cover of the rhizomatous sedge Cladium mariscoides increased nearly threefold in limed areas. These two sedges, which are relatively tall, are characteristic of more calcareous habitats. Cover of the grass Muhlenbergia uniflora, cover and importance were adversely affected or inhibited by lime. It is unclear whether liming directly inhibited the growth of these three small-statured species, or whether the adverse effects of lime were mediated through shifts in competitive interactions with other species. The limited responses that we observed to liming, along with changes that occurred in control plots over the study period, may indicate that in the short term watershed liming was no more of a perturbation than the environmental factors responsible for natural annual variation in wetland communities.

  8. Geochemistry and origin of albite gneisses, northeastern Adirondack Mountains, New York

    USGS Publications Warehouse

    Whitney, P.R.; Olmsted, J.F.

    1988-01-01

    Albite gneisses containing up to 8.7 percent Na2O and as little as 0.1% K2O comprise a significant part of the Proterozoic Lyon Mountain Gneiss in the Ausable Forks Quadrangle of the northeastern Adirondacks, New York State. Two distinct types of albite gneisses are present. One is a trondhjemitic leucogneiss (LAG) consisting principally of albite (Ab95-Ab98) and quartz with minor magnetite and, locally, minor amounts of amphibole or acmiterich pyroxene. LAG probably originated by metamorphism of a rhyolitie or rhyodacitic ash-flow tuff with A-type geochemical affinities, following post-depositional analcitization in a saline or saline-alkaline environment. The other type is a mafic albite gneiss (MAG) containing albite and pyroxene along with 0-45 percent quartz, minor amphibole, and titanite. MAG locally displays pinstripe banding and contains albite (Ab98) megacrysts up to 5 cm across. Its precursor may have been a sediment composed of diagenetic analcite or albite, dolomite, and quartz. Both types of albite gneiss are interlayered with granitic gneisses (LMG) of variable composition derived from less altered tuffs. A potassium-rich (up to 9.7% K2O) microcline gneiss facies may have had a protolith rich in diagenetic K feldspar. We propose that the albite gneisses and associated granitic gneisses are the granulite-facies metamorphic equivalent of a bimodal, dominantly felsic, volcanic suite with minor intercalated sediments, probably including evaporites. The volcanics were erupted in an anorogenic setting, such as an incipient or failed intracontinental rift. Deposition took place in a closed-basin, playa lake environment, where diagenetic alteration resulted in redistribution of the alkalis and strong oxidation. ?? 1988 Springer-Verlag.

  9. Modeling Central American basalts using the Arc Basalt Simulator

    NASA Astrophysics Data System (ADS)

    Feigenson, M.; Carr, M. J.

    2011-12-01

    We have used the Arc Basalt Simulator (ABS), developed by JI Kimura, to explore the conditions and components of melting beneath the Central American volcanic front. ABS is a comprehensive forward model that incorporates slab dehydration and melting and mantle wedge fluxing and melting using realistic P-T conditions and experimentally determined phase relations. We have applied ABS versions 3 and 4 to model representative magma types in Nicaragua, which span a broad geochemical range including proximal high- and low-Ti lavas in Nicaragua. Sr-Nd-Pb data require appropriate selection of previously identified sources, including: separate carbonate and hemipelagic sediments, DMM, an enriched mantle isotopically similar to the alkaline basalts of Yojoa, a Himu-influenced mantle derived from Galapagos material and altered oceanic crust (AOC) derived from both MORB and Galapagos seamounts. Following the dry solidus, the dominant arc basalts, exemplified by Cerro Negro lavas, can be generated at about 80-90 km where lawsonite and zoisite break down, releasing LILEs into a hydrous fluid that travels into the wedge. The fluid-triggered melting occurs just above the garnet stability field in the wedge to fit the HREEs. Below 90 Km, slab melting begins and the AOC component dominates, generating a fluid with little or no HFSE depletions, consistent with the unusual high-Ti lavas found in Nicaragua. However, the isotopic data require a much lower sediment input for the high-Ti lavas (consistent with 10Be results on the high-Ti lavas) and an enriched component for the AOC and/or mantle wedge. Following the wet solidus, fits to the Cerro Negro magma only occur in the absence of phengite in the AOC and with the presence of HFSE attracting minerals, rutile, zircon and allanite. The depth of the best fit is 135 km, consistent with current best estimates of the depth to the seismic zone beneath Cerro Negro. Below 150 km, the high-Ti lavas can be generated if the HFSE retaining

  10. Carbonate Mineralization of Volcanic Province Basalts

    SciTech Connect

    Schaef, Herbert T.; McGrail, B. Peter; Owen, Antionette T.

    2010-03-31

    Flood basalts are receiving increasing attention as possible host formations for geologic sequestration of anthropogenic CO2, with studies underway in the United States, India, Iceland, and Canada. As an extension of our previous experiments with Columbia River basalt, basalts from the eastern United States, India, and South Africa were reacted with aqueous dissolved CO2 and aqueous dissolved CO2-H2S mixtures under supercritical CO2 (scCO2) conditions to study the geochemical reactions resulting from injection of CO2 in such formations. The results of these studies are consistent with cation release behavior measured in our previous experiments (in press) for basalt samples tested in single pass flow through dissolution experiments under dilute solution and mildly acidic conditions. Despite the basalt samples having similar bulk chemistry, mineralogy and apparent dissolution kinetics, long-term static experiments show significant differences in rates of mineralization as well as compositions and morphologies of precipitates that form when the basalts are reacted with CO2-saturated water. For example, basalt from the Newark Basin in the United States was by far the most reactive of any basalt tested to date. Carbonate reaction products for the Newark Basin basalt were globular in form and contained significantly more Fe than the secondary carbonates that precipitated on the other basalt samples. In comparison, the post-reacted samples associated with the Columbia River basalts from the United States contained calcite grains with classic dogtooth spar morphology and trace cation substitution (Mg and Mn). Carbonation of the other basalts produced precipitates with compositions that varied chemically throughout the entire testing period. Examination of polished cross sections of the reacted grains by scanning electron microscopy and energy dispersive x-ray spectroscopy show precipitate overgrowths with varying chemical compositions. Compositional differences in the

  11. Landscape level estimate of lands and waters impacted by road runoff in the Adirondack Park of New York State.

    PubMed

    Regalado, Sean A; Kelting, Daniel L

    2015-08-01

    Road runoff is understood to be a significant stressor in terrestrial and aquatic ecosystems, yet the effects of this stressor are poorly understood at large spatial scales. We developed an efficient method for estimating the spatial impact of road runoff on lands and waters over large geographic areas and then applied our methodology to the 2.4 million ha Adirondack Park in New York State. We used TauDEM hydrologic modeling and a series of ESRI GIS processes to delineate surface flow downslope of paved roads, illustrating the potential movement of pollutants originating from paved roads through the USGS 10 m DEM topography. We then estimated the land and surface water areas, number of water bodies, and total stream length potentially impacted by road runoff from paved roads. We found that as much as 11% of land area, 77% of surface water area, 1/3 of the water bodies, and 52% of stream length in the Adirondack Park may be impacted by road runoff. The high degree of hydrologic association between paved roads and the lands and waters of this region strongly suggests that the environmental impacts of road runoff should be evaluated along with other regional stressors currently being studied. Being able to estimate the spatial impact of road runoff is important for designing monitoring programs that can explicitly monitor this stressor while also providing opportunities to understand the interaction of multiple environmental stressors.

  12. Long-term trends in breeding birds in an old-growth Adirondack forest and the surrounding region

    USGS Publications Warehouse

    McNulty, S.A.; Droege, S.; Masters, R.D.

    2008-01-01

    Breeding bird populations were sampled between 1954 and 1963, and 1990 and 2000 in an old-growth forest, the Natural Area of Huntington Wildlife Forest (HWF), in the Adirondack Mountains of New York. Trends were compared with data from regional North American Breeding Bird Surveys (BBS) and from a forest plot at Hubbard Brook Experimental Forest, New Hampshire. Trends for 22 species in the HWF Natural Area were negative, eight were positive, and one was zero; 20 were significant. Fifteen of 17 long-distance migrants declined, whereas 7 of 14 short-distance migrants and permanent residents declined. Most (74%) HWF Natural Area species, despite differences in sampling periods and local habitat features, matched in sign of trend when compared to Adirondack BBS routes, 61% matched northeastern BBS routes, and 71% matched eastern United States BBS routes, while 66% matched Hubbard Brook species. The agreement in population trends suggests that forest interior birds, especially long-distance migrants, are affected more by regional than local factors. The analysis indicated that bird trends generated from BBS routes may not be as biased toward roads as previously suggested.

  13. Sustainability and economics: The Adirondack Park experience, a forest economic-ecological model, and solar energy policy

    NASA Astrophysics Data System (ADS)

    Erickson, Jon David

    The long-term sustainability of human communities will depend on our relationship with regional environments, our maintenance of renewable resources, and our successful disengagement from nonrenewable energy dependence. This dissertation investigates sustainability at these three levels, following a critical analysis of sustainability and economics. At the regional environment level, the Adirondack Park of New York State is analyzed as a potential model of sustainable development. A set of initial and ongoing conditions are presented that both emerge from and support a model of sustainability in the Adirondacks. From these conditions, a clearer picture emerges of the definition of regional sustainability, consequences of its adoption, and lessons from its application. Next, an economic-ecological model of the northern hardwood forest ecosystem is developed. The model integrates economic theory and intertemporal ecological concepts, linking current harvest decisions with future forest growth, financial value, and ecosystem stability. The results indicate very different economic and ecological outcomes by varying opportunity cost and ecosystem recovery assumptions, and suggest a positive benefit to ecological recovery in the forest rotation decision of the profit maximizing manager. The last section investigates the motives, economics, and international development implications of renewable energy (specifically photovoltaic technology) in rural electrification and technology transfer, drawing on research in the Dominican Republic. The implications of subsidizing a photovoltaic market versus investing in basic research are explored.

  14. Age, field, and petrological relationships of the Hyde School Gneiss, Adirondack lowlands, New York: Criteria for an intrusive igneous origin

    SciTech Connect

    McLelland, J. ); Perham, A. ); Chiarenzelli, J.

    1992-01-01

    Alaskitic and tonalitic rocks constituting Hyde School Gneiss (HSG) occur in 14 domical bodies in the Adirondack lowlands. Recent models have interpreted these bodies as metamorphosed rhyolitic and dacitic ash-flow deposits forming the basal member of a regional stratigraphic package. In contrast, this paper presents criteria and evidence for an intrusive origin for HSG. Field evidence includes intrusion breccias and complex crosscutting relationships involving mafic layers resembling synplutonic dikes. Petrologic constraints supporting an intrusive origin include: (1) the common occurrence of quartz-mesoperthite hypersolvus assemblages; (2) magmatic features in tonalitic, trondhjemitic, and alaskitic facies, (3) local occurrences of orthopyroxene in all facies of HSG; and (4) the development of marginal garnet-sillimanite gneiss with corundum-spinel-garnet-sillimanite assemblages yielding paleotemperatures of 780-810C and interpreted as restite remaining after anatexis of country rock metapelite by intrusions of hypersolvus granitoids. U-Pb zircon ages reported here suggest that the majority of the HSG was intruded at ca. 1230 Ma, contemporaneous with high-grade metamorphic activity in the Adirondacks and elsewhere in the SW sector of the Grenville Province. Geochronological evidence from a leucogranitic rock crosscutting metasediments on Wellesley Island suggest that these metasediments are older than 1416 {plus minus} 5 Ma.

  15. Comparison of MAGIC and Diatom paleolimnological model hindcasts of lakewater acidification in the Adirondack region of New York

    SciTech Connect

    Sullivan, T.J.; Bernert, J.A.; Eliers, J.M. ); Jenne, E.A. ); Cosby, B.J. . School of Forestry and Environmental Studies); Charles, D.F.; Selle, A.R. . Environmental Research Lab.)

    1991-03-01

    Thirty-three lakes that had been statistically selected as part of the US Environmental Protection Agency's Eastern Lake Survey and Direct Delayed Response Project (DDRP) were used to compare the MAGIC (watershed) and Diatom (paleolimnological) models. The study lakes represented a well-defined group of Adirondack lakes, each larger than 4 ha in area and having acid-neutralizing capacity (ANC) <400 {mu}eq L{sup {minus}1}. The study first compared current and pre-industrial (before 1850) pH and ANC estimates from Diatom and MAGIC as they were calibrated in the preceding Paleocological Investigation of Recent Lake Acidification (PIRLA) and DDRP studies, respectively. Initially, the comparison of hindcasts of pre-industrial chemistry was confounded by seasonal and methodological differences in lake chemistry data used in calibration of the model. Although certain differences proved to be of little significance for comparison, MAGIC did predict significantly higher pre-industrial ANC and pH values than did Diatom, using calibrations in the preceding studies. Both models suggest acidification of low ANC Adirondack region lakes since preindustrial times, but differ primarily in that MAGIC inferred greater acidification and that acidification has occurred in all lakes in the comparison, whereas Diatom inferred that acidification has been restricted to low ANC lakes (

  16. Analysis of ambient, precipitation-weighted, and lake sulfate concentrations in the Adirondack region of New York.

    PubMed

    Civerolo, Kevin; Brankov, Elvira; Rao, S Trivikrama; Roy, Karen; Lewis, Preston; Galvin, Philip

    2003-01-01

    AbstractIt is well known that many ecosystems in the eastern United States, including the Adirondack Mountain region of New York, are particularly sensitive to acidic deposition because the soils and lakes in the region tend to have low values of base saturation and acid neutralizing capacity, respectively [e.g. Environ Sci Policy, 1 (1998), 185]. To facilitate tracking the impacts of anthropogenic emissions on air quality, acidic deposition, and surface water quality, the National Atmospheric Deposition Program, New York State Department of Environmental Conservation, and Adirondack Lake Survey Corporation have been monitoring ambient sulfur dioxide and aerosol sulfate levels, and anion and cation concentrations in wet deposition and lake water over the past few decades. In this paper, we discuss the seasonality and year-to-year variability, and illustrate some of the complexities in estimating temporal trends in these data. The periods of analysis extended through 2000, beginning in 1991 for the ambient air quality data, 1978 for the wet deposition data, and 1982 for the lake water quality data. While the lake water SO4(2-) concentrations appear to be decreasing gradually, the air concentration data appear to have changed abruptly in the 1990s and the precipitation-weighted concentrations exhibited both gradual and sharp decreases during the same period.

  17. Landscape level estimate of lands and waters impacted by road runoff in the Adirondack Park of New York State.

    PubMed

    Regalado, Sean A; Kelting, Daniel L

    2015-08-01

    Road runoff is understood to be a significant stressor in terrestrial and aquatic ecosystems, yet the effects of this stressor are poorly understood at large spatial scales. We developed an efficient method for estimating the spatial impact of road runoff on lands and waters over large geographic areas and then applied our methodology to the 2.4 million ha Adirondack Park in New York State. We used TauDEM hydrologic modeling and a series of ESRI GIS processes to delineate surface flow downslope of paved roads, illustrating the potential movement of pollutants originating from paved roads through the USGS 10 m DEM topography. We then estimated the land and surface water areas, number of water bodies, and total stream length potentially impacted by road runoff from paved roads. We found that as much as 11% of land area, 77% of surface water area, 1/3 of the water bodies, and 52% of stream length in the Adirondack Park may be impacted by road runoff. The high degree of hydrologic association between paved roads and the lands and waters of this region strongly suggests that the environmental impacts of road runoff should be evaluated along with other regional stressors currently being studied. Being able to estimate the spatial impact of road runoff is important for designing monitoring programs that can explicitly monitor this stressor while also providing opportunities to understand the interaction of multiple environmental stressors. PMID:26188804

  18. Responses of 20 lake-watersheds in the Adirondack region of New York to historical and potential future acidic deposition.

    PubMed

    Zhou, Qingtao; Driscoll, Charles T; Sullivan, Timothy J

    2015-04-01

    Critical loads (CLs) and dynamic critical loads (DCLs) are important tools to guide the protection of ecosystems from air pollution. In order to quantify decreases in acidic deposition necessary to protect sensitive aquatic species, we calculated CLs and DCLs of sulfate (SO4(2-))+nitrate (NO3-) for 20 lake-watersheds from the Adirondack region of New York using the dynamic model, PnET-BGC. We evaluated lake water chemistry and fish and total zooplankton species richness in response to historical acidic deposition and under future deposition scenarios. The model performed well in simulating measured chemistry of Adirondack lakes. Current deposition of SO4(2-)+NO3-, calcium (Ca2+) weathering rate and lake acid neutralizing capacity (ANC) in 1850 were related to the extent of historical acidification (1850-2008). Changes in lake Al3+ concentrations since the onset of acidic deposition were also related to Ca2+ weathering rate and ANC in 1850. Lake ANC and fish and total zooplankton species richness were projected to increase under hypothetical decreases in future deposition. However, model projections suggest that lake ecosystems will not achieve complete chemical and biological recovery in the future.

  19. Volcanogenic trace element volatiles in basalts

    SciTech Connect

    Jovanovic, S.; Reed, G.W. Jr.

    1984-03-01

    Br, Hg, As, Se, Sb, Zn, and Cu were measured in samples of mid-ocean ridge (MOR) and ocean island basalt. To assess sea-water effects glassy rinds and crystalline interiors of pillow basalts were measured as was subaerial glass from Kilauea volcano. Preliminary results are reported. 6 references, 3 figures. (ACR)

  20. Target loads of atmospheric sulfur and nitrogen deposition for protection of acid sensitive aquatic resources in the Adirondack Mountains, New York

    USGS Publications Warehouse

    Sullivan, T.J.; Cosby, B.J.; Driscoll, C.T.; McDonnell, T.C.; Herlihy, A.T.; Burns, Douglas A.

    2012-01-01

    The dynamic watershed acid-base chemistry model of acidification of groundwater in catchments (MAGIC) was used to calculate target loads (TLs) of atmospheric sulfur and nitrogen deposition expected to be protective of aquatic health in lakes in the Adirondack ecoregion of New York. The TLs were calculated for two future dates (2050 and 2100) and three levels of protection against lake acidification (acid neutralizing capacity (ANC) of 0, 20, and 50 eq L -1). Regional sulfur and nitrogen deposition estimates were combined with TLs to calculate exceedances. Target load results, and associated exceedances, were extrapolated to the regional population of Adirondack lakes. About 30% of Adirondack lakes had simulated TL of sulfur deposition less than 50 meq m -2 yr to protect lake ANC to 50 eq L -1. About 600 Adirondack lakes receive ambient sulfur deposition that is above this TL, in some cases by more than a factor of 2. Some critical criteria threshold values were simulated to be unobtainable in some lakes even if sulfur deposition was to be decreased to zero and held at zero until the specified endpoint year. We also summarize important lessons for the use of target loads in the management of acid-impacted aquatic ecosystems, such as those in North America, Europe, and Asia. Copyright 2012 by the American Geophysical Union.

  1. USE OF A LUMPED MODEL (MAGIC) TO BOUND THE ESTIMATION OF POTENTIAL FUTURE EFFECTS OF SULFUR AND NITROGEN DEPOSITION ON LAKE CHEMISTRY IN THE ADIRONDACK MOUNTAINS

    EPA Science Inventory

    Leaching of atmospherically deposited nitrogen from forested watersheds can acidify lakes and streams. Using a modified version of the Model of Acidification of Groundwater in Catchments, we made computer simulations of such effects for 36 lake catchments in the Adirondack Mount...

  2. Shock compression and adiabatic release of a titaniferous mare basalt

    NASA Technical Reports Server (NTRS)

    Ahrens, T. J.; Jackson, I.; Jeanloz, R.

    1977-01-01

    A report is presented regarding the dynamic properties of a rock indigenous to the mare basins of the moon. The reported data were obtained in a study of sample 70215, a very titanium-rich basalt (58% pyroxene, 18% ilmenite, 15% plagioclase, 6% olivine, and 3% quartz by weight). This rock is probably representative of a class of the earliest mare-filling extrusive rocks which are exposed on the present lunar surface. Two series of experiments were performed. One set of experiments involved the measuring of Hugoniot and release adiabats to 15.7 GPa with a propellant gun apparatus. In the second set of experiments, a light-gas gun was employed to yield Hugoniot data at about 120 GPa and release states at about 90 GPa. Lunar basalt 70215 appears to be among the densest rocks in the present lunar sample collection, having a crystal density of 3.38 g/cu cm and a porosity of about 1.3%. The results of the experiments have important implications for both the degree of shock metamorphism expected for impact processes and the extent of ejecta transport on mare surfaces with high-titanium basalt composition.

  3. Heterogeneity in titaniferous lunar basalts

    NASA Technical Reports Server (NTRS)

    Walker, D.; Longhi, J.; Hays, J. F.

    1976-01-01

    Small but real chemical differences exist between subsamples of fine-grained quench-textured titaniferous lunar basalts. The existence of different textural domains with different chemistries is thought to account for most of this variation. In addition to the textural domains, lunar sample 74275 has a population of olivine 'megacrysts' as well as dunite fragments. These materials are thought to be extraneous and to compromise the primary nature of 74275. Recognition of the small chemical variations present may aid in understanding some discrepancies in the experimental-petrology literature. However, these small variations have a distressing petrogenetic significance since they severely limit resolution in recognizing the number and depth of origin of primary magmas.

  4. Dissolved Organic Matter Characteristics Control Filtered Total Mercury Concentrations in an Adirondack River Basin

    NASA Astrophysics Data System (ADS)

    Burns, D. A.; Aiken, G.; Bradley, P. M.; Journey, C.

    2011-12-01

    Dissolved organic carbon (DOC) plays important roles in the transport and biogeochemical processes that affect mercury (Hg) cycling in the environment. Previous investigations have shown strong correlations between DOC and Hg concentrations in surface waters. Commonly, other DOC-related measures such as ultraviolet absorbance (UV254), and hydrophobic acid content (HPOA) show even stronger positive correlations with Hg in waters indicating the importance of the more aromatic fraction of DOC in Hg cycling. Finally, in-situ optical sensor-derived DOC concentrations have proven useful as inexpensive proxies for estimating Hg concentrations in some surface waters. Here, we describe results from the 493 km2 Upper Hudson River basin in the Adirondack Mountains of New York in which stream water samples were collected for filtered total Hg (FTHg) concentrations, DOC concentrations, UV254, HPOA, and specific ultraviolet absorbance (SUVA, derived from the absorbance and DOC measurements) at two temporal and spatial scales during 2006-09: (1) biweekly to monthly in a 66 km2 basin, and (2) seasonally at 27 synoptic sites distributed across the larger Upper Hudson basin. These results indicate that SUVA values are more strongly correlated with FTHg concentrations than are those of DOC concentrations, especially during summer. The presence of numerous open water bodies in this basin appears to greatly affect DOC and FTHg concentrations and SUVA values as reflected by data collected upstream and downstream of ponds and lakes. Multivariate regression models developed to examine the landscape factors that control spatial variation in SUVA values among synoptic sites indicate that open water area is inversely correlated with these values, reflecting autochthonous carbon sources in lakes/ponds that are more aliphatic in character than that found in streams. In contrast, metrics such as percent riparian area that reflect the influence of soils with high organic carbon content are

  5. Microbiological Survey of Adirondack Lakes with Various pH Values

    PubMed Central

    Boylen, Charles W.; Shick, Marcy O.; Roberts, Deborah A.; Singer, Robert

    1983-01-01

    Nine high-altitude oligotrophic Adirondack lakes in upstate New York having water of pH 4.3 to 7.0 were surveyed for total bacterial numbers and possible adaptation of the microbial communities to environmental pH. The number of heterotrophic bacteria from water samples recoverable on standard plate count agar were low (101 to 103 per ml) for most of the lakes. Acridine orange direct counts were approximately two orders of magnitude higher than plate counts for each lake. Sediment aerobic heterotrophs recovered on standard plate count agar ranged from 1.4 × 104 to 1.3 × 106 per g of sediment. Direct epifluorescence counts of bacteria in sediment samples ranged from 3.0 × 106 to 1.4 × 107 per g. Low density values were consistent with the oligotrophic nature of all the lakes surveyed. There were no apparent differences in numbers of bacteria originally isolated at pH 5.0 and pH 7.0 between circumneutral lakes (pH > 6.0) and acidic lakes (pH < 5.0). Approximately 1,200 isolates were recultured over a range of pH from 3.0 to 7.0. Regardless of the original isolation pH (pH 5.0 or pH 7.0), less than 10% of the isolates grew at pH < 5.0. Those originally isolated at pH 5.0 also grew at pH 6.0 and 7.0. Those originally isolated at pH 7.0 preferred pH 7.0, with 98% able to grow at pH 6.0 and 44% able to grow at pH 5.0. A chi-square contingency test clearly showed (P < 0.005) that two distinct heterotrophic populations had been originally isolated at pH 5.0 and pH 7.0, although there is undoubtedly some overlap between the two populations. PMID:16346291

  6. Mature and old-growth riparian forests: structure, dynamics, and effects on Adirondack stream habitats.

    PubMed

    Keeton, William S; Kraft, Clifford E; Warren, Dana R

    2007-04-01

    Riparian forests regulate linkages between terrestrial and aquatic ecosystems, yet relationships among riparian forest development, stand structure, and stream habitats are poorly understood in many temperate deciduous forest systems. Our research has (1) described structural attributes associated with old-growth riparian forests and (2) assessed linkages between these characteristics and in-stream habitat structure. The 19 study sites were located along predominantly first- and second-order streams in northern hardwood-conifer forests in the Adirondack Mountains of New York (U.S.A.). Sites were classified as mature forest (6 sites), mature with remnant old-growth trees (3 sites), and old-growth (10 sites). Forest-structure attributes were measured over stream channels and at varying distances from each bank. In-stream habitat features such as large woody debris (LWD), pools, and boulders were measured in each stream reach. Forest structure was examined in relation to stand age using multivariate techniques, ANOVA, and linear regression. We investigated linkages between forest structure and stream characteristics using similar methods, preceded by information-theoretic modeling (AIC). Old-growth riparian forest structure is more complex than that found in mature forests and exhibits significantly greater accumulations of aboveground tree biomass, both living and dead. In-stream LWD volumes were significantly (alpha = 0.05) greater at old-growth sites (200 m3/ha) compared to mature sites (34 m3/ha) and were strongly related to the basal area of adjacent forests. In-stream large-log densities correlated strongly with debris-dam densities. AIC models that included large-log density, debris-dam density, boulder density, and bankfull width had the most support for predicting pool density. There were higher proportions of LWD-formed pools relative to boulder-formed pools at old-growth sites as compared to mature sites. Old-growth riparian forests provide in

  7. Basalt CO2 Sequestration: Using Wireline Logs to Identify Subsurface Continental Flood Basalt Lithofacies

    NASA Astrophysics Data System (ADS)

    Sullivan, E. C.; Finn, S.; Davis, K. N.; Segovia, A. I.

    2010-12-01

    The flows of the Miocene Columbia River Basalt Group (CRBG) of the northwest United States are an important example of reactive flood basalts that are attractive targets for sequestration of anthropogenic carbon dioxide. Brecciated flow tops and dense flow interiors form layered regional aquifer systems in the Columbia Basin that have the potential to sequester gigatons of supercritical CO2 where they contain non-potable water and are at depths of greater than 800m. The demonstrated chemical reactivity of these continental flood basalts with supercritical CO2 in laboratory experiments suggests that part of the sequestered CO2 will be permanently entombed as carbonate minerals. Here we report on the use of conventional wire-line log data, along with full waveform sonic and resistivity-based image logs to identify subsurface basalt stratigraphy and lithofacies relevant to CO2 sequestration. We compare borehole data from the 2009 Big Sky Carbon Sequestration Partnership basalt pilot well near Wallula, Washington U.S.A. with regional outcrop analogs to determine patterns for recognizing basalt lithofacies in the subsurface. We examine quick-look techniques recently proposed for hydrocarbon exploration in basalt terranes and show that rescaled shear and compressional sonic log curves, which reflect changes in bulk modulus, appear to provide a robust tool for the identification of subsurface CRBG basalt lithofacies Resistivity-based Image Log of Vesicular Basalt and Fractures From the Wallula Basalt Pilot Well

  8. Preliminary Analysis of Borosilicate Minerals in Pegmatitic Leucosomes within Aluminous Granulites at Ledge Mountain, Central Adirondack Highlands, New York

    NASA Astrophysics Data System (ADS)

    Gervais, S. M.; Metzger, E. P.

    2011-12-01

    The borosilicates tourmaline and dumortierite have been identified by polarized light microscopy and electron microprobe analysis in anatectic abyssal-type pegmatites within aluminum-rich granulite-facies migmatites at Ledge Mountain, Central Adirondacks, New York. No other boron-bearing minerals are found in these rocks, and neither borosilicate has been found in the adjacent host gneiss. Tourmaline is ubiquitous in the granulite and upper amphibolite-facies metamorphic rocks of the Central Adirondacks. Dumortierite has been reported from pegmatites of the Batchellerville Province of the Southern Adirondacks, approximately 66 km to the southeast of Ledge Mountain, but not previously at this locality. The tourmaline is alkali dravite-schorl with Mg# = 0.49- 0.53. It is present as anhedral grains less than 2 mm wide intergrown with perthitic microcline and quartz, and as euhedral megacrysts several centimeters in diameter. The dumortierite is strongly pleochroic, ranging from deep indigo blue and violet to colorless. Two strikingly different habits of dumortierite coexist within centimeters of one another in the same sample: bundles of fine prisms less than a few tenths of a millimeter across, and larger granular intergrowths with quartz and chlorite. Apatite and xenotime are also present in both leucosomes and melanosomes, indicating phosphate-enrichment and yttrium in the granulites. According to experimentally determined fields of stability for boron-bearing minerals, the presence of tourmaline and dumortierite and absence of other boron-bearing minerals, especially prismatine, in the pegmatites is consistent with estimated metamorphic conditions of approximately 695-770°C and 7.4-8.2 kbar, as previously determined for this locality using garnet-biotite thermometry and GASP barometry (Boone, 1978). The presence of borosilicates in the leucosomes of these migmatites and the conspicuous lack of them in the paleosome may suggest destabilization of boron

  9. Trends in summer chemistry linked to productivity in lakes recovering from acid deposition in the Adirondack region of New York

    USGS Publications Warehouse

    Momen, B.; Lawrence, G.B.; Nierzwicki-Bauer, S. A.; Sutherland, J.W.; Eichler, L.W.; Harrison, J.P.; Boylen, C.W.

    2006-01-01

    The US Environmental Protection Agency established the Adirondack Effects Assessment Program (AEAP) to evaluate and monitor the status of biological communities in lakes in the Adirondack region of New York that have been adversely affected by acid deposition. This program includes chemical analysis of 30 lakes, sampled two to three times each summer. Results of trends analysis for lake chemistry and chlorophyll a (chlor a) are presented for 1994 to 2003, and a general comparison is made with recent results of the Adirondack Long-Term Monitoring (ALTM) Program, which included chemical analysis of all but two of these lakes (plus an additional 24 lakes) monthly, year-round for 1992-2004. Increases in pH were found in 25 of the 30 AEAP lakes (P < 0.05) and increases in acid-neutralizing capacity (ANC) were found in 12 of the 30 lakes (P < 0.05). Concentrations of both SO 42- and Mg 2+ decreased in 11 lakes (P < 0.05), whereas concentrations of NO 3- decreased in 20 lakes (P < 0.05). Concentrations of NH 4+ decreased in 10 lakes at a significance level of P < 0.05 and in three other lakes based on P < 0.1. Concentrations of inorganic and organic monomeric aluminum generally were below the reporting limit of 1.5 ??mol L-1, but decreases were detected in four and five lakes, respectively (P < 0.1). Concentrations of chlor a increased in seven lakes at a significance level of P < 0.05 and two lakes at a significance level of P < 0.1. A significant inverse correlation was also found between chlor a and NO 3- concentrations in nine lakes at a significance level of P < 0.05 and two lakes at a significance level of P < 0.1. Results of AEAP analysis of lake chemistry were similar to those of the ALTM Program, although decreases in SO 42- concentrations were more evident in the year-round ALTM record. Overall, the results suggest (a) a degree of chemical recovery from acidification during the summer, (b) an increase in phytoplankton productivity, and (c) a decreasing trend in

  10. Sensitivity of Stream Methyl Hg Concentrations to Environmental Change in the Adirondack Mountains of New York, USA

    NASA Astrophysics Data System (ADS)

    Burns, D. A.; Riva-Murray, K.; Nystrom, E.; Millard, G.; Driscoll, C. T.

    2014-12-01

    The Adirondacks of New York have high levels of mercury (Hg) bioaccumulation as demonstrated by a region-wide fish consumption advisory for children and women who may become pregnant. The source of this Hg is atmospheric deposition that originates from regional, continental, and global emissions. Soils in the region have large Hg stores equivalent to several decades of atmospheric deposition suggesting that the processes controlling Hg transport from soils to surface waters may greatly affect Hg concentrations and loads in surface waters. Furthermore, Hg can be converted to its neuro-toxic methyl form (MeHg), particularly in riparian and wetland soils where biogeochemical conditions favor net methylation. We measured MeHg concentrations during 33 months at Fishing Brook, a 65 km2 catchment in the upper Hudson River basin in the Adirondacks. Seasonal variation in stream MeHg concentrations was more than tenfold, consistent with temperature-driven variation in net methylation rates in soils and sediment. These data also indicate greater than twofold annual variation in stream MeHg concentrations among the three monitored growing seasons. The driest growing season had the lowest MeHg concentrations, and these values were greater during the two wetter growing seasons. We hypothesize that contact of the riparian water table with abundant organic matter and MeHg stored in the shallowest soil horizons is a dominant control on MeHg transport to the stream. An empirical model was developed that accounted for 81% of the variation in stream MeHg concentrations. Water temperature and the length of time the simulated riparian water table remained in the shallow soil were key predictive variables, highlighting the sensitivity of MeHg to climatic variation. Future changes in other factors such as Hg emissions and deposition and acid deposition will likely also influence stream MeHg concentrations and loads. For example, lime application to an Adirondack stream to increase pH and

  11. Anaglyph: Basalt Cliffs, Patagonia, Argentina

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Basalt cliffs along the northwest edge of the Meseta de Somuncura plateau near Sierra Colorada, Argentina show an unusual and striking pattern of erosion. Stereoscopic observation helps to clarify the landform changing processes active here. Many of the cliffs appear to be rock staircases that have the same color as the plateau's basaltic cap rock. Are these the edges of lower layers in the basalt or are they a train of slivers that are breaking off from, then sliding downslope and away from, the cap rock. They appear to be the latter. Close inspection shows that each stair step is too laterally irregular to be a continuous sheet of bedrock like the cap rock. Also, the steps are not flat but instead are little ridges, as one might expect from broken, tilted, and sliding slices of the cap rock. Stream erosion has cut some gullies into the cliffs and vegetation (appears bright in this infrared image) shows that water springs from and flows down some channels, but land sliding is clearly a major agent of erosion here.

    This anaglyph was generated by first draping a Landsat Thematic Mapper image over a topographic map from the Shuttle Radar Topography Mission, then producing the two differing perspectives, one for each eye. When viewed through special glasses, the result is a vertically exaggerated view of the Earth's surface in its full three dimensions. Anaglyph glasses cover the left eye with a red filter and the right eye with a blue filter.

    Landsat satellites have provided visible light and infrared images of the Earth continuously since 1972. SRTM topographic data match the 30-meter (99-foot) spatial resolution of most Landsat images and provide a valuable complement for studying the historic and growing Landsat data archive. The Landsat 7 Thematic Mapper image used here was provided to the SRTM project by the United States Geological Survey, Earth Resources Observation Systems (EROS) Data Center,Sioux Falls, South Dakota.

    Elevation data used in this

  12. Basaltic Crater in Color IR

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site]

    Released August 6, 2004 This image shows two representations of the same infra-red image near Nili Fosse in the the Isidis region of Mars. On the left is a grayscale image showing surface temperature, and on the right is a false-color composite made from 3 individual THEMIS bands. The false-color image is colorized using a technique called decorrelation stretch (DCS), which emphasizes the spectral differences between the bands to highlight compositional variations. In many cases craters trap sand in their topographic depressions, interrupting the sand's migration across the Martian surface. This image is particularly interesting because there appears to be more than 1 type of sand in the bottom of this crater and in the hummocky terrain near the bottom of the image. The pink/magenta areas are characteristic of a basaltic composition, but there are also orange areas that are likely caused by the presence of andesite. These two compositions, basalt and andesite, are some of the most common found on Mars.

    Image information: IR instrument. Latitude 24, Longitude 80.7 East (297.3 West). 100 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip

  13. The Origin of Noble Gas Isotopic Heterogeneity in Icelandic Basalts

    NASA Technical Reports Server (NTRS)

    Dixon, E. T.; Honda, M.; McDougall, I.

    2001-01-01

    Two models for generation of heterogeneous He, Ne and Ar isotopic ratios in Icelandic basalts are evaluated using a mixing model and the observed noble gas elemental ratios in Icelandic basalts,Ocean island Basalt (OIBs) and Mid-Ocean Ridge Basalt (MORBs). Additional information is contained in the original extended abstract.

  14. Shock metamorphism of granulated lunar basalt

    NASA Technical Reports Server (NTRS)

    Schaal, R. B.; Thompson, T. D.; Hoerz, F.; Bauer, J. F.

    1979-01-01

    The paper deals with an extensive series of shock-recovery experiments performed on both nonporous crystalline basalt and its granulated and sieved counterpart to study the role of porosity and grain size in shock motomorphic effects under otherwise identical conditions. Shocked samples are compared with unshocked starting material in terms of textural and mineralogical modifications attributable to shock. A comparative petrographic and chemical characterization is presented of pulverized and sieved lunar basalt 75035 shocked between 6 and 75 GPa in comparison with holocrystalline disks of the same basalts shocked in 10 earlier experiments. Specifically, a petrographic classification of shock features is given, along with an estimation of relative amounts of shock glasses and a chemical characterization of shock glasses in each shocked granular basalt.

  15. Basalts Dredged from the Northeastern Pacific Ocean.

    PubMed

    Engel, C G; Engel, A E

    1963-06-21

    Volcanic rocks dredged from seamounts, fault ridges, and other major geological features of the northeast Pacific Ocean include a wide variety of basalts. Most of these are vesicular, porphyritic types with near analogues in the Hawaiian and other oceanic islands. In addition, aluminous basalts and diabasic theoleiites impoverished in potassium also occur. There is no simple correlation of composition, degree of oxidation, vesiculation, or hydration of these basalts with texture, or depth of dredge site. Most samples appear to have been extruded at much shallower depths than those now pertaining at the dredge site. The distribution of these basalts suggests that the andesite line coincides with or lies on the continent side of the foot of the continental slope.

  16. Naming Lunar Mare Basalts: Quo Vadimus Redux

    NASA Astrophysics Data System (ADS)

    Ryder, G.

    1999-01-01

    Nearly a decade ago, I noted that the nomenclature of lunar mare basalts was inconsistent, complicated, and arcane. I suggested that this reflected both the limitations of our understanding of the basalts, and the piecemeal progression made in lunar science by the nature of the Apollo missions. Although the word "classification" is commonly attached to various schemes of mare basalt nomenclature, there is still no classification of mare basalts that has any fundamental grounding. We remain basically at a classification of the first kind in the terms of Shand; that is, things have names. Quoting John Stuart Mill, Shand discussed classification of the second kind: "The ends of scientific classification are best answered when the objects are formed into groups respecting which a greater number of propositions can be made, and those propositions more important than could be made respecting any other groups into which the same things could be distributed." Here I repeat some of the main contents of my discussion from a decade ago, and add a further discussion based on events of the last decade. A necessary first step of sample studies that aims to understand lunar mare basalt processes is to associate samples with one another as members of the same igneous event, such as a single eruption lava flow, or differentiation event. This has been fairly successful, and discrete suites have been identified at all mare sites, members that are eruptively related to each other but not to members of other suites. These eruptive members have been given site-specific labels, e.g., Luna24 VLT, Apollo 11 hi-K, A12 olivine basalts, and Apollo 15 Green Glass C. This is classification of the first kind, but is not a useful classification of any other kind. At a minimum, a classification is inclusive (all objects have a place) and exclusive (all objects have only one place). The answer to "How should rocks be classified?" is far from trivial, for it demands a fundamental choice about nature

  17. Basalts Dredged from the Northeastern Pacific Ocean.

    PubMed

    Engel, C G; Engel, A E

    1963-06-21

    Volcanic rocks dredged from seamounts, fault ridges, and other major geological features of the northeast Pacific Ocean include a wide variety of basalts. Most of these are vesicular, porphyritic types with near analogues in the Hawaiian and other oceanic islands. In addition, aluminous basalts and diabasic theoleiites impoverished in potassium also occur. There is no simple correlation of composition, degree of oxidation, vesiculation, or hydration of these basalts with texture, or depth of dredge site. Most samples appear to have been extruded at much shallower depths than those now pertaining at the dredge site. The distribution of these basalts suggests that the andesite line coincides with or lies on the continent side of the foot of the continental slope. PMID:17802173

  18. Basalts dredged from the northeastern Pacific Ocean

    USGS Publications Warehouse

    Engel, C.G.; Engel, A.E.J.

    1963-01-01

    Volcanic rocks dredged from seamounts, fault ridges, and other major geological features of the northeast Pacific Ocean include a wide variety of basalts. Most of these are vesicular, porphyritic types with near analogues in the Hawaiian and other oceanic islands. in addition, aluminous basalts and diabasic tholeiites impoverished in potassium also occur. There is no simple correlation of composition, degree of oxidation, vesiculation, or hydration of these basalts with texture, or depth of dredge site. Most samples appear to have been extruded at much shallower depths than those now pertaining at the dredge site. the distribution of these basalts suggests that the andesite line coincides with or lies on the continent side of the foot of the continental slope.

  19. Reduction of mare basalts by sulfur loss

    USGS Publications Warehouse

    Brett, R.

    1976-01-01

    Metallic Fe content and S abundance are inversely correlated in mare basalts. Either S volatilization from the melt results in reduction of Fe2+ to Fe0 or else high S content decreases Fe0 activity in the melt, thus explaining the correlation. All considerations favor the model that metallic iron in mare basalts is due to sulfur loss. The Apollo 11 and 17 mare basalt melts were probably saturated with S at the time of eruption; the Apollo 12 and 15 basalts were probably not saturated. Non-mare rocks show a positive correlation of S abundance with metallic Fe content; it is proposed that this is due to the addition of meteoritic material having a fairly constant Fe0/S ratio. If true, metallic Fe content or S abundance in non-mare rocks provides a measure of degree of meteoritic contamination. ?? 1976.

  20. A preliminary synthesis of structural, stratigraphic, and magnetic data from part of the northwest Adirondacks, New York

    USGS Publications Warehouse

    Foose, M.P.; Brown, C. Ervin

    1976-01-01

    Synthesis of recent work in the NW Adirondacks, New York allows the development of a coherent geologic picture. Mapping of the Precambrian rock units enables the recognition of four major units which are, from bottom to top, 1) Granitic Gneiss (alaskite), 2) Lower Marble, 3) Major Gneiss, and 4) Upper Marble. Additionally, lenses of amphibolite and granite occur as intrusives within this succession. These rock units have been complexly deformed by three major folding episodes, and by two distinctly different styles of faulting. The result has been to produce large northeast-southwest trending dome and basin structures. Patterns of magnetic intensity closely parallel distribution of rock units and provide additional information for a structural and stratigraphic synthesis-.

  1. Implications for Ecosystem Services of Watershed Processes that affect the Transport and Transformations of Mercury in an Adirondack Stream Basin

    NASA Astrophysics Data System (ADS)

    Burns, D. A.; Riva-Murray, K.; Bradley, P. M.

    2012-12-01

    Mercury (Hg) is a potent neurotoxin that can affect the health of humans and wildlife through the ingestion of methyl Hg. Mercury contamination of ecosystems originates from human activities such as mining, coal burning and other industrial emissions, and the use of Hg-containing products. Natural sources such as volcanic and geothermal emissions and the weathering of Hg-bearing minerals also contribute to Hg contamination, but are believed to be minor sources in most ecosystems. Various ecosystem disturbances including fires, forest harvesting, and the submergence of land by impoundment may also contribute to Hg ecosystem contamination by mobilizing stores that have previously originated from the sources described above. Mercury from a mix of regional and global emissions sources is transported in the atmosphere to remote landscapes that are distant from local emissions sources. The Adirondacks of New York State is a forested, mountainous region characterized by abundant lakes and streams, and is distant from local emissions sources. Recreational fishing, wildlife viewing, hiking, and hunting are valued ecosystem services in this region. Here, we report on the relevance to ecosystem services of findings based on five years of Hg data collection of stream water, groundwater, invertebrates, and fish in the upper Hudson River basin in the central part of the Adirondack region. The New York State Dept. of Health has issued fish consumption advisories for the entire Adirondacks based on elevated levels previously measured in lakes and rivers of this region. Our work seeks improved understanding and models of the landscape sources and watershed processes that control the transformation of Hg to its methyl form (MeHg), the transport of MeHg to streams, and bioaccumulation of MeHg in aquatic food webs. Mean annual atmospheric Hg deposition was 6.3 μg/m2/yr during 2007-09, compared to mean annual filtered total Hg stream yields of 1.66 μg/m2/yr and filtered MeHg stream

  2. In situ bioassays of brook trout (salvelinus fontinalis) and blacknose dace (rhinichthys atratulus) in adirondack streams affected by episodic acidification

    SciTech Connect

    Simonin, H.A.; Kretser, W.A.; Bath, D.W.; Olson, M.; Gallagher, J.

    1993-01-01

    In situ bioassays were conducted using native Adirondack brook trout and blacknose dace in four headwater streams. Conductivity, pH, temperature, and stage height were monitored continuously, and water samples for laboratory analysis were collected during hydrologic episodes. Fish survived well during baseflow conditions, but during periods of spring snowmelt or large precipitation events, survival was poor. Bioassay fish that had been in the stream 15-24 d survived episodes better than fish that had either not become acclimatized or recovered from handling. Duration of exposure to acidic episodes was critical. Extended periods of poor water quality resulted in fish mortality and may be more important to native populations than short acidic episodes.

  3. Patterns of epipelic algal distribution in an acidic adirondack lake. [Hapalosiphon pumilus; Fragilaria acidobiontica; Navicula tenuicephala; Navicula subtilissima

    SciTech Connect

    Roberts, D.A.; Boylen, C.W.

    1988-06-01

    The biovolume and species composition of epipelic algae along sediment depth gradients were sampled seasonally in an acidic oligotrophic lake in the Adirondack Park in New York State. The epipelic algal community of Woods Lake (Herkimer Co., NY) was dominated by diatoms and cyanobacteria. Distinct depth zonation patterns of community composition were evident. Total algal biovolume increased with depth due to a dense cyanobacterial mat on the sediments in deeper water (5-8 m). This mat was dominated by a single species of cyanobacteria, Hapalosiphon pumilus (Kuetz). Kirchner, which accounted for the later summer maximum in total biovolume at 7 m. The shallower (1-4 m) epipelic communities were dominated by diatoms, which showed a spring maximum in total biovolume and were dominated by Fragilaria acidobiontica Charles, Navicula tenuicephala Hust, and N. subtilissima Cl.

  4. Basaltic cannibalism at Thrihnukagigur volcano, Iceland

    NASA Astrophysics Data System (ADS)

    Hudak, M. R.; Feineman, M. D.; La Femina, P. C.; Geirsson, H.

    2014-12-01

    Magmatic assimilation of felsic continental crust is a well-documented, relatively common phenomenon. The extent to which basaltic crust is assimilated by magmas, on the other hand, is not well known. Basaltic cannibalism, or the wholesale incorporation of basaltic crustal material into a basaltic magma, is thought to be uncommon because basalt requires more energy than higher silica rocks to melt. Basaltic materials that are unconsolidated, poorly crystalline, or palagonitized may be more easily ingested than fully crystallized massive basalt, thus allowing basaltic cannibalism to occur. Thrihnukagigur volcano, SW Iceland, offers a unique exposure of a buried cinder cone within its evacuated conduit, 100 m below the main vent. The unconsolidated tephra is cross-cut by a NNE-trending dike, which runs across the ceiling of this cave to a vent that produced lava and tephra during the ~4 Ka fissure eruption. Preliminary petrographic and laser ablation inductively coupled mass spectrometry (LA-ICP-MS) analyses indicate that there are two populations of plagioclase present in the system - Population One is stubby (aspect ratio < 1.7) with disequilibrium textures and low Ba/Sr ratios while Population Two is elongate (aspect ratio > 2.1), subhedral to euhedral, and has much higher Ba/Sr ratios. Population One crystals are observed in the cinder cone, dike, and surface lavas, whereas Population Two crystals are observed only in the dike and surface lavas. This suggests that a magma crystallizing a single elongate population of plagioclase intruded the cinder cone and rapidly assimilated the tephra, incorporating the stubbier population of phenocrysts. This conceptual model for basaltic cannibalism is supported by field observations of large-scale erosion upward into the tephra, which is coated by magma flow-back indicating that magma was involved in the thermal etching. While the unique exposure at Thrihnukagigur makes it an exceptional place to investigate basaltic

  5. Starch columns: Analog model for basalt columns

    NASA Astrophysics Data System (ADS)

    Müller, Gerhard

    1998-07-01

    Desiccation of starch-water mixtures produces tensile-crack patterns which appear to be interesting, but largely unknown study objects for fracture mechanics, structural geology, and volcanology. This paper concentrates on columnar jointing and on columns in starch. Starch columns have polygonal cross sections and are very similar to basalt columns. They are produced by lamp drying starch specimens with dimensions of several centimeters and have diameters in the millimeter range. The columns develop behind a crack front which propagates from the surface into the interior. The experiments, supported by X ray tomograms, show that polygonal regularity of the crack pattern is not present at the surface but develops during penetration. This transition is steered by a minimum-fracture-energy principle. The analogy between basalt cooling and starch desiccation is far reaching: water concentration in starch is analogous to temperature in basalt, both quantities obey diffusion equations, water loss is equivalent to heat loss, the resulting contraction stresses have similar dependences on depth and time, and in both cases the material strength is exceeded. The starch experiments show that column diameters are controlled by the depth gradient of water concentration at the crack front. High (low) gradients are connected with thin (thick) columns. By analogy, a similar relation with the temperature gradient exists for basalt columns. The (normalized) starch gradients are about 3 orders of magnitude larger than the (normalized) gradients in basalt. This explains why starch columns are much thinner than basalt columns. The gradients are so different, because the crack front speeds differ by a factor of about 10: after 3 days the speed is about 10 mm/d in starch but about 100 mm/d in basalt [Peck, 1978]. The speed difference, in turn, results from the difference of the diffusion constants: the hydraulic diffusivity of starch is 2 orders of magnitude lower than the thermal

  6. Using Critical Loads to Look at Improvements in Acidic Surface Water Conditions since the 1990 Amendments to the Clear Air Act: Case Study Adirondack, NY

    NASA Astrophysics Data System (ADS)

    Lynch, J. A.; Kolian, M. J.; Haeuber, R.

    2008-12-01

    Acid deposition has affected hundreds of lakes and thousands of miles of headwater streams in the Adirondack region of New York State. The diversity of life in these acidic waters has been greatly reduced. The poor buffering capacity of the thin, acidic soils in the Adirondack Mountains makes the lakes and ponds particularly susceptible to acidification. Since the mid-1990's, lakes in the Adirondack region are finally showing signs of recovery. The good news is that emissions of sulfur dioxide and nitrogen oxides have been reduced and as a result acidic deposition of sulfate and nitrate has decreased in surface waters approximately 26 and 13%, respectively. This has led to improvement in the acid neutralizing capacity (ANC) of these water bodies. Although improvement in water quality is a good sign, it does not tell us if a particular lake or a group of lakes have recovered from decades of acidic deposition. However, the critical loads approach does allow for evaluation of whether a water body has reached recovery for acidic deposition. Critical loads and exceedances for lake surface water and acidity were calculated for 187 lakes in the Adirondack region. The Steady-State Water Chemistry (SSWC) model was used to calculate the critical load, relying on water chemistry data from the TIME/LTM network. An ANC threshold of 50 μeq/L was selected for this case study. Exceedances were calculated from deposition for the period before implementation of the Acid Rain program (ARP) (1989-1991) and for the period of 2004-2006 to judge improvements as a result of the ARP. On average, the critical load for lakes in the Adirondack region is 164 meq/m2/yr, while it is 48 meq/m2/yr for the most sensitive lakes (i.e. ANC less than 100 μeq/L). For the period from 2004 to 2006, 65% of the lakes within the TIME/LTM network continued to receive levels of acid deposition that exceeded the lake's critical load down from 72% of lakes before implementation of the Acid Rain Program

  7. Development of a total maximum daily load (TMDL) for acid-impaired lakes in the Adirondack region of New York

    NASA Astrophysics Data System (ADS)

    Fakhraei, Habibollah; Driscoll, Charles T.; Selvendiran, Pranesh; DePinto, Joseph V.; Bloomfield, Jay; Quinn, Scott; Rowell, H. Chandler

    2014-10-01

    Acidic deposition has impaired acid-sensitive surface waters in the Adirondack region of New York by decreasing pH and acid neutralizing capacity (ANC). In spite of air quality programs over past decades, 128 lakes in the Adirondacks were classified as “impaired” under Section 303(d) of the Clean Water Act in 2010 due to elevated acidity. The biogeochemical model, PnET-BGC, was used to relate decreases in atmospheric sulfur (S) and nitrogen (N) deposition to changes in lake water chemistry. The model was calibrated and confirmed using observed soil and lake water chemistry data and then was applied to calculate the maximum atmospheric deposition that the impaired lakes can receive while still achieving ANC targets. Two targets of ANC were used to characterize the recovery of acid-impaired lakes: 11 and 20 μeq L-1. Of the 128 acid-impaired lakes, 97 currently have ANC values below the target value of 20 μeq L-1 and 83 are below 11 μeq L-1. This study indicates that a moderate control scenario (i.e., 60% decrease from the current atmospheric S load) is projected to recover the ANC of lakes at a mean rate of 0.18 and 0.05 μeq L-1 yr-1 during the periods 2022-2050 and 2050-2200, respectively. The total maximum daily load (TMDL) of acidity corresponding to this moderate control scenario was estimated to be 7.9 meq S m-2 yr-1 which includes a 10% margin of safety.

  8. Interpretation of whole-rock Rb-Sr geochronology in the high grade rocks of the Adirondack Mountains, New York

    SciTech Connect

    Yang, Y.; Grant, N.K. . Dept. of Geology)

    1992-01-01

    Published and new Rb-Sr whole-rock isochrons for high grade metaigneous, gneissic and mylonitic rocks from the Adirondack Mountains have been evaluated in two ways. In the first, the Rb-Sr ages are compared to the published U-Pb zircon ages for metaigneous rocks. In the second, the ages are compared with forward modeling that employs Monte Carlo simulation and solid diffusion calculations to determine the probabilities of Rb-Sr resetting under various conditions of channelized and homogeneous fluid flow. The first comparison shows that the Rb-Sr isochrons fall into three groups. The first comprises isochrons of ca. 1050 Ma for mylonitic and metaigneous rocks from the Carthage-Colton Mylonite Zone that separates the Highlands from the Lowlands, and the zone of Trans-Adirondack Structural Discontinuities that separate the southern from the northern Highlands. These ages can be interpreted to the result of complete resetting during the Ottawan phase of the Grenville orogeny. The second group comprises isochrons that are concordant or consistent with the U-Pb zircon ages, and the third group isochrons with ages intermediate between the U-Pb zircon ages and that for high grade metamorphism at 1150 Ma and 1050 Ma in the Lowlands and Highlands respectively. The forward modeling suggests that complete resetting of Rb-Sr isochrons was associated with high fluid/rock ratios (>2) under conditions of homogeneous flow, and that fluid/rock ratios were low (<0.25) in cases where no resetting has occurred. Partial resetting, as can be demonstrated in the Lowlands, requires conditions intermediate between the first two cases or extremely heterogeneous fluid flow. These results show that whole-rock Rb-Sr age determination can recover useful information from high grade rocks, providing the samples are collected from clearly documented tectonic domains.

  9. Specific ultra-violet absorbance as an indicator measurement of merucry sources in an Adirondack River basin

    USGS Publications Warehouse

    Burns, Douglas A.; Aiken, George R.; Bradley, Paul M.; Journey, Celeste A.; Schelker, Jakob

    2013-01-01

    The Adirondack region of New York has been identified as a hot spot where high methylmercury concentrations are found in surface waters and biota, yet mercury (Hg) concentrations vary widely in this region. We collected stream and groundwater samples for Hg and organic carbon analyses across the upper Hudson River, a 493 km2 basin in the central Adirondacks to evaluate and model the sources of variation in filtered total Hg (FTHg) concentrations. Variability in FTHg concentrations during the growing seasons (May-Oct) of 2007-2009 in Fishing Brook, a 66-km2 sub-basin, was better explained by specific ultra-violet absorbance at 254 nm (SUVA254), a measure of organic carbon aromaticity, than by dissolved organic carbon (DOC) concentrations, a commonly used Hg indicator. SUVA254 was a stronger predictor of FTHg concentrations during the growing season than during the dormant season. Multiple linear regression models that included SUVA254 values and DOC concentrations could explain 75 % of the variation in FTHg concentrations on an annual basis and 84 % during the growing season. A multiple linear regression landscape modeling approach applied to 27 synoptic sites across the upper Hudson basin found that higher SUVA254 values are associated with gentler slopes, and greater riparian area, and lower SUVA254 values are associated with an increasing influence of open water. We hypothesize that the strong Hg?SUVA254 relation in this basin reflects distinct patterns of FTHg and SUVA254 that are characteristic of source areas that control the mobilization of Hg to surface waters, and that the seasonal influence of these source areas varies in this heterogeneous basin landscape.

  10. Effect of whole catchment liming on the episodic acidification of two adirondack streams

    USGS Publications Warehouse

    Newton, R.M.; Burns, Douglas A.; Blette, V.L.; Driscoll, C.T.

    1996-01-01

    During the fall of 1989 7.7Mg/ha of calcium carbonate was applied on two tributary catchments (40 ha and 60 ha) to Woods Lake, a small (25 ha) acidic headwater lake in the western Adirondack region of New York. Stream-water chemistry in both catchment tributaries responded immediately. Acid-neutralizing capacity (ANC) increased by more than 200 ??eq/L in one of the streams and more than 1000 ??eq/L in the other, from pre-liming values which ranged from -25 to +40 ??eq/L. The increase in ANC was primarily due to increases in dissolved Ca2+ concentrations. Most of the initial response of the streams was due to the dissolution of calcite that fell directly into the stream channels and adjacent wetlands. A small beaver impoundment and associated wetlands were probably responsible for the greater response observed in one of the streams. After the liming of subcatchmentIV (60 ha), Ca2+ concentrations increased with increasing stream discharge in the stream during fall rain events, suggesting a contribution from calcite dissolved within the soil and transported to the stream by surface runoff or shallow interflow. Concentrations of other ions not associated with the calcite (e.g. Na+) decreased during fall rain events, presumably due to mixing of solute-rich base flow with more dilute shallow interflow. The strong relation between changes in Ca2+ and changes in NO3- concentrations during spring snowmelt, (r2 = 0.93, slope = 0.96, on an equivalent basis) suggests that both solutes had a common source in the organic horizon of the soil. Increases in NO3- concentrations during snowmelt were balanced by increases in Ca2+ that was released either directly from the calcite or from exchange sites, mitigating episodic acidification of the stream. However, high ambient NO3- concentrations and relatively low ambient Ca2+ concentrations in the stream during the spring caused the stream to become acidic despite the CaCO3 treatment. In stream WO2 (40ha), Ca2+ concentrations were much

  11. A monitor for continuous measurement of temperature, pH, and conductance of wet precipitation: Preliminary results from the Adirondack Mountains, New York

    USGS Publications Warehouse

    Johnsson, P.A.; Reddy, M.M.

    1990-01-01

    This report describes a continuous wet-only precipitation monitor designed by the U.S. Geological Survey to record variations in rainfall temperature, pH, and specific conductance at 1-min intervals over the course of storms. Initial sampling in the Adirondack Mountains showed that rainfall acidity varied over the course of summer storms, with low initial pH values increasing as storm intensity increased.This report describes a continuous wet-only precipitation monitor designed by the U.S. Geological Survey to record variations in rainfall temperature, pH, and specific conductance at 1-min intervals over the course of storms. Initial sampling in the Adirondack Mountains showed that rainfall acidity varied over the course of summer storms, with low initial pH values increasing as storm intensity increased.

  12. Nickel and Cobalt Partitioning Between Spinel and Basaltic Melt: Applications to Planetary Basalt Suites

    NASA Technical Reports Server (NTRS)

    Righter, K.

    2002-01-01

    New experimental spinel/melt partition coefficients for Ni and Co have been measured in basalt samples with natural levels of Ni and Co, are lower than previous high doping experiments, and are applied to several planetary basalt suites. Additional information is contained in the original extended abstract.

  13. Are flood basalt eruptions monogenetic or polygenetic?

    NASA Astrophysics Data System (ADS)

    Sheth, Hetu C.; Cañón-Tapia, Edgardo

    2015-11-01

    A fundamental classification of volcanoes divides them into "monogenetic" and "polygenetic." We discuss whether flood basalt fields, the largest volcanic provinces, are monogenetic or polygenetic. A polygenetic volcano, whether a shield volcano or a stratovolcano, erupts from the same dominant conduit for millions of years (excepting volumetrically small flank eruptions). A flood basalt province, built from different eruptive fissures dispersed over wide areas, can be considered a polygenetic volcano without any dominant vent. However, in the same characteristic, a flood basalt province resembles a monogenetic volcanic field, with only the difference that individual eruptions in the latter are much smaller. This leads to the question how a flood basalt province can be two very different phenomena at the same time. Individual flood basalt eruptions have previously been considered monogenetic, contrasted by only their high magma output (and lava fluidity) with typical "small-volume monogenetic" volcanoes. Field data from Hawaiian shield volcanoes, Iceland, and the Deccan Traps show that whereas many feeder dykes were single magma injections, and the eruptions can be considered "large monogenetic" eruptions, multiple dykes are equally abundant. They indicate that the same dyke fissure repeatedly transported separate magma batches, feeding an eruption which was thus polygenetic by even the restricted definition (the same magma conduit). This recognition helps in understanding the volcanological, stratigraphic, and geochemical complexity of flood basalts. The need for clear concepts and terminology is, however, strong. We give reasons for replacing "monogenetic volcanic fields" with "diffuse volcanic fields" and for dropping the term "polygenetic" and describing such volcanoes simply and specifically as "shield volcanoes," "stratovolcanoes," and "flood basalt fields."

  14. Solubility of Csbnd Osbnd H volatiles in graphite-saturated martian basalts

    NASA Astrophysics Data System (ADS)

    Stanley, Ben D.; Hirschmann, Marc M.; Withers, Anthony C.

    2014-03-01

    To determine the speciation and concentrations of dissolved Csbnd Osbnd H volatiles in graphite-saturated martian primitive magmas, we conducted piston-cylinder experiments on graphite-encapsulated synthetic melt of Adirondack-class Humphrey basaltic composition. Experiments were performed over three orders of magnitude in oxygen fugacity (IW+2.3 to IW-0.8), and at pressures (1-3.2 GPa) and temperatures (1340-1617 °C) similar to those of possible martian source regions. Oxygen fugacities were determined from compositions of coexisting silicate melt + FePt alloy, olivine + pyroxene + FePt alloy, or melt + Fesbnd C liquid. Infrared spectra of quenched glasses all show carbonate absorptions at 1430 and 1520 cm-1, with CO2 concentrations diminishing under more reduced conditions, from 0.50 wt% down to 26 ppm. Carbon contents of silicate glasses and Fesbnd C liquids were measured using secondary ion mass spectrometry (SIMS) yielding 36-716 ppm and 6.71-7.03 wt%, respectively. Fourier transform infrared (FTIR) and SIMS analysis produced similar H2O contents of 0.26-0.85 and 0.29-0.40 wt%, respectively. Raman spectra of glasses reveal evidence for OH- ions, but no indication of methane-related species. FTIR-measured concentrations of dissolved carbonate diminish linearly with oxygen fugacity, but more reduced conditions yield greater dissolved carbonate concentrations than would be expected based on oxidized conditions in previous work. C contents of silicate glasses determined by SIMS are consistently higher than C as carbonate determined by FTIR. Their difference, termed non-carbonate C, correlates well with additional IR absorptions found in reduced glasses (f < IW+0.4) at 1615, 2205, and 3370 cm-1. These absorption bands are not seen in more oxidized glasses, except B441 (IW+1.7), presumably because they represent reduced C-bearing complexes. The 2205 cm-1 peak is attributed to a Cdbnd O complex, possibly an Fe-carbonyl ion. The 1615 cm-1 peak does not correlate with

  15. Lu-Hf constraints on the evolution of lunar basalts

    SciTech Connect

    Fujimaki, H.; Tatsumoto, M.

    1984-02-15

    Very low Ti basalts andd green glass samples from the moon show high Lu/Hf ratios and low Hf concentrations. Low-Ti lunar basalts show high and variable Lu/Hf ratios and higher Hf concentrations, whereas high-Ti lunar basalts show low Lu/Hf ratios and high Hf concentrations. KREEP basalts have constant Lu/Hf ratios and high but variable Hf concentrations. Using the Lu-Hf behavior as a constraint, we propose a model for the mare basalts evolution. This constraint requires extensive crystallization of the primary lunar magma ocean prior to formation of the lunar mare basalt sources and the KREEP basalts. Mare basalts are produced by the melting of the cumulate rocks, and KREEP basalts represent the residual liquid of the magma ocean.

  16. Evaluating crustal contamination in continental basalts: the isotopic composition of the Picture Gorge Basalt of the Columbia River Basalt Group

    NASA Astrophysics Data System (ADS)

    Brandon, Alan D.; Hooper, Peter R.; Goles, Gordon G.; Lambert, Richard St J.

    1993-09-01

    Crustal contamination of basalts located in the western United States has been generally under-emphasized, and much of their isotopic variation has been ascribed to multiple and heterogeneous mantle sources. Basalts of the Miocene Columbia River Basalt Group in the Pacific Northwest have passed through crust ranging from Precambrian to Tertiary in age. These flows are voluminous, homogenous, and underwent rapid effusion, all of which are disadvantages for crustal contamination while en route to the surface. The Picture Gorge Basalt of the Columbia River Basalt Group erupted through Paleozoic and Mesozoic oceanic accreted terranes in central Oregon, and earlier studies on these basalts provided no isotopic evidence for crustal contamination. New Sr, Nd, Pb, and O isotopic data presented here indicate that the isotopic variation of the Picture Gorge Basalt is very small, 87Sr/86Sr=0.70307 0.70371, ɛNd=+7.7-+4.8, δ18O=+5.6±6.1, and 206Pb/204Pb=18.80 18.91. Evaluation of the Picture Gorge compositional variation supports a model where two isotopic components contributed to Picture Gorge Basalt genesis. The first component (C1) is reflected by low 87Sr/86Sr, high ɛNd, and nonradiogenic Pb isotopic compositions. Basalts with C1 isotopic compositions have large MgO, Ni, and Cr contents and mantle-like δ18O=+5.6. C1 basalts have enrichments in Ba coupled with depletions in Nb and Ta. These characteristics are best explained by derivation from a depleted mantle source which has undergone a recent enrichment by fluids coming from a subducted slab. This C1 mantle component is prevalent throughout the Pacific Northwest. The second isotopic component has higher 87Sr/ 86Sr and δ18O, lower ɛNd, and more radiogenic Pb isotopic compositions than C1. There is a correlation in the Picture Gorge data of Sr, Nd, and Pb isotopes with differentiation indicators such as decreasing Mg#, and increasing K2O/TiO2, Ba, Ba/Zr, Rb/Sr, La/Sm, and La/Yb. Phase equilibrium and mineralogical

  17. Geochemical diversity of shergottite basalts: Mixing and fractionation, and their relation to Mars surface basalts

    NASA Astrophysics Data System (ADS)

    Treiman, Allan H.; Filiberto, Justin

    2015-04-01

    The chemical compositions of shergottite meteorites, basaltic rocks from Mars, provide a broad view of the origins and differentiation of these Martian magmas. The shergottite basalts are subdivided based on their Al contents: high-Al basalts (Al > 5% wt) are distinct from low-Al basalts and olivine-phyric basalts (both with Al < 4.5% wt). Abundance ratios of highly incompatible elements (e.g., Th, La) are comparable in all the shergottites. Abundances of less incompatible elements (e.g., Ti, Lu, Hf) in olivine-phyric and low-Al basalts correlate well with each other, but the element abundance ratios are not constant; this suggests mixing between components, both depleted and enriched. High-Al shergottites deviate from these trends consistent with silicate mineral fractionation. The "depleted" component is similar to the Yamato-980459 magma; approximately, 67% crystal fractionation of this magma would yield a melt with trace element abundances like QUE 94201. The "enriched" component is like the parent magma for NWA 1068; approximately, 30% crystal fractionation from it would yield a melt with trace element abundances like the Los Angeles shergottite. This component mixing is consistent with radiogenic isotope and oxygen fugacity data. These mixing relations are consistent with the compositions of many of the Gusev crater basalts analyzed on Mars by the Spirit rover (although with only a few elements to compare). Other Mars basalts fall off the mixing relations (e.g., Wishstone at Gusev, Gale crater rocks). Their compositions imply that basalt source areas in Mars include significant complexities that are not present in the source areas for the shergottite basalts.

  18. Oxygen consumption in subseafloor basaltic crust

    NASA Astrophysics Data System (ADS)

    Orcutt, B. N.; Wheat, C. G.; Hulme, S.; Edwards, K. J.; Bach, W.

    2012-12-01

    Oceanic crust is the largest potential habitat for life on Earth and may contain a significant fraction of Earth's total microbial biomass, yet little is known about the form and function of life in this vast subseafloor realm that covers nearly two-thirds of the Earth's surface. A deep biosphere hosted in subseafloor basalts has been suggested from several lines of evidence; yet, empirical analysis of metabolic reaction rates in basaltic crust is lacking. Here we report the first measure of oxygen consumption in young (~ 8 Ma) and cool (<25 degrees C) basaltic crust, calculated from modeling oxygen and strontium profiles in basal sediments collected during Integrated Ocean Drilling Program (IODP) Expedition 336 to 'North Pond', a sediment 'pond' on the western flank of the Mid-Atlantic Ridge (MAR), where vigorous fluid circulation within basaltic crust occurs. Dissolved oxygen concentrations increased towards the sediment-basement interface, indicating an upward diffusional supply from oxic fluids circulating within the crust. A parametric reaction-transport model suggests oxygen consumption rates on the order of 0.5-500 nmol per cubic centimeter fluid per day in young and cool basaltic crust, providing sufficient energy to support a subsurface crustal biosphere.

  19. Finding Basalt Chips from Distant Maria

    NASA Astrophysics Data System (ADS)

    Taylor, G. J.

    2006-04-01

    The Apollo 16 landing site is in the lunar highlands, over 200 kilometers away from the nearest maria. Nevertheless, the Apollo 16 regolith contains a small percentage (<1%) of tiny fragments thrown to the site from distant maria. Ryan Zeigler, his colleagues at Washington University in St. Louis: Randy Korotev, Brad Jolliff, and the late Larry Haskin, and Jeffrey Gillis-Davis (University of Hawaii) made a detailed study of the chemical composition and mineralogy of fragments (only 2-4 millimeters across) of mare basalts. The basalts vary in composition, but are similar to other types identified previously. The team matched the compositions of the fragments to compositions of mare surfaces in the Apollo 16 region using remote sensing data from the Clementine mission. This blending of cosmochemical and remote sensing analyses allowed them to make educated guesses about where each of the basalt fragments may have originated. We now have a fuller understanding of the range of compositions of mare basalts and, because basalts record a wealth of information about planetary interiors, this research enlightens us about the diversity of rock compositions in the lunar mantle.

  20. Can we identify source lithology of basalt?

    PubMed

    Yang, Zong-Feng; Zhou, Jun-Hong

    2013-01-01

    The nature of source rocks of basaltic magmas plays a fundamental role in understanding the composition, structure and evolution of the solid earth. However, identification of source lithology of basalts remains uncertainty. Using a parameterization of multi-decadal melting experiments on a variety of peridotite and pyroxenite, we show here that a parameter called FC3MS value (FeO/CaO-3*MgO/SiO2, all in wt%) can identify most pyroxenite-derived basalts. The continental oceanic island basalt-like volcanic rocks (MgO>7.5%) (C-OIB) in eastern China and Mongolia are too high in the FC3MS value to be derived from peridotite source. The majority of the C-OIB in phase diagrams are equilibrium with garnet and clinopyroxene, indicating that garnet pyroxenite is the dominant source lithology. Our results demonstrate that many reputed evolved low magnesian C-OIBs in fact represent primary pyroxenite melts, suggesting that many previous geological and petrological interpretations of basalts based on the single peridotite model need to be reconsidered.

  1. Can we identify source lithology of basalt?

    PubMed Central

    Yang, Zong-Feng; Zhou, Jun-Hong

    2013-01-01

    The nature of source rocks of basaltic magmas plays a fundamental role in understanding the composition, structure and evolution of the solid earth. However, identification of source lithology of basalts remains uncertainty. Using a parameterization of multi-decadal melting experiments on a variety of peridotite and pyroxenite, we show here that a parameter called FC3MS value (FeO/CaO-3*MgO/SiO2, all in wt%) can identify most pyroxenite-derived basalts. The continental oceanic island basalt-like volcanic rocks (MgO>7.5%) (C-OIB) in eastern China and Mongolia are too high in the FC3MS value to be derived from peridotite source. The majority of the C-OIB in phase diagrams are equilibrium with garnet and clinopyroxene, indicating that garnet pyroxenite is the dominant source lithology. Our results demonstrate that many reputed evolved low magnesian C-OIBs in fact represent primary pyroxenite melts, suggesting that many previous geological and petrological interpretations of basalts based on the single peridotite model need to be reconsidered. PMID:23676779

  2. Lithoautotrophic microbial ecosystems in deep basalt aquifers

    SciTech Connect

    Stevens, T.O.; McKinley, J.P.

    1995-10-20

    Bacterial communities were detected in deep crystalline rock aquifers within the Columbia River Basalt Group (CRB). CRB ground waters contained up to 60 {mu}M dissolved H{sub 2} and autotrophic microorganisms outnumbered heterotrophs. Stable carbon isotope measurements implied that autotrophic methanogenesis dominated this ecosystem and was coupled to the depletion of dissolved inorganic carbon. In laboratory experiments, H{sub 2} a potential energy source for bacteria, was produced by reactions between crushed basalt and anaerobic water. Microcosms containing only crushed basalt and ground water supported microbial growth. These results suggest that the CRB contains a lithoautotrophic microbial ecosystem that is independent of photosynthetic primary production. 38 refs., 4 figs., 3 tabs.

  3. Basaltic Volcanism and Ancient Planetary Crusts

    NASA Technical Reports Server (NTRS)

    Shervais, John W.

    1993-01-01

    The purpose of this project is to decipher the origin of rocks which form the ancient lunar crust. Our goal is to better understand how the moon evolved chemically and, more generally, the processes involved in the chemical fractionation of terrestrial planetoids. This research has implications for other planetary bodies besides the Moon, especially smaller planetoids which evolved early in the history of the solar system and are now thermally stable. The three main areas focused on in our work (lunar mare basalts, KREEP basalts, and plutonic rocks of the lunar highlands) provide complementary information on the lunar interior and the processes that formed it.

  4. Mercury Inputs, Outputs, Cycling, and Ambient Concentrations under the Forest Canopy in the Adirondacks of New York

    NASA Astrophysics Data System (ADS)

    Choi, H.; Holsen, T.

    2009-12-01

    This study investigated mercury inputs, outputs, cycling, and the interactions between deposition, emissions and atmospheric conditions in the Huntington Forest of the Adirondacks, New York. Continuous speciated mercury concentrations of gaseous elemental Hg (GEM), reactive gaseous Hg (RGM), and particulate Bound Hg (PBM) were made from June 2006 to May 2007. The average concentrations of GEM, RGM, and PBM were 1.4 ± 0.4 ng m-3, 1.8 ± 2.2 pg m-3, and 3.2 ± 3.7 pg m-3, respectively. A hybrid receptor modeling technique (potential source contribution function (PSCF)) was used with the speciated Hg concentrations to identify possible Hg sources. Major Hg sources that have a potential to contribute high Hg concentrations observed in the Adirondacks were found to be Pennsylvania, West Virginia, Ohio, Kentucky, Texas, Indiana, and Missouri. The volume-weighted mean (VWM) total Hg concentration in throughfall (Dec. 2004 to Dec. 2006) (6.6 ng L-1) was higher than in precipitation (4.9 ng L-1), while the total cumulative Hg flux in throughfall (12.0 µg m-2) was similar to precipitation (11.6 µg m-2). The emission flux of GEM from the forest floor measured using a polycarbonate dynamic flux chamber (DFC) was highest in spring, and summer, and lowest in winter. The yearly estimated Hg inputs into the forest canopy include throughfall (6.5 g m-2 year-1), litterfall (18.3 g m-2 year-1), and dry deposition during leaf-off periods (0.4g m-2 year-1). The yearly estimated Hg outputs from the forest canopy include emission from the forest floor (7.0g m-2 year-1), soil water (0.6 g m-2 year-1), and Hg loss via evaporation or overland flow during snow melt (1.0 g m-2 year-1). Litterfall represented the most significant input of Hg to this forest ecosystem. Based on this mass balance, 16.6 g m-2 of Hg is accumulating in the forest floor every year.

  5. Equilibration of Leachants with Basalt Rock for Repository Simulation Tests

    SciTech Connect

    Jantzen, C.M.

    2001-07-02

    In a nuclear waste repository in basalt, the groundwater will have a low redox potential (Eh) which may affect the leach rate of SRP waste glass. Accurate laboratory simulations of conditions in a basalt reposition must maintain low Eh values throughout the course of the experiment. In this report, important parameters affecting the ability of basalt to maintain appropriate Eh-pH conditions are examined, in particular basalt type and groundwater simulation.

  6. Basaltic injections into floored silicic magma chambers

    NASA Astrophysics Data System (ADS)

    Wiebe, R. A.

    Recent studies have provided compelling evidence that many large accumulations of silicic volcanic rocks erupted from long-lasting, floored chambers of silicic magma that were repeatedly injected by basaltic magma. These basaltic infusions are commonly thought to play an important role in the evolution of the silicic systems: they have been proposed as a cause for explosive silicic eruptions [Sparks and Sigurdsson, 1977], compositional variation in ash-flow sheets [Smith, 1979], mafic magmatic inclusions in silicic volcanic rocks [Bacon, 1986], and mixing of mafic and silicic magmas [Anderson, 1976; Eichelberger, 1978]. If, as seems likely, floored silicic magma chambers have frequently been invaded by basalt, then plutonic bodies should provide records of these events. Although plutonic evidence for mixing and commingling of mafic and silicic magmas has been recognized for many years, it has been established only recently that some intrusive complex originated through multiple basaltic injections into floored chambers of silicic magma [e.g., Wiebe, 1974; Michael, 1991; Chapman and Rhodes, 1992].

  7. Pressure grouting of fractured basalt flows

    SciTech Connect

    Shaw, P.; Weidner, J.; Phillips, S.; Alexander, J.

    1996-04-01

    This report describes a field trial of pressure grouting in basalt and the results of subsequent coring and permeability measurement activities. The objective was to show that the hydraulic conductivity of fractured basalt bedrock can be significantly reduced by pressure injection of cementitious materials. The effectiveness of the pressure grout procedure was evaluated by measuring the change in the hydraulic conductivity of the bedrock. The extent of grout penetration was established by analyzing postgrout injection drilling chips for the presence of a tracer in the grout and also by examining cores of the treated basalt. Downhole radar mapping was used to establish major lava flow patterns and follow water movement during a surface infiltration test. A site called Box Canyon, which is located northwest of the INEL, was chosen for this study due to the similarity of this surface outcrop geology to that of the underlying bedrock fracture system found at the Radioactive Waste Management Complex. This study showed that hydraulic conductivity of basalt can be reduced through pressure grouting of cementitious material.

  8. Thermal models for basaltic volcanism on Io

    USGS Publications Warehouse

    Keszthelyil, L.; McEwen, A.

    1997-01-01

    We present a new model for the thermal emissions from active basaltic eruptions on Io. While our methodology shares many similarities with previous work, it is significantly different in that (1) it uses a field tested cooling model and (2) the model is more applicable to pahoehoe flows and lava lakes than fountain-fed, channelized, 'a'a flows. This model demonstrates the large effect lava porosity has on the surface cooling rate (with denser flows cooling more slowly) and provides a preliminary tool for examining some of the hot spots on Io. The model infrared signature of a basaltic eruption is largely controlled by a single parameter, ??, the average survival time for a lava surface. During an active eruption surfaces are quickly covered or otherwise destroyed and typical values of ?? for a basaltic eruption are expected to be on the order of 10 seconds to 10 minutes. Our model suggests that the Galileo SSI eclipse data are consistent with moderately active to quiescent basaltic lava lakes but are not diagnostic of such activity. Copyright 1997 by the American Geophysical Union.

  9. The biological consequences of flood basalt volcanism

    NASA Astrophysics Data System (ADS)

    Clapham, M.

    2012-12-01

    Flood basalt eruptions are among the largest environmental perturbations of the Phanerozoic. The rapid release of CO2 from a large igneous province would have triggered a chain of events that can include climate warming, ocean acidification, reduced seawater carbonate saturation, and expanded oceanic anoxia. Those stressors have widely negative impacts on marine organisms, especially on calcified taxa, by affecting their respiratory physiology and reducing energy available for growth and reproduction. Many Phanerozoic extinctions, most notably the end-Permian and end-Triassic mass extinctions, coincided with flood basalt eruptions and shared distinctive patterns of taxonomic and ecological selectivity. In these extinctions, highly active organisms were more likely to survive because they possess physiological adaptations for maintaining internal pH during activity, which also proves useful when buffering pH against ocean acidification. In contrast, species that did not move and had low metabolic rates, such as brachiopods and sponges, suffered considerable losses during these extinctions. Heavily-calcified organisms, especially corals, were particularly vulnerable; as a result, ocean acidification and saturation state changes from flood basalt eruptions often triggered crises in reef ecosystems. This characteristic pattern of selectivity during "physiological" extinctions that closely coincided with flood basalts provides a template for assessing the causes of other extinction events. Because these crises also provide deep time analogues for the ongoing anthropogenic crisis of warming, ocean acidification, and expanded anoxia, the selectivity patterns can also help constrain "winners" and "losers" over upcoming decades.

  10. Hydrogen isotope systematics of submarine basalts

    USGS Publications Warehouse

    Kyser, T.K.; O'Neil, J.R.

    1984-01-01

    The D/H ratios and water contents in fresh submarine basalts from the Mid-Atlantic Ridge, the East Pacific Rise, and Hawaii indicate that the primary D/H ratios of many submarine lavas have been altered by processes including (1) outgassing, (2) addition of seawater at magmatic temperature, and (3) low-temperature hydration of glass. Decreases in ??D and H2O+ from exteriors to interiors of pillows are explained by outgassing of water whereas inverse relations between ??D and H2O+ in basalts from the Galapagos Rise and the FAMOUS Area are attributed to outgassing of CH4 and H2. A good correlation between ??D values and H2O is observed in a suite of submarine tholeiites dredged from the Kilauea East Rift Zone where seawater (added directly to the magma), affected only the isotopic compositions of hydrogen and argon. Analyses of some glassy rims indicate that the outer millimeter of the glass can undergo lowtemperature hydration by hydroxyl groups having ??D values as low as -100. ??D values vary with H2O contents of subaerial transitional basalts from Molokai, Hawaii, and subaerial alkali basalts from the Society Islands, indicating that the primary ??D values were similar to those of submarine lavas. Extrapolations to possible unaltered ??D values and H2O contents indicate that the primary ??D values of most thoteiite and alkali basalts are near -80 ?? 5: the weight percentages of water are variable, 0.15-0.35 for MOR tholeiites, about 0.25 for Hawaiian tholeiites, and up to 1.1 for alkali basalts. The primary ??D values of -80 for most basalts are comparable to those measured for deep-seated phlogopites. These results indicate that hydrogen, in marked contrast to other elements such as Sr, Nd, Pb, and O, has a uniform isotopic composition in the mantle. This uniformity is best explained by the presence of a homogeneous reservoir of hydrogen that has existed in the mantle since the very early history of the Earth. ?? 1984.

  11. Coatings on Atacama Desert Basalt: A Possible Analog for Coatings on Gusev Plains Basalt

    NASA Technical Reports Server (NTRS)

    Sutter, B.; Golden, D. C.; Amundson, R.; Chong-Diaz, G.; Ming, D. W.

    2007-01-01

    Surface coatings on Gusev Plains basalt have been observed and may contain hematite and nanophase Fe-oxides along with enrichments in P, S, Cl, and K relative to the underlying rock. The Gusev coatings may be derived from the dissolution of adhering soil and/or parent rock along with the addition of S and Cl from outside sources. Transient water for dissolution could be sourced from melting snow during periods of high obliquity, acid fog, and/or ground water (Haskin et al., 2005). Coatings on basalt in the hyper-arid (less than 2mm y(sup -1)) Atacama Desert may assist in understanding the chemistry, mineralogy and formation mechanisms of the Gusev basalt coatings. The Atacama Desert climate is proposed to be analogous to a paleo-Mars climate that was characterized by limited aqueous activity when the Gusev coatings could have formed. The objectives of this work are to (i) determine the chemical nature and extent of surface coatings on Atacama Desert basalt, and (ii) assess coating formation mechanisms in the Atacama Desert. Preliminary backscattered electron imaging of Atacama basalt thin-sections indicated that the coatings are as thick as 20 m. The boundary between the coating and the basalt labradorite, ilmenite, and augite grains was abrupt indicating that the basalt minerals underwent no chemical dissolution. The Atacama coatings have been added to the basalt instead of being derived from basalt chemical weathering. Semi-quantitative energy dispersive spectroscopy shows the coatings to be chemically homogeneous. The coating is depleted in Ca (0.9 wt% CaO) and enriched in K (1.3 wt.% K2O) and Si (69.1 wt.% SiO2) relative to the augite and labradorite grains. A dust source enriched in Si (e.g., poorly crystalline silica) and K and depleted in Ca appears to have been added to the basalt surface. Unlike the Gusev coatings, no P, S, and Cl enrichment was observed. However, Fe (3.2 wt.% FeO) was present in the Atacama coatings suggesting the present of Fe

  12. Compositional controls on spinel clouding and garnet formation in plagioclase of olivine metagabbros, Adirondack Mountains, New York

    USGS Publications Warehouse

    McLelland, J.M.; Whitney, P.R.

    1980-01-01

    Olivine metagabbros from the Adirondacks usually contain both clear and spinel-clouded plagioclase, as well as garnet. The latter occurs primarily as the outer rim of coronas surrounding olivine and pyroxene, and less commonly as lamellae or isolated grains within plagioclase. The formation of garnet and metamorphic spinel is dependent upon the anorthite content of the plagioclase. Plagioclase more sodic than An38??2 does not exhibit spinel clouding, and garnet rarely occurs in contact with plagioclase more albitic than An36??4. As a result of these compositional controls, the distribution of spinel and garnet mimics and visually enhances original igneous zoning in plagioclase. Most features of the arrangement of clear (unclouded) plagioclase, including the shells or moats of clear plagioclase which frequently occur inside the garnet rims of coronas, can be explained on the basis of igneous zoning. The form and distribution of the clear zones may also be affected by the metamorphic reactions which have produced the coronas, and by redistribution of plagioclase in response to local volume changes during metamorphism. ?? 1980 Springer-Verlag.

  13. Origin of biotite-hornblende-garnet coronas between oxides and plagioclase in olivine metagabbros, Adirondack region, New York

    USGS Publications Warehouse

    Whitney, P.R.; McLelland, J.M.

    1982-01-01

    Complex multivariant reactions involving Fe-Ti oxide minerals, plagioclase and olivine have produced coronas of biotite, hornblende and garnet between ilmenite and plagioclase in Adirondack olivine metagabbros. Both the biotite (6-10% TiO2) and the hornblende (3-6% TiO2) are exceptionally Titanium-rich. The garnet is nearly identical in composition to the garnet in coronas around olivine in the same rocks. The coronas form in two stages: (a) Plagioclase+Fe-Ti Oxides+Olivine+water =Hornblende+Spinel+Orthopyroxene??Biotite +more-sodic Plagioclase (b) Hornblende+Orthopyroxene??Spinel+Plagioclase =Garnet+Clinopyroxene+more-sodic Plagioclase The Orthopyroxene and part of the clinopyroxene form adjacent to olivine. Both reactions are linked by exchange of Mg2+ and Fe2+ with the reactions forming pyroxene and garnet coronas around olivine in the same rocks. The reactions occur under granulite fades metamorphic conditions, either during isobaric cooling or with increasing pressure at high temperature. ?? 1983 Springer-Verlag.

  14. The Carthage-Colton mylonite zone (Adirondack Mountains, New York): The site of a cryptic suture in the Grenville Orogen

    SciTech Connect

    Mezger, K.; Pluijm, B.A. van der; Essene, E.J.; Halliday, A.N. )

    1992-09-01

    U-Pb ages were determined on metamorphic sphenes and monazites from the Late Proterozoic Adirondack Highlands and Lowlands in the vicinity of the Carthage-Colton mylonite zone. Monazites were extracted from metapelites, and sphenes were separated from marbles, calc-silicate gneisses, and granite gneisses in order to determine the timing and the duration of metamorphism as well as the cooling histories for rocks on either side of the mylonite zone. Monazite ages from the Lowlands range from 1,171-1,137 Ma; sphene ages in the Lowlands range from 1,156-1,103 Ma, those from the Highlands immediately to the east of the mylonite zone range from 1,050-982 ma. The ages indicate that the last high-grade metamorphism in the Highlands is ca. 100 m.y. younger than in the Lowlands and that both terranes had separate cooling histories at least until ca. 1,000 Ma. Sphenes from within the Carthage-Colton mylonite zone yield ages of about 1,098 Ma, which are distinct from sphene ages on either side of the shear zone. The mineral ages, structures, and metamorphic histories suggests that the Carthage-Colton mylonite zone is a fundamental tectonic boundary within the Proterozoic Grenville Orogen of North America.

  15. Mercury cycling in litter and soil in different forest types in the Adirondack region, New York, USA.

    PubMed

    Demers, Jason D; Driscoll, Charles T; Fahey, Timothy J; Yavitti, Joseph B

    2007-07-01

    The fate of mercury in decomposing leaf litter and soil is key to understanding the biogeochemistry of mercury in forested ecosystems. We quantified mercury dynamics in decomposing leaf litter and measured fluxes and pools of mercury in litterfall, throughfall, and soil in two forest types of the Adirondack region, New York, USA. The mean content of total mercury in leaf litter increased to 134% of its original mass during two years of decomposition. The accumulation pattern was seasonal, with significant increases in mercury mass during the growing season (+4.9% per month). Litterfall dominated mercury fluxes into the soil in the deciduous forest, whereas throughfall dominated fluxes into the coniferous forest. The increase in mercury mass in decomposing deciduous litter during the growing season was greater than could be accounted for by throughfall inputs during the growing season (P < 0.05), suggesting translocation of mercury from the soil to the decomposing deciduous litter. This internal recycling mechanism concentrates mercury in the organic horizons and retards transport through the soil, thereby increasing the residence time of mercury in the forest floor. A mass balance assessment suggests that the ultimate fate of mercury in the landscape depends upon forest type and associated differences in the delivery and incorporation of mercury into the soil. Our results show that incorporation of mercury into decaying leaf litter increases its residence time in the landscape and may further delay the recovery of surface waters, fish, and associated biota following control of mercury emissions to the atmosphere.

  16. H 2O in basalt and basaltic andesite glass inclusions from four subduction-related volcanoes

    NASA Astrophysics Data System (ADS)

    Sisson, T. W.; Layne, G. D.

    1993-06-01

    Total dissolved H 2O and major element abundances were measured in basalt and basaltic andesite glass inclusions in olivine phenocrysts from Quaternary eruptions of four subduction-related volcanoes to test the hypothesis that low-MgO high-alumina basalts contain high H 2O at depth [1] and to reveal any petrogenetically significant correlations between arc basalt compositions and H 2O contents. Total dissolved H 2O (combined molecular H 2O and OH groups) measured by ion microprobe in mafic glass inclusions from the 1974 eruption of Fuego, Guatemala, reaches 6.2 wt.%. Dissolved H 2O contents decrease in more evolved Fuego glasses. Correlations of H 2O with MgO, Na 2O, K 2O, S and Cl indicate that aqueous fluid exsolution during magma ascent forced crystallization and differentiation of residual liquids. Low-K 2O magnesian high-alumina basalt glass inclusions from the 3 ka eruption of Black Crater (Medicine Lake volcano, California) have low H 2O contents, near 0.2 wt.%, which are consistent with the MORB-like character of these and other primitive lavas of the Medicine Lake region. Basalt and basaltic andesite glass inclusions from Copco Cone and Goosenest volcano on the Cascade volcanic front north of Mt. Shasta have H 2O contents of up to 3.3 wt.%. The range of H 2O contents in Cascade mafic magmas is too large to have resulted solely from enrichment by crystallization and indicates the participation of an H 2O-rich component in magma generation or crustal-level modification. Whereas fluid-absent melting of amphibole-bearing peridotite can account for the H 2O in most mafic arc liquids, the very high H 2O/alkali ratios of the 1974 Fuego eruptives suggest that an aqueous fluid was involved in the generation of Fuego basalts.

  17. Sulfur isotope homogeneity of lunar mare basalts

    NASA Astrophysics Data System (ADS)

    Wing, Boswell A.; Farquhar, James

    2015-12-01

    We present a new set of high precision measurements of relative 33S/32S, 34S/32S, and 36S/32S values in lunar mare basalts. The measurements are referenced to the Vienna-Canyon Diablo Troilite (V-CDT) scale, on which the international reference material, IAEA-S-1, is characterized by δ33S = -0.061‰, δ34S ≡ -0.3‰ and δ36S = -1.27‰. The present dataset confirms that lunar mare basalts are characterized by a remarkable degree of sulfur isotopic homogeneity, with most new and published SF6-based sulfur isotope measurements consistent with a single mass-dependent mean isotopic composition of δ34S = 0.58 ± 0.05‰, Δ33S = 0.008 ± 0.006‰, and Δ36S = 0.2 ± 0.2‰, relative to V-CDT, where the uncertainties are quoted as 99% confidence intervals on the mean. This homogeneity allows identification of a single sample (12022, 281) with an apparent 33S enrichment, possibly reflecting cosmic-ray-induced spallation reactions. It also reveals that some mare basalts have slightly lower δ34S values than the population mean, which is consistent with sulfur loss from a reduced basaltic melt prior to eruption at the lunar surface. Both the sulfur isotope homogeneity of the lunar mare basalts and the predicted sensitivity of sulfur isotopes to vaporization-driven fractionation suggest that less than ≈1-10% of lunar sulfur was lost after a potential moon-forming impact event.

  18. Two new basaltic objects in the Outer Main Belt

    NASA Astrophysics Data System (ADS)

    Duffard, R.; Roig, F.; Gil-Hutton, R.; Moskovitz, N. A.

    2007-08-01

    in the visible range of (7472) Kumakiri and (10537) 1991 RY16 have been obtained by us on November 14th, 2006, using the Calar Alto Faint Object Spectrograph (CAFOS) at the 2.2m telescope in Calar Alto Observatory, Spain. The reflectance spectra of the two bodies seem to correspond to that of a V-type asteroid. However, the presence of a shallow absorption band around 0.6 microns, which has never been observed before in other V-type spectra, precludes these objects from being classified by any existing taxonomic system [4]. It is worth noting that the observed band is real and its presence in the spectrum of (10537) has been confirmed independently by other observers [13]. Therefore, we do not know whether we have discovered two basaltic asteroids with a very particular and previously unseen mineralogical composition or two objects of non basaltic nature that have to be included in a totally new taxonomic class. To unambiguously determine whether our targets have basaltic surfaces, we will observe in the near-infrared range. References: [1] Binzel, R., Rivkin, A., Stuart, S., et al. 2004, Icarus, 170, 259 [2] Binzel, R.P., Masi, G., Foglia, S., 2006, American Astronomical Society, DPS meeting #38, #71.06. [3] Burbine, T. H.; Buchanan, P. C.; Binzel, R. P.; Bus, S. J.; Hiroi, T.; Hinrichs, J. L.; Meibom, A.; McCoy, T. J., 2001. Meteoritics & Planetary Science 36, 761-781. [4] Bus, S. J., 1999, PhD Thesis, Massachusetts Institute of Technology. [5] Cruikshank, D. P.; Tholen, D. J.; Bell, J. F.; Hartmann,W. K.; Brown, R. H., 1991. Icarus 89, 1-13. [6] Duffard, R.; de Leon, J.; Licandro, J.; Lazzaro, D.; Serra-Ricart, M., 2006. Astronomy and Astrophysics, 456, 775-781. [7] Ivezic et al. 2001. Astronomical Journal 122, 2749-2784. [8] Florczak, M., Lazzaro, D., and Duffard, R. 2002. Icarus 159, 178. [9] Juric et al. 2002. Astronomical Journal 124, 1776-1787. [10] Lazzaro, D., Michtchenko, T.A., Carvano, J.M., Binzel, R.P., Bus, S.J., Burbine, T.H., Mothe-Diniz, T

  19. Additive Construction using Basalt Regolith Fines

    NASA Technical Reports Server (NTRS)

    Mueller, Robert P.; Sibille, Laurent; Hintze, Paul E.; Lippitt, Thomas C.; Mantovani, James G.; Nugent, Matthew W.; Townsend, Ivan I.

    2014-01-01

    Planetary surfaces are often covered in regolith (crushed rock), whose geologic origin is largely basalt. The lunar surface is made of small-particulate regolith and areas of boulders located in the vicinity of craters. Regolith composition also varies with location, reflecting the local bedrock geology and the nature and efficiency of the micrometeorite-impact processes. In the lowland mare areas (suitable for habitation), the regolith is composed of small granules (20 - 100 microns average size) of mare basalt and volcanic glass. Impacting micrometeorites may cause local melting, and the formation of larger glassy particles, and this regolith may contain 10-80% glass. Studies of lunar regolith are traditionally conducted with lunar regolith simulant (reconstructed soil with compositions patterned after the lunar samples returned by Apollo). The NASA Kennedy Space Center (KSC) Granular Mechanics & Regolith Operations (GMRO) lab has identified a low fidelity but economical geo-technical simulant designated as Black Point-1 (BP-1). It was found at the site of the Arizona Desert Research and Technology Studies (RATS) analog field test site at the Black Point lava flow in adjacent basalt quarry spoil mounds. This paper summarizes activities at KSC regarding the utilization of BP-1 basalt regolith and comparative work with lunar basalt simulant JSC-1A as a building material for robotic additive construction of large structures. In an effort to reduce the import or in-situ fabrication of binder additives, we focused this work on in-situ processing of regolith for construction in a single-step process after its excavation. High-temperature melting of regolith involves techniques used in glassmaking and casting (with melts of lower density and higher viscosity than those of metals), producing basaltic glass with high durability and low abrasive wear. Most Lunar simulants melt at temperatures above 1100 C, although melt processing of terrestrial regolith at 1500 C is not

  20. Geochemistry of apollo 15 basalt 15555 and soil 15531.

    PubMed

    Schnetzler, C C; Philpotts, J A; Nava, D F; Schuhmann, S; Thomas, H H

    1972-01-28

    Major and trace element concentrations have been determined by atomic absorption spectrophotometry, colorimetry, and isotope dilution in Apollo 15 mare basalt 15555 from the Hadley Rille area; trace element concentrations have also been determined in plagioclase and pyroxene separates from basalt 15555 and in soil 15531 from the same area. Basalt 15555 most closely resembles in composition the Apollo 12 olivine-rich basalts. The concentrations of lithium, potassium, rubidium, barium, rare-earth elements, and zirconium in basalt 15555 are the lowest, and the negative europium anomaly is the smallest, reported for lunar basalts; this basalt might be the least differentiated material yet returned from the moon. Crystallization and removal of about 6 percent of plagioclase similar to that contained in the basalt would account for the observed europium anomaly; if plagioclase is not on the liquidus of this basalt, a multistage origin is indicated. Mineral data indicate that plagioclase and pyroxene approached quasi-equilibrium. Most of the chemical differences between basalt 15555 and soil 15531 would be accounted for if the soil were a mixture of 88 percent basalt, 6 percent KREEP (a component, identified in other Apollo soils, rich in potassium, rare-earth elements, and phosphorus) and 6 percent plagioclase (anorthosite?). PMID:17731364

  1. Geochemistry of apollo 15 basalt 15555 and soil 15531.

    PubMed

    Schnetzler, C C; Philpotts, J A; Nava, D F; Schuhmann, S; Thomas, H H

    1972-01-28

    Major and trace element concentrations have been determined by atomic absorption spectrophotometry, colorimetry, and isotope dilution in Apollo 15 mare basalt 15555 from the Hadley Rille area; trace element concentrations have also been determined in plagioclase and pyroxene separates from basalt 15555 and in soil 15531 from the same area. Basalt 15555 most closely resembles in composition the Apollo 12 olivine-rich basalts. The concentrations of lithium, potassium, rubidium, barium, rare-earth elements, and zirconium in basalt 15555 are the lowest, and the negative europium anomaly is the smallest, reported for lunar basalts; this basalt might be the least differentiated material yet returned from the moon. Crystallization and removal of about 6 percent of plagioclase similar to that contained in the basalt would account for the observed europium anomaly; if plagioclase is not on the liquidus of this basalt, a multistage origin is indicated. Mineral data indicate that plagioclase and pyroxene approached quasi-equilibrium. Most of the chemical differences between basalt 15555 and soil 15531 would be accounted for if the soil were a mixture of 88 percent basalt, 6 percent KREEP (a component, identified in other Apollo soils, rich in potassium, rare-earth elements, and phosphorus) and 6 percent plagioclase (anorthosite?).

  2. Biogenic Mn-Oxides in Subseafloor Basalts

    PubMed Central

    Ivarsson, Magnus; Broman, Curt; Gustafsson, Håkan; Holm, Nils G.

    2015-01-01

    The deep biosphere of the subseafloor basalts is recognized as a major scientific frontier in disciplines like biology, geology, and oceanography. Recently, the presence of fungi in these environments has involved a change of view regarding diversity and ecology. Here, we describe fossilized fungal communities in vugs in subseafloor basalts from a depth of 936.65 metres below seafloor at the Detroit Seamount, Pacific Ocean. These fungal communities are closely associated with botryoidal Mn oxides composed of todorokite. Analyses of the Mn oxides by Electron Paramagnetic Resonance spectroscopy (EPR) indicate a biogenic signature. We suggest, based on mineralogical, morphological and EPR data, a biological origin of the botryoidal Mn oxides. Our results show that fungi are involved in Mn cycling at great depths in the seafloor and we introduce EPR as a means to easily identify biogenic Mn oxides in these environments. PMID:26107948

  3. Lead isotope studies of mare basalt 70017

    NASA Technical Reports Server (NTRS)

    Mattinson, J. M.; Tilton, G. R.; Todt, W.; Chen, J. H.

    1977-01-01

    Uranium, thorium, and isotopic lead data for components of basalt 70017 are reported, and it is found that the whole rock, pyroxene, and ilmenite points in a concordia diagram plot along a chord intersecting the curve at 3.7 and 4.33 eons. The plagioclase data do not seem to lie on this line. The data for 70017 appear to plot along a distinctly different chord in a concordia diagram than do the data for 75055 and 75035, two other Apollo 17 mare basalts. The lead data are in accord with Sm-Nd results. A 3.7 eon crystallization age for 70017 would be consistent with the same kind of parentless lead that is indicated by previous studies of soils and soil breccias from stations at Taurus-Littrow. The Th/U ratio in ilmenite is 2.2, and the concentrations of these two elements are approximately twice those in pyroxene.

  4. Biogenic Mn-Oxides in Subseafloor Basalts.

    PubMed

    Ivarsson, Magnus; Broman, Curt; Gustafsson, Håkan; Holm, Nils G

    2015-01-01

    The deep biosphere of the subseafloor basalts is recognized as a major scientific frontier in disciplines like biology, geology, and oceanography. Recently, the presence of fungi in these environments has involved a change of view regarding diversity and ecology. Here, we describe fossilized fungal communities in vugs in subseafloor basalts from a depth of 936.65 metres below seafloor at the Detroit Seamount, Pacific Ocean. These fungal communities are closely associated with botryoidal Mn oxides composed of todorokite. Analyses of the Mn oxides by Electron Paramagnetic Resonance spectroscopy (EPR) indicate a biogenic signature. We suggest, based on mineralogical, morphological and EPR data, a biological origin of the botryoidal Mn oxides. Our results show that fungi are involved in Mn cycling at great depths in the seafloor and we introduce EPR as a means to easily identify biogenic Mn oxides in these environments. PMID:26107948

  5. Northwest Africa 5298: A Basaltic Shergottite

    NASA Technical Reports Server (NTRS)

    Hui, Hejiu; Peslier, Anne; Lapen, Thomas J.; Brandon, Alan; Shafer, John

    2009-01-01

    NWA 5298 is a single 445 g meteorite found near Bir Gandouz, Morocco in March 2008 [1]. This rock has a brown exterior weathered surface instead of a fusion crust and the interior is composed of green mineral grains with interstitial dark patches containing small vesicles and shock melts [1]. This meteorite is classified as a basaltic shergottite [2]. A petrologic study of this Martian meteorite is being carried out with electron microprobe analysis and soon trace element analyses by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Oxygen fugacity is calculated from Fe-Ti oxides pairs in the sample. The data from this study constrains the petrogenesis of basaltic shergottites.

  6. Total nitrogen content of deep sea basalts

    NASA Technical Reports Server (NTRS)

    Norris, T. L.; Schaeffer, O. A.

    1982-01-01

    An estimate of the total nitrogen content of the earth's mantle, aimed at furnishing a further constraint for earth atmosphere origin and evolution models, was attempted through thermal neutron activation analysis via N-14(n,p)C-14 for the case of deep sea basalt glasses from the East Pacific Rise, the Mid-Atlantic Rift, and the Juan de Fuca Ridge. The increased nitrogen abundance of matrix material from the same samples as the glasses may be due to the incorporation of chemically-bound nitrogen from sea water, rather than dissolved molecular nitrogen. A discussion is presented of factors affecting observed basalt nitrogen content and its interpretation in terms of mantle nitrogen abundance. A 2 ppm N lower limit is estimated for the mantle.

  7. Nanoparticulate mineral matter from basalt dust wastes.

    PubMed

    Dalmora, Adilson C; Ramos, Claudete G; Querol, Xavier; Kautzmann, Rubens M; Oliveira, Marcos L S; Taffarel, Silvio R; Moreno, Teresa; Silva, Luis F O

    2016-02-01

    Ultra-fine and nano-particles derived from basalt dust wastes (BDW) during "stonemeal" soil fertilizer application have been the subject of some concern recently around the world for their possible adverse effects on human health and environmental pollution. Samples of BDW utilized were obtained from companies in the mining district of Nova Prata in southern Brazil for chemical characterization and nano-mineralogy investigation, using an integrated application of advanced characterization techniques such as X-ray diffraction (XRD), High Resolution-Transmission Electron microscopy (HR-TEM)/(Energy Dispersive Spectroscopy) EDS/(selected-area diffraction pattern) SAED, Field Emission-Scanning Electron Microscopy (FE-SEM)/EDS and granulometric distribution analysis. The investigation has revealed that BDW materials are dominated by SiO2, Al2O3 and Fe2O3, with a complex micromineralogy including alkali feldspar, augite, barite, labradorite, hematite, heulandrite, gypsum, kaolinite, quartz, and smectite. In addition we have identified a number of trace metals such as Cd, Cu, Cr, Zn that are preferentially concentrated into the finer, inhalable, dust fraction and could so present a health hazard in the urban areas around the basalt mining zone. The implication of this observation is that use of these nanometric-sized particulates as soil fertilizer may present different health challenges to those of conventional fertilizers, inviting future work regarding the relative toxicities of these materials. Our investigation on the particle size distribution, nano-particle mineralogy and chemical composition in typical BDW samples highlights the need to develop cleaning procedures to minimise exposure to these natural fertilizing basalt dust wastes and is thus of direct relevance to both the industrial sector of basalt mining and to agriculture in the region.

  8. Nanoparticulate mineral matter from basalt dust wastes.

    PubMed

    Dalmora, Adilson C; Ramos, Claudete G; Querol, Xavier; Kautzmann, Rubens M; Oliveira, Marcos L S; Taffarel, Silvio R; Moreno, Teresa; Silva, Luis F O

    2016-02-01

    Ultra-fine and nano-particles derived from basalt dust wastes (BDW) during "stonemeal" soil fertilizer application have been the subject of some concern recently around the world for their possible adverse effects on human health and environmental pollution. Samples of BDW utilized were obtained from companies in the mining district of Nova Prata in southern Brazil for chemical characterization and nano-mineralogy investigation, using an integrated application of advanced characterization techniques such as X-ray diffraction (XRD), High Resolution-Transmission Electron microscopy (HR-TEM)/(Energy Dispersive Spectroscopy) EDS/(selected-area diffraction pattern) SAED, Field Emission-Scanning Electron Microscopy (FE-SEM)/EDS and granulometric distribution analysis. The investigation has revealed that BDW materials are dominated by SiO2, Al2O3 and Fe2O3, with a complex micromineralogy including alkali feldspar, augite, barite, labradorite, hematite, heulandrite, gypsum, kaolinite, quartz, and smectite. In addition we have identified a number of trace metals such as Cd, Cu, Cr, Zn that are preferentially concentrated into the finer, inhalable, dust fraction and could so present a health hazard in the urban areas around the basalt mining zone. The implication of this observation is that use of these nanometric-sized particulates as soil fertilizer may present different health challenges to those of conventional fertilizers, inviting future work regarding the relative toxicities of these materials. Our investigation on the particle size distribution, nano-particle mineralogy and chemical composition in typical BDW samples highlights the need to develop cleaning procedures to minimise exposure to these natural fertilizing basalt dust wastes and is thus of direct relevance to both the industrial sector of basalt mining and to agriculture in the region. PMID:26551199

  9. Pb isotopic heterogeneity in basaltic phenocrysts

    SciTech Connect

    Bryce, Julia G.; DePaolo, Donald J.

    2002-06-01

    The Pb isotopic compositions of phenocrystic phases in young basaltic lavas have been investigated using the Getty-DePaolo method (Getty S. J. and DePaolo D. J. [1995] Quaternary geochronology by the U-Th-Pb method. Geochim. Cosmochim. Acta 59, 3267 3272), which allows for the resolution of small isotopic differences. Phenocryst, matrix, and whole rock analyses were made on samples from the 17 Myr-old Imnaha basalts of the Columbia River Group, a zero-age MORB from the Mid-Atlantic Ridge, and a ca. 260 kyr-old tholeiite from Mount Etna. Plagioclase feldspar phenocrysts have low-(U, Th)/Pb, and in each sample the plagioclase has significantly lower 206Pb/207Pb and 208Pb/207Pb values than whole rock, matrix, and magnetite-rich separates. The Pb isotopic contrast between plagioclase and matrix/whole rock is found in three samples with varying grain sizes (0.5 2 cm for the Imnaha basalt and MORB and <1 mm for the Etna sample) from different tectonic settings, suggesting that these results are not unique. The isotopic contrasts are only slightly smaller in magnitude than the variations exhibited by whole rock samples from the region. The Imnaha basalts also have Sr isotopic heterogeneity evident only in plagioclase phenocrysts, but the MORB and Etna lavas do not. The isotopic heterogeneities reflect magma mixing, and indicate that isotopically diverse magmas were mixed together just prior to eruption. The results reinforce indications from melt inclusion studies that magma source region isotopic heterogeneities have large amplitudes at short length scales, and that the isotopic variations imparted to the magmas are not entirely homogenized during segregation and transport processes.

  10. How thick are lunar mare basalts

    NASA Technical Reports Server (NTRS)

    Hoerz, F.

    1978-01-01

    It is argued that De Hon's estimates of the thickness of lunar mare basalts, made by analyzing 'ghost' craters on mare surfaces, were inflated as the result of the crater morphometric data of Pike (1977) to reconstruct rim heights of degraded craters. Crater rim heights of 82 randomly selected highland craters of various states of degradation were determined, and median rim height was compared to that of corresponding fresh impact structures. Results indicate that the thickness estimates of De Hon may be reduced by a factor of 2, and that the total volume of mare basalt produced throughout lunar history could be as little as 1-2 million cubic kilometers. A survey of geochemical and petrographic evidence indicates that lateral transport of regolith components over distances of much greater than 10 km is relatively inefficient; it is suggested that vertical mixing of a highland substrate underlying the basaltic fill may have had a primordial role in generating the observed mare width distributions and high concentrations of exotic components in intrabasin regoliths.

  11. Voluminous granitic magmas from common basaltic sources

    USGS Publications Warehouse

    Sisson, T.W.; Ratajeski, K.; Hankins, W.B.; Glazner, A.F.

    2005-01-01

    Granitic-rhyolitic liquids were produced experimentally from moderately hydrous (1.7-2.3 wt% H2O) medium-to-high K basaltic compositions at 700 MPa and f O2 controlled from Ni-NiO -1.3 to +4. Amount and composition of evolved liquids and coexisting mineral assemblages vary with fO2 and temperature, with melt being more evolved at higher fO2s, where coexisting mineral assemblages are more plagioclase- and Fe-Ti oxide-rich and amphibole-poor. At fO2 of Ni-NiO +1, typical for many silicic magmas, the samples produce 12-25 wt% granitic-rhyolitic liquid, amounts varying with bulk composition. Medium-to-high K basalts are common in subduction-related magmatic arcs, and near-solidus true granite or rhyolite liquids can form widely, and in geologically significant quantities, by advanced crystallization-differentiation or by low-degree partial remelting of mantle-derived basaltic sources. Previously differentiated or weathered materials may be involved in generating specific felsic magmas, but are not required for such magmas to be voluminous or to have the K-rich granitic compositions typical of the upper continental crust. ?? Springer-Verlag 2005.

  12. Lunar sample studies. [breccias basalts, and anorthosites

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Lunar samples discussed and the nature of their analyses are: (1) an Apollo 15 breccia which is thoroughly analyzed as to the nature of the mature regolith from which it derived and the time and nature of the lithification process, (2) two Apollo 11 and one Apollo 12 basalts analyzed in terms of chemistry, Cross-Iddings-Pirsson-Washington norms, mineralogy, and petrography, (3) eight Apollo 17 mare basalts, also analyzed in terms of chemistry, Cross-Iddings-Pirsson-Washington norms, mineralogy, and petrography. The first seven are shown to be chemically similar although of two main textural groups; the eighth is seen to be distinct in both chemistry and mineralogy, (4) a troctolitic clast from a Fra Mauro breccia, analyzed and contrasted with other high-temperature lunar mineral assemblages. Two basaltic clasts from the same breccia are shown to have affinities with rock 14053, and (5) the uranium-thorium-lead systematics of three Apollo 16 samples are determined; serious terrestrial-lead contamination of the first two samples is attributed to bandsaw cutting in the lunar curatorial facility.

  13. Middle Proterozoic emplacement and deformation of metanorthosite and related rocks in the northeastern Marcy massif, Adirondack Mountains, New York

    SciTech Connect

    Fakundiny, R.H. ); Muller, P.D. . Dept. of Earth Sciences)

    1993-03-01

    Geologic mapping in the Elizabethtown and Mount Marcy 15 foot quadrangles in the northeastern Adirondack Mountains has shown that Middle Proterozoic anorthosite suite rocks of the Marcy massif were intruded in at least two temporally distinguishable episodes separated by a period of localized ductile shearing. Strain was concentrated in a 100 m to > 1 km thick zone consisting mainly of metamorphosed gabbroic anorthosite, ferrodiorite, and ferrosyenite gneiss with subordinate granite gneiss, calc-silicate gneiss, amphibolite, and marble. This zone of flat to steeply-dipping layered gneisses, designated the Elizabethtown ductile deformation zone (EDDZ) for exposures along Rt 9 south of Elizabethtown, appears to extend from Lake Champlain on the east to at least Lake Placid on the west. Its upper boundary is most clearly evident where it occurs in olivine metagabbro bodies of Jay and Iron Mountain. Massive metagabbro is sheared and recrystallized into amphibolite gneiss. The lower boundary of the zone is more difficult to map, but commonly lies within contaminated metamorphosed gabbroic anorthosite and ferrodiorite gneiss that characterize the margins of the massif in the area. Rocks of the EDDZ display pervasive mesoscopic S and LS fabrics, but exhibit totally recrystallized microtextures. Kinematic indicators such as winged porphyroclasts and S-C fabrics are sporadically developed and provide a regionally ambiguous sense of shear. The authors favor a regional extension origin for the fabrics. Mineral assemblages defining the EDDZ fabrics are consistent with granulite facies conditions during shear-zone development and suggest a lower crustal position. Mapping suggests that the younger anorthosite intrusions were mainly domical and generated a chaotic contact zone typified by block structure and dikes of ferrodiorite, ferromonzonite, and ferrosyenite.

  14. A Discussion of the Area Method for Hydrograph Separation, Case Study in the Adirondacks, New York State (USA)

    NASA Astrophysics Data System (ADS)

    Jutras, B. A.; Romanowicz, E. A.

    2004-05-01

    Many hydrology texts refer to the area method for estimating the end of surface runoff after the peak discharge in storm hydrographs. This method is used to aid in separating base flow from surface runoff in stream flow during storm events. The area method assumes that the duration of surface runoff after peak discharge is a function of the area of the drainage basin. The duration of surface runoff in days is equal to the area of the drainage basin (sq. miles) raised to the 0.2 power. References to the type of watersheds for which this relationship is true are vague. The method is assumed to be applicable for large watersheds. In our poster we report the results of a study to test the validity of this relationship. Five nested watersheds (2.1 to 19.2 sq. km) were selected in the Adirondack Mountains near Jay, NY (USA). Stage was monitored every 15-minutes using a 1500 mm capacitance rod at the mouth of each watershed. The capacitance rods were installed in stilling wells adjacent to the natural channel. Select storm hydrographs were picked for hydrograph separation during the fall 2003. Preliminary results indicate that the area method is a reasonable predictor of the duration of runoff in these watersheds. Our original intent in pursuing this investigation was to determine how changes in the relationship between drainage area and runoff duration could be attributed to different properties of the watershed. We hypothesized that we would observe a different relationship. The difference could be attributed to differences in our watersheds and the ordinal watersheds from which the relationship was derived. However, in investigating the literature we could find no references that give any information on the original watersheds. This would appear to be a serious handicap for an often-cited method.

  15. Identification of Mineral Phases on Basalt Surfaces by Imaging SIMS.

    PubMed

    Ingram, J C; Groenewold, G S; Olson, J E; Gianotto, A K; McCurry, M O

    1999-05-01

    A method for the identification of mineral phases on basalt surfaces utilizing secondary ion mass spectrometry (SIMS) with imaging capability is described. The goal of this work is to establish the use of imaging SIMS for characterization of the surface of basalt. The basalt surfaces were examined by interrogating the intact basalt (heterogeneous mix of mineral phases) as well as mineral phases that have been separated from the basalt samples. Mineral separates from the basalt were used to establish reference spectra for the specific mineral phases. Electron microprobe and X-ray photoelectron spectroscopy were used as supplemental techniques for providing additional characterization of the basalt. Mineral phases that make up the composition of the basalt were identified from single-ion images which were statistically grouped. The statistical grouping is performed by utilizing a program that employs a generalized learning vector quantization technique. Identification of the mineral phases on the basalt surface is achieved by comparing the mass spectra from the statistically grouped regions of the basalt to the mass spectral results from the mineral separates. The results of this work illustrate the potential for using imaging SIMS to study adsorption chemistry at the top surface of heterogeneous mineral samples.

  16. Isotopic and REE studies of lunar basalt 12038 - Implications for petrogenesis of aluminous mare basalts

    NASA Technical Reports Server (NTRS)

    Nyquist, L. E.; Wooden, J. L.; Shih, C.-Y.; Wiesmann, H.; Bansal, B. M.

    1981-01-01

    Sr, Nd, and Sm isotopic studies of lunar basalt 12038, one of the so-called aluminous mare basalts, are reported. The evolution of the Sr and Nd isotopic compositions and the rare earth element (REE) abundances is successfully modeled within the framework of the model developed by Nyquist et al. (1977, 1979) for Apollo 12 olivine-pigeonite and ilmenite basalts. It is pointed out that the isotopic and trace element features of 12038 can by modeled as produced by partial melting of a cumulate mantle source which crystallized from a lunar magma ocean with a chondrite-normalized REE pattern of constant negative slope. Chondrite-normalized La/Yb is equal to 2.2 for this hypothetical magma ocean pattern.

  17. Making rhyolite in a basalt crucible

    NASA Astrophysics Data System (ADS)

    Eichelberger, John

    2016-04-01

    Iceland has long attracted the attention of those concerned with the origin of rhyolitic magmas and indeed of granitic continental crust, because it presents no alternative for such magmas other than deriving them from a basaltic source. Hydrothermally altered basalt has been identified as the progenitor. The fact that rhyolite erupts as pure liquid requires a process of melt-crustal separation that is highly efficient despite the high viscosity of rhyolite melt. Volcanoes in Iceland are foci of basaltic magma injection along the divergent plate boundary. Repeated injection produces remelting, digestion, and sometimes expulsion or lateral withdrawal of material resulting in a caldera, a "crucible" holding down-dropped and interlayered lava flows, tephras, and injected sills. Once melting of this charge begins, a great deal of heat is absorbed in the phase change. Just 1% change in crystallinity per degree gives a melt-present body an effective heat capacity >5 times the subsolidus case. Temperature is thus buffered at the solidus and melt composition at rhyolite. Basalt inputs are episodic ("fires") so likely the resulting generation of rhyolite by melting is too. If frequent enough to offset cooling between events, rhyolite melt extractions will accumulate as a rhyolite magma reservoir rather than as discrete crystallized sills. Evidently, such magma bodies can survive multiple firings without themselves erupting, as the 1875 eruption of Askja Caldera of 0.3 km3 of rhyolite equilibrated at 2-km depth without previous leakage over a ten-millennium period and the surprise discovery of rhyolite magma at 2-km depth in Krafla suggest. Water is required for melting; otherwise melting cannot begin at a temperature lower than that of the heat source. Because the solubility of water in melt is pressure-dependent and almost zero at surface pressure, there must be a minimum depth at which basalt-induced melting can occur and a rhyolite reservoir sustained. In practice, the

  18. Identifying common patterns in diverse systems: effects of exurban development on birds of the Adirondack Park and the Greater Yellowstone Ecosystem, USA.

    PubMed

    Glennon, Michale J; Kretser, Heidi E; Hilty, Jodi A

    2015-02-01

    We examined the impacts of exurban development on bird communities in Essex County, New York and Madison County, Montana by comparing differences in abundance of songbirds between subdivisions and control sites in both regions. We hypothesized that impacts to bird communities would be greater in the relatively homogeneous, closed canopy Adirondack forest of northern New York State than they would be in the more naturally heterogeneous grasslands interspersed with trees and shrubs of the Greater Yellowstone Ecosystem. We examined birds in five functional groups expected to be responsive to exurban development, and determined relative abundance within subdivisions and control sites across these two distinct regions. We found little support for our hypothesis. For birds in the area-sensitive, low nesting, and Neotropical migrant functional groups, relative abundance was lower in subdivisions in the Adirondacks and in Madison County, while relative abundance of edge specialists was greater in subdivisions in both regions. The direction and magnitude of change in the avian communities between subdivisions and controls was similar in both regions for all guilds except microhabitat specialists. These similarities across diverse ecosystems suggest that the ecological context of the encompassing region may be less important than other elements in shaping avian communities in exurban systems. This finding suggests that humans and their specific behaviors and activities in exurban areas may be underappreciated but potentially important drivers of change in these regions.

  19. Identifying common patterns in diverse systems: effects of exurban development on birds of the Adirondack Park and the Greater Yellowstone Ecosystem, USA.

    PubMed

    Glennon, Michale J; Kretser, Heidi E; Hilty, Jodi A

    2015-02-01

    We examined the impacts of exurban development on bird communities in Essex County, New York and Madison County, Montana by comparing differences in abundance of songbirds between subdivisions and control sites in both regions. We hypothesized that impacts to bird communities would be greater in the relatively homogeneous, closed canopy Adirondack forest of northern New York State than they would be in the more naturally heterogeneous grasslands interspersed with trees and shrubs of the Greater Yellowstone Ecosystem. We examined birds in five functional groups expected to be responsive to exurban development, and determined relative abundance within subdivisions and control sites across these two distinct regions. We found little support for our hypothesis. For birds in the area-sensitive, low nesting, and Neotropical migrant functional groups, relative abundance was lower in subdivisions in the Adirondacks and in Madison County, while relative abundance of edge specialists was greater in subdivisions in both regions. The direction and magnitude of change in the avian communities between subdivisions and controls was similar in both regions for all guilds except microhabitat specialists. These similarities across diverse ecosystems suggest that the ecological context of the encompassing region may be less important than other elements in shaping avian communities in exurban systems. This finding suggests that humans and their specific behaviors and activities in exurban areas may be underappreciated but potentially important drivers of change in these regions. PMID:25421994

  20. Identifying Common Patterns in Diverse Systems: Effects of Exurban Development on Birds of the Adirondack Park and the Greater Yellowstone Ecosystem, USA

    NASA Astrophysics Data System (ADS)

    Glennon, Michale J.; Kretser, Heidi E.; Hilty, Jodi A.

    2015-02-01

    We examined the impacts of exurban development on bird communities in Essex County, New York and Madison County, Montana by comparing differences in abundance of songbirds between subdivisions and control sites in both regions. We hypothesized that impacts to bird communities would be greater in the relatively homogeneous, closed canopy Adirondack forest of northern New York State than they would be in the more naturally heterogeneous grasslands interspersed with trees and shrubs of the Greater Yellowstone Ecosystem. We examined birds in five functional groups expected to be responsive to exurban development, and determined relative abundance within subdivisions and control sites across these two distinct regions. We found little support for our hypothesis. For birds in the area-sensitive, low nesting, and Neotropical migrant functional groups, relative abundance was lower in subdivisions in the Adirondacks and in Madison County, while relative abundance of edge specialists was greater in subdivisions in both regions. The direction and magnitude of change in the avian communities between subdivisions and controls was similar in both regions for all guilds except microhabitat specialists. These similarities across diverse ecosystems suggest that the ecological context of the encompassing region may be less important than other elements in shaping avian communities in exurban systems. This finding suggests that humans and their specific behaviors and activities in exurban areas may be underappreciated but potentially important drivers of change in these regions.

  1. Hotspots, basalts, and the evolution of the mantle.

    PubMed

    Anderson, D L

    1981-07-01

    The trace element concentration patterns of continental and ocean island basalts and of mid-ocean ridge basalts are complementary. The relative sizes of the source regions for these fundamentally different basalt types can be estimated from the trace element enrichment-depletion patterns. Their combined volume occupies most of the mantle above the 670 kilometer discontinuity. The source regions separated as a result of early mantle differentiation and crystal fractionation from the resulting melt. The mid-ocean ridge basalts source evolved from an eclogite cumulate that lost its late-stage enriched fluids at various times to the shallower mantle and continental crust. The mid-ocean ridge basalts source is rich in garnet and clinopyroxene, whereas the continental and ocean island basalt source is a garnet peridotite that has experienced secondary enrichment. These relationships are consistent with the evolution of a terrestrial magma ocean. PMID:17741173

  2. Trace element composition of Luna 24 Crisium VLT basalt

    NASA Technical Reports Server (NTRS)

    Haskin, L. A.

    1978-01-01

    The origins of the individual particles analyzed from the Luna 24 core and the information they provide on the trace-element composition of Mare Crisium basalt are considered. Previous analyses of several Luna 24 soil fragments are reviewed. It is concluded that: (1) the average trace-element concentrations for 12 VLT basalt fragments are the best available estimates for bulk samples of Crisium VLT basalt; (2) there is weak evidence that the average Crisium basalt might have a small positive Eu anomaly relative to chondritic matter; (3) the soils contain components from sources other than the Crisium VLT basalt; and (4) there is no convincing information in concentrations of rare-earth elements, Co, Sc, FeO, or Na2O among the analyzed fragments to indicate more than one parent basalt.

  3. Hotspots, basalts, and the evolution of the mantle.

    PubMed

    Anderson, D L

    1981-07-01

    The trace element concentration patterns of continental and ocean island basalts and of mid-ocean ridge basalts are complementary. The relative sizes of the source regions for these fundamentally different basalt types can be estimated from the trace element enrichment-depletion patterns. Their combined volume occupies most of the mantle above the 670 kilometer discontinuity. The source regions separated as a result of early mantle differentiation and crystal fractionation from the resulting melt. The mid-ocean ridge basalts source evolved from an eclogite cumulate that lost its late-stage enriched fluids at various times to the shallower mantle and continental crust. The mid-ocean ridge basalts source is rich in garnet and clinopyroxene, whereas the continental and ocean island basalt source is a garnet peridotite that has experienced secondary enrichment. These relationships are consistent with the evolution of a terrestrial magma ocean.

  4. The mean composition of ocean ridge basalts

    NASA Astrophysics Data System (ADS)

    Gale, Allison; Dalton, Colleen A.; Langmuir, Charles H.; Su, Yongjun; Schilling, Jean-Guy

    2013-03-01

    mean composition of mid-ocean ridge basalts (MORB) is determined using a global data set of major elements, trace elements, and isotopes compiled from new and previously published data. A global catalog of 771 ridge segments, including their mean depth, length, and spreading rate enables calculation of average compositions for each segment. Segment averages allow weighting by segment length and spreading rate and reduce the bias introduced by uneven sampling. A bootstrapping statistical technique provides rigorous error estimates. Based on the characteristics of the data, we suggest a revised nomenclature for MORB. "ALL MORB" is the total composition of the crust apart from back-arc basins, N-MORB the most likely basalt composition encountered along the ridge >500 km from hot spots, and D-MORB the depleted end-member. ALL MORB and N-MORB are substantially more enriched than early estimates of normal ridge basalts. The mean composition of back-arc spreading centers requires higher extents of melting and greater concentrations of fluid-mobile elements, reflecting the influence of water on back-arc petrogenesis. The average data permit a re-evaluation of several problems of global geochemistry. The K/U ratio reported here (12,340 ± 840) is in accord with previous estimates, much lower than the estimate of Arevalo et al. (2009). The low Sm/Nd and 143Nd/144Nd ratio of ALL MORB and N-MORB provide constraints on the hypothesis that Earth has a non-chondritic primitive mantle. Either Earth is chondritic in Sm/Nd and the hypothesis is incorrect or MORB preferentially sample an enriched reservoir, requiring a large depleted reservoir in the deep mantle.

  5. Nontronite Mineralization in Columbia River Basalts

    NASA Astrophysics Data System (ADS)

    Baker, L.

    2015-12-01

    The ferric smectite nontronite is one of the first minerals formed by secondary weathering of Columbia River Basalts (CRB). Although nontronite is a common weathering product of CRB, it is not ubiquitous; field relations in near-surface flows suggest it only forms where sufficient water is available. In near-surface flows that are above the water table, nontronite is found filling cracks or vesicles, or in association with paleosols now preserved between flows in many localities. Field relations strongly suggest that porosity and permeability at the millimeter to meter scale control the supply of water for weathering and are key to the chemical composition of secondary clays and to the overall abundance of individual secondary weathering minerals. Weathering in the basalts initiates in void spaces that hold water, where high-Fe nontronite forms radiating acicular sprays. Small void spaces fill completely with nontronite of uniform composition, which penetrates the walls and replaces surrounding glass and ferromagnesian minerals. This process produces a relatively limited quantity of high-purity ferric nontronite. In large void spaces where water is limiting, nontronite lines the interior of vesicles but does not fill them; vermicular clay strands grow into the space from nucleation sites at the vesicle wall. Nontronitic cores are coated by layers of Mg- and Al-rich clays, and Mn oxides coat the exteriors. Thus, weathering under water-limited conditions appears to produce more compositionally complex mineral assemblages. In more extensively weathered basalts, nontronite is not present except in isolated, enclosed spaces. Results of this study may be useful in interpreting remotely sensed mineralogical data on Mars. The compositions of ferromagnesian smectites and spatial relationships between different clays on Mars may hold clues to the original conditions of water-rock interaction.

  6. Products of a Subglacial Flood Basalt Eruption

    NASA Astrophysics Data System (ADS)

    Gorny, C. F.; White, J. D. L.; Gudmundsson, M. T.

    2015-12-01

    The Snæbýlisheiði unit, SE Iceland, is a ca. 26 km³ elongate, flat-topped ridge of volcaniclastic debris coupled with and intruded by coherent basalt stretching over 34 km from the eruption site perpendicular to the rift fissure source. It formed from a single subglacial flood basalt eruption during a recent glaciation, and its elongation reflects glacial control on dispersal via the hydraulic potential gradient at the glacier's base, which drove towards the glacier terminus the meltwater+debris formed during the eruption by quenching and fragmentation. High magma discharge and outgassing drove segregation of magma into down-flow propagating intrusions. Edifice growth was mediated by the extent of ice melting, extent and efficiency of meltwater+debris drainage, and hydraulic gradients locally favoring meltwater accumulation. Eruption style reflected magma flux, edifice stability, and accessibility of water to the vent area via flooding or infiltration. Deposits reflect these competing factors in their chaotic internal organization and stratigraphy, limited lithofacies continuity, and diverse particle populations from multiple source vents. Linear growth of the ridge down-gradient from the eruption site was driven primarily by propagation and continuous fragmentation of shoaling intrusions that formed an interconnected intrusive complex with extensive peperites. Advance was along gently meandering and locally bifurcating sub-ice conduits within hyaloclastite with sheet-lobe levees and lobate fingered intrusions. Irregular dikes, apophyses, horns, and tendrils extended from the main body and generated voluminous lapilli tuff and contorticlasts while providing additional heat to the system. Prolonged transport and deposition of debris produced complexly bedded volcaniclastic deposits derived from and intruded by the basalt sheet. The bedding and depositional features of volcaniclastic debris and relationship to their adjacent intrusions suggest transport and

  7. Trace Element Diffusion in Basaltic Melt

    NASA Astrophysics Data System (ADS)

    Holycross, M.; Watson, E. B.

    2015-12-01

    We conducted high pressure, high temperature experiments to determine simultaneously the diffusivities of 24 trace elements (Sc, V, Rb, Y, Zr, Nb, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Yb, Lu, Hf, Ta, Th, U) in liquids of basaltic composition. Pre-synthesis runs were conducted in graphite capsules in a piston-cylinder apparatus to create two glasses having relatively high and low trace element contents. These glasses were then powdered and paired in diffusion couples by repacking in graphite capsules. All diffusion experiments were executed in a piston cylinder apparatus at 1 GPa pressure and temperatures ranging from 1250-1500º C. Concentration gradients that developed in the glasses were characterized using a laser ablation inductively coupled plasma mass spectrometer (LA-ICP-MS). Diffusion coefficients were determined from concentration profiles and show Arrhenian behavior within experimental error. Errors were assigned based on the linear fit of five time series experiments conducted over 500-9000 s to accurately represent the total experimental reproducibility of our results. Data show the highest activation energies are obtained for high field strength elements. Values for the pre-exponential factor, D0, also peak for the high field strength elements. We suggest that trace element diffusion in basaltic melts follows the compensation law (Winchell, 1969), with log D0 exhibiting linear dependence on activation energy. Calculated diffusivities indicate that transport through basaltic melt could be an effective mechanism for fractionating high field strength elements over geologically relevant time scales. Winchell (1969) High Temp. Sci. 1: 200-215

  8. Mare basalt genesis - Modeling trace elements and isotopic ratios

    NASA Astrophysics Data System (ADS)

    Binder, A. B.

    1985-11-01

    Various types of mare basalt data have been synthesized, leading to the production of an internally consistent model of the mare basalt source region and mare basalt genesis. The model accounts for the mineralogical, major oxide, compatible siderophile trace element, incompatible trace element, and isotopic characteristics of most of the mare basalt units and of all the pyroclastic glass units for which reliable data are available. Initial tests of the model show that it also reproduces the mineralogy and incompatible trace element characteristics of the complementary highland anorthosite suite of rocks and, in a general way, those of the lunar granite suite of rocks.

  9. An estimate of the juvenile sulfur content of basalt

    USGS Publications Warehouse

    Moore, J.G.; Fabbi, Brent P.

    1971-01-01

    Sulfur analyses by X-ray fluorescence give an average content of 107 ppm for 9 samples of fresh subaerially-erupted oceanic basalt and 680 ppm for 38 samples of submarine erupted basalt. This difference is the result of retention of sulfur in basalt quenched on the sea floor and loss of sulfur in basalt by degassing at the surface. The outer glassy part of submarine erupted basalt contains 800??150 ppm sulfur, and this amount is regarded as an estimate of the juvenile sulfur content of the basalt melt from the mantle. The slower cooled interiors of basalt pillows are depleted relative to the rims owing to degassing and escape through surface fractures. Available samples of deep-sea basalts do not indicate a difference in original sulfur content between low-K tholeiite, Hawaiian tholeiite, and alkali basalt. The H2O/S ratio of analyzed volcanic gases is generally lower than the H2O/S ratio of gases presumed lost from surface lavas as determined by chemical differences between pillow rims and surface lavas. This enrichment of volcanic gases in sulfur relative to water may result from a greater degassing of sulfur relative to water from shallow intrusive bodies beneath the volcano. ?? 1971 Springer-Verlag.

  10. Quantifying glassy and crystalline basalt partitioning in the oceanic crust

    NASA Astrophysics Data System (ADS)

    Moore, Rachael; Ménez, Bénédicte

    2016-04-01

    The upper layers of the oceanic crust are predominately basaltic rock, some of which hosts microbial life. Current studies of microbial life within the ocean crust mainly focus on the sedimentary rock fraction, or those organisms found within glassy basalts while the potential habitability of crystalline basalts are poorly explored. Recently, there has been recognition that microbial life develops within fractures and grain boundaries of crystalline basalts, therefore estimations of total biomass within the oceanic crust may be largely under evaluated. A deeper understanding of the bulk composition and fractionation of rocks within the oceanic crust is required before more accurate estimations of biomass can be made. To augment our understanding of glassy and crystalline basalts within the oceanic crust we created two end-member models describing basalt fractionation: a pillow basalt with massive, or sheet, flows crust and a pillow basalt with sheeted dike crust. Using known measurements of massive flow thickness, dike thickness, chilled margin thickness, pillow lava size, and pillow lava glass thickness, we have calculated the percentage of glassy versus crystalline basalts within the oceanic crust for each model. These models aid our understanding of textural fractionation within the oceanic crust, and can be applied with bioenergetics models to better constrain deep biomass estimates.

  11. Study on basalt fiber parameters affecting fiber-reinforced mortar

    NASA Astrophysics Data System (ADS)

    Orlov, A. A.; Chernykh, T. N.; Sashina, A. V.; Bogusevich, D. V.

    2015-01-01

    This article considers the effect of different dosages and diameters of basalt fibers on tensile strength increase during bending of fiberboard-reinforced mortar samples. The optimal dosages of fiber, providing maximum strength in bending are revealed. The durability of basalt fiber in an environment of cement, by means of microscopic analysis of samples of fibers and fiberboard-reinforced mortar long-term tests is examined. The article also compares the behavior of basalt fiber in the cement stone environment to a glass one and reveals that the basalt fiber is not subject to destruction.

  12. Microbial colonization and alteration of basaltic glass

    NASA Astrophysics Data System (ADS)

    Einen, J.; Kruber, C.; Øvreås, L.; Thorseth, I. H.; Torsvik, T.

    2006-03-01

    Microorganisms have been reported to be associated with the alteration of the glassy margin of seafloor pillow basalts (Thorseth et al., 2001, 2003; Lysnes et al., 2004). The amount of iron and other biological important elements present in basalts and the vast abundance of basaltic glass in the earth's crust, make glass alteration an important process in global element cycling. To gain further insight into microbial communities associated with glass alteration, five microcosm experiments mimicking seafloor conditions were inoculated with seafloor basalt and incubated for one year. Mineral precipitations, microbial attachment to the glass and glass alteration were visualized by scanning electron microscopy (SEM), and the bacterial community composition was fingerprinted by PCR and denaturing gradient gel electrophoresis (DGGE) in combination with sequencing. SEM analysis revealed a microbial community with low morphological diversity of mainly biofilm associated and prosthecate microorganisms. Approximately 30 nm thick alteration rims developed on the glass in all microcosms after one year of incubation; this however was also seen in non inoculated controls. Calcium carbonate precipitates showed parallel, columnar and filamentous crystallization habits in the microcosms as well as in the sterile controls. DGGE analysis showed an alteration in bacterial community profiles in the five different microcosms, as a response to the different energy and redox regimes and time. In all microcosms a reduction in number of DGGE bands, in combination with an increase in cell abundance were recorded during the experiment. Sequence analysis showed that the microcosms were dominated by four groups of organisms with phylogenetic affiliation to four taxa: The Rhodospirillaceae, a family containing phototrophic marine organisms, in which some members are capable of heterotrophic growth in darkness and N2 fixation; the family Hyphomicrobiaceae, a group of prosthecate oligotrophic

  13. The nomenclature of polymict basaltic achondrites

    NASA Technical Reports Server (NTRS)

    Delaney, J. S.; Prinz, M.; Harlow, G. E.; Takeda, H.; Nehru, C. E.

    1983-01-01

    The system of nomenclature for basaltic achondrite meteorites is discussed, and new classification criteria are proposed. Under the new system, all achondrites are divided intno the broad groupings 'monomict' and 'polymict' by the number of lithologies present. The monomicts are classified structurally as brecciated or unbreccciated and as eucrites, diogenites, or cumulate eucrites. The polymicts are classified using an arbitrary mineral-chemical standard based on the percentage content of diogenite (magnesium orthopyroxenite): diogenites have more than 90 percent, eucrites have less than 10 percent, and all other polymicts area howardites. Tables listing all known achondrites by classification are provided.

  14. Plagioclase mineralogy of olivine alkaline basalt

    NASA Technical Reports Server (NTRS)

    Hoffer, J. M.

    1973-01-01

    A geological and mineralogical study of the Potrillo volcanics is reported. The investigation consisted first of field mapping to establish and identify the different rock types and volcanic features in order to determine the geological history. Next, samples were collected and analyzed petrographically to determine suitable rocks from the various stratigraphic units for study of plagioclase. Samples selected for further study were crushed and the plagioclase extracted for the determination of composition and structural state. These results were then related to the petrology and crystallization of the basalt.

  15. Thermal Infrared Spectra of Experimentally Shocked Basalt

    NASA Astrophysics Data System (ADS)

    Johnson, J. R.; Horz, F.

    2003-12-01

    We acquired thermal infrared (3-40 microns) emissivity and hemispherical reflectance spectra of experimentally shocked samples of a fine-grained basalt from Grand Falls, AZ to document the spectral effects of shock as a function of increasing shock pressures (17-57 GPa). This sample contains 25% pyroxene, 20% olivine, and 45% feldspar, making it a suitable analog to the Surface Type 1 (basalt) observed in Thermal Emission Spectrometer (TES) data of Mars. Reflectance data (3-14 microns) were acquired using a Nexus 470 FTIR spectrometer at the HIGP, University of Hawaii, and emission spectra (5-40 microns) were acquired using a Nicolet Nexus 670 emission spectrometer at Arizona State University. These data complement similar previous measurements of experimentally shocked plagioclase and pyroxene relevant to interpreting spectra provided by TES. The samples were shocked using the 25-mm barrel gun at Johnson Space Center and provided ~400 mg per sample. Large (2-10 mm) chips of recovered material were separated from the samples and washed to remove clinging fines, and the residual was powdered to provide a consistent grain size ( ˜20 microns). Spectra were obtained of both the chips and the powder samples. Results for the chips show a shift in band positions in the 900-1200 wavenumber (wn) region compared to unshocked samples, consistent with the structural degradation of feldspar and subsequent formation of maskelynite and glass. The development of a band near 460 wn at high pressures is also consistent with glass formation in feldspars. Conversely, absorptions related to pyroxene remain present even at high pressures, consistent with previous work. Results for the powders show little variations with increasing pressure except for the loss of minor transparency features in the 800-900 wn region. Additional visible/near-infrared (0.35-2.50 microns) measurements of the powdered basalt samples also will be acquired at the RELAB facility. Future work will include

  16. Vesiculation of basaltic magma during eruption

    USGS Publications Warehouse

    Mangan, M.T.; Cashman, K.V.; Newman, S.

    1993-01-01

    Vesicle size distributions in vent lavas from the Pu'u "O'o-Kupaianaha eruption of Kilauea volcano are used to estimate nucleation and growth rates of H2O-rich gas bubbles in basaltic magma nearing the earth's surface (???120 m depth). By using well-constrained estimates for the depth of volatile exsolution and magma ascent rate, nucleation rates of 35.9 events.cm-3.s-1 and growth rates of 3.2 ?? 10-4cm/s are determined directly from size-distribution data. The results are consistent with diffusion-controlled growth as predicted by a parabolic growth law. -from Authors

  17. East Mariana Basin tholeiites: Cretaceous intraplate basalts or rift basalts related to the Ontong Java plume?

    USGS Publications Warehouse

    Castillo, P.R.; Pringle, M.S.; Carlson, R.W.

    1994-01-01

    Studies of seafloor magnetic anomaly patterns suggest the presence of Jurassic oceanic crust in a large area in the western Pacific that includes the East Mariana, Nauru and Pigafetta Basins. Sampling of the igneous crust in this area by the Deep Sea Drilling Program (DSDP) and the Ocean Drilling Program (ODP) allows direct evaluation of the age and petrogenesis of this crust. ODP Leg 129 drilled a 51 m sequence of basalt pillows and massive flows in the central East Mariana Basin. 40Ar 39Ar ages determined in this study for two Leg 129 basalts average 114.6 ?? 3.2 Ma. This age is in agreement with the Albian-late Aptian paleontologic age of the overlying sediments, but is distinctively younger than the Jurassic age predicted by magnetic anomaly patterns in the basin. Compositionally, the East Mariana Basin basalts are uniformly low-K tholeiites that are depleted in highly incompatible elements compared to moderately incompatible ones, which is typical of mid-ocean ridge basalts (MORB) erupted near hotspots. The Sr, Nd and Pb isotopic compositions of the tholeiites ( 87Sr 86Srinit = 0.70360-0.70374; 143Nd 144Ndinit = 0.512769-0.512790; 206Pb 204Pbmeas = 18.355-18.386) also overlap with some Indian Ocean Ridge MORB, although they are distinct from the isotopic compositions of Jurassic basalts drilled in the Pigafetta Basin, the oldest Pacific MORB. The isotopic compositions of the East Mariana Basin tholeiites are also similar to those of intraplate basalts, and in particular, to the isotopic signature of basalts from the nearby Ontong Java and Manihiki Plateaus. The East Mariana Basin tholeiites also share many petrologic and isotopic characteristics with the oceanic basement drilled in the Nauru Basin at DSDP Site 462. In addition, the new 110.8 ?? 1.0 Ma 40Ar 39Ar age for two flows from the bottom of Site 462 in the Nauru Basin is indistinguishable from the age of the East Mariana Basin flows. Thus, while magnetic anomaly patterns predict that the igneous

  18. Crystal Stratigraphy of Two Basalts from Apollo 16: Unique Crystallization of Picritic Basalt 606063,10-16 and Very-Low-Titanium Basalt 65703,9-13

    NASA Technical Reports Server (NTRS)

    Donohue, P. H.; Neal, C. R.; Stevens, R. E.; Zeigler, R. A.

    2014-01-01

    A geochemical survey of Apollo 16 regolith fragments found five basaltic samples from among hundreds of 2-4 mm regolith fragments of the Apollo 16 site. These included a high-Ti vitrophyric basalt (60603,10-16) and one very-low-titanium (VLT) crystalline basalt (65703,9-13). Apollo 16 was the only highlands sample return mission distant from the maria (approx. 200 km). Identification of basaltic samples at the site not from the ancient regolith breccia indicates input of material via lateral transport by post-basin impacts. The presence of basaltic rocklets and glass at the site is not unprecedented and is required to satisfy mass-balance constraints of regolith compositions. However, preliminary characterization of olivine and plagioclase crystal size distributions indicated the sample textures were distinct from other known mare basalts, and instead had affinities to impact melt textures. Impact melt textures can appear qualitatively similar to pristine basalts, and quantitative analysis is required to distinguish between the two in thin section. The crystal stratigraphy method is a powerful tool in studying of igneous systems, utilizing geochemical analyses across minerals and textural analyses of phases. In particular, trace element signatures can aid in determining the ultimate origin of these samples and variations document subtle changes occurring during their petrogenesis.

  19. The effects of liming an Adirondack lake watershed on downstream water chemistry: Effects of liming on stream chemistry

    USGS Publications Warehouse

    Burns, Douglas A.

    1996-01-01

    Calcite treatment of chronically acidic lakes has improved fish habitat, but the effects on downstream water quality have not previously been examined. In this study, the spatial and temporal effects of watershed CaCO3 treatment on the chemistry of a lake outlet stream in the Adirondack Mountains of New York were examined. Before CaCO3 treatment, the stream was chronically acidic. During spring snowmelt before treatment, pH and acid-neutralizing capacity (ANC) in the outlet stream declined, and NO3- and inorganic monomeric aluminum (AlIM) concentrations increased sharply. During that summer, SO42- and NO3- concentrations decreased downstream, and dissolved organic carbon (DOC) concentrations and ANC increased, in association with the seasonal increase in decomposition of organic matter and the attendant SO42--reduction process. A charge-balance ANC calculation closely matched measured downstream changes in ANC in the summer and indicated that SO42- reduction was the major process contributing to summer increases in ANC. Increases in Ca2+ concentration and ANC began immediately after CaCO3 application, and within 3 months, exceeded their pretreatment values by more than 130 ??eq/L. Within 2 months after treatment, downstream decreases in Ca2+ concentration, ANC, and pH, were noted. Stream mass balances between the lake and the sampling site 1.5 km downstream revealed that the transport of all chemical constituents was dominated by conservative mixing with tributaries and ground water; however, non-conservative processes resulted in significant Ca2+ losses during the 13-month period after CaCO3 treatment. Comparison of substrate samples from the buffered outlet stream with those from its untreated tributaries showed that the percentage of cation-exchange sites occupied by Ca2+, as well as non-exchangeable Ca, were higher in the outlet-stream substrate than in tributary-stream substrate. Mass-balance data for Ca2+, H+, AlIM, and DOC revealed net downstream losses of

  20. Is Ishtar Terra a thickened basaltic crust?

    NASA Technical Reports Server (NTRS)

    Arkani-Hamed, Jafar

    1992-01-01

    The mountain belts of Ishtar Terra and the surrounding tesserae are interpreted as compressional regions. The gravity and surface topography of western Ishtar Terra suggest a thick crust of 60-110 km that results from crustal thickening through tectonic processes. Underthrusting was proposed for the regions along Danu Montes and Itzpapalotl Tessera. Crustal thickening was suggested for the entire Ishtar Terra. In this study, three lithospheric models with total thicknesses of 40.75 and 120 km and initial crustal thicknesses of 3.9 and 18 km are examined. These models could be produced by partial melting and chemical differentiation in the upper mantle of a colder, an Earth-like, and a hotter Venus having temperatures of respectively 1300 C, 1400 C, and 1500 C at the base of their thermal boundary layers associated with mantle convection. The effects of basalt-granulite-eclogite transformation (BGET) on the surface topography of a thickening basaltic crust is investigated adopting the experimental phase diagram and density variations through the phase transformation.

  1. Degassing of reduced carbon from planetary basalts

    PubMed Central

    Wetzel, Diane T.; Rutherford, Malcolm J.; Jacobsen, Steven D.; Hauri, Erik H.; Saal, Alberto E.

    2013-01-01

    Degassing of planetary interiors through surface volcanism plays an important role in the evolution of planetary bodies and atmospheres. On Earth, carbon dioxide and water are the primary volatile species in magmas. However, little is known about the speciation and degassing of carbon in magmas formed on other planets (i.e., Moon, Mars, Mercury), where the mantle oxidation state [oxygen fugacity (fO2)] is different from that of the Earth. Using experiments on a lunar basalt composition, we confirm that carbon dissolves as carbonate at an fO2 higher than -0.55 relative to the iron wustite oxygen buffer (IW-0.55), whereas at a lower fO2, we discover that carbon is present mainly as iron pentacarbonyl and in smaller amounts as methane in the melt. The transition of carbon speciation in mantle-derived melts at fO2 less than IW-0.55 is associated with a decrease in carbon solubility by a factor of 2. Thus, the fO2 controls carbon speciation and solubility in mantle-derived melts even more than previous data indicate, and the degassing of reduced carbon from Fe-rich basalts on planetary bodies would produce methane-bearing, CO-rich early atmospheres with a strong greenhouse potential. PMID:23569260

  2. Identifying recycled ash in basaltic eruptions

    NASA Astrophysics Data System (ADS)

    D'Oriano, Claudia; Bertagnini, Antonella; Cioni, Raffaello; Pompilio, Massimo

    2014-07-01

    Deposits of mid-intensity basaltic explosive eruptions are characterized by the coexistence of different types of juvenile clasts, which show a large variability of external properties and texture, reflecting alternatively the effects of primary processes related to magma storage or ascent, or of syn-eruptive modifications occurred during or immediately after their ejection. If fragments fall back within the crater area before being re-ejected during the ensuing activity, they are subject to thermally- and chemically-induced alterations. These `recycled' clasts can be considered as cognate lithic for the eruption/explosion they derive. Their exact identification has consequences for a correct interpretation of eruption dynamics, with important implications for hazard assessment. On ash erupted during selected basaltic eruptions (at Stromboli, Etna, Vesuvius, Gaua-Vanuatu), we have identified a set of characteristics that can be associated with the occurrence of intra-crater recycling processes, based also on the comparison with results of reheating experiments performed on primary juvenile material, at variable temperature and under different redox conditions.

  3. Emplacement of Columbia River flood basalt

    SciTech Connect

    Reidel, Stephen P. )

    1997-11-01

    Evidence is examined for the emplacement of the Umatilla, Wilbur Creek, and the Asotin Members of Columbia River Basalt Group. These flows erupted in the eastern part of the Columbia Plateau during the waning phases of volcanism. The Umatilla Member consists of two flows in the Lewiston basin area and southwestern Columbia Plateau. These flows mixed to form one flow in the central Columbia Plateau. The composition of the younger flow is preserved in the center and the composition of the older flow is at the top and bottom. There is a complete gradation between the two. Flows of the Wilbur Creek and Asotin Members erupted individually in the eastern Columbia Plateau and also mixed together in the central Columbia Plateau. Comparison of the emplacement patterns to intraflow structures and textures of the flows suggests that very little time elapsed between eruptions. In addition, the amount of crust that formed on the earlier flows prior to mixing also suggests rapid emplacement. Calculations of volumetric flow rates through constrictions in channels suggest emplacement times of weeks to months under fast laminar flow for all three members. A new model for the emplacement of Columbia River Basalt Group flows is proposed that suggests rapid eruption and emplacement for the main part of the flow and slower emplacement along the margins as the of the flow margin expands.

  4. Hafnium isotope variations in oceanic basalts.

    USGS Publications Warehouse

    Patchett, P.J.; Tatsumoto, M.

    1980-01-01

    Routine low-blank chemistry and 0.01-0.04% precision on the ratio 176Hf/177Hf allows study of Hf isotopic variations, generated by beta --decay of 176Lu, in volcanic rocks derived from the suboceanic mantle. Normalized to 176Hf/177Hf = 0.7325, 176Hf/177Hf ranges 0.2828-0.2835, based on 24 basalt samples. 176Hf/177Hf is positively correlated with 143Nd/144Nd, and negatively correlated with 87Sr/86Sr and 206Pb/204Pb. Along the Iceland-Reykjanes ridge traverse, 176Hf/177Hf increases southwards. The coherence of Hf, Nd and Sr isotopes in the oceanic mantle allows an approximate bulk Earth 176Hf/177Hf of 0.28295 to be inferred from the bulk Earth 143Nd/144Nd. This requires the bulk Earth Lu/Hf to be 0.25, similar to that of the Juvinas eucrite. 60% of the Hf isotopic variation in oceanic basalts occurs among mid-ocean ridge samples. Lu-Hf fractionation probably decouples from Sm-Nd and Rb-Sr fractionation in very depleted source regions, with high Lu/Hf, and consequent high 176Hf/177Hf ratios developing in mantle residual from partial melting. (Authors' abstract) -T.R.

  5. Identifying recycled ash in basaltic eruptions.

    PubMed

    D'Oriano, Claudia; Bertagnini, Antonella; Cioni, Raffaello; Pompilio, Massimo

    2014-07-28

    Deposits of mid-intensity basaltic explosive eruptions are characterized by the coexistence of different types of juvenile clasts, which show a large variability of external properties and texture, reflecting alternatively the effects of primary processes related to magma storage or ascent, or of syn-eruptive modifications occurred during or immediately after their ejection. If fragments fall back within the crater area before being re-ejected during the ensuing activity, they are subject to thermally- and chemically-induced alterations. These 'recycled' clasts can be considered as cognate lithic for the eruption/explosion they derive. Their exact identification has consequences for a correct interpretation of eruption dynamics, with important implications for hazard assessment. On ash erupted during selected basaltic eruptions (at Stromboli, Etna, Vesuvius, Gaua-Vanuatu), we have identified a set of characteristics that can be associated with the occurrence of intra-crater recycling processes, based also on the comparison with results of reheating experiments performed on primary juvenile material, at variable temperature and under different redox conditions.

  6. Degassing of reduced carbon from planetary basalts.

    PubMed

    Wetzel, Diane T; Rutherford, Malcolm J; Jacobsen, Steven D; Hauri, Erik H; Saal, Alberto E

    2013-05-14

    Degassing of planetary interiors through surface volcanism plays an important role in the evolution of planetary bodies and atmospheres. On Earth, carbon dioxide and water are the primary volatile species in magmas. However, little is known about the speciation and degassing of carbon in magmas formed on other planets (i.e., Moon, Mars, Mercury), where the mantle oxidation state [oxygen fugacity (fO2)] is different from that of the Earth. Using experiments on a lunar basalt composition, we confirm that carbon dissolves as carbonate at an fO2 higher than -0.55 relative to the iron wustite oxygen buffer (IW-0.55), whereas at a lower fO2, we discover that carbon is present mainly as iron pentacarbonyl and in smaller amounts as methane in the melt. The transition of carbon speciation in mantle-derived melts at fO2 less than IW-0.55 is associated with a decrease in carbon solubility by a factor of 2. Thus, the fO2 controls carbon speciation and solubility in mantle-derived melts even more than previous data indicate, and the degassing of reduced carbon from Fe-rich basalts on planetary bodies would produce methane-bearing, CO-rich early atmospheres with a strong greenhouse potential. PMID:23569260

  7. "Racializing" Class

    ERIC Educational Resources Information Center

    Hatt-Echeverria, Beth; Urrieta, Luis, Jr.

    2003-01-01

    In an effort to explore how racial and class oppressions intersect, the authors use their autobiographical narratives to depict cultural and experiential continuity and discontinuity in growing up white working class versus Chicano working class. They specifically focus on "racializing class" due to the ways class is often used as a copout by…

  8. Submarine basalt from the Revillagigedo Islands region, Mexico

    USGS Publications Warehouse

    Moore, J.G.

    1970-01-01

    Ocean-floor dredging and submarine photography in the Revillagigedo region off the west coast of Mexico reveal that the dominant exposed rock of the submarine part of the large island-forming volcanoes (Roca Partida and San Benedicto) is a uniform alkali pillow basalt; more siliceous rocks are exposed on the upper, subaerial parts of the volcanoes. Basalts dredged from smaller seamounts along the Clarion fracture zone south of the Revillagigedo Islands are tholeiitic pillow basalts. Pillows of alkali basalts are more vesicular than Hawaiian tholeiitic pillows collected from the same depths. This difference probably reflects a higher original volatile content of the alkali basalts. Manganese-iron oxide nodules common in several dredge hauls generally contain nucleii of rhyolitic pumice or basalt pillow fragments. The pumice floated to its present site from subaerial eruptions, became waterlogged and sank, and was then coated with manganese-iron oxides. The thickness of palagonite rinds on the glassy pillow fragments is proportional to the thickness of manganese-iron oxide layers, and both are a measure of the age of the nodule. Both oldest basalts (10-100 m.y.) and youngest (less than 1 m.y.) are along the Clarion fracture zone, whereas basalts from Roca Partida and San Benedicto volcanoes are of intermediate age. ?? 1970.

  9. Constructibility issues associated with a nuclear waste repository in basalt

    SciTech Connect

    Turner, D.A.

    1981-12-04

    This report contains the text and slide reproductions of a speech on nuclear waste disposal in basalt. The presentation addresses the layout of repository access shafts and subsurface facilities resulting from the conceptual design of a nuclear repository in basalt. The constructibility issues that must be resolved prior to construction are described. (DMC)

  10. Germanium abundances in lunar basalts: Evidence of mantle metasomatism

    SciTech Connect

    Dickinson, T.; Taylor, G.J.; Keil, T.K.; Bild, R.W.

    1988-01-01

    To fill in gaps in the present Ge data base, mare basalts were analyzed for Ge and other elements by RNAA and INAA. Mare basalts from Apollo 11, 12, 15, 17 landing sites are rather uniform in Ge abundance, but Apollo 14 aluminous mare basalts and KREEP are enriched in Ge by factors of up to 300 compared to typical mare basalts. These Ge enrichments are not associated with other siderophile element enrichments and, thus, are not due to differences in the amount of metal segregated during core formation. Based on crystal-chemical and inter-element variations, it does not appear that the observed Ge enrichments are due to silicate liquid immiscibility. Elemental ratios in Apollo 14 aluminous mare basalts, green and orange glass, average basalts and KREEP suggest that incorporation of late accreting material into the source regions or interaction of the magmas with primitive undifferentiated material is not a likely cause for the observed Ge enrichments. We speculate that the most plausible explanation for these Ge enrichments is complexing and concentration of Ge by F, Cl or S in volatile phases. In this manner, the KREEP basalt source regions may have been metasomatized and Apollo 14 aluminous mare basalt magmas may have become enriched in Ge by interacting with these metasomatized areas. The presence of volatile- and Ge-rich regions in the Moon suggests that the Moon was never totally molten. 71 refs., 1 fig., 6 tabs.

  11. Hydrothermal interactions of cesium and strontium phases from spent unreprocessed fuel with basalt phases and basalts

    SciTech Connect

    Komarneni, S.; Scheetz, B.E.; McCarthy, G.J.; Coons, W.E.

    1980-03-01

    This investigation is a segment of an extensive research program aimed at investigating the feasibility of long-term, subsurface storage of commercial nuclear waste. Specifically, it is anticipated that the waste will be housed in a repository mined from the basalt formations which lie beneath the Hanford Site. The elements monitored during the present experiments were Cs and Sr. These two elements represent significant biohazards if released from a repository and are the major heat producing radionuclides present in commercial radioactive waste. Several Cs phases and/or solutions were reacted with either isolated basalt phases or bulk-rock basalt, and the resulting solids and solutions were analyzed. The hydrothermal reactivity of SrZrO/sub 3/, which is believed to be a probable host for Sr in SFE was investigated. While so far no evidence exists which indicates that Sr is present in a water soluble phase in spent fuel elements (SFE), detailed investigation of a potential hazard is warranted. This investigation has determined that some Cs compounds likely to be stable components of spent fuel (i.e., CsOH, Cs/sub 2/MoO/sub 4/, Cs/sub 2/U/sub 2/O/sub 7/) have significant hydrothermal solubilities. These solubilities are greatly decreased in the presence of basalt and/or basalt minerals. The decrease in the amount of Cs in solution results from reactions which form pollucite and/or CsAlSiO/sub 4/, with the production of pollucite exceeding that of CsAlSiO/sub 4/. Dissolution of ..beta..-Cs/sub 2/U/sub 2/O/sub 7/ implies solubilizing a uranium species to an undetermined extent. The production of schoepite (UO/sub 3/.3H/sub 2/O) during some experiments containing basalt phases, indicates a tendency to oxidize U/sup 4 +/ to U/sup 6 +/. When diopside (nominally CaMgSi/sub 2/O/sub 6/) and ..beta..-Cs/sub 2/U/sub 2/O/sub 7/ were hydrothermally reacted, at 300/sup 0/C both UO/sub 2/ and UO/sub 3/.3H/sub 2/O were produced. Results of experiments on SrZrO/sub 3/ show it to be

  12. Differences between oceanic basalts by multitrace element ratio topology

    NASA Astrophysics Data System (ADS)

    Allegre, Claude J.; Schiano, Pierre; Lewin, Eric

    1995-01-01

    Trace element multidimensional analysis of ocean island basalts defines a structure delimited by the same four end members (Hawaiian Islands, St. Helena-Tubuai-Mangaia Islands, Kerguelen-Gough-Tristan da Cunha and the Society Islands) as determined by isotope ratios. In contrast to the results obtained for the distribution of isotopic ratios, the dispersions of trace element concentrations in mid-ocean ridge basalts are greater than those for ocean island basalts. This can be accounted for by a two-component mantle source composed of pyroxenite layers embedded in a peridotitic matrix, which melts to varying degrees; ocean island basalts are produced by a relatively uniform low degree of melting of the pyroxenite and limited isotopic exchange with the surrounding matrix, whereas mid-ocean ridge basalts are melts of both components with higher and more variable extents of melting and complete isotopic exchange between the pyroxenite strips and the peridotitic matrix.

  13. Origin of High-Alumina Basalt, Andesite, and Dacite Magmas.

    PubMed

    Hamilton, W

    1964-10-30

    The typical volcanic rocks of most island arcs and eugeosynclines, and of some continental environments, are basalt, andesite, and dacite, of high alumina content. The high-alumina basalt differs from tholeiitic basalt primarily in having a greater content of the components of calcic plagioclase. Laboratory data indicate that in the upper mantle, below the level at which the basaltic component of mantle rock is transformed by pressure to eclogite or pyroxenite, the entire basaltic portion probably is melted within a narrow temperature range, but that above the level of that transformation plagioclase is melted selectively before pyroxene over a wide temperature range. The broad spectrum of high-alumina magmas may represent widely varying degrees of partial melting above the transformation level, whereas narrow-spectrum tholeiite magma may represent more complete melting beneath it.

  14. [Determination of Total Iron and Fe2+ in Basalt].

    PubMed

    Liu, Jian-xun; Chen, Mei-rong; Jian, Zheng-guo; Wu, Gang; Wu, Zhi-shen

    2015-08-01

    Basalt is the raw material of basalt fiber. The content of FeO and Fe2O3 has a great impact on the properties of basalt fibers. ICP-OES and dichromate method were used to test total Fe and Fe(2+) in basalt. Suitable instrument parameters and analysis lines of Fe were chosen for ICP-OES. The relative standard deviation (RSD) of ICP-OES is 2.2%, and the recovery is in the range of 98%~101%. The method shows simple, rapid and highly accurate for determination of total Fe and Fe(2+) in basalt. The RSD of ICP-OES and dichromate method is 0.42% and 1.4%, respectively.

  15. Use and Features of Basalt Formations for Geologic Sequestration

    SciTech Connect

    McGrail, B. Peter; Ho, Anita M.; Reidel, Steve P.; Schaef, Herbert T.

    2003-01-01

    Extrusive lava flows of basalt are a potential host medium for geologic sequestration of anthropogenic CO2. Flood basalts and other large igneous provinces occur worldwide near population and power-producing centers and could securely sequester a significant fraction of global CO2 emissions. We describe the location, extent, and general physical and chemical characteristics of large igneous provinces that satisfy requirements as a good host medium for CO2 sequestration. Most lava flows have vesicular flow tops and bottoms as well as interflow zones that are porous and permeable and serve as regional aquifers. Additionally, basalt is iron-rich, and, under the proper conditions of groundwater pH, temperature, and pressure, injected CO2 will react with iron released from dissolution of primary minerals in the basalt to form stable ferrous carbonate minerals. Conversion of CO2 gas into a solid form was confirmed in laboratory experiments with supercritical CO2 in contact with basalt samples from Washington state.

  16. Ibitira: A basaltic achondrite from a distinct parent asteroid

    NASA Technical Reports Server (NTRS)

    Mittlefehldt, David W.

    2004-01-01

    I have done detailed petrologic study of Ibitira, nominally classified as a basaltic eucrite. The Fe/Mn ratio of Ibitira pyroxenes with <10 mole % wollastonite component is 36.4 0.4, and is well-resolved from those of five basaltic eucrites studied for comparison; 31.2-32.2. Data for the latter completely overlap. Ibitira pyroxenes have lower Fe/Mg than the basaltic eucrite pyroxenes. Thus, the higher Fe/Mn ratio does not reflect a simple difference in oxidation state. Ibitira also has an oxygen isotopic composition, alkali element contents and a Ti/Hf ratio that distinguish it from basaltic eucrites. These differences support derivation from a distinct parent asteroid. Ibitira is the first recognized representative of the fifth known asteroidal basaltic crust.

  17. [Determination of Total Iron and Fe2+ in Basalt].

    PubMed

    Liu, Jian-xun; Chen, Mei-rong; Jian, Zheng-guo; Wu, Gang; Wu, Zhi-shen

    2015-08-01

    Basalt is the raw material of basalt fiber. The content of FeO and Fe2O3 has a great impact on the properties of basalt fibers. ICP-OES and dichromate method were used to test total Fe and Fe(2+) in basalt. Suitable instrument parameters and analysis lines of Fe were chosen for ICP-OES. The relative standard deviation (RSD) of ICP-OES is 2.2%, and the recovery is in the range of 98%~101%. The method shows simple, rapid and highly accurate for determination of total Fe and Fe(2+) in basalt. The RSD of ICP-OES and dichromate method is 0.42% and 1.4%, respectively. PMID:26672315

  18. Origin of High-Alumina Basalt, Andesite, and Dacite Magmas.

    PubMed

    Hamilton, W

    1964-10-30

    The typical volcanic rocks of most island arcs and eugeosynclines, and of some continental environments, are basalt, andesite, and dacite, of high alumina content. The high-alumina basalt differs from tholeiitic basalt primarily in having a greater content of the components of calcic plagioclase. Laboratory data indicate that in the upper mantle, below the level at which the basaltic component of mantle rock is transformed by pressure to eclogite or pyroxenite, the entire basaltic portion probably is melted within a narrow temperature range, but that above the level of that transformation plagioclase is melted selectively before pyroxene over a wide temperature range. The broad spectrum of high-alumina magmas may represent widely varying degrees of partial melting above the transformation level, whereas narrow-spectrum tholeiite magma may represent more complete melting beneath it. PMID:17794034

  19. Lu-Hf constraints on the evolution of lunar basalts

    NASA Technical Reports Server (NTRS)

    Fujimaki, H.; Tatsumoto, M.

    1984-01-01

    It is shown that a cumulate-remelting model best explains the recently acquired data on the Lu-Hf systematics of lunar mare basalts. The model is constructed using Lu and Hf concentration data and is strengthened by Hf isotopic evidence of Unruh et al. (1984). It is shown that the similarity in MgO/FeO ratios and Cr2O3 content in high-Ti and low-Ti basalts are not important constraints on lunar basalt petrogenesis. The model demonstrates that even the very low Ti or green glass samples are remelting products of a cumulate formed after at least 80-90 percent of the lunar magma ocean had solidified. In the model, all the mare basalts and green glasses were derived from 100-150 km depth in the lunar mantle. The Lu-Hf systematics of KREEP basalts clearly indicate that they would be the final residual liquid of the lunar magma ocean.

  20. Origin of high-alumina basalt, andesite, and dacite magmas

    USGS Publications Warehouse

    Hamilton, W.

    1964-01-01

    The typical volcanic rocks of most island arcs and eugeosynclines, and of some continental environments, are basalt, andesite, and dacite, of high alumina content. The high-alumina basalt differs from tholeiitic basalt primarily in having a greater content of the components of calcic plagioclase. Laboratory data indicate that in the upper mantle, below the level at which the basaltic component of mantle rock is transformed by pressure to eclogite or pyroxenite, the entire basaltic portion probably is melted within a narrow temperature range, but that above the level of that transformation plagioclase is melted selectively before pyroxene over a wide temperature range. The broad spectrum of high-alumina magmas may represent widely varying degrees of partial melting above the transformation level, whereas narrow-spectrum tholeiite magma may represent more complete melting beneath it.

  1. Composition of basalts from the Mid-Atlantic Ridge

    USGS Publications Warehouse

    Engel, A.E.J.; Engel, C.G.

    1964-01-01

    Studies of volcanic rocks in dredge hauls from the submerged parts of the Mid-Atlantic Ridge suggest that it consists largely of tholeiitic basalt with low values of K, Ti, and P. In contrast, the volcanic islands which form the elevated caps on the Ridge are built of alkali basalt with high values of Ti, Fe3+, P, Na, and K. This distinct correlation between the form of the volcanic structures, elevation above the sea floor, and composition suggests that the islands of alkali basalt are derived from a parent tholeiitic magma by differentiation in shallow reservoirs. The volume of low-potassium tholeiites along the Mid-Atlantic Ridge and elsewhere in the oceans appears to be many times that of the alkali basalts exposed on oceanic islands. Tholeiitic basalts with about 0.2 K2O appear to be the primary and predominant magma erupted on the oceanic floor.

  2. Decompression-Induced Crystallization of Hydrous Basalt

    NASA Astrophysics Data System (ADS)

    Teasdale, R.; Brooker, R. A.

    2014-12-01

    Decompression-induced crystallization of hydrous basalt during magma ascent from 1.5 kb (150 MPa) is quantified using isothermal decompression TZM experiments. The starting composition is a synthetic glass based on the 1921 Kilauea basalt, with 1% H2O added. In all cases, the liquidus phase is aluminous spinel, followed by clinopyroxene, then plagioclase. The plagioclase liquidus temperatures for isobaric (equilibrium) experiments range from 1175°C (at 1.5 kb) to 1217°C (at 200b), which are 35-75°C hotter than predicted by MELTS (Ghiorso & Sack 1995). Experiments were decompressed at 1kb/hr and quenched at 800, 400, 200, or 100b for three temperatures (1160°, 1150°, and 1140°C). Plagioclase crystals formed during decompression have long axes that range from less than 1 micron to 20 microns. Increasing decompression yields larger plagioclase crystal sizes and aspect ratios for experiments at equal temperatures. However, the number of crystals does not vary systematically, indicating that crystallization is dominated by growth rather than nucleation during decompression. Plagioclase compositions for experiments were measured with University of Bristol's Electron Microprobe and the Hyperprobe with Field Emission Gun. Plagioclase compositions from equilibrium experiments (An60-An80) span the range of those from decompression experiments (An60-An73). Equilibrium experiments generated higher An compositions at lower pressures (500b) than at higher pressure (1.5kb) but do not systematically vary with temperature. Variations in plagioclase compositions are minimal above H2O saturation (100-200°C, based on Papale et al., 2006). Below H2O saturation, An content decreases slightly, by approximately 4% An. One application of this work is better characterization of groundmass crystallization in hydrous basalt as it traverses the conduit during eruption. This work also provides a means of distinguishing groundmass plagioclase related to decompression from crystals

  3. Flood basalt eruptions, comet showers, and mass extinction events

    NASA Technical Reports Server (NTRS)

    Rampino, Michael R.; Stothers, Richard B.

    1988-01-01

    A chronology of initiation dates of the major continental flood basalt episodes has been established from compilation of published K-Ar and Ar-Ar ages of basaltic flows and related basic intrusions. The dating is therefore independent of the biostratigraphic and paleomagnetic time scales, and the estimated errors of the inititation dates are approximately + or - 4 pct. There are 11 distinct episodes of continental flood basalts known during the past 250 Myr. The data show that flood basalt episodes are generally relatively brief geologic events, with intermittent eruptions during peak output periods lasting ony 2 to 3 Myr or less. Statistical analyses suggest that these episodes may have occurred quasi-periodically with a mean cycle time of 32 + or - 1 Myr. The initiation dates of the flood basalts are close to the estimated dates of marine mass extinctions and impact-crater clusters. Although a purely internal forcing might be argued for the flood basalt volcanism, quasi-periodic comet impacts may be the trigger for both the flood basalts and the extinctions. Impact cratering models suggest that large-body impactors lead to deep initial cratering, and therefore may cause mantle disturbances and initiate mantle plume activity. The flood basalt episodes commonly mark the initiation or jump of a mantle hotspot, and are often followed by continental rifting and separation. Evidence from dynamical studies of impacts, occurrences of craters and hotspots, and the geochemistry of boundary layers is synthesized to provide a possible model of impact-generated volcanism. Flood basalt eruptions may themselves have severe effects on climate, and possibly on life. Impacts might, as a result, have led to mass extinctions through direct atmospheric disturbances, and/or indirectly through prolonged flood basalt volcanism.

  4. Molybdenum Valence in Basaltic Silicate Melts

    NASA Technical Reports Server (NTRS)

    Danielson, L. R.; Righter, K.; Newville, M.; Sutton, S.; Pando, K.

    2010-01-01

    The moderately siderophile element molybdenum has been used as an indicator in planetary differentiation processes, and is particularly relevant to core formation [for example, 1-6]. However, models that apply experimental data to an equilibrium differentiation scenario infer the oxidation state of molybdenum from solubility data or from multivariable coefficients from metal-silicate partitioning data [1,3,7]. Partitioning behavior of molybdenum, a multivalent element with a transition near the J02 of interest for core formation (IW-2) will be sensitive to changes in JO2 of the system and silicate melt structure. In a silicate melt, Mo can occur in either 4+ or 6+ valence state, and Mo6+ can be either octahedrally or tetrahedrally coordinated. Here we present first XANES measurements of Mo valence in basaltic run products at a range of P, T, and JO2 and further quantify the valence transition of Mo.

  5. Giant Plagioclase "Mosaicrysts" and Other Textures in the Steens Basalt, Columbia River Flood Basalt Province

    NASA Astrophysics Data System (ADS)

    Grunder, A.; Moore, N. E.; Bohrson, W. A.

    2015-12-01

    The Steens Basalts (~16.7 Ma), the oldest and most mafic stage of Columbia River flood basalt volcanism, are known for lavas with conspicuous giant plagioclase laths (2 - 5 cm in diameter). Such flows are intercalated with ones that are nearly aphyric or that bear plagioclase (plag) phenocrysts of 0.5-2 cm. Addition textures are distinctive radial, snowflake plag clusters and sandwich glomerocrysts of plag, with olivine trapped between laths. These clusters and glomerocrysts are typically 1, but as large as 3 cm in diameter. Plag composition of all textural types is limited (An76-60). Plag dominates the phenocryst mode; rare flows, mainly low in the section, have olivine > plag and phenocrystic clinopyroxene occurs rarely, and mainly high in the section. Unlike the flows, dikes have few phenocrysts; giant laths are rare and the snowflake texture has not been observed. Giant plag laths are euhedral and make up a few percent to more than 50% of the rock. Many plag megacrysts are made of several plag crystals that form a mosaic, where the constituent crystals are crystallographically distinct and are overgrown with feldspar to make the crystal euhedral. We describe these composite megacrysts as "mosaicrysts". We are exploring magmatic conditions that would trigger oversaturation to spawn rapid growth yielding clusters and overgrowths that form mosaicrysts. Giant plagioclase basalts (so-called GPB) are also described for the Deccan and Emeishan flood basalt provinces attesting to similar magmatic processes. Plag laths typically define strong flow foliation at the flow base, have a swirled distribution in the flow core, and are sparse in the top. Some particularly crystal-rich flows (or sills) have an abrupt transition to a crystal-poor upper few decimeters of the several-m- thick flow. We interpret the crystal-poor top to be the expelled melt from crystal accumulation in the flow, which locally reinjects and is entrained in lower crystal mush.

  6. Isotope geochemistry of caliche developed on basalt

    NASA Astrophysics Data System (ADS)

    Knauth, L. Paul; Brilli, Mauro; Klonowski, Stan

    2003-01-01

    Enormous variations in oxygen and carbon isotopes occur in caliche developed on < 3 Ma basalts in 3 volcanic fields in Arizona, significantly extending the range of δ 18O and δ 13C observed in terrestrial caliche. Within each volcanic field, δ 18O is broadly co-variant with δ 13C and increases as δ 13C increases. The most 18O and 13C enriched samples are for subaerial calcite developed on pinnacles, knobs, and flow lobes that protrude above tephra and soil. The most 18O and 13C depleted samples are for pedogenic carbonate developed in soil atmospheres. The pedogenic caliche has δ 18O fixed by normal precipitation in local meteoric waters at ambient temperatures and has low δ 13C characteristic of microbial soil CO 2. Subaerial caliche has formed from 18O-rich evapoconcentrated meteoric waters that dried out on surfaces after local rains. The associated 13C enrichment is due either to removal of 12C by photosynthesizers in the evaporating drops or to kinetic isotope effects associated with evaporation. Caliche on basalt lava flows thus initially forms with the isotopic signature of evaporation and is subsequently over-layered during burial by calcite carrying the isotopic signature of the soil environment. The large change in carbon isotope composition in subsequent soil calcite defines an isotopic biosignature that should have developed in martian examples if Mars had a "warm, wet" early period and photosynthesizing microbes were present in the early soils. The approach can be similarly applied to terrestrial Precambrian paleocaliche in the search for the earliest record of life on land. Large variations reported for δ 18O of carbonate in Martian meteorite ALH84001 do not necessarily require high temperatures, playa lakes, or flood runoff if the carbonate is an example of altered martian caliche.

  7. The application of an integrated biogeochemical model (PnET-BGC) to five forested watersheds in the Adirondack and Catskill regions of New York

    USGS Publications Warehouse

    Chen, L.; Driscoll, C.T.; Gbondo-Tugbawa, S.; Mitchell, M.J.; Murdoch, Peter S.

    2004-01-01

    PnET-BGC is an integrated biogeochemical model formulated to simulate the response of soil and surface waters in northern forest ecosystems to changes in atmospheric deposition and land disturbances. In this study, the model was applied to five intensive study sites in the Adirondack and Catskill regions of New York. Four were in the Adirondacks: Constable Pond, an acid-sensitive watershed; Arbutus Pond, a relatively insensitive watershed; West Pond, an acid-sensitive watershed with extensive wetland coverage; and Willy's Pond, an acid-sensitive watershed with a mature forest. The fifth was Catskills: Biscuit Brook, an acid-sensitive watershed. Results indicated model-simulated surface water chemistry generally agreed with the measured data at all five sites. Model-simulated internal fluxes of major elements at the Arbutus watershed compared well with previously published measured values. In addition, based on the simulated fluxes, element and acid neutralizing capacity (ANC) budgets were developed for each site. Sulphur budgets at each site indicated little retention of inputs of sulphur. The sites also showed considerable variability in retention of NO3-. Land-disturbance history and in-lake processes were found to be important in regulating the output of NO3- via surface waters. Deposition inputs of base cations were generally similar at these sites. Various rates of base cation outputs reflected differences in rates of base cation supply at these sites. Atmospheric deposition was found to be the largest source of acidity, and cation exchange, mineral weathering and in-lake processes served as sources of ANC. ?? 2004 John Wiley and Sons, Ltd.

  8. The phylogeny of endolithic microbes associated with marine basalts.

    PubMed

    Mason, Olivia U; Stingl, Ulrich; Wilhelm, Larry J; Moeseneder, Markus M; Di Meo-Savoie, Carol A; Fisk, Martin R; Giovannoni, Stephen J

    2007-10-01

    We examined the phylogenetic diversity of microbial communities associated with marine basalts, using over 300 publicly available 16S rDNA sequences and new sequence data from basalt enrichment cultures. Phylogenetic analysis provided support for 11 monophyletic clades originating from ocean crust (sediment, basalt and gabbro). Seven of the ocean crust clades (OCC) are bacterial, while the remaining four OCC are in the Marine Group I (MGI) Crenarchaeota. Most of the OCC were found at diverse geographic sites, suggesting that these microorganisms have cosmopolitan distributions. One OCC in the Crenarchaeota consisted of sequences derived entirely from basalts. The remaining OCC were found in both basalts and sediments. The MGI Crenarchaeota were observed in all studies where archaeal diversity was evaluated. These results demonstrate that basalts are occupied by cosmopolitan clades of microorganisms that are also found in marine sediments but are distinct from microorganisms found in other marine habitats, and that one OCC in the ubiquitous MGI Crenarchaeota clade may be an ecotype specifically adapted to basalt.

  9. Deep degassing and the eruptibility of flood basalt magmas

    NASA Astrophysics Data System (ADS)

    Black, B. A.; Manga, M.

    2015-12-01

    Individual flood basalt lavas often exceed 103 km3 in volume, and many such lavas erupt during emplacement of flood basalt provinces. The large volume of individual flood basalt lavas demands correspondingly large magma reservoirs within or at the base of the crust. To erupt, some fraction of this magma must become buoyant and overpressure must be sufficient to encourage failure and dike propagation. Because the overpressure associated with a new injection of magma is inversely proportional to the total reservoir volume, buoyancy overpressure has been proposed as a trigger for flood basalt eruptions. To test this hypothesis, we develop a new one-dimensional model for buoyancy overpressure-driven eruptions that combines volatile exsolution, bubble growth and rise, assimilation, and permeable fluid escape through the surrounding country rocks. Degassing during emplacement of flood basalt provinces may have major environmental repercussions. We investigate the temporal evolution of permeable degassing through the crust and degassing during eruptive episodes. We find that assimilation of volatile-rich country rocks strongly enhances flood basalt eruptibility, implying that the eruptive dynamics of flood basalts may be intertwined with their climatic consequences.

  10. The phylogeny of endolithic microbes associated with marine basalts.

    PubMed

    Mason, Olivia U; Stingl, Ulrich; Wilhelm, Larry J; Moeseneder, Markus M; Di Meo-Savoie, Carol A; Fisk, Martin R; Giovannoni, Stephen J

    2007-10-01

    We examined the phylogenetic diversity of microbial communities associated with marine basalts, using over 300 publicly available 16S rDNA sequences and new sequence data from basalt enrichment cultures. Phylogenetic analysis provided support for 11 monophyletic clades originating from ocean crust (sediment, basalt and gabbro). Seven of the ocean crust clades (OCC) are bacterial, while the remaining four OCC are in the Marine Group I (MGI) Crenarchaeota. Most of the OCC were found at diverse geographic sites, suggesting that these microorganisms have cosmopolitan distributions. One OCC in the Crenarchaeota consisted of sequences derived entirely from basalts. The remaining OCC were found in both basalts and sediments. The MGI Crenarchaeota were observed in all studies where archaeal diversity was evaluated. These results demonstrate that basalts are occupied by cosmopolitan clades of microorganisms that are also found in marine sediments but are distinct from microorganisms found in other marine habitats, and that one OCC in the ubiquitous MGI Crenarchaeota clade may be an ecotype specifically adapted to basalt. PMID:17803778

  11. Petrologic models of 15388, a unique Apollo 15 mare basalt

    NASA Technical Reports Server (NTRS)

    Hughes, S. S.; Dasch, E. J.; Nyquist, L. E.

    1993-01-01

    Mare basalt 15388, a feldspathic microgabbro from the Apennine Front, is chemically and petrographically distinct from Apollo 15 picritic, olivine-normative (ON), and quartz-normative basalts. The evolved chemistry, coarse texture, lack of olivine, and occurrence of cristobalite in 15388 argue for derivation by a late-stage magmatic process that is significantly removed from parental magma. It either crystallized from a magma evolved from the more mafic Apollo 15 basalts, or it crystallized from a currently unrepresented magma. Rb-Sr and Sm-Nd isotopic systematics yield isochron ages of 3.391 plus or minus 0.036 and 3.42 plus or minus 0.07 Ga, respectively, and epsilon(sub Nd) = 8.6 plus or minus 2.4, which is relatively high for Apollo 15 mare basalts. In contrast to chemical patterns of average Apollo 15 ON basalts and Apollo 15 picritic basalt, 15388 has a strongly positive LREE slope, high Ti, shallower HREE slope and a slightly positive Eu anomaly. These features argue against 15388 evolution by simple olivine fractionation of a parental ON or picritic basalt magma, although olivine is a dominant liquidus phase in both potential parents.

  12. Modeling Cooling Rates of Martian Flood Basalt Columns

    NASA Astrophysics Data System (ADS)

    Weiss, D. K.; Jackson, B.; Milazzo, M. P.; Barnes, J. W.

    2011-12-01

    Columnar jointing in large basalt flows have been extensively studied and can provide important clues about the emplacement conditions and cooling history of a basalt flow. The recent discovery of basalt columns on Mars in crater walls near Marte Vallis provides an opportunity to infer conditions on early Mars when the Martian basalt flows were laid down. Comparison of the Martian columns to Earth analogs allows us to gain further insight into the early Martian climate, and among the best terrestrial analogs are the basalt columns in the Columbia River Basalt Group (CRBG) in eastern Washington. The CRBG is one of the youngest (< 17 Myrs old) and most extensively studied basalt provinces in the world, extending over 163,700 square km with total thickness exceeding 1 km in some places. The morphologies and textures of CRBG basalt columns suggest that in many places flows ~100 m thick cooled at uniform rates, even deep in the flow interior. Such cooling seems to require the presence of water in the column joints since the flow interiors should have cooled much more slowly than the flow margins if conductive cooling dominated. Secondary features, such pillow basalts, likewise suggest the basalt flows were in direct contact with standing water in many places. At the resolution provided by the orbiting HiRISE camera (0.9 m), the Martian basalt columns resemble the CRBG columns in many respects, and so, subject to important caveats, inferences linking the morphologies of the CRBG columns to their thermal histories can be extended in some respects to the Martian columns. In this presentation, we will describe our analysis of the HiRISE images of the Martian columns and what can be reasonably inferred about their thermal histories and the conditions under which they were emplaced. We will also report on a field expedition to the CRBG in eastern Washington State. During that expedition, we surveyed basalt column outcrops on the ground and from the air using Unmanned Aerial

  13. Mineral chemistry of Pangidi basalt flows from Andhra Pradesh

    NASA Astrophysics Data System (ADS)

    Nageswara Rao, P. V.; Swaroop, P. C.; Karimulla, Syed

    2012-04-01

    This paper elucidates the compositional studies on clinopyroxene, plagioclase, titaniferous magnetite and ilmenite of basalts of Pangidi area to understand the geothermometry and oxybarometry conditions. Petrographic evidence and anorthite content (up to 85%) of plagioclase and temperature estimates of clinopyroxene indicate that the clinopyroxene is crystallized later than or together with plagioclase. The higher An content indicates that the parent magma is tholeiitic composition. The equilibration temperatures of clinopyroxene (1110-1190°C) and titaniferous magnetite and ilmenite coexisting mineral phases (1063-1103°C) are almost similar in lower basalt flow and it is higher for clinopyroxene (900-1110°C) when compared to titaniferous magnetite and ilmenite coexisting mineral phases (748-898°C) in middle and upper basalt flows. From this it can be inferred that the clinopyroxene is crystallized earlier than Fe-Ti oxide phases reequilibration, which indicates that the clinopyroxene temperature is the approximate eruption temperature of the present lava flows. The wide range of temperatures (900-1190°C) attained by clinopyroxene may point out that the equilibration of clinopyroxene crystals initiated from depth till closer to the surface before the melt erupted. Pangidi basalts follow the QFM buffer curve which indicates the more evolved tholeiitic composition. This suggests the parent tholeiitic magma suffered limited fractionation at high temperature under increasing oxygen fugacity in lower basalt flow and more fractionation at medium to lower temperatures under decreasing oxygen fugacity conditions during cooling of middle and upper basalt flows. The variation of oxygen fugacity indicates the oxidizing conditions for lower basalt flow (9.48-10.3) and extremely reducing conditions for middle (12.1-15.5) and upper basalt (12.4-15.54) flows prevailed at the time of cooling. Temperature vs. (FeO+Fe2O3)/(FeO+Fe2O3 +MgO) data plots for present basalts suggested

  14. An Apollo 15 Mare Basalt Fragment and Lunar Mare Provinces

    NASA Technical Reports Server (NTRS)

    Ryder, Graham; Burling, Trina Cox

    1996-01-01

    Lunar sample 15474,4 is a tiny fragment of olivine-augite vitrophyre that is a mare basalt. Although petroraphically distinct from all other Apollo 15 samples, it has been ignored since its first brief description. Our new petrographic and mineral chemical data show that the olivines and pyroxenes are distinct from those in other basalts. The basalt cooled and solidified extremely rapidly; some of the olivine might be cumulate or crystallized prior to extrusion. Bulk-chemical data show that the sample is probably similar to an evolved Apollo 15 olivine-normative basalt in major elements but is distinct in its rare earth element pattern. Its chemical composition and petrography both show that 15474,4 cannot be derived from other Apollo 15 mare basalts by shallow-level crystal fractionation. It represents a distinct extrusion of magma. Nonetheless, the chemical features that 15474,4 has in common with other Apollo 15 mare basalts, including the high FeO/Sc, the general similarity of the rare earth element pattern, and the common (and chondritic) TiO2/Sm ratio, emphasize the concept of a geochemical province at the Apollo 15 site that is distinct from basalts and provinces elsewhere. In making a consistent picture for the derivation of all of the Apollo 15 basalts, both the commonalities and the differences among the basalts must be explained. The Apollo 15 commonalities and differences suggest that the sources must have consisted of major silicate phases with the same composition but with varied amounts of a magma trapped from a contemporary magma ocean. They probably had a high olivine/pyroxene ratio and underwent small and reasonably consistent degrees of partial melting to produce the basalts. These inferences may be inconsistent with models that suggest greatly different depths of melting among basalts, primitive sources for the green glasses, or extensive olivine fractionation during ascent. An integrated approach to lunar mare provinces, of which the Apollo 15

  15. Pliocene Basaltic Volcanism in The East Anatolia Region (EAR), Turkey

    NASA Astrophysics Data System (ADS)

    Oyan, Vural; Özdemir, Yavuz; Keskin, Mehmet

    2016-04-01

    East Anatolia Region (EAR) is one of the high Plateau which is occurred with north-south compressional regime formed depending on continent-continent collision between Eurasia and Arabia plates (Şengör and Kidd, 1979). Recent studies have revealed that last oceanic lithosphere in the EAR have completely depleted to 20 million years ago based on fission track ages (Okay et al. 2010). Our initial studies suggest that extensively volcanic activity in the EAR peaked in the Pliocene and continued in the same productivity throughout Quaternary. Voluminous basaltic lava plateaus and basaltic lavas from local eruption centers occurred as a result of high production level of volcanism during the Pliocene time interval. In order to better understand the spatial and temporal variations in Pliocene basaltic volcanism and to reveal isotopic composition, age and petrologic evolution of the basaltic volcanism, we have started to study basaltic volcanism in the East Anatolia within the framework of a TUBITAK project (project number:113Y406). Petrologic and geochemical studies carried out on the Pliocene basaltic lavas indicate the presence of subduction component in the mantle source, changing the character of basaltic volcanism from alkaline to subalkaline and increasing the amount of spinel peridotitic melts (contributions of lithospheric mantle?) in the mantle source between 5.5-3.5 Ma. FC, AFC and EC-AFC modelings reveal that the while basaltic lavas were no or slightly influenced by crustal contamination and fractional crystallization, to more evolved lavas such as bazaltictrachyandesite, basalticandesite, trachybasalt might have been important processes. Results of our melting models and isotopic analysis data (Sr, Nd, Pb, Hf, 18O) indicate that the Pliocene basaltic rocks were derived from both shallow and deep mantle sources with different melting degrees ranging between 0.1 - 4 %. The percentage of spinel seems to have increased in the mantle source of the basaltic

  16. Iron-induced hydroxyl radical generation from basaltic volcanic ash

    NASA Astrophysics Data System (ADS)

    Horwell, C. J.; Fenoglio, I.; Fubini, B.

    2007-09-01

    Iron-induced hydroxyl radical generation from the surface of volcanic ash particles is a possible mechanism of respiratory toxicity in addition to crystalline silica induced pathogenicity. Here we show that volcanic ash generates hydroxyl radicals, with greater reactivity in iron-rich, silica-poor samples, such as basaltic ash. Basaltic particles expose at the surface high levels of poorly-coordinated iron ions in both Fe(II) and Fe(III) oxidation states which are likely to be the cause of such reactivity. Hitherto, basaltic ash has been disregarded as a hazard due to the lack of crystalline silica particulate but future hazard assessment should consider its toxic potential.

  17. Basaltic volcanic episodes of the Yucca Mountain region

    SciTech Connect

    Crowe, B.M.

    1990-03-01

    The purpose of this paper is to summarize briefly the distribution and geologic characteristics of basaltic volcanism in the Yucca Mountain region during the last 10--12 Ma. This interval largely postdates the major period of silicic volcanism and coincides with and postdates the timing of major extensional faulting in the region. Field and geochronologic data for the basaltic rocks define two distinct episodes. The patterns in the volume and spatial distribution of these basaltic volcanic episodes in the central and southern part of the SNVF are used as a basis for forecasting potential future volcanic activity in vicinity of Yucca Mountain. 33 refs., 2 figs.

  18. Stereo Pair: Basalt Cliffs, Patagonia, Argentina

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Basalt cliffs along the northwest edge of the Meseta de Somuncura plateau near Sierra Colorada, Argentina show an unusual and striking pattern of erosion. Stereoscopic observation helps to clarify the landform changing processes active here. Many of the cliffs appear to be rock staircases that have the same color as the plateau's basaltic cap rock. Are these the edges of lower layers in the basalt or are they a train of slivers that are breaking off from, then sliding downslope and away from, the cap rock. They appear to be the latter. Close inspection shows that each stair step is too laterally irregular to be a continuous sheet of bedrock like the cap rock. Also, the steps are not flat but instead are little ridges, as one might expect from broken, tilted, and sliding slices of the cap rock. Stream erosion has cut some gullies into the cliffs and green vegetation shows that water springs from and flows down some channels, but landsliding is clearly a major agent of erosion here.

    This cross-eyed stereoscopic image pair was generated using topographic data from the Shuttle Radar Topography Mission, combined with an enhanced Landsat 7satellite color image. The topography data are used to create two differing perspectives of a single image, one perspective for each eye. In doing so, each point in the image is shifted slightly, depending on its elevation. When stereoscopically merged, the result is a vertically exaggerated view of the Earth's surface in its full three dimensions.

    Landsat satellites have provided visible light and infrared images of the Earth continuously since 1972. SRTM topographic data match the 30-meter (99-foot) spatial resolution of most Landsat images and provide a valuable complement for studying the historic and growing Landsat data archive. The Landsat 7 Thematic Mapper image used here was provided to the SRTM project by the United States Geological Survey, Earth Resources Observation Systems (EROS) Data Center,Sioux Falls, South

  19. Melt rock components in KREEPy breccia 15205: Petrography and mineral chemistry of KREEP basalts and quartz-normative mare basalts

    NASA Technical Reports Server (NTRS)

    Shervais, John W.; Vetter, Scott K.

    1993-01-01

    Many current models for the origin of lunar highland rocks feature as an essential component the assimilation of KREEPy material by primitive magmas parental to the Mg-rich suite and alkali suite plutonic rocks. Similar models have also been proposed for the origin of various mare basalt suites. However, any model which considers assimilation of KREEP an important petrologic process must sooner-or-later deal with the question: what is KREEP? Because pristine KREEP basalts are rare, and most known samples are small (e.g., 15382/15386), the geochemical variability of KREEP basalts is poorly known. Other KREEP compositions which are commonly used in these models include the hypothetical 'high-K KREEP' component of Warren and Wasson, which is derived from Apollo 14 soil data, and the 'superKREEP' quartz-monzodiorite 15405. Lunar breccia 15205 is a polymict regolith breccia that consists of approximately 20% KREEP basalt clasts and 20% quartz-normative basalt clasts in a KREEP-rich matrix. Bulk rock mixing calculations show that this sample comprises about 84% KREEP. The clasts range up to 1 cm in size, but most are considerably smaller. The primary aim is to characterize pristine KREEP basalts petrographically, to establish the range in chemical compositions of KREEP basalts, and to test models that were proposed for their origin. In addition, we may be able to extend the compositional range recognized in the quartz-normative basalt suite and cast some light on its origin as well. Preliminary whole rock geochemical data on the KREEP basalts are presented in a companion paper by M.M. Lindstrom and co-workers. Concentration is on petrography and mineral chemistry of these clasts, and the implications these data have for the origin of the different melt rock suites.

  20. Spreading and collapse of big basaltic volcanoes

    NASA Astrophysics Data System (ADS)

    Puglisi, Giuseppe; Bonforte, Alessandro; Guglielmino, Francesco; Peltier, Aline; Poland, Michael

    2016-04-01

    Among the different types of volcanoes, basaltic ones usually form the most voluminous edifices. Because volcanoes are growing on a pre-existing landscape, the geologic and structural framework of the basement (and earlier volcanic landforms) influences the stress regime, seismicity, and volcanic activity. Conversely, the masses of these volcanoes introduce a morphological anomaly that affects neighboring areas. Growth of a volcano disturbs the tectonic framework of the region, clamps and unclamps existing faults (some of which may be reactivated by the new stress field), and deforms the substratum. A volcano's weight on its basement can trigger edifice spreading and collapse that can affect populated areas even at significant distance. Volcano instability can also be driven by slow tectonic deformation and magmatic intrusion. The manifestations of instability span a range of temporal and spatial scales, ranging from slow creep on individual faults to large earthquakes affecting a broad area. In the frame of MED-SVU project, our work aims to investigate the relation between basement setting and volcanic activity and stability at three Supersite volcanoes: Etna (Sicily, Italy), Kilauea (Island of Hawaii, USA) and Piton de la Fournaise (La Reunion Island, France). These volcanoes host frequent eruptive activity (effusive and explosive) and share common features indicating lateral spreading and collapse, yet they are characterized by different morphologies, dimensions, and tectonic frameworks. For instance, the basaltic ocean island volcanoes of Kilauea and Piton de la Fournaise are near the active ends of long hotspot chains while Mt. Etna has developed at junction along a convergent margin between the African and Eurasian plates and a passive margin separating the oceanic Ionian crust from the African continental crust. Magma supply and plate velocity also differ in the three settings, as to the sizes of the edifices and the extents of their rift zones. These

  1. Alteration of hydrovolcanic basaltic ash - Observations with visible and near-infrared spectrometry

    NASA Technical Reports Server (NTRS)

    Farrand, William H.; Singer, Robert B.

    1992-01-01

    Altered basaltic tephras from tuff rings and tuff cones across the Basin and Range were examined using visible and NIR (Vis/IR) reflectance spectrometry and a variety of other techniques. It was found that Vis/IR spectrometry is sensitive to subtle changes in the hydration and oxidation state of these tephras. In the tuffs examined, ferrous and ferric iron minerals produce one composite absorption feature rather than two resolvable bands. Different styles of alteration were noted between thinly bedded tuff ring deposits emplaced by high energy, largely dry, pyroclastic surge and massively bedded tuff cone deposits emplaced by wetter, lower energy pyroclastic flow. The former class of tephras become hydrated and only moderately oxidized with some limited development of dioctehedral smectite clay minerals and minimal palagomitization. The latter class of tephras are highly palagonitized which implies a high degree of hydration and oxidation. In the most of highly altered tephras, all the Fe(2+) that is initially in the volcanic glass is converted to Fe(3+) within nanophase and bulk ferric oxide phases in the palagonite. There is also more extensive development in tuff cone beds of zeolite and phyllosilicate minerals. The differences in reflectance spectra of altered basaltic tephras can be traced to initial differences in the water/magma ratio extant at the volcanic vent.

  2. Computation of EABF and EBF for basalt rock samples

    NASA Astrophysics Data System (ADS)

    Karabul, Yaşar; Amon Susam, Lidya; İçelli, Orhan; Eyecioğlu, Önder

    2015-10-01

    In this study, certain photon absorption parameters including the energy absorption buildup factor (EABF) and exposure buildup factor (EBF) have been investigated for three different basalt samples collected from different parts of Van city. Radiation shielding properties of the basalt samples indicated a strong correlation between photon energy absorption parameters and values of EABF and EBF of basalt samples. It was found that EABF and EBF parameters are related to radiation shielding properties of basalt samples. A new method and algorithm based on ZXCOM was used. Instead of calculating G-P fitting parameters for every effective atomic number (Zeff), EABF and EBF were calculated for Zeff by interpolation, using ANSI/ANS 6.4.3 standard data available for Zeff.

  3. Mineralogy of Silica Polymorphs in Basaltic Clasts in Eucrites

    NASA Astrophysics Data System (ADS)

    Ono, H.; Takenouchi, A.; Mikouchi, T.

    2016-08-01

    We analyzed silica polymorphs in basaltic clasts in Y-75011, Pasamonte and Stannern eucrites. Cristobalite and quartz have been found, which suggests wide occurrence of hydrothermal activity throughout the crust of Vesta.

  4. A Modified CIPW Norm Calculation for Lunar Mare Basalts

    NASA Technical Reports Server (NTRS)

    Milliken, R. E.; Basu, A.

    2000-01-01

    CIPW norms of lunar mare basalts are anomalously low in pyroxene. A modified norm calculation allowing higher Ca, Ti, Al, Cr, and Mn in di' and hy' obtains closer matches between normative and modal mineralogy.

  5. Systematics of Vanadium in Olivine from Planetary Basalts

    NASA Technical Reports Server (NTRS)

    Karner, J. M.; Papike, J. J.; Shearer, C. K.

    2002-01-01

    The systematics of vanadium in olivines from the Earth, Moon and Mars allows for the comparison of planetary basalt origin and igneous setting and process. Additional information is contained in the original extended abstract.

  6. Basaltic Cone Suggests Constructional Origin of Some Guyots.

    PubMed

    Christensen, M N; Gilbert, C M

    1964-01-17

    A basaltic cinder cone was built beneath the waters of Mono Lake in Pleistocene time. This cone is now exposed. Its internal structure, external form, and petrography suggest that it was constructed with a flat top.

  7. Basaltic Cone Suggests Constructional Origin of Some Guyots.

    PubMed

    Christensen, M N; Gilbert, C M

    1964-01-17

    A basaltic cinder cone was built beneath the waters of Mono Lake in Pleistocene time. This cone is now exposed. Its internal structure, external form, and petrography suggest that it was constructed with a flat top. PMID:17753148

  8. Potential for Carbon Dioxide Sequestration in Flood Basalts

    SciTech Connect

    McGrail, B. PETER; Schaef, Herbert T.; Ho, Anita M.; Chien, Yi-Ju; Dooley, James J.; Davidson, Casie L.

    2006-12-01

    Flood basalts are a potentially important host medium for geologic sequestration of anthropogenic CO2. Most lava flows have flow tops that are porous, permeable, and have enormous capacity for storage of CO2. Interbedded sediment layers and dense low-permeability basalt rock overlying sequential flows may act as effective seals allowing time for mineralization reactions to occur. Laboratory experiments confirm relatively rapid chemical reaction of CO2-saturated pore water with basalts to form stable carbonate minerals. Calculations suggest a sufficiently short time frame for onset of carbonate precipitation after CO2 injection that verification of in situ mineralization rates appears feasible in field pilot studies. If proven viable, major flood basalts in the U.S. and India would provide significant additional CO2 storage capacity and additional geologic sequestration options in certain regions where more conventional storage options are limited.

  9. Experimental Confirmation of the Volatility of Germanium in Martian Basalts

    NASA Astrophysics Data System (ADS)

    Humayun, M.; DiFrancesco, N.; Ustunisik, G.

    2016-08-01

    Experimental degassing of a synthetic martian basalt doped with Ge and Zn resulted in nearly total loss of both elements after 6 hours of heating, implying that the Ge depletion in shergottites is complemented by Ge excesses in sedimentary rocks.

  10. [Comparative carcinogenic properties of basalt fiber and chrysotile-asbestos].

    PubMed

    Nikitina, O V; Kogan, F M; Vanchugova, N N; Frash, V N

    1989-01-01

    In order to eliminate asbestos adverse effect on workers' health it was necessary to use mineral rayon, primarily basalt fibre, instead of asbestos. During a chronic experiment on animals the oncogenicity of 2 kinds of basalt fibre was studied compared to chrysotile asbestos. The dust dose of 25 mg was twice administered by intraperitonial route. All types of dust induced the onset of intraperitonial mesotheliomas but neoplasm rates were significantly lower in the groups exposed to basalt fibre. There was no credible data on the differences between the groups exposed to various types of basalt fibre. Since the latter produced some oncogenic effect, it was necessary to develop a complex of antidust measures, fully corresponding to the measures adopted for carcinogenic dusts.

  11. Low temperature aqueous alteration of basalt: Mineral assemblages of Deccan basalts and implications for Mars

    NASA Astrophysics Data System (ADS)

    Greenberger, R. N.; Mustard, J. F.; Kumar, P. S.; Dyar, M. D.; Breves, E. A.; Sklute, E. C.

    2012-09-01

    Al-rich phyllosilicates (kaolinite, montmorillonite) have been found in layers overlying Fe/Mg-smectites on Mars, and it has been suggested that this stratigraphy formed through in situ leaching at the surface, similar to terrestrial weathering profiles. We are investigating the remotely sensed signatures of this type of weathering using ten samples from a vertical section of altered Deccan basalts and four samples collected nearby as an analog for leaching resulting in Al-rich phyllosilicate over Fe/Mg-smectite stratigraphies. Samples were analyzed with reflectance spectroscopy from 0.28 to 25.0 μm, inductively coupled plasma atomic emission spectrometry for 10 major element concentrations (Al, Ca, Fe, K, Mg, Mn, Na, P, Si, Ti), loss on ignition for volatiles, x-ray diffraction (XRD) for mineralogies, and Mössbauer spectroscopy for Fe redox state. Spectra of basalt samples were dominated by Fe2+ crystal field transitions with weak alteration bands near 1.4 and/or 1.9 μm. Reststrahlen bands in mid-infrared showed the convolution of plagioclase and pyroxene features typical of basalts. Saprolite samples were incompletely leached, and their spectra were dominated by complex Al- and Fe/Mg-bearing smectite clays and retained no original mafic signatures. XRD and Mössbauer detected pyroxene and plagioclase not visible by reflectance spectroscopy in some saprolite samples. Zeolites were present throughout the saprolite. The laterite was the most leached horizon, and all analyses showed kaolinite and iron oxide assemblages. This kaolinite and hematite association would be expected if kaolinite on Mars formed through leaching under conditions similar to those on Earth and has implications for abundant freshwater on the Martian surface.

  12. Basalt Waste Isolation Project Reclamation Support Project:

    SciTech Connect

    Brandt, C.A.; Rickard, W.H. Jr.; Cadoret, N.A.

    1992-06-01

    The Basalt Waste Isolation Project (BWIP) Reclamation Support Project began in the spring of 1988 by categorizing sites distributed during operations of the BWIP into those requiring revegetation and those to be abandoned or transferred to other programs. The Pacific Northwest Laboratory's role in this project was to develop plans for reestablishing native vegetation on the first category of sites, to monitor the implementation of these plans, to evaluate the effectiveness of these efforts, and to identify remediation methods where necessary. The Reclamation Support Project focused on three major areas: geologic hydrologic boreholes, the Exploratory Shaft Facility (ESF), and the Near-Surface Test Facility (NSTF). A number of BWIP reclamation sites seeded between 1989 and 1990 were found to be far below reclamation objectives. These sites were remediated in 1991 using various seedbed treatments designed to rectify problems with water-holding capacity, herbicide activity, surficial crust formation, and nutrient imbalances. Remediation was conducted during November and early December 1991. Sites were examined on a monthly basis thereafter to evaluate plant growth responses to these treatments. At all remediation sites early plant growth responses to these treatments. At all remediation sites, early plant growth far exceeded any previously obtained using other methods and seedbed treatments. Seeded plants did best where amendments consisted of soil-plus-compost or fertilizer-only. Vegetation growth on Gable Mountain was less than that found on other areas nearby, but this difference is attributed primarily to the site's altitude and north-facing orientation.

  13. Hafnium isotope variations in oceanic basalts

    NASA Technical Reports Server (NTRS)

    Patchett, P. J.; Tatsumoto, M.

    1980-01-01

    Hafnium isotope ratios generated by the beta(-) decay of Lu-176 are investigated in volcanic rocks derived from the suboceanic mantle. Hf-176/Hf-177 and Lu/Hf ratios were determined to precisions of 0.01-0.04% and 0.5%, respectively, by routine, low-blank chemistry. The Hf-176/Hf-177 ratio is found to be positively correlated with the Nd-143/Nd-144 ratio and negatively correlated with the Sr-87/Sr-86 and Pb-206/Pb-204 ratios, and to increase southwards along the Iceland-Reykjanes ridge traverse. An approximate bulk earth Hf-176/Hf-177 ratio of 0.28295 is inferred from the bulk earth Nd-143/Nd-144 ratio, which requires a bulk earth Lu/Hf ratio of 0.25, similar to the Juvinas eucrite. Midocean ridge basalts are shown to account for 60% of the range of Hf isotope ratios, and it is suggested that Lu-Hf fractionation is decoupled from Sm-Nd and Rb-Sr fractionation in very trace-element-depleted source regions as a result of partial melting.

  14. Diversity of life in ocean floor basalt

    NASA Astrophysics Data System (ADS)

    Thorseth, I. H.; Torsvik, T.; Torsvik, V.; Daae, F. L.; Pedersen, R. B.

    2001-12-01

    Electron microscopy and biomolecular methods have been used to describe and identify microbial communities inhabiting the glassy margins of ocean floor basalts. The investigated samples were collected from a neovolcanic ridge and from older, sediment-covered lava flows in the rift valley of the Knipovich Ridge at a water depth around 3500 m and an ambient seawater temperature of -0.7°C. Successive stages from incipient microbial colonisation, to well-developed biofilms occur on fracture surfaces in the glassy margins. Observed microbial morphologies are various filamentous, coccoidal, oval, rod-shaped and stalked forms. Etch marks in the fresh glass, with form and size resembling the attached microbes, are common. Precipitation of alteration products around microbes has developed hollow subspherical and filamentous structures. These precipitates are often enriched in Fe and Mn. The presence of branching and twisted stalks that resemble those of the iron-oxidising Gallionella, indicate that reduced iron may be utilised in an energy metabolic process. Analysis of 16S-rRNA gene sequences from microbes present in the rock samples, show that the bacterial population inhabiting these samples cluster within the γ- and ɛ-Proteobacteria and the Cytophaga/Flexibacter/Bacteroides subdivision of the Bacteria, while the Archaea all belong to the Crenarchaeota kingdom. This microbial population appears to be characteristic for the rock and their closest relatives have previously been reported from cold marine waters in the Arctic and Antarctic, deep-sea sediments and hydrothermal environments.

  15. Lead isotope systematics of mare basalt 75075

    NASA Technical Reports Server (NTRS)

    Chen, J. H.; Tilton, G. R.; Mattinson, J. M.; Vidal, P.

    1978-01-01

    Uranium, thorium and isotopic lead data are reported for two bulk samples and separated pyroxene, ilmenite and plagioclase from basalt 75075. In a concordia diagram the whole rock, ilmenite and four pyroxene samples define a chord intersecting the concordia curve at approximately 4.25 and 2.8 AE. Three plagioclase samples plot distinctly off the chord. The crystallization age of 75075 is accurately determined at 3.74 AE by Rb-Sr, Sm-Nd and K-Ar measurements from other laboratories. It is not possible to adjust the isotopic composition of initial lead so as to reconcile the U-Pb data with a crystallization age of 3.74 AE. The data therefore indicate some type of post-crystallization disturbance of the U-Pb system that is not detected by the other systems. The 75075 data are one of the few examples of this type of age pattern found on the moon. If the disturbance was a single event, it probably occurred around 2.8 AE ago, the time indicated by the pyroxene, whole rock and ilmenite data.

  16. ON THE PUZZLE OF SPACE WEATHERING ALTERATION OF BASALTIC ASTEROIDS

    SciTech Connect

    Marchi, S.; Lazzarin, M.; Magrin, S.; De Sanctis, M. C. E-mail: monica.lazzarin@unipd.i E-mail: mariacristina.desanctis@iasf-roma.inaf.i

    2010-10-01

    The majority of basaltic asteroids are found in the inner main belt, although a few have also been observed in the outer main belt and near-Earth space. These asteroids-referred to as V-types-have surface compositions that resemble that of the 530 km sized asteroid Vesta. Besides the compositional similarity, dynamical evidence also links many V-type asteroids to Vesta. Moreover, Vesta is one of the few asteroids to have been identified as source of specific classes of meteorites, the howardite, eucrite, and diogenite achondrites (HEDs). Despite the general consensus on the outlined scenario, several questions remain unresolved. In particular, it is not clear if the observed spectral diversity among Vesta, V-types, and HEDs is due to space weathering, as is thought to be the case for S-type asteroids. In this Letter, SDSS photometry is used to address the question of whether the spectral diversity among candidate V-types and HEDs can be explained by space weathering. We show that visible spectral slopes of V-types are systematically redder with respect to HEDs, in a similar way to what is found for ordinary chondrite meteorites and S-types. On the assumption that space weathering is responsible for the slope mismatch, we estimated an upper limit for the reddening timescale of about 0.5 Ga. Nevertheless, the observed slope mismatch between HEDs and V-types poses several puzzles to understanding its origin. The implication of our findings is also discussed in light of the Dawn mission to Vesta.

  17. Class Size.

    ERIC Educational Resources Information Center

    Ellis, Thomas I.

    1985-01-01

    After a brief introduction identifying current issues and trends in research on class size, this brochure reviews five recent studies bearing on the relationship of class size to educational effectiveness. Part 1 is a review of two interrelated and highly controversial "meta-analyses" or statistical integrations of research findings on class size,…

  18. Class Matters

    ERIC Educational Resources Information Center

    Valdata, Patricia

    2005-01-01

    Ever since George Washington opted for the title of president rather than king, Americans have been uncomfortable with the idea of class distinctions. This article presents an interview with Dr. Janet Galligani Casey regarding the idea of class distinctions. Galligani Casey, who grew up in a working-class neighborhood in Somerville, Massachusetts,…

  19. Radiolytic Hydrogen Production in the Subseafloor Basaltic Aquifer.

    PubMed

    Dzaugis, Mary E; Spivack, Arthur J; Dunlea, Ann G; Murray, Richard W; D'Hondt, Steven

    2016-01-01

    Hydrogen (H2) is produced in geological settings by dissociation of water due to radiation from radioactive decay of naturally occurring uranium ((238)U, (235)U), thorium ((232)Th) and potassium ((40)K). To quantify the potential significance of radiolytic H2 as an electron donor for microbes within the South Pacific subseafloor basaltic aquifer, we use radionuclide concentrations of 43 basalt samples from IODP Expedition 329 to calculate radiolytic H2 production rates in basement fractures. The samples are from three sites with very different basement ages and a wide range of alteration types. U, Th, and K concentrations vary by up to an order of magnitude from sample to sample at each site. Comparison of our samples to each other and to the results of previous studies of unaltered East Pacific Rise basalt suggests that significant variations in radionuclide concentrations are due to differences in initial (unaltered basalt) concentrations (which can vary between eruptive events) and post-emplacement alteration. However, there is no clear relationship between alteration type and calculated radiolytic yields. Local maxima in U, Th, and K produce hotspots of H2 production, causing calculated radiolytic rates to differ by up to a factor of 80 from sample to sample. Fracture width also greatly influences H2 production, where microfractures are hotspots for radiolytic H2 production. For example, H2 production rates normalized to water volume are 190 times higher in 1 μm wide fractures than in fractures that are 10 cm wide. To assess the importance of water radiolysis for microbial communities in subseafloor basaltic aquifers, we compare electron transfer rates from radiolysis to rates from iron oxidation in subseafloor basalt. Radiolysis appears likely to be a more important electron donor source than iron oxidation in old (>10 Ma) basement basalt. Radiolytic H2 production in the volume of water adjacent to a square cm of the most radioactive SPG basalt may support as

  20. Basalt: Biologic Analog Science Associated with Lava Terrains

    NASA Astrophysics Data System (ADS)

    Lim, D. S. S.; Abercromby, A.; Kobs-Nawotniak, S. E.; Kobayashi, L.; Hughes, S. S.; Chappell, S.; Bramall, N. E.; Deans, M. C.; Heldmann, J. L.; Downs, M.; Cockell, C. S.; Stevens, A. H.; Caldwell, B.; Hoffman, J.; Vadhavk, N.; Marquez, J.; Miller, M.; Squyres, S. W.; Lees, D. S.; Fong, T.; Cohen, T.; Smith, T.; Lee, G.; Frank, J.; Colaprete, A.

    2015-12-01

    This presentation will provide an overview of the BASALT (Biologic Analog Science Associated with Lava Terrains) program. BASALT research addresses Science, Science Operations, and Technology. Specifically, BASALT is focused on the investigation of terrestrial volcanic terrains and their habitability as analog environments for early and present-day Mars. Our scientific fieldwork is conducted under simulated Mars mission constraints to evaluate strategically selected concepts of operations (ConOps) and capabilities with respect to their anticipated value for the joint human and robotic exploration of Mars. a) Science: The BASALT science program is focused on understanding habitability conditions of early and present-day Mars in two relevant Mars-analog locations (the Southwest Rift Zone (SWRZ) and the East Rift Zone (ERZ) flows on the Big Island of Hawai'i and the eastern Snake River Plain (ESRP) in Idaho) to characterize and compare the physical and geochemical conditions of life in these environments and to learn how to seek, identify, and characterize life and life-related chemistry in basaltic environments representing these two epochs of martian history. b) Science Operations: The BASALT team will conduct real (non-simulated) biological and geological science at two high-fidelity Mars analogs, all within simulated Mars mission conditions (including communication latencies and bandwidth constraints) that are based on current architectural assumptions for Mars exploration missions. We will identify which human-robotic ConOps and supporting capabilities enable science return and discovery. c) Technology: BASALT will incorporate and evaluate technologies in to our field operations that are directly relevant to conducting the scientific investigations regarding life and life-related chemistry in Mars-analogous terrestrial environments. BASALT technologies include the use of mobile science platforms, extravehicular informatics, display technologies, communication

  1. Genesis of highland basalt breccias - A view from 66095

    NASA Technical Reports Server (NTRS)

    Garrison, J. R., Jr.; Taylor, L. A.

    1980-01-01

    Electron microprobe and defocused beam analyses of the lunar highland breccia sample 66095 show it consists of a fine-grained subophitic matrix containing a variety of mineral and lithic clasts, such as intergranular and cataclastic ANT, shocked and unshocked plagioclase, and basalts. Consideration of the chemistries of both matrix and clasts provides a basis for a qualitative three-component mixing model consisting of an ANT plutonic complex, a Fra Mauro basalt, and minor meteoric material.

  2. Radiolytic Hydrogen Production in the Subseafloor Basaltic Aquifer.

    PubMed

    Dzaugis, Mary E; Spivack, Arthur J; Dunlea, Ann G; Murray, Richard W; D'Hondt, Steven

    2016-01-01

    Hydrogen (H2) is produced in geological settings by dissociation of water due to radiation from radioactive decay of naturally occurring uranium ((238)U, (235)U), thorium ((232)Th) and potassium ((40)K). To quantify the potential significance of radiolytic H2 as an electron donor for microbes within the South Pacific subseafloor basaltic aquifer, we use radionuclide concentrations of 43 basalt samples from IODP Expedition 329 to calculate radiolytic H2 production rates in basement fractures. The samples are from three sites with very different basement ages and a wide range of alteration types. U, Th, and K concentrations vary by up to an order of magnitude from sample to sample at each site. Comparison of our samples to each other and to the results of previous studies of unaltered East Pacific Rise basalt suggests that significant variations in radionuclide concentrations are due to differences in initial (unaltered basalt) concentrations (which can vary between eruptive events) and post-emplacement alteration. However, there is no clear relationship between alteration type and calculated radiolytic yields. Local maxima in U, Th, and K produce hotspots of H2 production, causing calculated radiolytic rates to differ by up to a factor of 80 from sample to sample. Fracture width also greatly influences H2 production, where microfractures are hotspots for radiolytic H2 production. For example, H2 production rates normalized to water volume are 190 times higher in 1 μm wide fractures than in fractures that are 10 cm wide. To assess the importance of water radiolysis for microbial communities in subseafloor basaltic aquifers, we compare electron transfer rates from radiolysis to rates from iron oxidation in subseafloor basalt. Radiolysis appears likely to be a more important electron donor source than iron oxidation in old (>10 Ma) basement basalt. Radiolytic H2 production in the volume of water adjacent to a square cm of the most radioactive SPG basalt may support as

  3. Radiolytic Hydrogen Production in the Subseafloor Basaltic Aquifer

    PubMed Central

    Dzaugis, Mary E.; Spivack, Arthur J.; Dunlea, Ann G.; Murray, Richard W.; D’Hondt, Steven

    2016-01-01

    Hydrogen (H2) is produced in geological settings by dissociation of water due to radiation from radioactive decay of naturally occurring uranium (238U, 235U), thorium (232Th) and potassium (40K). To quantify the potential significance of radiolytic H2 as an electron donor for microbes within the South Pacific subseafloor basaltic aquifer, we use radionuclide concentrations of 43 basalt samples from IODP Expedition 329 to calculate radiolytic H2 production rates in basement fractures. The samples are from three sites with very different basement ages and a wide range of alteration types. U, Th, and K concentrations vary by up to an order of magnitude from sample to sample at each site. Comparison of our samples to each other and to the results of previous studies of unaltered East Pacific Rise basalt suggests that significant variations in radionuclide concentrations are due to differences in initial (unaltered basalt) concentrations (which can vary between eruptive events) and post-emplacement alteration. However, there is no clear relationship between alteration type and calculated radiolytic yields. Local maxima in U, Th, and K produce hotspots of H2 production, causing calculated radiolytic rates to differ by up to a factor of 80 from sample to sample. Fracture width also greatly influences H2 production, where microfractures are hotspots for radiolytic H2 production. For example, H2 production rates normalized to water volume are 190 times higher in 1 μm wide fractures than in fractures that are 10 cm wide. To assess the importance of water radiolysis for microbial communities in subseafloor basaltic aquifers, we compare electron transfer rates from radiolysis to rates from iron oxidation in subseafloor basalt. Radiolysis appears likely to be a more important electron donor source than iron oxidation in old (>10 Ma) basement basalt. Radiolytic H2 production in the volume of water adjacent to a square cm of the most radioactive SPG basalt may support as many as

  4. Shocked basalt from Lonar Impact Crater, India, and experimental analogues

    NASA Technical Reports Server (NTRS)

    Kieffer, S. W.; Schaal, R. B.; Gibbons, R.; Horz, F.; Milton, D. J.; Dube, A.

    1976-01-01

    Samples of Lonar basalts were experimentally shocked in vacuum to pressures between 200 and 650 kbar by a 20 mm, high-velocity gun. Plagioclase and palagonite in experimentally shocked samples show deformation similar to that in the naturally shocked rocks, but pyroxene does not show optically resolvable edge melting. It is estimated that pressures in excess of 800-1000 kbar are required for the formation of totally shock-melted rocks from nonporous basalt.

  5. Modes of emplacement of basalt terrains and an analysis of mare volcanism in the Orientale Basin

    NASA Technical Reports Server (NTRS)

    Greeley, R.

    1976-01-01

    Three distinctive types of basalt terrains can be recognized on earth on the basis of surface morphology: flood basalts, shield basalts, and plains basalts, each of which reflects unique styles of eruption and modes of emplacement. Two of these, flood basalts and plains basalts, appear to be important in the emplacement of mare basalts on the moon. Using surface features as identifying criteria, mare units in the Orientale Basin were examined and the following emplacement sequence was derived: (1) initial emplacement of impact melt in the basin center, (2) eruption of flood-type basalts in the basin center and approximately concurrent emplacement of plains type basalts in Lacus Veris, and (3) emplacement of plains type basalts in Lacus Autumni

  6. Testing the Origins of Basalt Fragments fro Apollo 16

    NASA Technical Reports Server (NTRS)

    Donohue, P. H.; Stevens, R. E.; Neal, C. R.; Zeigler, R. A.

    2013-01-01

    Several 2-4 mm regolith fragments of basalt from the Apollo 16 site were recently described by [1]. These included a high-Ti vitrophyric basalts (60603,10-16) and one very-low-titanium (VLT) crystalline basalt (65703,9-13). As Apollo 16 was the only highlands sample return mission distant from the maria, identification of basaltic samples at the site indicates input from remote sites via impact processes [1]. However, distinguishing between impact melt and pristine basalt can be notoriously difficult and requires significant sample material [2-6]. The crystal stratigraphy method utilizes essentially non-destructive methods to make these distinctions [7,8]. Crystal stratigraphy combines quantitative petrography in the form of crystal size distributions (CSDs) coupled with mineral geochemistry to reveal the petrogenetic history of samples. The classic CSD plot of crystal size versus population density can reveal insights on growth/cooling rates, residence times, and magma history which in turn can be used to evaluate basaltic vs impact melt origin [7-9]. Electron microprobe (EMP) and laser ablation (LA)-ICP-MS analyses of mineral phases complement textural investigations. Trace element variations document subtle changes occurring during the formation of the samples, and are key in the interpretation and preservation of this rare lunar sample collection.

  7. Thermal infrared spectroscopy and modeling of experimentally shocked basalts

    USGS Publications Warehouse

    Johnson, J. R.; Staid, M.I.; Kraft, M.D.

    2007-01-01

    New measurements of thermal infrared emission spectra (250-1400 cm-1; ???7-40 ??m) of experimentally shocked basalt and basaltic andesite (17-56 GPa) exhibit changes in spectral features with increasing pressure consistent with changes in the structure of plagioclase feldspars. Major spectral absorptions in unshocked rocks between 350-700 cm-1 (due to Si-O-Si octahedral bending vibrations) and between 1000-1250 cm-1 (due to Si-O antisymmetric stretch motions of the silica tetrahedra) transform at pressures >20-25 GPa to two broad spectral features centered near 950-1050 and 400-450 cm-1. Linear deconvolution models using spectral libraries composed of common mineral and glass spectra replicate the spectra of shocked basalt relatively well up to shock pressures of 20-25 GPa, above which model errors increase substantially, coincident with the onset of diaplectic glass formation in plagioclase. Inclusion of shocked feldspar spectra in the libraries improves fits for more highly shocked basalt. However, deconvolution models of the basaltic andesite select shocked feldspar end-members even for unshocked samples, likely caused by the higher primary glass content in the basaltic andesite sample.

  8. Hotspots, basalts, and the evolution of the mantle

    NASA Technical Reports Server (NTRS)

    Anderson, D. L.

    1981-01-01

    It is noted that the trace element concentration patterns of continental and ocean island basalts and of mid-ocean ridge basalts are complementary. Estimates of the relative sizes of the source regions for these fundamentally different basalt types can be arrived at from the trace element enrichment-depletion patterns. Their combined volume occupies the greater part of the mantle above the 670 km discontinuity. It is pointed out that the source regions separated as a result of early mantle differentiation and crystal fractionation from the resulting melt. The mid-ocean ridge basalts source evolved from an eclogite cumulate that gave up its late-stage enriched fluids at various times to the shallower mantle and continental crust. The mid-ocean ridge basalts source is rich in garnet and clinopyroxene, while the continental and ocean island basalt source is a garnet peridotite that has experienced secondary enrichment. These relationships are found to be consistent with the evolution of a terrestrial magma ocean.

  9. Insulation from basaltic stamp sand. Final technical report

    SciTech Connect

    Williams, F. D.

    1981-04-01

    A Midwest Appropriate Technology Grant was awarded to determine the technical and economic feasibility of producing mineral-fiber insulation directly from extensive deposits of basaltic sand produced during former mining and milling operations in the Keweenaw Peninsula region of Michigan's Upper Peninsula. The amounts of local basaltic sands available and representative chemical compositions were determined. The variation of viscosity with temperature and chemical composition was estimated. Samples were melted and either pulled or blown into fiber. In all cases fiber could be made with a reasonable tensile strength to ensure usefulness. It was concluded that it was technically feasible to produce fibers from basaltic stamp sands of the Upper Peninsula of Michigan. A technical feasibility study using published data, a cost and design analysis of a basalt fiber production plant, a market survey of fiber needs, and an economic analysis for investing in a basalt fiber venture was undertaken. These studies concluded that the local production of basaltic insulation was both feasible and economically reasonable. It was suggested that the plant be located in a region of greater population density with lower utility costs. A representative one-third of these studies is included as appendices A, B, C, and D.

  10. A basalt trigger for the 1991 eruptions of Pinatubo volcano?

    USGS Publications Warehouse

    Pallister, J.S.; Hoblitt, R.P.; Reyes, A.G.

    1992-01-01

    THE eruptive products of calc-alkaline volcanos often show evidence for the mixing of basaltic and acid magmas before eruption (see, for example, refs 1, 2). These observations have led to the suggestion3 that the injection of basaltic magma into the base of a magma chamber (or the catastrophic overturn of a stably stratified chamber containing basaltic magma at its base) might trigger an eruption. Here we report evidence for the mixing of basaltic and dacitic magmas shortly before the paroxysmal eruptions of Pinatubo volcano on 15 June 1991. Andesitic scoriae erupted on 12 June contain minerals and glass with disequilibrium compositions, and are considerably more mafic than the dacitic pumices erupted on 15 June. Differences in crystal abundance and glass composition among the pumices may arise from pre-heating of the dacite magma by the underlying basaltic liquid before mixing. Degassing of this basaltic magma may also have contributed to the climatologically important sulphur dioxide emissions that accompanied the Pinatubo eruptions.

  11. 87Sr/86Sr ratios in basalts from islands in the Indian Ocean

    USGS Publications Warehouse

    Hedge, C.E.; Watkins, N.D.; Hildreth, R.A.; Doering, W.P.

    1973-01-01

    87Sr/86Sr ratios of basalts from islands in the Indian Ocean (0.7040) are higher than those of basalts dredged from the Mid-Indian Ocean Ridge (0.7034). The sources of the island basalts have apparently not been in equilibrium with the source of the ridge basalts for roughly 109 years. Both ridge and island basalts in the Indian Ocean are higher in 87Sr/86Sr than are rocks from similar settings in the eastern Pacific. ?? 1973.

  12. Importance of lunar granite and KREEP in very high potassium (VHK) basalt petrogenesis

    NASA Technical Reports Server (NTRS)

    Neal, Clive R.; Taylor, Lawrence A.; Lindstrom, Marilyn M.

    1988-01-01

    Analysis of five very high potassium (VHK) basalts from Apollo 14 breccia 14303 shows the presence of a KREEP component. An assimilation and fractional crystallization model is presented to describe the basalt evolution. The influence of granite assimilation on the basalt evolution is discussed. The presence of VHK basalts containing only a granite signature and those with both granite and KREEP signatures suggests that there are at least two different VHK basalt flows at the Apollo 14 site.

  13. Discovery of Alkaline Volcanic Rocks on Mars

    NASA Astrophysics Data System (ADS)

    McSween, H. Y.; Team, A. S.

    2006-05-01

    Based on remote sensing measurements and the compositions of martian meteorites, the surface of Mars is inferred to be dominated by subalkaline mafic volcanic rocks. However, the Spirit rover has recently discovered lavas of alkalic composition. Picritic (Adirondack class) basalts with high alkali and low silica contents were previously analyzed on the plains of Gusev Crater, and two new classes of dark, fine-grained, relatively unaltered volcanic rocks with distinctive thermal emission spectra have now been found as float and in a possible dike at high elevations in the Columbia Hills. Chemical analyses indicate that these rocks are mildly alkaline basalt and trachybasalt, respectively. Their mineralogy consists of Na- and K-rich feldspar(s), low- and high-Ca pyroxenes, ferroan olivine, Fe-Ti (and possibly Cr) oxides, phosphate, and possibly glass. Chemical compositions of these rocks lie along a MELTS-calculated liquid line of descent for Adirondack class basalt. Systematic changes in normative mineralogy are consistent with the calculated magmatic fractionation. We infer that Backstay- and Irvine-class magmas may have formed by low-pressure fractionation of primitive, oxidized Adirondack-class magmas and were possibly emplaced coevally with the plains basalts. The compositions of these rocks reveal that the Gusev magmatic province is alkaline, distinct from the subalkaline volcanic rocks thought to dominate most of the planet's surface. This discovery may have implications for the composition of the martian mantle source region and the conditions under which it melted.

  14. Icelandic basaltic geothermal field: A natural analog for nuclear waste isolation in basalt

    SciTech Connect

    Ulmer, G.C.; Grandstaff, D.E. . Dept. of Geology)

    1984-11-21

    Analog studies of Icelandic geothermal fields have shown that the design of nuclear waste repositories in basalt can benefit by comparison to the data base already available from the development of these geothermal fields. A high degree of similarity exists between these two systems: their petrology, groundwater geochemistry, mineral solubilities, hydrologic parameters, temperature ranges, water-rock redox equilibria, hydrothermal pH values, and secondary mineralogies all show considerable overlap in the range of values. The experimentally-simulated hydrothermal studies of the basaltic nuclear waste repository rocks have, at this time, produced a data base that receives a strong confirmation from the Icelandic analog. Furthermore, the Icelandic analog should eventually be employed to extrapolate into higher and lower temperatures, into longer time-base chemical comparisons, and into more realistic mineral deposition studies, than have been possible in the laboratory evaluations of the nuclear waste repository designs. This eventual use of the Icelandic analog will require cooperative work with the Icelandic Geological Survey. 46 refs., 4 figs., 2 tabs.

  15. Strength and durability of basalt fiber and basalt-fiber cement composites

    SciTech Connect

    Vedagiri, V.

    1987-01-01

    Basalt fibers melt drawn from naturally occurring igneous rock in an inert atmosphere of helium, argon or nitrogen show significantly improved mean strength (3.7 GPa). Weibull analysis of fiber strengths at different gage lengths indicates a high-strength population governing strength below 6.5-mm gage and a low-strength population at higher gage lengths. The durability of the basalt-cement composites was studied by conducting tensile and flexural tests, after water immersion at different temperatures for different times. By measuring the mirror-zone radius on the fiber surfaces in fractured composite specimens, the retention of fiber strength within the composite was also measured. The chemical and microstructural changes in the fiber-matrix interphase region were investigated by using electron probe microanalysis (EPMA). The fiber-matrix bond strength was evaluated by investigating multiple crack failure modes of composite specimens. The results indicate that although the strength values are comparable to other fiber systems, the precipitation of calcium hydroxide at the interface and the degradation of the fiber in the alkaline matrix decrease the strength of the composites, over extended period of time.

  16. Vapor segregation and loss in basaltic melts

    USGS Publications Warehouse

    Edmonds, M.; Gerlach, T.M.

    2007-01-01

    Measurements of volcanic gases at Pu'u'O??'o??, Kilauea Volcano, Hawai'i, reveal distinct degassing regimes with respect to vapor segregation and loss during effusive activity in 2004-2005. Three styles of vapor loss are distinguished by the chemical character of the emitted volcanic gases, measured by open path Fourier transform infrared spectroscopy: 1 persistent continuous gas emission, 2 gas piston events, and 3 lava spattering. Persistent continuous gas emission is associated with magma ascent and degassing beneath the crater vents, then eruption of the degassed magma from flank vents. Gas piston events are the result of static gas accumulation at depths of 400-900 m beneath Pu'u'O??'o??. A CO2-rich gas slug travels up the conduit at a few meters per second, displacing magma as it expands. Lava spattering occurs due to dynamic bubble coalescence in a column of relatively stagnant magma. The Large gas bubbles are H2O rich and are generated by open-system degassing at depths of <150 m. Static gas accumulation and dynamic bubble coalescence are both manifestations of vapor segregation in basaltic melts, but their implications differ. Accumulation and segregation of CO2-rich vapor at depth does not deplete the melt of H2O (required to drive lava fountains near to the surface) and therefore gas piston events can occur interspersed with lava fountaining activity. Lava spattering, however, efficiently strips H2O-rich vapor from magma beneath the crater vents; the magma must then erupt effusively from vents on the flank of the cone. ?? 2007 The Geological Society of America.

  17. Geomechanical rock properties of a basaltic volcano

    NASA Astrophysics Data System (ADS)

    Schaefer, Lauren; Kendrick, Jackie; Lavallée, Yan; Oommen, Thomas; Chigna, Gustavo

    2015-06-01

    In volcanic regions, reliable estimates of mechanical properties for specific volcanic events such as cyclic inflation-deflation cycles by magmatic intrusions, thermal stressing, and high temperatures are crucial for building accurate models of volcanic phenomena. This study focuses on the challenge of characterizing volcanic materials for the numerical analyses of such events. To do this, we evaluated the physical (porosity, permeability) and mechanical (strength) properties of basaltic rocks at Pacaya Volcano (Guatemala) through a variety of laboratory experiments, including: room temperature, high temperature (935 °C), and cyclically-loaded uniaxial compressive strength tests on as-collected and thermally-treated rock samples. Knowledge of the material response to such varied stressing conditions is necessary to analyze potential hazards at Pacaya, whose persistent activity has led to 13 evacuations of towns near the volcano since 1987. The rocks show a non-linear relationship between permeability and porosity, which relates to the importance of the crack network connecting the vesicles in these rocks. Here we show that strength not only decreases with porosity and permeability, but also with prolonged stressing (i.e., at lower strain rates) and upon cooling. Complimentary tests in which cyclic episodes of thermal or load stressing showed no systematic weakening of the material on the scale of our experiments. Most importantly, we show the extremely heterogeneous nature of volcanic edifices that arise from differences in porosity and permeability of the local lithologies, the limited lateral extent of lava flows, and the scars of previous collapse events. Input of these process-specific rock behaviors into slope stability and deformation models can change the resultant hazard analysis. We anticipate that an increased parameterization of rock properties will improve mitigation power.

  18. Space-Time-Isotopic Trends of Snake River Plain Basalts

    NASA Astrophysics Data System (ADS)

    Jean, M. M.; Hanan, B. B.; Shervais, J. W.

    2010-12-01

    The Snake River Plain (SRP) volcanic province is an 800 km track of basalt extending from the Owyhee Plateau to its current terminus, the Yellowstone Plateau. It is one of several late-Tertiary magmatic terranes that also include the Cascades magmatic arc, the Columbia River basalts, and the Oregon Plateau basalts; all of which are adjacent to the Basin and Range Province extensional system (Hughes and McCurry, 2002). This province represents the track of the Yellowstone plume and consists of basalt that is compositionally similar to ocean-island basalt. This basalt overlies a series of rhyolitic eruptive centers (overlapping caldera complexes, ignimbrites, and caldera-filling eruptions) that signal the arrival of the plume head (Christiansen, 2001) and herald the onset of plume-related rhyolitic and basaltic volcanism (Pierce et al., 2002). Observed within the SRP are two basalt types: the dominant low-K olivine tholeiites and less common high-K alkaline basalts. We report new Sr-, Nd-, and Pb-isotopic analyses of these two basalt types from all three SRP provinces: eastern, central, and western. Low-K tholeiites are enriched in 143Nd/144Nd and 86Sr/87Sr and forms a quasi-linear array in Pb-isotope space, along with Craters of the Moon and eastern SRP basalts. High-K lavas are found largely in the western plain, and have a uniquely different isotopic signature. They are depleted in 143Nd/144Nd and 86Sr/87Sr, relative to the low-K tholeiites, and plot closer to the BSE component of Zindler and Hart (1986). They also share the same Pb-isotopic space with high-K basalts from Smith Prairie (Boise River Group 2 of Vetter and Shervais, 1992). One low-K tholeiite - Eureka North, plots with these high alkali basalts. Mass balance models have demonstrated an increasing plume component from the Yellowstone caldera in the east to the craton edge in the west. The lavas analyzed in this study conform remarkably to this model. The mass fraction of plume component in western

  19. A new lunar high-Ti basalt type defined from clasts in Apollo 16 breccia 60639

    NASA Astrophysics Data System (ADS)

    Fagan, A. L.; Neal, C. R.

    2016-01-01

    This paper reports the detailed examination of three basalt clasts from Apollo 16 breccia 60639 that represent a new variant of high-Ti basalt returned from the Moon by the Apollo 16 mission. Mineral chemistry and whole-rock analyses were conducted on aliquots from three clasts (breccia matrix, basalt, and basalt + breccia matrix). The basalt clasts, which are not overtly porphyritic, contain compositionally zoned pyroxene, olivine, and plagioclase crystals that represent the evolution of the magma during crystallization; ilmenite does not exhibit major-element compositional zoning within individual crystals. Mineral compositions are distinct between the basalt and breccia matrix lithologies. In addition, whole-rock analyses identify clear compositional differences between the basalt and breccia matrix lithologies in both major and trace element concentrations. The composition of the mixed lithology aliquots (i.e., basalt + breccia matrix) do not indicate simple two component mixing (i.e., compositions are not intermediate to the basalt and breccia end-members); this apparent incongruity can be accounted for by adding ∼19-40% plagioclase to an amalgamation of the average basalt and individual breccia clast compositions via impact mixing. Whole-rock analyses are consistent with previous analyses of one 60639 basalt clast, which were interpreted to indicate chemical similarity with Apollo 11 and 17 basalts. However, both major and trace elements suggest that the 60639 basalt clasts examined here have compositions that are distinct from Apollo 11 and 17 high-Ti basalts. Although the 60639 basalt clasts have similar characteristics to a variety of previously identified basalt types, the more extensive whole-rock analyses reported here indicate that they represent a type of Apollo high-Ti basalt heretofore unrecognized in the Apollo and lunar meteorite collections. By placing these new analyses in the context of other mare basalt compositions, a petrogenetic model for

  20. Paleosecular variation, geochemistry, correlation, and timing of Grande Ronde Basalt lava flows, Columbia River Basalt Group

    NASA Astrophysics Data System (ADS)

    Hagstrum, J. T.; Sawlan, M. G.

    2013-12-01

    Co-located paleomagnetic and geochemical sampling of lava flows at eight sections within the Grande Ronde Basalt (GRB) was undertaken across the Columbia Plateau in WA and OR. The GRB represents roughly 87% (151,000 km3) of the Miocene Columbia River flood basalt province (174,000 km3) by volume (exclusive of the Steens Mountain Basalt), and recently published 40Ar/39Ar age estimates indicate that it was most likely emplaced within a time interval of less than 400 ka [Barry et al., Lithos 118(3), 213-222, 2010]. GRB flows include four stratigraphic magnetozones within the formation (R1, N1, R2, N2), and the sections currently sampled are mostly within the upper two magnetozones. Because Plateau GRB flows have undergone pervasive low-temperature alteration to varying degrees [see M. Sawlan's abstract, this meeting], particular care has been taken to collect the freshest available rock. Several new flow units have been identified, and similar, but unusual, paleomagnetic directions in stratigraphically adjacent flows of different chemical composition indicate, with high probability, that these flows were emplaced contemporaneously relative to the rate of geomagnetic paleosecular variation (PSV). Thus, several magma sources and their vent systems apparently operated nearly simultaneously and produced a stratigraphic framework in which compositionally distinct flows are intercalated. In addition, transitional directions have been found in flows near the N1/R2 and R2/N2 geomagnetic reversal boundaries, and an excursion to low inclinations occurred during emplacement of the Winter Water member (N2) flows. The detail and sequential nature of the PSV curve recovered from the upper GRB lava flows (R2 & N2) so far indicate extraordinarily rapid eruption of these flows. Comparison of the rate of change shown by our nascent PSV curve for the upper GRB with a recently published one for the Holocene of western North America [Hagstrum and Blinman, G3 11(6), 2010], which covers in

  1. Breakthroughs in Seismic and Borehole Characterization of Basalt Sequestration Targets

    SciTech Connect

    Sullivan, E. C.; Hardage, Bob A.; McGrail, B. Peter; Davis, Klarissa N.

    2011-04-01

    Mafic continental flood basalts form a globally important, but under-characterized CO2 sequestration target. The Columbia River Basalt Group (CRBG) in the northwestern U.S. is up to 5 km thick and covers over 168,000 km2. In India, flood basalts are 3 km thick and cover greater than 500,000 km2. Laboratory experiments demonstrate that the CRBG and other basalts react with formation water and super critical (sc) CO2 to precipitate carbonates, thus adding a potential mineral trapping mechanism to the standard trapping mechanisms of most other types of CO2 sequestration reservoirs. Brecciated tops of individual basalt flows in the CRBG form regional aquifers that locally have greater than 30% porosity and three Darcies of permeability. Porous flow tops are potential sites for sequestration of gigatons of scCO2 in areas where the basalts contain unpotable water and are at depths greater than 800 m. In this paper we report on the U.S. DOE Big Sky Regional Carbon Sequestration Partnership surface seismic and borehole geophysical characterization that supports a field test of capacity, integrity, and geochemical reactivity of CRBG reservoirs in eastern Washington, U.S.A. Traditional surface seismic methods have had little success in imaging basalt features in on-shore areas where the basalt is thinly covered by sediment. Processing of the experimental 6.5 km, 5 line 3C seismic swath included constructing an elastic wavefield model, identifying and separating seismic wave modes, and processing the swath as a single 2D line. Important findings include: (1) a wide variety of shear wave energy modes swamp the P-wave seismic records; (2) except at very short geophone offsets, ground roll overprints P-wave signal; and (3) because of extreme velocity contrasts, P-wave events are refracted at incidence angles greater than 7-15 degrees. Subsequent removal of S-wave and other noise during processing resulted in tremendous improvement in image quality. The application of wireline

  2. Petrogenesis of pillow basalts from Baolai in southwestern Taiwan

    NASA Astrophysics Data System (ADS)

    Liu, Chih-Chun; Yang, Huai-Jen

    2016-04-01

    The pillow basalts from Baolai in southwestern Taiwan have been inferred to bear Dupal signautres based on their Th/Ce ratio, linking the Baolai basalts to the South China Sea (SCS) seamounts that are characterized by Dupal Pb isotope signatures (Smith and Lewis, 2007). In this study, thirty-two Baolai basalt samples were analyzed for abundances of major and trace elements as well as Pb and Nd isotope ratios to verify their Dupal characters and to constrain their petrogenesis significance. The Baolai basalts contain 4-10 % L.O.I.. Three stages of alteration are inferred from plots of L.O.I. abundance versus concentrations major oxides as well as mineral textures and compositions. The first alteration stage was characterized by albitization that converted Ca-rich plagioclase to albite. The second alteration stage was dominated by chloritization of olivine and augite, resulting in increases in L.O.I. abundance. The last alteration stage is represented by formation of secondary calcite in vesicles and cracks. These alteration processes reflect interaction with seawater and apparently did not affect the magmatic Pb isotope composition for the low Pb concentration in seawater. Relative to the North Hemisphere Reference Line (NHRL), the Baolai pillow basalts have higher 208Pb/204Pb ratios at a given 206Pb/204Pb value, showing Dupal anomaly. For their relatively higher 208Pb/204Pb, 207Pb/204Pb, and 206Pb/204Pb ratios, the Baolai basalts are distinct from majority of the Cenozoic basalts in the Hainan-Leizhou peninsula, the Indochina peninsula, and the SCS seamounts, for which derivation from the Hainan mantle plume has been recently proposed (Wang et al., 2013). In contrast, the Baolai basalts and the Cenozoic basalts from eastern Guangdong at southeastern China have similar Pb and Nd isotope compositions, indicating derivation from similar mantle sources. However, the Baolai basalts have lower abundance ratios of Zr/Hf (40.3-45.6 versus 46.5-50.5), La/Yb (12

  3. Effect of carbon nanotube addition on the wear behavior of basalt/epoxy woven composites.

    PubMed

    Kim, M T; Rhee, K Y; Lee, B H; Kim, C J

    2013-08-01

    The effect of acid-treated carbon nanotube (CNT) addition on the wear and dynamic mechanical thermal properties of basalt/epoxy woven composites was investigated in this study. Basalt/CNT/epoxy composites were fabricated by impregnating woven basalt fibers into epoxy resin mixed with 1 wt% CNTs which were acid-treated. Wear and DMA (dynamic mechanical analyzer) tests were performed on basalt/epoxy composites and basalt/CNT/epoxy composites. The results showed that the addition of the acid-treated CNTs improved the wear properties of basalt/epoxy woven composites. Specifically, the friction coefficient of the basalt/epoxy composite was stabilized in the range of 0.5-0.6 while it fell in the range of 0.3-0.4 for basalt/CNT/epoxy composites. The wear volume loss of the basalt/CNT/epoxy composites was approximately 68% lower than that of the basalt/epoxy composites. The results also showed that the glass transition temperature of basalt/CNT/epoxy composites was higher than that of basalt/epoxy composites. The improvement of wear properties of basalt/epoxy composites by the addition of acid-treated CNTs was caused by the homogeneous load transfer between basalt fibers and epoxy matrix due to the reinforcement of CNTs.

  4. Basalt-radionuclide distribution coefficient determinations. FY-1979 annual report

    SciTech Connect

    Ames, L.L.; McGarrah, J.E.

    1980-09-01

    Experimental radionuclide distribution coefficients (Kd') were determined for Pomona, Flow E, Umtanum basalts, and secondary mineralization associated with Pomona basalt at 23/sup 0/, 60/sup 0/ and 150/sup 0/C. Radionuclides used were /sup 75/Se, /sup 85/Sr, /sup 99/Tc, /sup 125/I, /sup 135/Cs, /sup 226/Ra, /sup 237/Np, /sup 238/U, /sup 241/Am, and /sup 241/Pu. Solution oxygen contents were controlled by the basalt/groundwater system (Eh = 600 to 700 mV), and were high (8.2 to 8.4 mg/l) at 23/sup 0/C. Oxygen contents and pH changed little in contact with basalt. The effects of temperature changes on radionuclide Kd' results varied depending upon the radionuclide involved, solution-solid reactions, and the relationship of the radionuclide to these reactions. For example, cesium Kd' values decreased from 3100 ml/g for Umtanum basalt at 23/sup 0/C to 120 ml/g at 150/sup 0/C. At the same time, strontium Kd' values increased for Umtanum basalt from 105 ml/g at 23/sup 0/C to complete removal at 150/sup 0/C and 40 days. Radionuclide adsorption coefficient measurements at higher temperatures and pressures were made in addition to the 23/sup 0/C, solution-solid contact time-conditional Kd (Kd') measurements. These include Kd' measurements with Umtanum basalt, Pomona basalt, Flow E basalt and secondary mineralization and radioisotopes of americium, cesium, iodine, neptunium, plutonium, radium, selenium, strontium, technetium and uranium. The additional temperatures involved were 60/sup 0/C, 150/sup 0/C, and 300/sup 0/C. At 150/sup 0/C, argon pressures of 6.9, 13.8, 20.7, and 27.6 MPa will be used to ascertain the effects of pressure changes on Kd' values. So far only the 6.9 MPa argon pressure has been investigated. The upper temperature of 250/sup 0/C is where thermal breakdown of dioctahedral smectites (secondary mineralization) begins.

  5. Preliminary Hydrogeologic Characterization Results from the Wallula Basalt Pilot Study

    SciTech Connect

    B.P. McGrail; E. C. Sullivan; F. A. Spane; D. H. Bacon; G. Hund; P. D. Thorne; C. J. Thompson; S. P. Reidel; F. S. Colwell

    2009-12-01

    The DOE's Big Sky Regional Carbon Sequestration Partnership has completed drilling the first continental flood basalt sequestration pilot borehole to a total depth (TD) of 4,110 feet on the Boise White Paper Mill property at Wallula, Washington. Site suitability was assessed prior to drilling by the 2007-2008 acquisition, processing and analysis of a four-mile, five-line three component seismic swath, which was processed as a single data-dense line. Analysis of the seismic survey data indicated a composite basalt formation thickness of {approx}8,000 feet and absence of major geologic structures (i.e., faults) along the line imaged by the seismic swath. Drilling of Wallula pilot borehole was initiated on January 13, 2009 and reached TD on April 6, 2009. Based on characterization results obtained during drilling, three basalt breccia zones were identified between the depth interval of 2,716 and 2,910 feet, as being suitable injection reservoir for a subsequent CO2 injection pilot study. The targeted injection reservoir lies stratigraphically below the massive Umtanum Member of the Grande Ronde Basalt, whose flow-interior section possesses regionally recognized low-permeability characteristics. The identified composite injection zone reservoir provides a unique and attractive opportunity to scientifically study the reservoir behavior of three inter-connected reservoir intervals below primary and secondary caprock confining zones. Drill cuttings, wireline geophysical logs, and 31one-inch diameter rotary sidewall cores provided geologic data for characterization of rock properties. XRF analyses of selected rock samples provided geochemical characterizations of the rocks and stratigraphic control for the basalt flows encountered by the Wallula pilot borehole. Based on the geochemical results, the pilot borehole was terminated in the Wapshilla Ridge 1 flow of the Grande Ronde Basalt Formation. Detailed hydrologic test characterizations of 12 basalt interflow reservoir

  6. Convective Regimes in Crystallizing Basaltic Magma Chambers

    NASA Astrophysics Data System (ADS)

    Gilbert, A. J.; Neufeld, J. A.; Holness, M. B.

    2015-12-01

    Cooling through the chamber walls drives crystallisation in crustal magma chambers, resulting in a cumulate pile on the floor and mushy regions at the walls and roof. The liquid in many magma chambers, either the bulk magma or the interstitial liquid in the mushy regions, may convect, driven either thermally, due to cooling, or compositionally, due to fractional crystallization. We have constructed a regime diagram of the possible convective modes in a system containing a basal mushy layer. These modes depend on the large-scale buoyancy forcing characterised by a global Rayleigh number and the proportion of the chamber height constituting the basal mushy region. We have tested this regime diagram using an analogue experimental system composed of a fluid layer overlying a pile of almost neutrally buoyant inert particles. Convection in this system is driven thermally, simulating magma convection above and within a porous cumulate pile. We observe a range of possible convective regimes, enabling us to produce a regime diagram. In addition to modes characterised by convection of the bulk and interstitial fluid, we also observe a series of regimes where the crystal pile is mobilised by fluid motions. These regimes feature saltation and scouring of the crystal pile by convection in the bulk fluid at moderate Rayleigh numbers, and large crystal-rich fountains at high Rayleigh numbers. For even larger Rayleigh numbers the entire crystal pile is mobilised in what we call the snowglobe regime. The observed mobilisation regimes may be applicable to basaltic magma chambers. Plagioclase in basal cumulates crystallised from a dense magma may be a result of crystal mobilisation from a plagioclase-rich roof mush. Compositional convection within such a mush could result in disaggregation, enabling the buoyant plagioclase to be entrained in relatively dense descending liquid plumes and brought to the floor. The phenocryst load in porphyritic lavas is often interpreted as a

  7. Similar Microbial Communities Found on Two Distant Seafloor Basalts.

    PubMed

    Singer, Esther; Chong, Lauren S; Heidelberg, John F; Edwards, Katrina J

    2015-01-01

    The oceanic crust forms two thirds of the Earth's surface and hosts a large phylogenetic and functional diversity of microorganisms. While advances have been made in the sedimentary realm, our understanding of the igneous rock portion as a microbial habitat has remained limited. We present the first comparative metagenomic microbial community analysis from ocean floor basalt environments at the Lō'ihi Seamount, Hawai'i, and the East Pacific Rise (EPR; 9°N). Phylogenetic analysis indicates the presence of a total of 43 bacterial and archaeal mono-phyletic groups, dominated by Alpha- and Gammaproteobacteria, as well as Thaumarchaeota. Functional gene analysis suggests that these Thaumarchaeota play an important role in ammonium oxidation on seafloor basalts. In addition to ammonium oxidation, the seafloor basalt habitat reveals a wide spectrum of other metabolic potentials, including CO2 fixation, denitrification, dissimilatory sulfate reduction, and sulfur oxidation. Basalt communities from Lō'ihi and the EPR show considerable metabolic and phylogenetic overlap down to the genus level despite geographic distance and slightly different seafloor basalt mineralogy. PMID:26733957

  8. An ancient recipe for flood-basalt genesis.

    PubMed

    Jackson, Matthew G; Carlson, Richard W

    2011-07-27

    Large outpourings of basaltic lava have punctuated geological time, but the mechanisms responsible for the generation of such extraordinary volumes of melt are not well known. Recent geochemical evidence suggests that an early-formed reservoir may have survived in the Earth's mantle for about 4.5 billion years (ref. 2), and melts of this reservoir contributed to the flood basalt emplaced on Baffin Island about 60 million years ago. However, the volume of this ancient mantle domain and whether it has contributed to other flood basalts is not known. Here we show that basalts from the largest volcanic event in geologic history--the Ontong Java plateau--also exhibit the isotopic and trace element signatures proposed for the early-Earth reservoir. Together with the Ontong Java plateau, we suggest that six of the largest volcanic events that erupted in the past 250 million years derive from the oldest terrestrial mantle reservoir. The association of these large volcanic events with an ancient primitive mantle source suggests that its unique geochemical characteristics--it is both hotter (it has greater abundances of the radioactive heat-producing elements) and more fertile than depleted mantle reservoirs-may strongly affect the generation of flood basalts.

  9. Similar Microbial Communities Found on Two Distant Seafloor Basalts.

    PubMed

    Singer, Esther; Chong, Lauren S; Heidelberg, John F; Edwards, Katrina J

    2015-01-01

    The oceanic crust forms two thirds of the Earth's surface and hosts a large phylogenetic and functional diversity of microorganisms. While advances have been made in the sedimentary realm, our understanding of the igneous rock portion as a microbial habitat has remained limited. We present the first comparative metagenomic microbial community analysis from ocean floor basalt environments at the Lō'ihi Seamount, Hawai'i, and the East Pacific Rise (EPR; 9°N). Phylogenetic analysis indicates the presence of a total of 43 bacterial and archaeal mono-phyletic groups, dominated by Alpha- and Gammaproteobacteria, as well as Thaumarchaeota. Functional gene analysis suggests that these Thaumarchaeota play an important role in ammonium oxidation on seafloor basalts. In addition to ammonium oxidation, the seafloor basalt habitat reveals a wide spectrum of other metabolic potentials, including CO2 fixation, denitrification, dissimilatory sulfate reduction, and sulfur oxidation. Basalt communities from Lō'ihi and the EPR show considerable metabolic and phylogenetic overlap down to the genus level despite geographic distance and slightly different seafloor basalt mineralogy.

  10. Similar Microbial Communities Found on Two Distant Seafloor Basalts

    PubMed Central

    Singer, Esther; Chong, Lauren S.; Heidelberg, John F.; Edwards, Katrina J.

    2015-01-01

    The oceanic crust forms two thirds of the Earth’s surface and hosts a large phylogenetic and functional diversity of microorganisms. While advances have been made in the sedimentary realm, our understanding of the igneous rock portion as a microbial habitat has remained limited. We present the first comparative metagenomic microbial community analysis from ocean floor basalt environments at the Lō’ihi Seamount, Hawai’i, and the East Pacific Rise (EPR; 9°N). Phylogenetic analysis indicates the presence of a total of 43 bacterial and archaeal mono-phyletic groups, dominated by Alpha- and Gammaproteobacteria, as well as Thaumarchaeota. Functional gene analysis suggests that these Thaumarchaeota play an important role in ammonium oxidation on seafloor basalts. In addition to ammonium oxidation, the seafloor basalt habitat reveals a wide spectrum of other metabolic potentials, including CO2 fixation, denitrification, dissimilatory sulfate reduction, and sulfur oxidation. Basalt communities from Lō’ihi and the EPR show considerable metabolic and phylogenetic overlap down to the genus level despite geographic distance and slightly different seafloor basalt mineralogy. PMID:26733957

  11. Three basaltic earth-approaching asteroids and the source of the basaltic meteorites

    SciTech Connect

    Cruikshank, D.P.; Tholen, D.J.; Bell, J.F.; Hartmann, W.K.; Brown, R.H. Hawaii Univ., Honolulu Planetary Science Institute, Tucson, AZ JPL, Pasadena, CA )

    1991-01-01

    Diameters of 1.2, 1.0, and 3.4 km are respectively derived for the earth-approaching asteroids 1983 RD, 1980 PA, and 1985 DO2, whose spectra are virtually identical to that of the basaltic-surfaced large asteroid, Vesta. While probably not fragments of Vesta, the three asteroids may be fragments of one or more Vesta-like parent bodies; it is suggested that they may be fragments of the source body or bodies of the HED meteorites. While these asteroids regoliths have significant insulating properties, they differ from that of the moon in that lunar-like glasses and agglutinates are largely absent. It is noted that asteroids of this kind may have impacted the earth without leaving the chemical signatures associated with the K-T boundary event. 59 refs.

  12. Modeling the response of soil and surface waters in the Adirondack and Catskill regions of New York to changes in atmospheric deposition and historical land disturbance

    NASA Astrophysics Data System (ADS)

    Chen, Limin; Driscoll, Charles T.

    In this study, an integrated biogeochemical model (PnET-BGC) was used to evaluate the response of five forest ecosystems in the Adirondack and Catskill regions of New York to changes in atmospheric deposition and land disturbance. Model simulations showed that over the past 150 years, acidic deposition caused depletion of nutrient base cations (i.e., Ca 2+, Mg 2+), enhanced mobilization of aluminum (Al) and accumulation of sulfur (S) within the soil. Model simulations also showed that acidic deposition resulted in elevated concentrations of inorganic monomeric Al, sulfate (SO 42-) and nitrate (NO 3-), and low values of pH and acid neutralizing capacity (ANC) in surface waters. Model results also indicated that forest harvests resulted in enhanced leaching of base cations and NO 3- over the short term (˜5 yr). Over the long term, forest harvesting influences surface water NO 3- and base cation concentrations, and pH and ANC. The model was also used to predict the responses of these forest ecosystems to three emission control scenarios. Model simulations indicated that under the 1990 Clean Air Act Amendment, these ecosystems showed little recovery after 2010. Additional reductions in strong acid inputs will result in significant benefits in terms of recovery from acidification. Under an aggressive control scenario, surface water ANC of these ecosystems was predicted to recover at rates ranging from 0.28 to 0.58 μeq l -1 yr -1.

  13. Hydrologic analysis of two headwater lake basins of differing lake pH in the west-central Adirondack Mountains of New York

    USGS Publications Warehouse

    Murdoch, Peter S.; Peters, N.E.; Newton, R.M.

    1987-01-01

    Hydrologic analysis of two headwater lake basins in the Adirondack Mountains, New York, during 1980-81 indicates that the degree of neutralization of acid precipitation is controlled by the groundwater contribution to the lake. According to flow-duration analyses, daily mean outflow/unit area from the neutral lake (Panther Lake, pH 5-7) was more sustained and contained a higher percentage of groundwater than that of the acidic lake (Woods Lake, pH 4-5). Outflow recession rates and maximum base-flow rates, derived from individual recession curves, were 3.9 times and 1.5 times greater, respectively, in the neutral-lake basin than in the acidic-lake basin. Groundwater contribution to lake outflow was also calculated from a lake-water budget; the groundwater contribution to the neutral lake was about 10 times greater than that to the acidic lake. Thick sandy till forms the groundwater reservoir and the major recharge area in both basins but covers 8.5 times more area in the neutral-lake basin than in the acidic-lake basin. More groundwater storage within the neutral basin provides longer contact time with neutralizing minerals and more groundwater discharge. As a result, the neutral lake has relatively high pH and alkalinity, and more net cation transport. (USGS)

  14. Mineralogy of the last lunar basalts: Results from Clementine

    USGS Publications Warehouse

    Staid, M.I.; Pieters, C.M.

    2001-01-01

    The last major phase of lunar volcanism produced extensive high-titanium mare deposits on the western nearside which remain unsampled by landing missions. The visible and near-infrared reflectance properties of these basalts are examined using Clementine multispectral images to better constrain their mineralogy. A much stronger 1 ??m ferrous absorption was observed for the western high-titanium basalts than within earlier maria, suggesting that these last major mare eruptions also may have been the most iron-rich. These western basalts also have a distinctly long-wavelength, 1 ??m ferrous absorption which was found to be similar for both surface soils and materials excavated from depth, supporting the interpretation of abundant olivine within these deposits. Spectral variation along flows within the Imbrium basin also suggests variations in ilmenite content along previously mapped lava flows as well as increasing olivine content within subsequent eruptions. Copyright 2001 by the American Geophysical Union.

  15. Evidence against hydrogen-based microbial ecosystems in basalt aquifers

    PubMed

    Anderson; Chapelle; Lovley

    1998-08-14

    It has been proposed that hydrogen produced from basalt-ground-water interactions may serve as an energy source that supports the existence of microorganisms in the deep subsurface on Earth and possibly on other planets. However, experiments demonstrated that hydrogen is not produced from basalt at an environmentally relevant, alkaline pH. Small amounts of hydrogen were produced at a lower pH in laboratory incubations, but even this hydrogen production was transitory. Furthermore, geochemical considerations suggest that previously reported rates of hydrogen production cannot be sustained over geologically significant time frames. These findings indicate that hydrogen production from basalt-ground-water interactions may not support microbial metabolism in the subsurface.

  16. Geochemical characteristics of the Cenozoic basaltic rocks, Northwestern Saudi Arabia

    NASA Astrophysics Data System (ADS)

    Saif, S. I.; Shah, S. M. A.

    1992-02-01

    In northwestern Saudi Arabia, an area of about 15 200 km is intermittently covered by basaltic rocks representing Cenozoic, intraplate continental volcanism. The present study is focused on the geochemical characteristics of these rocks, which are distinguished on the basis of field occurrences into three suites: 1. layered basalt (LB), 2. fragmented basalt (FB), and 3. cinder-cone material (CM), with varied ages. The rocks are olivine normative, belonging to the basanite-picrite-ankaramite series, with sodic and potassic varieties. A high degree of ferromagnesian fractionation and some compositional layering in the magma chamber are concluded. Crustal contamination indicated by some trace elements, progressively decreases with age, and hence, is interpreted as time dependent.

  17. Lunar basalt meteorite EET 87521: Petrology of the clast population

    NASA Technical Reports Server (NTRS)

    Semenova, A. S.; Nazarov, M. A.; Kononkova, N. N.

    1993-01-01

    The Elephant Moraine meteorite EET 87521 was classified as a lunar mare basalt breccia which is composed mainly of VLT basalt clasts. Here we report on our petrological study of lithic clasts and monomineralic fragments in the thin sections EET 87521,54 and EET 87521,47,1, which were prepared from the meteorite. The results of the study show that EET 87521 consists mainly of Al-rich ferrobasalt clasts and olivine pyroxenite clasts. The bulk composition of the meteorite can be well modelled by the mixing of these lithic components which appear to be differentiates of the Luna 25 basalt melt. KREEP and Mg-rich gabbro components are minor constituents of EET 87521.

  18. Evidence against hydrogen-based microbial ecosystems in basalt aquifers

    USGS Publications Warehouse

    Anderson, R.T.; Chapelle, F.H.; Lovley, D.R.

    1998-01-01

    It has been proposed that hydrogen produced from basalt-ground-water interactions may serve as an energy source that supports the existence of microorganisms in the deep subsurface on Earth and possibly on other planets. However, experiments demonstrated that hydrogen is not produced from basalt at an environmentally relevant, alkaline pH. Small amounts of hydrogen were produced at a lower pH in laboratory incubations, but even this hydrogen production was transitory. Furthermore, geochemical considerations suggest that previously reported rates of hydrogen production cannot be sustained over geologically significant time frames. These findings indicate that hydrogen production from basalt-ground-water interactions may not support microbial metabolism in the subsurface.

  19. Basalt fiber reinforced polymer composites: Processing and properties

    NASA Astrophysics Data System (ADS)

    Liu, Qiang

    A high efficiency rig was designed and built for in-plane permeability measurement of fabric materials. A new data derivation procedure to acquire the flow fluid pattern in the experiment was developed. The measurement results of the in-plane permeability for basalt twill 31 fabric material showed that a high correlation exists between the two principal permeability values for this fabric at 35% fiber volume fraction. This may be the most important scientific contribution made in this thesis. The results from radial measurements corresponded quite well with those from Unidirectional (UD) measurements, which is a well-established technique. No significant differences in mechanical properties were found between basalt fabric reinforced polymer composites and glass composites reinforced by a fabric of similar weave pattern. Aging results indicate that the interfacial region in basalt composites may be more vulnerable to environmental damage than that in glass composites. However, the basalt/epoxy interface may have been more durable than the glass/epoxy interface in tension-tension fatigue because the basalt composites have significantly longer fatigue life. In this thesis, chapter I reviews the literature on fiber reinforced polymer composites, with concentration on permeability measurement, mechanical properties and durability. Chapter II discusses the design of the new rig for in-plane permeability measurement, the new derivation procedure for monitoring of the fluid flow pattern, and the permeability measurement results. Chapter III compares the mechanical properties and durability between basalt fiber and glass fiber reinforced polymer composites. Lastly, chapter IV gives some suggestions and recommendations for future work.

  20. On causal links between flood basalts and continental breakup

    NASA Astrophysics Data System (ADS)

    Courtillot, V.; Jaupart, C.; Manighetti, I.; Tapponnier, P.; Besse, J.

    1999-03-01

    Temporal coincidence between continental flood basalts and breakup has been noted for almost three decades. Eight major continental flood basalts have been produced over the last 300 Ma. The most recent, the Ethiopian traps, erupted in about 1 Myr at 30 Ma. Rifting in the Red Sea and Gulf of Aden, and possibly East African rift started at about the same time. A second trap-like episode occurred around 2 Ma and formation of true oceanic crust is due in the next few Myr. We find similar relationships for the 60 Ma Greenland traps and opening of the North Atlantic, 65 Ma Deccan traps and opening of the NW Indian Ocean, 132 Ma Parana traps and South Atlantic, 184 Ma Karoo traps and SW Indian Ocean, and 200 Ma Central Atlantic Margin flood basalts and opening of the Central Atlantic Ocean. The 250 Ma Siberian and 258 Ma Emeishan traps seem to correlate with major, if aborted, phases of rifting. Rifting asymmetry, apparent triple junctions and rift propagation (towards the flood basalt area) are common features that may, together with the relative timings of flood basalt, seaward dipping reflector and oceanic crust production, depend on a number of plume- and lithosphere- related factors. We propose a mixed scenario of `active/passive' rifting to account for these observations. In all cases, an active component (a plume and resulting flood basalt) is a pre-requisite for the breakup of a major oceanic basin. But rifting must be allowed by plate-boundary forces and is influenced by pre-existing heterogeneities in lithospheric structure. The best example is the Atlantic Ocean, whose large-scale geometry with three large basins was imposed by the impact points of three mantle plumes.

  1. Mineral CO2 Sequestration into Basalt: The Carbfix Project

    NASA Astrophysics Data System (ADS)

    Gislason, S. R.; Broecker, W. S.; Oelkers, E. H.; Gunnlaugsson, E.; Stefansson, A.; Wolff-Boenisch, D.; Matter, J.; Björnsson, G.

    2008-12-01

    The reduction of industrial CO2 emissions is considered one of the main challenges of this century. Among commonly proposed CO2 storage techniques, the injection of anthropogenic CO2 into deep geological formations is quite promising due their large potential storage capacity and geographic ubiquity. Finding a storage solution that is long lasting, thermodynamically stable and environmentally benign would be ideal. Storage of CO2, as solid calcium magnesium iron carbonate, in basaltic rocks may provide such a long lasting, thermodynamically stable and environmentally benign solution. In nature, the carbonization of basaltic rocks occurs in a variety of well-documented settings, such as the hydrothermal alteration in geothermal systems and in deep ocean vent systems. The goal of this research project is to optimize industrial methods for storing CO2 in basaltic rocks through a combined program consisting of, field scale injection of CO2 charged waters into basaltic rocks, laboratory based experiments, study of natural CO2 waters as natural analogue and state of the art geochemical modelling. A second and equally important goal of this research project is to generate the human capital and expertise to apply the advances made in this project in the future. Towards this goal the bulk of the research is to be performed by graduate student and post-doctoral trainees. At the Hellisheidi Iceland site, the hot gases released from geothermal energy production will be processed to separate the CO2. It will then be dissolved in water at about 25 bar pressure and pumped into the porous basalt at 400 to 700 m depth, at the rate of 30 000 tonnes per year. Model simulations, natural analogues and experimental work suggest that the CO2 charged waters will reacts with the basalt and form carbonate minerals such as FeCO3 - MgCO3 solid solutions and CaCO3. By this method the fixed CO2 will remain trapped as mineral for millions of years.

  2. Isotope fractionation by chemical diffusion between molten basalt and rhyolite

    NASA Astrophysics Data System (ADS)

    Richter, Frank M.; Davis, Andrew M.; DePaolo, Donald J.; Watson, E. Bruce

    2003-10-01

    Experimental diffusion couples were used to study chemical diffusion between molten rhyolite and basalt with special emphasis on the associated fractionation of calcium and lithium isotopes. Diffusion couples were made by juxtaposing firmly packed powders of a natural basalt (SUNY MORB) and a natural rhyolite (Lake County Obsidian) and then annealing them in a piston cylinder apparatus for times ranging from 0.1 to 15.7 h, temperatures of 1350-1450°C, and pressures of 1.2-1.3 GPa. Profiles of the major elements and many trace elements were measured on the recovered quenched glasses. The diffusivities of all elements except lithium were found to be remarkably similar, while the diffusivity of lithium was two to three orders of magnitude larger than that of any of the other elements measured. Chemical diffusion of calcium from molten basalt into rhyolite was driven by a concentration ratio of ˜18 and produced a fractionation of 44Ca from 40Ca of about 6 ‰. Because of the relatively low concentration of lithium in the natural starting materials a small amount of spodumene (LiAlSi 2O 6) was added to the basalt in order to increase the concentration difference between basalt and rhyolite, which was expected to increase the magnitude of diffusive isotopic fractionation of lithium. The concentration ratio between Li-doped basalt and natural rhyolite was ˜15 and the resulting diffusion of lithium into the rhyolite fractionated 7Li from 6Li by about 40‰. We anticipate that several other major rock-forming elements such as magnesium, iron and potassium will also exhibit similarly larger isotopic fractionation whenever they diffuse between natural melts with sufficiently large differences in the abundance of these elements.

  3. Seismic wave propagation through an extrusive basalt sequence

    NASA Astrophysics Data System (ADS)

    Sanford, Oliver; Hobbs, Richard; Brown, Richard; Schofield, Nick

    2016-04-01

    Layers of basalt flows within sedimentary successions (e.g. in the Faeroe-Shetland Basin) cause complex scattering and attenuation of seismic waves during seismic exploration surveys. Extrusive basaltic sequences are highly heterogeneous and contain strong impedance contrasts between higher velocity crystalline flow cores (˜6 km s-1) and the lower velocity fragmented and weathered flow crusts (3-4 km s-1). Typically, the refracted wave from the basaltic layer is used to build a velocity model by tomography. This velocity model is then used to aid processing of the reflection data where direct determination of velocity is ambiguous, or as a starting point for full waveform inversion, for example. The model may also be used as part of assessing drilling risk of potential wells, as it is believed to constrain the total thickness of the sequence. In heterogeneous media, where the scatter size is of the order of the seismic wavelength or larger, scattering preferentially traps the seismic energy in the low velocity regions. This causes a build-up of energy that is guided along the low velocity layers. This has implications for the interpretation of the observed first arrival of the seismic wave, which may be a biased towards the low velocity regions. This will then lead to an underestimate of the velocity structure and hence the thickness of the basalt, with implications for the drilling of wells hoping to penetrate through the base of the basalts in search of hydrocarbons. Using 2-D acoustic finite difference modelling of the guided wave through a simple layered basalt sequence, we consider the relative importance of different parameters of the basalt on the seismic energy propagating through the layers. These include the proportion of high to low velocity material, the number of layers, their thickness and the roughness of the interfaces between the layers. We observe a non-linear relationship between the ratio of high to low velocity layers and the apparent velocity

  4. Seismic wave propagation through an extrusive basalt sequence

    NASA Astrophysics Data System (ADS)

    Sanford, Oliver; Hobbs, Richard; Brown, Richard; Schofield, Nick

    2016-04-01

    Layers of basalt flows within sedimentary successions (e.g. in the Faeroe-Shetland Basin) cause complex scattering and attenuation of seismic waves during seismic exploration surveys. Extrusive basaltic sequences are highly heterogeneous and contain strong impedance contrasts between higher velocity crystalline flow cores (˜6 km s‑1) and the lower velocity fragmented and weathered flow crusts (3-4 km s‑1). Typically, the refracted wave from the basaltic layer is used to build a velocity model by tomography. This velocity model is then used to aid processing of the reflection data where direct determination of velocity is ambiguous, or as a starting point for full waveform inversion, for example. The model may also be used as part of assessing drilling risk of potential wells, as it is believed to constrain the total thickness of the sequence. In heterogeneous media, where the scatter size is of the order of the seismic wavelength or larger, scattering preferentially traps the seismic energy in the low velocity regions. This causes a build-up of energy that is guided along the low velocity layers. This has implications for the interpretation of the observed first arrival of the seismic wave, which may be a biased towards the low velocity regions. This will then lead to an underestimate of the velocity structure and hence the thickness of the basalt, with implications for the drilling of wells hoping to penetrate through the base of the basalts in search of hydrocarbons. Using 2-D acoustic finite difference modelling of the guided wave through a simple layered basalt sequence, we consider the relative importance of different parameters of the basalt on the seismic energy propagating through the layers. These include the proportion of high to low velocity material, the number of layers, their thickness and the roughness of the interfaces between the layers. We observe a non-linear relationship between the ratio of high to low velocity layers and the apparent

  5. Crustal influence in the generation of continental flood basalts

    NASA Technical Reports Server (NTRS)

    Carlson, R. W.; Lugmair, G. W.; Macdougall, J. D.

    1981-01-01

    The suggestion that primordial undifferentiated material may exist in the earth's mantle has recently been revived on the strength of Nd isotope data for two types of young continental rocks - flood basalts and kimberlites. The limited published data show a clustering of Nd isotopic compositions close to those for meteorites with chondritic relative rare-earth (REE) abundance. In contrast, data are presented for samples from the Columbia flood basalt province of the northwestern United States which show large isotopic variability suggestive of mixing processes acting after the separation of the primary magmas from their mantle source.

  6. Earliest Silicic Volcanism Associated with Mid-Miocene Flood Basalts: Tuffs Interbedded with Steens Basalt, Nevada and Oregon

    NASA Astrophysics Data System (ADS)

    Luckett, M.; Mahood, G. A.; Benson, T. R.

    2013-12-01

    During the main phase of Steens and Columbia River flood basalt eruptions between ~16.7 and 15.0 Ma, spatially associated silicic volcanism was widespread, ~4,000 km3 of silicic magma erupting at calderas and smaller centers dispersed across ~25,000 km2 in eastern Oregon and northern Nevada (Coble and Mahood, 2012). The oldest flood basalts erupted from a focus at Steens Mountain in eastern Oregon, where the section of lavas is ~1 km thick. The Steens Basalt thins southward to only a few flows thick in northern Nevada, either because fewer flows were emplaced this far from the focus or because fewer dikes propagated to the surface on encountering thicker continental crust and/or were intercepted by growing bodies of silicic magma that ultimately erupted in McDermitt Caldera Field (Rytuba and McKee, 1984), High Rock Caldera Complex, and the Lone Mountain/Hawks Valley center (Wypych et al., 2011). Rhyolitic tuffs have not been recognized interbedded with the basalt lavas in the type section, but we have identified several silicic tuffs interbedded with Steens Basalt in the southern Pueblo Mountains and in the Trout Creek Mountains. Although noted by previous workers (e.g., Avent, 1965; Minor, 1986; Hart et al., 1989), they have not been studied. We identified six tuffaceous intervals 20 cm to 15 m thick in the escarpment of the southern Pueblo Mountains near the Oregon-Nevada border where the Steens basalt section is ~250 m thick, with the base unexposed. Two intervals are lithic-rich, reworked volcaniclastic sediments, but four are primary or only slightly reworked sequences of fall deposits that range from fine ash to lapilli in grain size. The heat and weight of the overlying basaltic lava flows has fused the tuffs so that the upper parts of thicker tuffaceous intervals and entire thinner ones are converted to vitrophyres, with crystals of alkali feldspar × quartz × biotite typically 1-2 mm in diameter set in a dense, black, variably hydrated, glassy matrix. We

  7. Application of the PnET-BGC - An integrated biogeochemical model - To assess the surface water ANC recovery in the Adirondack region of New York under three multi-pollutant proposals

    NASA Astrophysics Data System (ADS)

    Wu, Wei; Driscoll, Charles T.

    2009-11-01

    SummaryWe applied an integrated biogeochemical model PnET-BGC to predict the response of acid neutralizing capacity (ANC) in lakes - a measure of the ability of water to neutralize inputs of strong acid - from 2001 to 2050 in the Adirondack region of New York, USA under three multi-pollutant proposal scenarios. Through model predictions, we assessed the impacts of these proposals on ecosystem recovery for research and policy initiatives. Our analysis indicated that the predicted recovery rates of surface water ANC obtained from the PnET-BGC model show low spatial autocorrelation. Predicted recovery rates are also closely related with the percentage of watershed areas of coniferous vegetation and deciduous vegetation, elevation and lake area, which turn out not to be significantly different from each other over the entire period of future scenarios (2001-2050). We applied a Geographic Weighted Regression model (GWR) to study the spatial patterns of predicted lake ANC in the Adirondacks through 2050 due to its high spatial autocorrelation. These results showed that lake depth and square of elevation can explain 40% of variation in the predicted ANC, which is 26% more variation than explained by the non-spatial Ordinary Least-Squares Regression (OLS). Our calculations also suggest that even under the Carper Bill, the most aggressive air pollutant control scenario considered, not all Adirondack lakes will recover (i.e., ANC > 50 μeq/L) from elevated acidic deposition by 2050. The research provides a basis for more informed emission controls and land use/land cover (LULC) policy-making in the north-eastern USA and elsewhere.

  8. Interpreting chemical compositions of small scale basaltic systems: A review

    NASA Astrophysics Data System (ADS)

    McGee, Lucy E.; Smith, Ian E. M.

    2016-10-01

    Small scale basaltic magmatic systems occur in all of the major tectonic environments of planet Earth and are characteristically expressed at the Earth's surface as fields of small monogenetic cones. The chemical compositions of the materials that make up these cones reflect processes of magma generation and differentiation that occur in their plumbing system. The volumes of magmas involved are very small and significantly their compositional ranges reveal remarkably complex processes which are overwhelmed or homogenized in larger scale systems. Commonly, compositions are basaltic, alkalic and enriched in light rare earth elements and large ion lithophile elements, although the spectrum extends from highly enriched nephelinites to subalkalic and tholeiitic basalts. Isotopic analyses of rocks from volcanic fields almost always display compositions which can only be explained by the interaction of two or more mantle sources. Ultimately their basaltic magmas originate by small scale melting of mantle sources. Compositional variety is testament to melting processes at different depths, a range of melting proportions, a heterogeneous source and fractionation, magma mixing and assimilation within the plumbing system that brings magmas to the surface. The fact that such a variety of compositions is preserved in a single field shows that isolation of individual melting events and their ascent is an important and possibly defining feature of monogenetic volcanism, as well as the window their chemical behavior provides into the complex process of melt generation and extraction in the Earth's upper mantle.

  9. Assesment of Alkali Resistance of Basalt Used as Concrete Aggregates

    NASA Astrophysics Data System (ADS)

    al-Swaidani, Aref M.; Baddoura, Mohammad K.; Aliyan, Samira D.; Choeb, Walid

    2015-11-01

    The objective of this paper is to report a part of an ongoing research on the influence of using crushed basalt as aggregates on one of durability-related properties of concrete (i.e. alkali-silica reaction which is the most common form of Alkali-Aggregate Reaction). Alkali resistance has been assessed through several methods specified in the American Standards. Results of petrographic examination, chemical test (ASTM C289) and accelerated mortar bar test (ASTM C1260) have particularly been reported. In addition, the weight change and compressive strength of 28 days cured concrete containing basaltic aggregates were also reported after 90 days of exposure to 10% NaOH solution. Dolomite aggregate were used in the latter test for comparison. The experimental results revealed that basaltic rocks quarried from As-Swaida'a region were suitable for production of aggregates for concrete. According to the test results, the studied basalt aggregates can be classified as innocuous with regard to alkali-silica reaction. Further, the 10% sodium hydroxide attack did not affect the compressive strength of concrete.

  10. Vesicularity and CO2 in mid-ocean ridge basalt

    USGS Publications Warehouse

    Moore, J.G.

    1979-01-01

    Vesicles and included CO2are enriched in deep-sea basalts that are also enriched in light rare earth and incompatible elements. This enrichment probably results from a unique deep mantle origin of such melts but may have been modified by CO2 bubbles rising in shallow magma chambers. ?? 1979 Nature Publishing Group.

  11. Automated identification of basalt spectra in Clementine lunar data

    NASA Astrophysics Data System (ADS)

    Antonenko, I.; Osinski, G. R.

    2011-06-01

    The identification of fresh basalt spectra plays an important role in lunar stratigraphic studies; however, the process can be time consuming and labor intensive. Thus motivated, we developed an empirically derived algorithm for the automated identification of fresh basalt spectra from Clememtine UVVIS data. This algorithm has the following four parameters and limits: BC Ratio=3(R950-R900)/(R900-R750)<1.1, CD Delta=(R1000-R950)/R750-1.09(R950-R900)/R750>0.003 and <0.06, B Slope=(R900-R750)/(3R750)<-0.012, and Band Depth=(R750-R950)/(R750-R415)>0.1, where R750 represents the unnormalized reflectance of the 750 nm Clementine band, and so on. Algorithm results were found to be accurate to within an error of 4.5% with respect to visual classification, though olivine spectra may be under-represented. Overall, fresh basalts identified by the algorithm are consistent with expectations and previous work in the Mare Humorum area, though accuracy in other areas has not yet been tested. Great potential exists in using this algorithm for identifying craters that have excavated basalts, estimating the thickness of mare and cryptomare deposits, and other applications.

  12. Detail of basaltic rock retaining walls just below top switchback. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Detail of basaltic rock retaining walls just below top switchback. 500 ft long retaining wall at left, scale figure in distance, view south. - La Bajada Historic Trails and Roads, Approximately 1 mile East/Northeast of intersection of State Highway 16 and Indian Service Road 841, La Bajada, Santa Fe County, NM

  13. Swale built up of drylaid basaltic rock along the Route ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Swale built up of dry-laid basaltic rock along the Route 66 section. Sandia Peak in distance, facing south. - La Bajada Historic Trails and Roads, Approximately 1 mile East/Northeast of intersection of State Highway 16 and Indian Service Road 841, La Bajada, Santa Fe County, NM

  14. [The dust factor in the manufacture of basalt fibers].

    PubMed

    Gorban', L N; Riazanov, A V; Voloboeva, A A; Rybak, E A

    1996-01-01

    A study was made of the labour conditions of those workers engaged in the production of basalt fibre (BF). Morphological makeup is examined as is dispersity and cytotoxicity of the dust produced in the process of BF making. An issue is addressed of usefulness of setting special hygienic regulations for BF dust.

  15. Notice of Release of NBR-1 Germplasm Basalt Milkvetch

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Basalt milkvetch or threadstalk milkvetch (Astragalus filipes Torr. ex A. Gray) is a perennial legume that is widely distributed on rangelands in western North America and holds promise for rangeland revegetation and restoration programs. No germplasms or cultivars are commercially available for ba...

  16. 69. Photocopy of General Arrangement of Engine Room. Basalt Rock ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    69. Photocopy of General Arrangement of Engine Room. Basalt Rock Co. Inc., Shipbuilding Division, Napa, California. Coast Guard Headquarters Drawing No. 540-WAGL-4000-2 (right side), dated July 1943. Original drawing property of the U.S. Coast Guard. - U.S. Coast Guard Cutter WHITE HEATH, USGS Integrated Support Command Boston, 427 Commercial Street, Boston, Suffolk County, MA

  17. 68. Photocopy of General Arrangement of Engine Room. Basalt Rock ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    68. Photocopy of General Arrangement of Engine Room. Basalt Rock Co. Inc., Shipbuilding Division, Napa, California. Coast Guard Headquarters Drawing No. 540-WAGL-4000-2 (left side), dated July 1943. Original drawing property of the U.S. Coast Guard. - U.S. Coast Guard Cutter WHITE HEATH, USGS Integrated Support Command Boston, 427 Commercial Street, Boston, Suffolk County, MA

  18. The Nature of Mare Basalts in the Procellarum KREEP Terrane

    NASA Technical Reports Server (NTRS)

    Haskin, Larry A.; Gillis, Jeffrey J.; Korotev, Randy L.; Jolliff, Bradley L.

    2000-01-01

    Unlike Apollo 12 and 15 basalts, many mare lavas of the Procellarum KREEP Terrane (PKT) have Th concentrations of 2.5-6 ppm and perhaps greater, as well as high TiO2. Lunar "picritic" volcanic glasses from the PKT have a similar range.

  19. Nuclear waste package materials testing report: basaltic and tuffaceous environments

    SciTech Connect

    Bradley, D.J.; Coles, D.G.; Hodges, F.N.; McVay, G.L.; Westerman, R.E.

    1983-03-01

    The disposal of high-level nuclear wastes in underground repositories in the continental United States requires the development of a waste package that will contain radionuclides for a time period commensurate with performance criteria, which may be up to 1000 years. This report addresses materials testing in support of a waste package for a basalt (Hanford, Washington) or a tuff (Nevada Test Site) repository. The materials investigated in this testing effort were: sodium and calcium bentonites and mixtures with sand or basalt as a backfill; iron and titanium-based alloys as structural barriers; and borosilicate waste glass PNL 76-68 as a waste form. The testing also incorporated site-specific rock media and ground waters: Reference Umtanum Entablature-1 basalt and reference basalt ground water, Bullfrog tuff and NTS J-13 well water. The results of the testing are discussed in four major categories: Backfill Materials: emphasizing water migration, radionuclide migration, physical property and long-term stability studies. Structural Barriers: emphasizing uniform corrosion, irradiation-corrosion, and environmental-mechanical testing. Waste Form Release Characteristics: emphasizing ground water, sample surface area/solution volume ratio, and gamma radiolysis effects. Component Compatibility: emphasizing solution/rock, glass/rock, glass/structural barrier, and glass/backfill interaction tests. This area also includes sensitivity testing to determine primary parameters to be studied, and the results of systems tests where more than two waste package components were combined during a single test.

  20. Genetic relations of oceanic basalts as indicated by lead isotopes

    USGS Publications Warehouse

    Tatsumoto, M.

    1966-01-01

    The isotopic compositions of lead and the concentrations of lead, uranium, and thorium in samples of oceanic tholeiite and alkali suites are determined, and the genetic relations of the oceanic basalts are discussed. Lead of the oceanic tholeiites has a varying lead-206 : lead-204 ratio between 17.8 and 18.8, while leads of the alkali basalt suites from Easter Island and Guadalupe Island are very radiogenic with lead-206 : lead-204 ratios between 19.3 and 20.4. It is concluded that (i) the isotopic composition of lead in oceanic tholeiite suggests that the upper mantle source region of the tholeiite was differentiated from an original mantle material more than 1 billion years ago and that the upper mantle is not homogeneous at the present time, (ii) less than 20 million years was required for the crystal differentiation within the alkali suite from Easter Island, (iii) no crustal contamination was involved in the course of differentiation of rocks from Easter Island; however, some crustal contamination may have affected Guadalupe Island rocks, and (iv) alkali basalt may be produced from the tholeiite in the oceanic region by crystal differentiation. Alternatively the difference in the isotopic composition of lead in oceanic basalts may be produced by partial melting at different depths of a differentiated upper mantle.

  1. Injection and Monitoring at the Wallula Basalt Pilot Project

    SciTech Connect

    McGrail, B. Peter; Spane, Frank A.; Amonette, James E.; Thompson, Christopher J.; Brown, Christopher F.

    2014-01-01

    Continental flood basalts represent one of the largest geologic structures on earth but have received comparatively little attention for geologic storage of CO2. Flood basalt lava flows have flow tops that are porous, permeable, and have large potential capacity for storage of CO2. In appropriate geologic settings, interbedded sediment layers and dense low-permeability basalt rock flow interior sections may act as effective seals allowing time for mineralization reactions to occur. Previous laboratory experiments showed the relatively rapid chemical reaction of CO2-saturated pore water with basalts to form stable carbonate minerals. However, recent laboratory tests with water-saturated supercritical CO2 show that mineralization reactions occur in this phase as well, providing a second and potentially more important mineralization pathway than was previously understood. Field testing of these concepts is proceeding with drilling of the world’s first supercritical CO2 injection well in flood basalt being completed in May 2009 near the township of Wallula in Washington State and corresponding CO2 injection permit granted by the State of Washington in March 2011. Injection of a nominal 1000 MT of CO2 was completed in August 2013 and site monitoring is in progress. Well logging conducted immediately after injection termination confirmed the presence of CO2 predominantly within the upper flow top region, and showed no evidence of vertical CO2 migration outside the well casing. Shallow soil gas samples collected around the injection well show no evidence of leakage and fluid and gas samples collected from the injection zone show strongly elevated concentrations of Ca, Mg, Mn, and Fe and 13C/18O isotopic shifts that are consistent with basalt-water chemical reactions. If proven viable by this field test and others that are in progress or being planned, major flood basalts in the U.S., India, and perhaps Australia would provide significant additional CO2 storage capacity

  2. Injection and Monitoring at the Wallula Basalt Pilot Project

    DOE PAGES

    McGrail, B. Peter; Spane, Frank A.; Amonette, James E.; Thompson, Christopher J.; Brown, Christopher F.

    2014-01-01

    Continental flood basalts represent one of the largest geologic structures on earth but have received comparatively little attention for geologic storage of CO2. Flood basalt lava flows have flow tops that are porous, permeable, and have large potential capacity for storage of CO2. In appropriate geologic settings, interbedded sediment layers and dense low-permeability basalt rock flow interior sections may act as effective seals allowing time for mineralization reactions to occur. Previous laboratory experiments showed the relatively rapid chemical reaction of CO2-saturated pore water with basalts to form stable carbonate minerals. However, recent laboratory tests with water-saturated supercritical CO2 show thatmore » mineralization reactions occur in this phase as well, providing a second and potentially more important mineralization pathway than was previously understood. Field testing of these concepts is proceeding with drilling of the world’s first supercritical CO2 injection well in flood basalt being completed in May 2009 near the township of Wallula in Washington State and corresponding CO2 injection permit granted by the State of Washington in March 2011. Injection of a nominal 1000 MT of CO2 was completed in August 2013 and site monitoring is in progress. Well logging conducted immediately after injection termination confirmed the presence of CO2 predominantly within the upper flow top region, and showed no evidence of vertical CO2 migration outside the well casing. Shallow soil gas samples collected around the injection well show no evidence of leakage and fluid and gas samples collected from the injection zone show strongly elevated concentrations of Ca, Mg, Mn, and Fe and 13C/18O isotopic shifts that are consistent with basalt-water chemical reactions. If proven viable by this field test and others that are in progress or being planned, major flood basalts in the U.S., India, and perhaps Australia would provide significant additional CO2 storage

  3. Plant-induced weathering of a basaltic rock: experimental evidence

    NASA Astrophysics Data System (ADS)

    Hinsinger, Philippe; Fernandes Barros, Omar Neto; Benedetti, Marc F.; Noack, Yves; Callot, Gabriel

    2001-01-01

    The active role of higher plants in the weathering of silicate minerals and rocks is still a question for debate. The present work aimed at providing experimental evidence of the important role of a range of crop plants in such processes. In order to quantitatively assess the possible effect of these diverse plant species on the weathering of a basaltic rock, two laboratory experiments were carried out at room temperature. These compared the amounts of elements released from basalt when leached with a dilute salt solution in the presence or absence of crop plants grown for up to 36 days. For Si, Ca, Mg, and Na, plants resulted in an increase in the release rate by a factor ranging from 1 to 5 in most cases. Ca and Na seemed to be preferentially released relative to other elements, suggesting that plagioclase dissolved faster than the other constituents of the studied basalt. Negligible amounts of Fe were released in the absence of plants as a consequence of the neutral pH and atmospheric pO 2 that were maintained in the leaching solution. However, the amounts of Fe released from basalt in the presence of plants were up to 100- to 500-fold larger than in the absence of plants, for banana and maize. The kinetics of dissolution of basalt in the absence of plants showed a constantly decreasing release rate over the whole duration of the experiment (36 days). No steady state value was reached both in the absence and presence of banana plants. However, in the latter case, the rates remained at a high initial level over a longer period of time (up to 15 days) before starting to decrease. For Fe, the maximum rate of release was reached beyond 4 days and this rate remained high up to 22 days of growth of banana. The possible mechanisms responsible for this enhanced release of elements from basalt in the presence of plants are discussed. Although these mechanisms need to be elucidated, the present results clearly show that higher plants can considerably affect the kinetics

  4. Structural studies in columnar basalts from crystallographic and magnetic fabrics

    NASA Astrophysics Data System (ADS)

    Tiphaine, Boiron; Jérôme, Bascou; Pierre, Camps; Eric, Ferre; Claire, Maurice; Bernard, Guy; Marie-Christine, Gerbe

    2010-05-01

    The purpose of this study is to better characterize the columnar and the associated microstructure development in basalt flows. The thermal contraction (O'Reilly, 1879) is the main hypothesis to explain the columnar formation. However, neither the structures which appear in basalt flow constituted of three levels (Tomkeieff, 1940) nor circular and radial structures within the prisms (for which weathering nor fracturing can account for) can be explained by the thermal contraction theory alone. An early structuring process during solidification (Guy and Le Coze, 1990) could play for a part that must be discussed (Guy, 2010). We studied two recent basalt flows (75 000 years) from the French Massif Central, in which the three flow levels are clearly observed. In the first basalt flow (La Palisse, Ardèche), the emission centre and the flow direction are known. In the second one (Saint Arcons d'Allier, Haute Loire), the prismatic columns are particularly well developed. In order to characterize the flow structure at different scales, from the flow to the grain scale, anisotropy of magnetic susceptibility (AMS) measurements were performed. The AMS data were coupled with crystallographic preferred orientation measurements of magnetite, plagioclase and clinopyroxene using Electron Backscattered Diffraction (EBSD) and image analyses from perpendicular thin sections. Magnetic mineralogy studies of the La Palisse basalts, in particular the thermomagnetic curves, indicate that the main carrier of AMS is high-Ti titanomagnetite (Tc≈130°C). AMS measurements of about a hundred samples show a higher degree of AMS (P parameter) in the middle level in comparison to the base. Inversely, the bulk magnetic susceptibility (Km) is higher at the flow base. Distinctive parameters for the different levels of the basaltic flows could be then provided by AMS measurements.. Moreover, the comparison between AMS and EBSD data indicate that the magnetic susceptibility carried by the magnetic

  5. Th-230 - U-238 series disequilibrium of the Olkaria basalts Gregory Rift Valley, Kenya

    NASA Technical Reports Server (NTRS)

    Black, S.; Macdonald, R.; Kelly, M.

    1993-01-01

    U-Th disequilibrium analyses of the Naivasha basalts show a very small (U-238/Th-230) ratios which are lower than any previously analyzed basalts. The broadly positive internal isochron trend from one sample indicates that the basalts may have source heterogeneities, this is supported by earlier work. The Naivasha complex comprises a bimodal suite of basalts and rhyolites. The basalts are divided into two stratigraphic groups each of a transitional nature. The early basalt series (EBS) which were erupted prior to the Group 1 comendites and, the late basalt series (LBS) which erupted temporally between the Broad Acres and the Ololbutot centers. The basalts represent a very small percentage of the overall eruptive volume of material at Naivasha (less than 2 percent). The analyzed samples come from four stratigraphic units in close proximity around Ndabibi, Hell's Gate and Akira areas. The earliest units occur as vesicular flows from the Ndabibi plain. These basalts are olivine-plagioclase phyric with the associated hawaiites being sparsely plagioclase phyric. An absolute age of 0.5Ma was estimated for these basalts. The next youngest basalts flows occur as younger tuft cones in the Ndabibi area and are mainly olivine-plagioclase-clinopyroxcene phyric with one purely plagioclase phyric sample. The final phase of activity at Ndabibi resulted in much younger tuft cones consisting of air fall ashes and lapilli tufts. Many of these contain resorbed plagioclase phenocrysts with sample number 120c also being clinopyroxene phyric. The isotopic evidence for the basalt formation is summarized.

  6. Carbon fixation by basalt-hosted microbial communities.

    PubMed

    Orcutt, Beth N; Sylvan, Jason B; Rogers, Daniel R; Delaney, Jennifer; Lee, Raymond W; Girguis, Peter R

    2015-01-01

    Oceanic crust is a massive potential habitat for microbial life on Earth, yet our understanding of this ecosystem is limited due to difficulty in access. In particular, measurements of rates of microbial activity are sparse. We used stable carbon isotope incubations of crustal samples, coupled with functional gene analyses, to examine the potential for carbon fixation on oceanic crust. Both seafloor-exposed and subseafloor basalts were recovered from different mid-ocean ridge and hot spot environments (i.e., the Juan de Fuca Ridge, the Mid-Atlantic Ridge, and the Loihi Seamount) and incubated with (13)C-labeled bicarbonate. Seafloor-exposed basalts revealed incorporation of (13)C-label into organic matter over time, though the degree of incorporation was heterogeneous. The incorporation of (13)C into biomass was inconclusive in subseafloor basalts. Translating these measurements into potential rates of carbon fixation indicated that 0.1-10 nmol C g(-1) rock d(-1) could be fixed by seafloor-exposed rocks. When scaled to the global production of oceanic crust, this suggests carbon fixation rates of 10(9)-10(12) g C year(-1), which matches earlier predictions based on thermodynamic calculations. Functional gene analyses indicate that the Calvin cycle is likely the dominant biochemical mechanism for carbon fixation in basalt-hosted biofilms, although the reductive acetyl-CoA pathway and reverse TCA cycle likely play some role in net carbon fixation. These results provide empirical evidence for autotrophy in oceanic crust, suggesting that basalt-hosted autotrophy could be a significant contributor of organic matter in this remote and vast environment. PMID:26441854

  7. Carbon fixation by basalt-hosted microbial communities.

    PubMed

    Orcutt, Beth N; Sylvan, Jason B; Rogers, Daniel R; Delaney, Jennifer; Lee, Raymond W; Girguis, Peter R

    2015-01-01

    Oceanic crust is a massive potential habitat for microbial life on Earth, yet our understanding of this ecosystem is limited due to difficulty in access. In particular, measurements of rates of microbial activity are sparse. We used stable carbon isotope incubations of crustal samples, coupled with functional gene analyses, to examine the potential for carbon fixation on oceanic crust. Both seafloor-exposed and subseafloor basalts were recovered from different mid-ocean ridge and hot spot environments (i.e., the Juan de Fuca Ridge, the Mid-Atlantic Ridge, and the Loihi Seamount) and incubated with (13)C-labeled bicarbonate. Seafloor-exposed basalts revealed incorporation of (13)C-label into organic matter over time, though the degree of incorporation was heterogeneous. The incorporation of (13)C into biomass was inconclusive in subseafloor basalts. Translating these measurements into potential rates of carbon fixation indicated that 0.1-10 nmol C g(-1) rock d(-1) could be fixed by seafloor-exposed rocks. When scaled to the global production of oceanic crust, this suggests carbon fixation rates of 10(9)-10(12) g C year(-1), which matches earlier predictions based on thermodynamic calculations. Functional gene analyses indicate that the Calvin cycle is likely the dominant biochemical mechanism for carbon fixation in basalt-hosted biofilms, although the reductive acetyl-CoA pathway and reverse TCA cycle likely play some role in net carbon fixation. These results provide empirical evidence for autotrophy in oceanic crust, suggesting that basalt-hosted autotrophy could be a significant contributor of organic matter in this remote and vast environment.

  8. Carbon fixation by basalt-hosted microbial communities

    PubMed Central

    Orcutt, Beth N.; Sylvan, Jason B.; Rogers, Daniel R.; Delaney, Jennifer; Lee, Raymond W.; Girguis, Peter R.

    2015-01-01

    Oceanic crust is a massive potential habitat for microbial life on Earth, yet our understanding of this ecosystem is limited due to difficulty in access. In particular, measurements of rates of microbial activity are sparse. We used stable carbon isotope incubations of crustal samples, coupled with functional gene analyses, to examine the potential for carbon fixation on oceanic crust. Both seafloor-exposed and subseafloor basalts were recovered from different mid-ocean ridge and hot spot environments (i.e., the Juan de Fuca Ridge, the Mid-Atlantic Ridge, and the Loihi Seamount) and incubated with 13C-labeled bicarbonate. Seafloor-exposed basalts revealed incorporation of 13C-label into organic matter over time, though the degree of incorporation was heterogeneous. The incorporation of 13C into biomass was inconclusive in subseafloor basalts. Translating these measurements into potential rates of carbon fixation indicated that 0.1–10 nmol C g-1rock d-1 could be fixed by seafloor-exposed rocks. When scaled to the global production of oceanic crust, this suggests carbon fixation rates of 109–1012 g C year-1, which matches earlier predictions based on thermodynamic calculations. Functional gene analyses indicate that the Calvin cycle is likely the dominant biochemical mechanism for carbon fixation in basalt-hosted biofilms, although the reductive acetyl-CoA pathway and reverse TCA cycle likely play some role in net carbon fixation. These results provide empirical evidence for autotrophy in oceanic crust, suggesting that basalt-hosted autotrophy could be a significant contributor of organic matter in this remote and vast environment. PMID:26441854

  9. Modeled effects of soil acidification on long-term ecological and economic outcomes for managed forests in the Adirondack region (USA)

    USGS Publications Warehouse

    Caputo, Jesse PhD.; Beier, Colin M.; Sullivan, Timothy J.; Lawrence, Gregory B.

    2016-01-01

    Sugar maple (Acer saccharum) is among the most ecologically and economically important tree species in North America, and its growth and regeneration is often the focus of silvicultural practices in northern hardwood forests. A key stressor for sugar maple (SM) is acid rain, which depletes base cations from poorly-buffered forest soils and has been associated with much lower SM vigor, growth, and recruitment. However, the potential interactions between forest management and soil acidification – and their implications for the sustainability of SM and its economic and cultural benefits – have not been investigated. In this study, we simulated the development of 50 extant SM stands in the western Adirondack region of NY (USA) for 100 years under different soil chemical conditions and silvicultural prescriptions. We found that interactions between management prescription and soil base saturation will strongly shape the ability to maintain SM in managed forests. Below 12% base saturation, SM did not regenerate sufficiently after harvest and was replaced mainly by red maple (Acer rubrum) and American beech (Fagus grandifolia). Loss of SM on acid-impaired sites was predicted regardless of whether the shelterwood or diameter-limit prescriptions were used. On soils with sufficient base saturation, models predicted that SM will regenerate after harvest and be sustained for future rotations. We then estimated how these different post-harvest outcomes, mediated by acid impairment of forest soils, would affect the potential monetary value of ecosystem services provided by SM forests. Model simulations indicated that a management strategy focused on syrup production – although not feasible across the vast areas where acid impairment has occurred – may generate the greatest economic return. Although pollution from acid rain is declining, its long-term legacy in forest soils will shape future options for sustainable forestry and ecosystem stewardship in the northern

  10. Modeled effects of soil acidification on long-term ecological and economic outcomes for managed forests in the Adirondack region (USA).

    PubMed

    Caputo, Jesse; Beier, Colin M; Sullivan, Timothy J; Lawrence, Gregory B

    2016-09-15

    Sugar maple (Acer saccharum) is among the most ecologically and economically important tree species in North America, and its growth and regeneration is often the focus of silvicultural practices in northern hardwood forests. A key stressor for sugar maple (SM) is acid rain, which depletes base cations from poorly-buffered forest soils and has been associated with much lower SM vigor, growth, and recruitment. However, the potential interactions between forest management and soil acidification - and their implications for the sustainability of SM and its economic and cultural benefits - have not been investigated. In this study, we simulated the development of 50 extant SM stands in the western Adirondack region of NY (USA) for 100years under different soil chemical conditions and silvicultural prescriptions. We found that interactions between management prescription and soil base saturation will strongly shape the ability to maintain SM in managed forests. Below 12% base saturation, SM did not regenerate sufficiently after harvest and was replaced mainly by red maple (Acer rubrum) and American beech (Fagus grandifolia). Loss of SM on acid-impaired sites was predicted regardless of whether the shelterwood or diameter-limit prescriptions were used. On soils with sufficient base saturation, models predicted that SM will regenerate after harvest and be sustained for future rotations. We then estimated how these different post-harvest outcomes, mediated by acid impairment of forest soils, would affect the potential monetary value of ecosystem services provided by SM forests. Model simulations indicated that a management strategy focused on syrup production - although not feasible across the vast areas where acid impairment has occurred - may generate the greatest economic return. Although pollution from acid rain is declining, its long-term legacy in forest soils will shape future options for sustainable forestry and ecosystem stewardship in the northern hardwood

  11. Modeled effects of soil acidification on long-term ecological and economic outcomes for managed forests in the Adirondack region (USA).

    PubMed

    Caputo, Jesse; Beier, Colin M; Sullivan, Timothy J; Lawrence, Gregory B

    2016-09-15

    Sugar maple (Acer saccharum) is among the most ecologically and economically important tree species in North America, and its growth and regeneration is often the focus of silvicultural practices in northern hardwood forests. A key stressor for sugar maple (SM) is acid rain, which depletes base cations from poorly-buffered forest soils and has been associated with much lower SM vigor, growth, and recruitment. However, the potential interactions between forest management and soil acidification - and their implications for the sustainability of SM and its economic and cultural benefits - have not been investigated. In this study, we simulated the development of 50 extant SM stands in the western Adirondack region of NY (USA) for 100years under different soil chemical conditions and silvicultural prescriptions. We found that interactions between management prescription and soil base saturation will strongly shape the ability to maintain SM in managed forests. Below 12% base saturation, SM did not regenerate sufficiently after harvest and was replaced mainly by red maple (Acer rubrum) and American beech (Fagus grandifolia). Loss of SM on acid-impaired sites was predicted regardless of whether the shelterwood or diameter-limit prescriptions were used. On soils with sufficient base saturation, models predicted that SM will regenerate after harvest and be sustained for future rotations. We then estimated how these different post-harvest outcomes, mediated by acid impairment of forest soils, would affect the potential monetary value of ecosystem services provided by SM forests. Model simulations indicated that a management strategy focused on syrup production - although not feasible across the vast areas where acid impairment has occurred - may generate the greatest economic return. Although pollution from acid rain is declining, its long-term legacy in forest soils will shape future options for sustainable forestry and ecosystem stewardship in the northern hardwood

  12. Acid-base characteristics of the Grass Pond watershed in the Adirondack Mountains of New York State, USA: interactions between soil, vegetation and surface waters

    NASA Astrophysics Data System (ADS)

    McEathron, K. M.; Mitchell, M. J.; Zhang, L.

    2012-09-01

    Grass Pond watershed is located within the Southwestern Adirondack Mountain region of New York State, USA. This region receives some of the highest rates of acidic deposition in North America and is particularly sensitive to acidic inputs due to many of its soils having shallow depths and being generally base-poor. Differences in soil chemistry and tree species between seven subwatersheds were examined in relation to acid-base characteristics of the seven major streams that drain into Grass Pond. Mineral soil pH, stream water BCS and pH exhibited a positive correlation with sugar maple basal area (p = 0.055; 0.48 and 0.39, respectively). Black cherry basal area was inversely correlated with stream water BCS, ANCc and NO3- (p = 0.23; 0.24 and 0.20, respectively). Sugar maple basal areas were positively correlated with watershed characteristics associated with the neutralization of atmospheric acidic inputs while in contrast, black cherry basal areas showed opposite relationships to these same watershed characteristics. Canonical Correspondence Analysis indicated that black cherry had a distinctive relationship with forest floor chemistry apart from the other tree species, specifically a strong positive association with forest floor NH4 while sugar maple had a distinctive relationship with stream chemistry variables, specifically a strong positive association with stream water ANCc, BCS and pH. Our results provide evidence that sugar maple is acid-intolerant or calciphilic tree species and also demonstrate that black cherry is likely an acid-tolerant tree species.

  13. Acid-base characteristics of the Grass Pond watershed in the Adirondack Mountains of New York State, USA: interactions among soil, vegetation and surface waters

    NASA Astrophysics Data System (ADS)

    McEathron, K. M.; Mitchell, M. J.; Zhang, L.

    2013-07-01

    Grass Pond watershed is located within the southwestern Adirondack Mountain region of New York State, USA. This region receives some of the highest rates of acidic deposition in North America and is particularly sensitive to acidic inputs due to many of its soils having shallow depths and being generally base poor. Differences in soil chemistry and tree species between seven subwatersheds were examined in relation to acid-base characteristics of the seven major streams that drain into Grass Pond. Mineral soil pH, stream water BCS (base-cation surplus) and pH exhibited a positive correlation with sugar maple basal area (p = 0.055; 0.48 and 0.39, respectively). Black cherry basal area was inversely correlated with stream water BCS, ANC (acid neutralizing capacity)c and NO3- (p = 0.23; 0.24 and 0.20, respectively). Sugar maple basal areas were positively associated with watershed characteristics associated with the neutralization of atmospheric acidic inputs while in contrast, black cherry basal areas showed opposite relationships to these same watershed characteristics. Canonical correspondence analysis indicated that black cherry had a distinctive relationship with forest floor chemistry apart from the other tree species, specifically a strong positive association with forest floor NH4, while sugar maple had a distinctive relationship with stream chemistry variables, specifically a strong positive association with stream water ANCc, BCS and pH. Our results provide evidence that sugar maple is acid-intolerant or calciphilic tree species and also demonstrate that black cherry is likely an acid-tolerant tree species.

  14. Concentration and flux of solutes from snow and forest floor during snowmelt in the West-Central Adirondack region of New York

    USGS Publications Warehouse

    Rascher, C.M.; Driscoll, C.T.; Peters, N.E.

    1987-01-01

    Decreases in pH and increases in the concentration of Al and NO3- have been observed in surface waters draining acid-sensitive regions in the northeastern U.S. during spring snowmelt. To assess the source of this acidity, we evaluated solute concentrations in snowpack, and in meltwater collected from snow and forest floor lysimeters in the west-central Adirondack Mountains of New York during the spring snowmelt period, 29 March through 15 April 1984. During the initial phase of snowmelt, ions were preferentially leached from the snowpack resulting in elevated concentrations in snowmelt water (e.g. H+ = 140 ??eq.l-1; NO42- = 123 ??eq.l-1; SO3- = 160 ??eq.l-1). Solute concentrations decreased dramatically within a few days of the initial melt (< 50 ??eq.l-1). The concentrations of SO42- and NO3- in snowpack and snowmelt water were similar, whereas NO-3 in the forest floor leachate was at least two times the concentration of SO42-. Study results suggest that the forest floor was a sink for snowmelt inputs of alkalinity, and a net source of H+, NO3-, dissolved organic carbon, K+ and Al inputs to the mineral soil. The forest floor was relatively conservative with respect to snowmelt inputs of Ca2+, SO42- and Cl-. These results indicate that mineralization of N, followed by nitrification in the forest floor may be an important process contributing to elevated concentrations of H+ and NO3- in streams during the snowmelt period. ?? 1987 Martinus Nijhoff/Dr W. Junk Publishers.

  15. Zr and Nb partition coefficients - Implications for the genesis of mare basalts, KREEP, and sea floor basalts

    NASA Technical Reports Server (NTRS)

    Mccallum, I. S.; Charette, M. P.

    1978-01-01

    The distribution coefficients of Zr and Nb have been found between armalcolite, ilmenite, clinopyroxene, rutile, plagioclase, and a coexisting high-Ti mare basalt melt in the 1105-1128 C temperature range. Henry's Law is not broken over the compositional range evaluated. The distribution coefficients of clinopyroxene are strongly dependent on melt and crystal compositions. The Al2O3 activity in the melt is a strong controlling parameter. It is concluded that: (1) Apollo 11 (low K) and Apollo 17 high-Ti mare basalts may have been generated by the partial melting of an ilmenite-rich cumulate, (2) Apollo 11 (high K) basalts may have been generated by a small amount of partial melting of a more fractionated ilmenite-rich cumulate, (3) KREEP magmas may have been formed as residual melts produced by fractional crystallization of the lunar magma ocean, and (4) anomalous (type II) MOR basalts may have been generated by small degrees of partial melting of a relatively undepleted mantle with clinopyroxene remaining in the residium.

  16. Phase relations of a simulated lunar basalt as a function of oxygen fugacity, and their bearing on the petrogenesis of the Apollo 11 basalts

    USGS Publications Warehouse

    Tuthill, R.L.; Sato, M.

    1970-01-01

    A glass of Apollo 11 basalt composition crystallizing at 1 atm at low f{hook}02 showed the following crystallization sequence; ferropseudobrookite at 1210??C, olivine at 1200??C, ilmenite and plagioclase at 1140??C, clinopyroxene at 1113??C. Ferropseudobrookite and olivine have a reaction relation to the melt. This sequence agrees with that assumed on textural grounds for some Apollo 11 basalts. It also indicates that the Apollo 11 basalts cannot have been modified by low-pressure fractionation. ?? 1970.

  17. Architecture and emplacement of flood basalt flow fields: case studies from the Columbia River Basalt Group, NW USA

    NASA Astrophysics Data System (ADS)

    Vye-Brown, C.; Self, S.; Barry, T. L.

    2013-03-01

    The physical features and morphologies of collections of lava bodies emplaced during single eruptions (known as flow fields) can be used to understand flood basalt emplacement mechanisms. Characteristics and internal features of lava lobes and whole flow field morphologies result from the forward propagation, radial spread, and cooling of individual lobes and are used as a tool to understand the architecture of extensive flood basalt lavas. The features of three flood basalt flow fields from the Columbia River Basalt Group are presented, including the Palouse Falls flow field, a small (8,890 km2, ˜190 km3) unit by common flood basalt proportions, and visualized in three dimensions. The architecture of the Palouse Falls flow field is compared to the complex Ginkgo and more extensive Sand Hollow flow fields to investigate the degree to which simple emplacement models represent the style, as well as the spatial and temporal developments, of flow fields. Evidence from each flow field supports emplacement by inflation as the predominant mechanism producing thick lobes. Inflation enables existing lobes to transmit lava to form new lobes, thus extending the advance and spread of lava flow fields. Minimum emplacement timescales calculated for each flow field are 19.3 years for Palouse Falls, 8.3 years for Ginkgo, and 16.9 years for Sand Hollow. Simple flow fields can be traced from vent to distal areas and an emplacement sequence visualized, but those with multiple-layered lobes present a degree of complexity that make lava pathways and emplacement sequences more difficult to identify.

  18. Whole rock major element chemistry of KREEP basalt clasts in lunar breccia 15205: Implications for the petrogenesis of volcanic KREEP basalts

    NASA Technical Reports Server (NTRS)

    Vetter, Scott K.; Shervais, John W.

    1993-01-01

    KREEP basalts are a major component of soils and regolith at the Apollo 15 site. Their origin is controversial: both endogenous (volcanic) and exogenous (impact melt) processes have been proposed, but it is now generally agreed that KREEP basalts are volcanic rocks derived from the nearby Apennine Bench formation. Because most pristine KREEP basalts are found only as small clasts in polymict lunar breccias, reliable chemical data are scarce. The primary aim of this study is to characterize the range in chemical composition of pristine KREEP basalt, and to use these data to decipher the petrogenesis of these unique volcanic rocks.

  19. Class Trash.

    ERIC Educational Resources Information Center

    Chemecology, 1992

    1992-01-01

    Presents a classroom activity in which students calculate the amount and types of trash thrown out by their class at school to investigate how much trash is generated, where it goes, and speculate about alternatives. Students need to be familiar with the concepts of weight, volume, and numbers. (MCO)

  20. Neodymium isotopes in flood basalts from the Siberian Platform and inferences about their mantle sources

    PubMed Central

    DePaolo, D. J.; Wasserburg, G. J.

    1979-01-01

    The initial isotopic compositions of Nd and Sr in basalts from the Central Siberian Plateau and other major continental flood basalts are reported. The continental flood basalts appear to be the product of partial melting of mantle sources that consist of relatively primitive undifferentiated material and are clearly distinct from midocean ridge basalts, which sample mantle reservoirs that have been modified by extraction of continental crust earlier in earth history. These observations provide fundamental constraints on models of mantle structure and dynamics. Isotopic effects of crustal contamination are clearly recognizable in some continental flood basalts, but these effects can be distinguished from isotopic patterns inherited from the mantle magma sources. PMID:16592671

  1. Neodymium isotopes in flood basalts from the Siberian Platform and inferences about their mantle sources.

    PubMed

    Depaolo, D J; Wasserburg, G J

    1979-07-01

    The initial isotopic compositions of Nd and Sr in basalts from the Central Siberian Plateau and other major continental flood basalts are reported. The continental flood basalts appear to be the product of partial melting of mantle sources that consist of relatively primitive undifferentiated material and are clearly distinct from midocean ridge basalts, which sample mantle reservoirs that have been modified by extraction of continental crust earlier in earth history. These observations provide fundamental constraints on models of mantle structure and dynamics. Isotopic effects of crustal contamination are clearly recognizable in some continental flood basalts, but these effects can be distinguished from isotopic patterns inherited from the mantle magma sources.

  2. Aqueous Alteration of Basalts: Earth, Moon, and Mars

    NASA Technical Reports Server (NTRS)

    Ming, Douglas W.

    2007-01-01

    The geologic processes responsible for aqueous alteration of basaltic materials on Mars are modeled beginning with our knowledge of analog processes on Earth, i.e., characterization of elemental and mineralogical compositions of terrestrial environments where the alteration and weathering pathways related to aqueous activity are better understood. A key ingredient to successful modeling of aqueous processes on Mars is identification of phases that have formed by those processes. The purpose of this paper is to describe what is known about the elemental and mineralogical composition of aqueous alteration products of basaltic materials on Mars and their implications for specific aqueous environments based upon our knowledge of terrestrial systems. Although aqueous alteration has not occurred on the Moon, it is crucial to understand the behaviors of basaltic materials exposed to aqueous environments in support of human exploration to the Moon over the next two decades. Several methods or indices have been used to evaluate the extent of basalt alteration/weathering based upon measurements made at Mars by the Mars Exploration Rover (MER) Moessbauer and Alpha Particle X-Ray Spectrometers. The Mineralogical Alteration Index (MAI) is based upon the percentage of total Fe (Fe(sub T)) present as Fe(3+) in alteration products (Morris et al., 2006). A second method is the evaluation of compositional trends to determine the extent to which elements have been removed from the host rock and the likely formation of secondary phases (Nesbitt and Young, 1992; Ming et al., 2007). Most of the basalts that have been altered by aqueous processes at the two MER landing sites in Gusev crater and on Meridiani Planum have not undergone extensive leaching in an open hydrolytic system with the exception of an outcrop in the Columbia Hills. The extent of aqueous alteration however ranges from relatively unaltered to pervasively altered materials. Several experimental studies have focused upon

  3. Discrimination among tectonic settings using trace element abundances of basalts

    NASA Astrophysics Data System (ADS)

    Butler, John C.; Woronow, Alex

    1986-09-01

    A wealth of chemical information may provide a false sense of security to the petrologist interested in extracting petrogenetic information from a set of major and/or trace element abundances. Such data are said to be closed, as each analysis sums to a constant (100%). Failure to sum to a constant results from a combination of errors of commission and omission. A correlation coefficient between a pair of closed components has a contribution from the linear association between the components and a contribution from the effects of closure itself. Standard statistical procedures cannot separate these two sources; therefore, the investigator cannot tell if a strong correlation (as revealed by a nearly linear trend on a binary scatter diagram, for example, is due to a strong linear association between the components or due to closure. Techniques developed by Aitchison (1984a, b) appear to be capable of providing a framework within which the user can begin to assess the relationship among closed components. These techniques are applied to a set of 35 TiO2, Zr, Y, and Sr analyses of basalts. A statistical analysis permits rejection of Aitchison's (1984a, b) hypothesis of complete subcompositional independence, indicating that there is a degree of dependency within the data set. The first two principal components extracted from the covariance matrix of the log-centered form of these data account for more than 90% of the total variation, and three major tectonic-related fields can be clearly recognized in the space defined by the first two principal components: ocean floor basalts, within-plate basalts and arc-related basalts. Analyses from six additional data sets taken from the literature were plotted on this diagram, and all reclaim the tectonic settings stated in the literature. Simple modeling reveals that the addition or subtraction of Sr from an analysis results in a linear locus of points which is parallel to the boundary between the ocean floor and the within

  4. Similarities in basalt and rhyolite lava flow emplacement processes

    NASA Astrophysics Data System (ADS)

    Magnall, Nathan; James, Mike; Tuffen, Hugh; Vye-Brown, Charlotte

    2016-04-01

    Here we use field observations of rhyolite and basalt lava flows to show similarities in flow processes that span compositionally diverse lava flows. The eruption, and subsequent emplacement, of rhyolite lava flows is currently poorly understood due to the infrequency with which rhyolite eruptions occur. In contrast, the emplacement of basaltic lava flows are much better understood due to very frequent eruptions at locations such as Mt Etna and Hawaii. The 2011-2012 eruption of Cordón Caulle in Chile enabled the first scientific observations of the emplacement of an extensive rhyolite lava flow. The 30 to 100 m thick flow infilled a topographic depression with a negligible slope angle (0 - 7°). The flow split into two main channels; the southern flow advanced 4 km while the northern flow advanced 3 km before stalling. Once the flow stalled the channels inflated and secondary flows or breakouts formed from the flow front and margins. This cooling rather than volume-limited flow behaviour is common in basaltic lava flows but had never been observed in rhyolite lava flows. We draw on fieldwork conducted at Cordón Caulle and at Mt Etna to compare the emplacement of rhyolite and basaltic flows. The fieldwork identified emplacement features that are present in both lavas, such as inflation, breakouts from the flow font and margins, and squeeze-ups on the flow surfaces. In the case of Cordón Caulle, upon extrusion of a breakout it inflates due to a combination of continued lava supply and vesicle growth. This growth leads to fracturing and breakup of the breakout surface, and in some cases a large central fracture tens of metres deep forms. In contrast, breakouts from basaltic lava flows have a greater range of morphologies depending on the properties of the material in the flows core. In the case of Mt Etna, a range of breakout morphologies are observed including: toothpaste breakouts, flows topped with bladed lava as well as breakouts of pahoehoe or a'a lava. This

  5. Basalt characterization by means of nuclear and electrical well logging techniques. Case study from Southern Syria.

    PubMed

    Asfahani, Jamal

    2011-03-01

    Nuclear well logging, including natural gamma ray, density, and neutron-porosity techniques are used with electrical well logging of long and short normal techniques to characterize the basaltic areas largely extended in Southern Syria. Statistical analysis approach with the threshold concept has been adapted for such characterization, where four kinds of basalt have been identified: very hard basalt, hard basalt, fractured basalt, and basalt alteration products. The spectrometric gamma technique has also been applied on the retrieved rock samples in order to determine the radioactive content (eU, eTh, and K%) of the basaltic section in the study area. No radioactive anomalies have been detected, the radioactive values are normal and in the expected range.

  6. Automated interpretation of nuclear and electrical well loggings for basalt characterization (case study from southern Syria).

    PubMed

    Asfahani, J; Abdul Ghani, B

    2012-10-01

    Nuclear well logging, including natural gamma ray, density and neutron-porosity techniques are used with electrical well logging of long and short normal techniques in order to characterize the large extended basaltic areas in southern Syria. Four kinds of basalt have been identified: hard massive basalt, hard basalt, pyroclastic basalt and the alteration basalt products, clay, based on a statistical analysis approach with the threshold concept. The statistical conditions for such basalt characterization have been programmed in the present research to automatically interpret the well logging data for establishing and predicting the lithological cross-section of the studied well. A specific computer program has been written in Delphi for such purposes. The program is flexible and it can be used for other well logging applications by changing the statistical conditions and the well logging parameters. The program has been successfully tested on the Kodanah well logging data in southern Syria.

  7. Very low Ti /VLT/ basalts - A new mare rock type from the Apollo 17 drill core

    NASA Technical Reports Server (NTRS)

    Vaniman, D. T.; Papike, J. J.

    1977-01-01

    Phaneritic fragments, vitrophyres, and glass beads of a new very low Ti (VLT) mare basalt are found in the Apollo 17 drill core. VLT lithic fragments are characterized by TiO2 content of approximately 0.5%, Mg/(Mg + Fe) of approximately 0.52, CaO/Al2O3 of approximately 0.9, and low alkali content. Although mineral systematics and modal composition of VLT basalt are similar to Apollo 12 and 15 low Ti basalts, VLT basalts cannot be related to these mare basalts by crystal fractionation. Since VLT basalt is isochemical with some of the less mafic green glasses, fractionation of VLT magma from a liquid of green-glass composition is a possibility. Spectral reflectance studies suggest that VLT-type basalts may be relatively common in mare basins.

  8. Flood basalt volcanism during the past 250 million years

    NASA Technical Reports Server (NTRS)

    Rampino, Michael R.; Stothers, Richard B.

    1988-01-01

    A chronology of the initiation dates of major continental flood basalt volcanism is established from published potassium-argon (K-Ar) and argon-argon (Ar-Ar) ages of basaltic rocks and related basic intrusions. The dating is therefore independent of the biostratigraphic and paleomagnetic time scales. Estimated errors of the initiation dates of the volcanic episodes determined from the distributions of the radiometric ages are, approximately, + or - 4 percent. There were 11 distinct episodes during the past 250 million years. Sometimes appearing in pairs, the episodes have occurred quasi-periodically with a mean cycle time of 32 + or - 1 (estimated error of the mean) million years. The initiation dates of the episodes are close to the estimated dates of mass extinctions of marine organisms. Showers of impacting comets may be the cause.

  9. Effect of chromate action on morphology of basalt-inhabitingbacteria

    SciTech Connect

    Lin, Z.; Zhu, Y.; Kalabegishvili, T.L.; Tsibakhashvili, N.Y.; Holman, H-Y.

    2006-03-01

    Basalt-inhabiting bacteria isolated from polluted basaltshave been demonstrated to be able to tolerate moderate to highconcentrations of chromium oxyanions such as chromate. Previous resultshave shown that macromolecules outside the cell wall of bacteria may playan important role in this survival ability. In this paper, ScanningElectron Microscopy (SEM) and Transmission Electron Microscopy (TEM) wereapplied to study the chromate-induced morphological changes inchromate-resistant basalt-inhabiting Arthrobacter K-2 and K-4, which wereisolated from the Republic of Georgia. The surfaces of both strainschanged in the presence of chromate. TEM thin sections show that chromatestimulates the appearance of bacteria capsular polysaccharide outside thecell wall, although the chromate concentration does not have a strongeffect on the capsular thickness. These results, in conjunction withthose reported earlier, provide direct evidence to show that capsularpolysaccharides of the bacteria play very important role for thereduction and localization of chromate.

  10. The solubility of olivine in basaltic liquids - An ionic model

    NASA Technical Reports Server (NTRS)

    Herzberg, C. T.

    1979-01-01

    A model is presented which enables the temperature at which olivine is in equilibrium with any alkali-depleted basaltic compound to be calculated to within + or - 30 C. It is noted that the error increases substantially when applied to terrestrial basalts which contain several weight percent alkalis. In addition the model predicts and quantifies the reduced activity of SiO4(4-) monomers due to increasing SiO2 concentrations in the melt. It is shown that the coordination of alumina in melts which precipitate olivine only appears to be dominantly octahedral, while titanium acts as a polmerizing agent by interconnecting previously isolated SiO4(4-) monomers. It is concluded that the model is sufficiently sensitive to show that there are small repulsive forces between Mg(2+) and calcium ions which are in association with normative diopside in the melt.

  11. Basaltic rocks analyzed by the Spirit Rover in Gusev Crater

    NASA Technical Reports Server (NTRS)

    McSween, H. Y.; Arvidson, R. E.; Bell, J. F., III; Blaney, D.; Cabrol, N. A.; Christensen, P. R.; Clark, B. C.; Crisp, J. A.; Crumpler, L. S.; DesMarais, D. J.; Farmer, J. D.; Gellert, R.; Ghosh, A.; Gorevan, S.; Graff, T.; Grant, J.; Haskin, L. A.; Herkenhoff, K. E.; Johnson, J. R.; Jolliff, B. L.; Klingelhoefer, G.; Morris, R. V.; Yen, A.

    2004-01-01

    The Spirit landing site in Gusev Crater on Mars contains dark, fine-grained, vesicular rocks interpreted as lavas. Pancam and Mini-Thermal Emission Spectrometer (Mini-TES) spectra suggest that all of these rocks are similar but have variable coatings and dust mantles. Magnified images of brushed and abraded rock surfaces show alteration rinds and veins. Rock interiors contain basalts, containing normative olivine, pyroxenes, plagioclase, and accessory FeTi oxides. Mossbauer, Pancam, and Mini-TES spectra confirm the presence of olivine, magnetite, and probably pyroxene. These basalts extend the known range of rock compositions composing the martian crust.

  12. Americium migration in basalt and implications to repository risk analysis

    SciTech Connect

    Rickert, P.G.

    1980-01-01

    Experiments were performed with americium as a minor component in groundwater. Batch adsorption, migration through column, and filtration experiments were performed. It was determined in batch experiments that americium is strongly adsorbed from solution. It was determined with filtration experiments that large percentages of the americium concentrations suspended by the contact solutions in batch experiments and suspended by the infiltrating groundwater in migration experiments were associated with particulate. Filtration was determined to be the primary mode of removal of americium from infiltrating groundwater in a column of granulated basalt (20 to 50 mesh) and an intact core of permeable basalt. Fractionally, 0.46 and 0.22 of the americium component in the infiltrating groundwater was transported through the column and core respectively. In view of these filtration and migration experiment results, the concept of K/sub d/ in the chromatographic sense is meaningless for predicting americium migration in bedrock by groundwater transport at near neutral pH.

  13. Solidification and crystallization kinetics of synthetic and lunar simulant basalts

    NASA Astrophysics Data System (ADS)

    Dela'o, J. D.; Hellawell, A.; Pletka, B. J.; Rose, W. I.

    A program of extraterrestrial materials research has been initiated in order to improve understanding of the evolution of planetary crystal structures and to devise methods of processing extraterrestrial materials at their source. As part of this program, samples of synthetic silicates with compositions in the quasi-binary eutectic system Diopside-Anorthite and naturally occurring terrestrial basalts having compositions approximating lunar basalts (Minnesota Lunar Simulant, MLS) were float zone-melted and solidified in an arc image furnace. At growth rates less than 6 mm/yr, samples of each composition solidified as wholly crystalline materials, while at higher growth rates samples of MLS and synthetics of compositions intermediate between anorthite and diopside showed decreasing proportions of crystalline material. MLS samples grown in air showed greater crystallization rates than those grown in argon; the crystalline phases had compositions corresponding to common igneous materials.

  14. AR-39-AR-40 "Age" of Basaltic Shergottite NWA-3171

    NASA Technical Reports Server (NTRS)

    Bogard, Donald D.; Park, Jisun

    2007-01-01

    North-West-Africa 3171 is a 506 g, relatively fresh appearing, basaltic shergottite with similarities to Zagami and Shergotty, but not obviously paired with any of the other known African basaltic shergottites. Its exposure age has the range of 2.5-3.1 Myr , similar to those of Zagami and Shergotty. We made AR-39-AR-40 analyses of a "plagioclase" (now shock-converted to maskelynite) separate and of a glass hand-picked from a vein connected to shock melt pockets.. Plagioclase was separated using its low magnetic susceptibility and then heavy liquid with density of <2.85 g/cm(exp 3). The AR-39-AR-40 age spectrum of NWA-317 1 plag displays a rise in age over 20-100% of the 39Ar release, from 0.24 Gyr to 0.27 Gy.

  15. Continental flood basalts derived from the hydrous mantle transition zone

    NASA Astrophysics Data System (ADS)

    Wang, Xuan-Ce; Wilde, Simon A.; Li, Qiu-Li; Yang, Ya-Nan

    2015-07-01

    It has previously been postulated that the Earth's hydrous mantle transition zone may play a key role in intraplate magmatism, but no confirmatory evidence has been reported. Here we demonstrate that hydrothermally altered subducted oceanic crust was involved in generating the late Cenozoic Chifeng continental flood basalts of East Asia. This study combines oxygen isotopes with conventional geochemistry to provide evidence for an origin in the hydrous mantle transition zone. These observations lead us to propose an alternative thermochemical model, whereby slab-triggered wet upwelling produces large volumes of melt that may rise from the hydrous mantle transition zone. This model explains the lack of pre-magmatic lithospheric extension or a hotspot track and also the arc-like signatures observed in some large-scale intracontinental magmas. Deep-Earth water cycling, linked to cold subduction, slab stagnation, wet mantle upwelling and assembly/breakup of supercontinents, can potentially account for the chemical diversity of many continental flood basalts.

  16. Lunar ferroan anorthosites and mare basalt sources - The mixed connection

    NASA Technical Reports Server (NTRS)

    Ryder, Graham

    1991-01-01

    Global overturn of a hot, gravitationally unstable lunar mantle immediately following the solidification of a magma ocean explains several characteristics of lunar petrology. Lunar mare basalt sources are inferred to be depleted in europium and alumina. These depletions are consensually attributed to complementary plagioclase floating from a magma ocean. However, in contrast to the mare basalt source parent magma, the ferroan anorthosite parent magma was more evolved by virtue of its lower Mg/Fe ratio and Ni abundances, although less evolved in its poverty of clinopyroxene constituents, flat rare earth pattern, and lower incompatible element abundances. The europium anomaly in mare sources is inferred to be present at 400 km depth, too deep to have been directly influenced by plagioclase crystallization. Massive overturning of the post-magma ocean mantle would have carried down clinopyroxene, ilmenite, and phases containing fractionated rare earths, europium anomalies, and some heat-producing radionuclides.

  17. Basaltic rocks analyzed by the Spirit rover in Gusev crater

    USGS Publications Warehouse

    McSween, H.Y.; Arvidson, R. E.; Bell, J.F.; Blaney, D.; Cabrol, N.A.; Christensen, P.R.; Clark, B. C.; Crisp, J.A.; Crumpler, L.S.; Des Marias, D.J.; Farmer, J.D.; Gellert, Ralf; Ghosh, A.; Gorevan, S.; Graff, T.; Grant, J.; Haskin, L.A.; Herkenhoff, K. E.; Johnson, J. R.; Jolliff, B.L.; Klingelhoefer, G.; Knudson, A.T.; McLennan, S.; Milam, K.A.; Moersch, J.E.; Morris, R.V.; Rieder, R.; Ruff, S.W.; De Souza, P.A.; Squyres, S. W.; Wanke, H.; Wang, A.; Wyatt, M.B.; Yen, A.; Zipfel, J.

    2004-01-01

    The Spirit landing site in Gusev Crater on Mars contains dark, fine-grained, vesicular rocks interpreted as lavas. Pancam and Mini-Thermal Emission Spectrometer (Mini-TES) spectra suggest that all of these rocks are similar but have variable coatings and dust mantles. Magnified images of brushed and abraded rock surfaces show alteration rinds and veins. Rock interiors contain ???25% megacrysts. Chemical analyses of rocks by the Alpha Particle X-ray Spectrometer are consistent with picritic basalts, containing normative olivine, pyroxenes, plagioclase, and accessory FeTi oxides. Mo??ssbauer, Pancam, and Mini-TES spectra confirm the presence of olivine, magnetite, and probably pyroxene. These basalts extend the known range of rock compositions composing the martian crust.

  18. Test drilling in basalts, Lalamilo area, South Kohala District, Hawaii

    USGS Publications Warehouse

    Teasdale, Warren E.

    1980-01-01

    Test drilling has determined that a downhole-percussion airhammer can be used effectively to drill basalts in Hawaii. When used in conjunction with a foam-type drilling fluid, the hammer-bit penetration rate was rapid. Continuous drill cuttings from the materials penetrated were obtained throughout the borehole except from extremely fractured or weathered basalt zones where circulation was lost or limited. Cementing of these zones as soon as encountered reduced problems of stuck tools, washouts, and loss of drill-cuttings. Supplies and logistics on the Hawaiian Islands, always a major concern, require that all anticipated drilling supplies, spare rig and tool parts, drilling muds and additives, foam, and miscellaneous hardware be on hand before starting to drill. If not, the resulting rig downtime is costly in both time and money. (USGS)

  19. Mars weathering analogs - Secondary mineralization in Antarctic basalts

    NASA Technical Reports Server (NTRS)

    Berkley, J. L.

    1982-01-01

    Alkalic basalt samples from Ross Island, Antarctica, are evaluated as terrestrial analogs to weathered surface materials on Mars. Secondary alteration in the rocks is limited to pneumatolytic oxidation of igneous minerals and glass, rare groundmass clay and zeolite mineralization, and hydrothermal minerals coating fractures and vesicle surfaces. Hydrothermal mineral assemblages consist mainly of K-feldspar, zeolites (phillipsite and chabazite), calcite, and anhydrite. Low alteration rates are attributed to cold and dry environmental factors common to both Antarctica and Mars. It is noted that mechanical weathering (aeolian abrasion) of Martian equivalents to present Antarctic basalts would yield minor hydrothermal minerals and local surface fines composed of primary igneous minerals and glass but would produce few hydrous products, such as palagonite, clay or micas. It is thought that leaching of hydrothermal vein minerals by migrating fluids and redeposition in duricrust deposits may represent an alternate process for incorporating secondary minerals of volcanic origin into Martian surface fines.

  20. The petrogenesis of primary mid-ocean ridge basalts

    NASA Technical Reports Server (NTRS)

    Elthon, Don

    1990-01-01

    The nature of primary mid-ocean ridge basalts (MORB) is reviewed from the primary-magma composition point of view. The concept of primary MORB magma used in the study stipulates that melting of the mantle produces a discrete identifiable magma that separates from the mantle and ascends toward the surface. Constraints from abyssal peridotites are considered along with constraints from high-pressure phase equilibria studies with emphasis on partial melting of mantle peridotites, basalt-peridotite sandwich techniques, high-pressure experiments on MORB-type compositions, and constraints on the pressure of origin from mineral compositions. Compositional variations in primitive MORB glasses are discussed, and possible models for the origin of these glasses are presented.

  1. Continental flood basalts derived from the hydrous mantle transition zone.

    PubMed

    Wang, Xuan-Ce; Wilde, Simon A; Li, Qiu-Li; Yang, Ya-Nan

    2015-07-14

    It has previously been postulated that the Earth's hydrous mantle transition zone may play a key role in intraplate magmatism, but no confirmatory evidence has been reported. Here we demonstrate that hydrothermally altered subducted oceanic crust was involved in generating the late Cenozoic Chifeng continental flood basalts of East Asia. This study combines oxygen isotopes with conventional geochemistry to provide evidence for an origin in the hydrous mantle transition zone. These observations lead us to propose an alternative thermochemical model, whereby slab-triggered wet upwelling produces large volumes of melt that may rise from the hydrous mantle transition zone. This model explains the lack of pre-magmatic lithospheric extension or a hotspot track and also the arc-like signatures observed in some large-scale intracontinental magmas. Deep-Earth water cycling, linked to cold subduction, slab stagnation, wet mantle upwelling and assembly/breakup of supercontinents, can potentially account for the chemical diversity of many continental flood basalts.

  2. Disequilibrium of the 238U series in basalt

    USGS Publications Warehouse

    Somayajulu, B.L.K.; Tatsumoto, M.; Rosholt, J.N.; Knight, R.J.

    1966-01-01

    Radioisotope analyses of basalt samples from Hawaii, Japan, and Iwo Jima show that: (1) 234U and 238U are virtually in radioactive equilibrium, (2) 230Th exceeds equilibrium values in all these samples, (3) 210Pb concentrations range from 10-200% of the equilibrium values and average 30% deficient, and (4) 226Ra is probably not in equilibrium with 234U. The source regions of the basalts or magma forming processes are open systems, chemically. The enrichment of some of the uranium-daughter nuclides is insufficient to account for the excess 206Pb in volcanic rocks. The isotopic composition of lead and specific activity of 210Pb in sublimates from Showa-shinzan, Japan are also reported. ?? 1966.

  3. Rock billboards on the basaltic cliff along the Route 66 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Rock billboards on the basaltic cliff along the Route 66 alignment, ca. 1926. The sign on the left is for "La Bajada Service Shop" (faint "da" visible), "Santa Fe Camp" in the center, and a petroglyph at far right. View facing northwest. - La Bajada Historic Trails and Roads, Approximately 1 mile East/Northeast of intersection of State Highway 16 and Indian Service Road 841, La Bajada, Santa Fe County, NM

  4. Lead isotope systematics of three Apollo 17 mare basalts

    NASA Technical Reports Server (NTRS)

    Tilton, G. R.; Chen, J. H.

    1979-01-01

    The paper deals with new and more accurate determinations of uranium, thorium, and isotopic lead data for five bulk samples and separate pyroxene, ilmenite, and plagioclase from basalt 71055. In a concordia diagram, the samples suggest a postcrystallization disturbance of the U-Pb systems of the rock. There is no compelling reason, from U-Pb data, to believe that the moon is younger than 4.55 AE.

  5. Dissolution of olivine in basaltic liquids: experimental observations and applications.

    USGS Publications Warehouse

    Thornber, C.R.; Huebner, J.S.

    1985-01-01

    Rates of olivine dissolution in synthetic lunar basalt 77115 and a silica-enriched 77115 composition (Sil-77115) at superliquidus temperatures have been determined. Dissolution-rate data have been applied to the problem of the thermal history of fragment-laden impact-melt rocks of the lunar highlands. Textural and chemical criteria are discussed for the recognition of olivine resorption (and growth) phenomena in igneous rocks. -J.A.Z.

  6. Initial effects of vegetation on Hawaiian basalt weathering rates

    SciTech Connect

    Cochran, M.F.; Berner, R.A. )

    1992-01-01

    Weathering of Ca and Mg silicates on land and ensuing precipitation and burial of Ca and Mg carbonates in marine sediments is the principal sink for carbon dioxide from the atmosphere/ocean system on geologic time scales. Model calculations of ancient atmospheric CO[sub 2] partial pressure depend strongly on the authors assumptions about the enhancement of silicate weathering rates first by primitive terrestrial biota, then by the appearance and evolution of the vascular plants. Aa and pahoehoe basalts were collected from Mauna Loa and Kilauea volcanoes on the island of Hawaii. Flows ranged in age (one year to several thousand years) and in ambient climate. Where possible, each flow was sampled beneath a suite of current plant covers: none, lichens, and higher plants. Rocks were embedded in epoxy to preserve the plant-rock interface, then sectioned and subjected to electron probe microanalysis. During initial weathering, vascular plants appeared to promote congruent dissolution of minerals (particularly olivine and Ca-rich plagioclase) and glass near the surfaces of underlying basalts. In the neighborhood of roots, primary cracks widened with time into networks of open channels. This effect was observed prior to the formation of measurable leached zones in exterior grains and prior to the appearance of secondary minerals. As a result, initial mass loss from young, plant-covered basalts appeared to be up to one or more orders of magnitude greater than from bare-rock controls. Despite earlier reports of substantial enhancement of Hawaiian basalt weathering rates by the lichen Stereocaulon vulcani, weathering observed beneath this lichen was comparable to that of unvegetated rocks.

  7. A model composition of the basaltic achondrite planetoid

    NASA Astrophysics Data System (ADS)

    Boesenberg, Joseph S.; Delaney, Jeremy S.

    1997-08-01

    The basaltic achondrites, eucrites, diogenites, and howardites have compositions on a common oxygen isotope mass fractionation line and probably formed from a chondritic precursor also lying on that same line. No chondritic meteorite group has the same isotopic signature as the basaltic achondrites, so the oxygen isotope ratios of several known chondritic groups were used to construct a two component mixing model for the composition of the precursor. This model does not provide a unique solution, as several mixtures of ordinary and carbonaceous precursors will satisfy the isotopic constraints. The FeMnMg abundances of the precursors and of the eucrites were used to provide an additional constraint. The precursor composition selected for study is a mixture of 70% (wt) H-chondrite with 30% (wt) CM-chondrtte. This mixture generates a slightly FeO-rich silicate precursor that, after reduction and separation of an iron + sulfide core, is compatible with the mantle of the basaltic achondrite planetoid (BAP) having a similar composition to that modeled by Dreibus and Wänke (1980). Partial melting experiments of this H-CM precursor composition suggest that eucritic magmas could be formed in such a mantle. These experiments also suggest that the mantle must have experienced metal loss to constrain the Fe/Mn ratios and probably significant olivine fractionation as well. Diogenite precursors may also be generated in this mantle composition as FeO reduction and olivine fractionation lead to the formation of SiO 2 enriched compositions from which diogenite source magmas may be extracted. If mixing of material from two very distinct chondritic reservoirs (H and CM-chondrites) is realistic, then an asteroid scale mixing process is needed to generate the achondrite precursor. Large impact events would provide a plausible method for mixing material from reservoirs with quite different oxygen isotope characteristics to assemble the basaltic achondrite planetoid.

  8. New Insights into Basaltic Balloon Formation during Submarine Eruptions

    NASA Astrophysics Data System (ADS)

    Carey, S.; Kelly, J.; Rosi, M.; Pistolesi, M.; Marani, M.; Roman, C.; Croff Bell, K. L.

    2014-12-01

    Remotely operated vehicle (ROV) explorations in the area of the 1891 Foerstner submarine eruption (Pantelleria, Italy) during cruise NA-018 of the E/V Nautilus has provided the first examination of the vent site of a basaltic balloon-forming eruption. Ultra high-resolution bathymetric mapping defined a mound-like vent morphology in water depths of ~250 meter, constructed dominantly of highly vesicular scoriaceous fragments with minor pillow lava flows. The formation of floating basaltic balloons that reached the surface of the Strait of Sicily during the eruption is attributed to a hybrid Strombolian eruption mechanism that involved pre-concentration of volatiles into gas-rich portions of magma beneath the vent. An important difference of this Strombolian mechanism compared to its subaerial counterpart is the occurrence of buoyant magma discharge in the submarine environment caused by localized high gas contents. The added buoyancy flux modifies the fluid dynamic configuration of magma venting on the seafloor allowing for detachment of highly-inflated parcels of gas-rich magma. Some of these parcels contain large gas cavities that are enveloped in a partially quenched shell and maintain sufficient buoyancy to rise to the sea surface as a basaltic balloon. The majority of the vesicular magma maintains only partial positive buoyancy or negative buoyancy and is explosively fragmented to form large quantities of decimeter-scale fragments that accumulate close to the vent. Formation of the basaltic balloons is thus considered a somewhat accidental process that involves a subset of the total erupted volume of magma during the eruption. Suitable conditions for balloon formation include low magma viscosity, pre-concentration of gas, and moderate pressures (i.e.water depth). The dampening effect of seawater greatly reduces the dispersal of pyroclasts resulting in a mound-like vent morphology compared to subaerial scoria cones typically associated with Strombolian activity.

  9. Dissolved amino acids in oceanic basaltic basement fluids

    NASA Astrophysics Data System (ADS)

    Lin, Huei-Ting; Amend, Jan P.; LaRowe, Douglas E.; Bingham, Jon-Paul; Cowen, James P.

    2015-09-01

    The oceanic basaltic basement contains the largest aquifer on Earth and potentially plays an important role in the global carbon cycle as a net sink for dissolved organic carbon (DOC). However, few details of the organic matter cycling in the subsurface are known because great water depths and thick sediments typically hinder direct access to this environment. In an effort to examine the role of water-rock-microorganism interaction on organic matter cycling in the oceanic basaltic crust, basement fluid samples collected from three borehole observatories installed on the eastern flank of the Juan de Fuca Ridge were analyzed for dissolved amino acids. Our data show that dissolved free amino acids (1-13 nM) and dissolved hydrolyzable amino acids (43-89 nM) are present in the basement. The amino acid concentrations in the ridge-flank basement fluids are at the low end of all submarine hydrothermal fluids reported in the literature and are similar to those in deep seawater. Amino acids in recharging deep seawater, in situ amino acid production, and diffusional input from overlying sediments are potential sources of amino acids in the basement fluids. Thermodynamic modeling shows that amino acid synthesis in the basement can be sustained by energy supplied from inorganic substrates via chemolithotrophic metabolisms. Furthermore, an analysis of amino acid concentrations and compositions in basement fluids support the notion that heterotrophic activity is ongoing. Similarly, the enrichment of acidic amino acids and depletion of hydrophobic ones relative to sedimentary particulate organic matter suggests that surface sorption and desorption also alters amino acids in the basaltic basement. In summary, although the oceanic basement aquifer is a net sink for deep seawater DOC, similar amino acid concentrations in basement aquifer and deep seawater suggest that DOC is preferentially removed in the basement over dissolved amino acids. Our data also suggest that organic carbon

  10. A new basaltic glass microanalytical reference material for multiple techniques

    USGS Publications Warehouse

    Wilson, Steve; Koenig, Alan; Lowers, Heather

    2012-01-01

    The U.S. Geological Survey (USGS) has been producing reference materials since the 1950s. Over 50 materials have been developed to cover bulk rock, sediment, and soils for the geological community. These materials are used globally in geochemistry, environmental, and analytical laboratories that perform bulk chemistry and/or microanalysis for instrument calibration and quality assurance testing. To answer the growing demand for higher spatial resolution and sensitivity, there is a need to create a new generation of microanalytical reference materials suitable for a variety of techniques, such as scanning electron microscopy/X-ray spectrometry (SEM/EDS), electron probe microanalysis (EPMA), laser ablation inductively coupled mass spectrometry (LA-ICP-MS), and secondary ion mass spectrometry (SIMS). As such, the microanalytical reference material (MRM) needs to be stable under the beam, be homogeneous at scales of better than 10–25 micrometers for the major to ultra-trace element level, and contain all of the analytes (elements or isotopes) of interest. Previous development of basaltic glasses intended for LA-ICP-MS has resulted in a synthetic basaltic matrix series of glasses (USGS GS-series) and a natural basalt series of glasses (BCR-1G, BHVO-2G, and NKT-1G). These materials have been useful for the LA-ICP-MS community but were not originally intended for use by the electron or ion beam community. A material developed from start to finish with intended use in multiple microanalytical instruments would be useful for inter-laboratory and inter-instrument platform comparisons. This article summarizes the experiments undertaken to produce a basalt glass reference material suitable for distribution as a multiple-technique round robin material. The goal of the analytical work presented here is to demonstrate that the elemental homogeneity of the new glass is acceptable for its use as a reference material. Because the round robin exercise is still underway, only

  11. On the natural remanent magnetism of certain mare basalts

    NASA Technical Reports Server (NTRS)

    Fuller, M.; Meshkov, E.; Cisowski, S. M.; Hale, C. J.

    1979-01-01

    The natural remanent magnetization (NRM) and magnetic properties of five fine-grain mare basalts were investigated. The NRM of two vitrophyres has a large soft component, and the directional stability during AF demagnetization is poor. The remaining samples have NRM which is too soft to be of thermal origin and yet too hard to be simply isothermal contamination. It is suggested that the NRM of the samples could be shock remanent magnetization.

  12. The Habitability of Basaltic Hydrovolcanic Tuffs: Implications for Mars

    NASA Astrophysics Data System (ADS)

    Nikitczuk, M. P. C.; Schmidt, M. E.; Flemming, R. L.

    2014-12-01

    Reed and South Reed Rock are two hydrovolcanic tuff ring deposits in the Fort Rock Volcanic Field (FRVF), Oregon, where microbial ichnofossils (endolithic microbores) exist within basaltic glass pyroclasts. Their presence indicates that continental volcanic settings can provide a habitable environment. The secondary phase assemblage of smectite clays (nontronite), zeolites (chabazite), calcite and palagonite point to a contemporaneous to post depositional hydrothermal alteration temperature range (~25-120°C), below which microbes introduced through groundwater were able to inhabit. Electron Dispersive Spectroscopy reveals geochemical differences between fresh glass and microbore interiors (eg., Fe, Mg depletion and K and Ca enrichment). These differences are interpreted to reflect acquisition by microbes of nutrients and energy by oxidizing and dissolving fresh basaltic glass. The Black Hills, a second study area located 20 km south the Reed Rocks, consists of a series of at least 6 hydrovolcanic vents. Petrographic observations from the Black Hills also reveal microbial ichnofossil features within basaltic glass pyroclasts. Conditions necessary for a habitable environment may therefore be common throughout the FRVF. In both locations, eruptive, depositional, and hydrothermal processes led to an environment conducive to microbial activity in which glass-rich deposits possess a source of biogenic elements, energy, and water. The histories of these deposits however, may be quite different in terms of peak hydrothermal temperatures, age relationships, water content and timing. Comparison of the textural, mineralogical and geochemical properties of the Reed Rocks and Black Hills deposits is ongoing in order to gain a better understanding of the conditions of habitability in these types of deposits. These results have important astrobiological implications for Mars where basaltic pyroclastic materials are widely distributed and may represent a habitable environment.

  13. Basaltic Shergottite NWA 856: Differentiation of a Martian Magma

    NASA Technical Reports Server (NTRS)

    Ferdous, J.; Brandon, A. D.; Peslier, A. H.; Pirotte, Z.

    2016-01-01

    NWA 856 or Djel Ibone, is a basaltic shergottite discovered as a single stone of 320 g in South Morocco in April, 2001. This meteorite is fresh, i.e. shows minimal terrestrial weathering for a desert find. No shergottite discovered in North Africa can be paired with NWA 856. The purpose of this study is to constrain its crystallization history using textural observations, crystallization sequence modeling and in-situ trace element analysis in order to understand differentiation in shergottite magmatic systems.

  14. Supertoxic Flood Basalts: The CAMP - Siberian Trap Connection

    NASA Astrophysics Data System (ADS)

    Puffer, J. H.

    2007-12-01

    Several diverse magma types are represented throughout the CAMP and Siberian Trap LIPs, however, the main extrusive phase of each province is highly unusual among continental flood basalts. The most widespread extrusions were intermediate titanium (ITi-type) CAMP basalt and the lower portion of the Upper Sequence of Siberian Trap. New and recently published data indicate that the geochemistry and petrology of these basalt suites closely resemble each other and infer similar origins. The basalts are characterized by strong negative Nb- Ta anomalies and unusual island arc-like depletion in high field strength elements, particularly Ti, plotted on spider diagrams. The geochemical data is consistent with significant contributions from subducted slabs into the magma source regions. If contaminated, volatile enriched mantle wedges were trapped beneath thick continental plates during the assembly of Pangea, fertile magma sources would have remained dormant until decompression melting was triggered during failed rift, then early rift stages of continental plate disassembly. The combination of volatile enriched sources and highly extensional tectonism would create rare perfect storms of toxicity. Calculated low viscosities assuming negligible carbon dioxide are consistent with rapid crustal penetration. Resulting aphyric melts extruded at enormous effusive rates as thick sub-parallel flows across wide subareal terrains through fissures extending several hundred km in length. High fountain heights would afford ample opportunity for efficient degassing, perhaps into the stratosphere. When the supply of volatile flux was exhausted magmatism ceased. The mass extinctions that coincide with CAMP and Siberian volcanism contrast with some large plume and superplume events that correlate with expansions of biodiversity. This may be due in part to contrasting magma access to sources of toxic volatiles, particularly sulfur concentrations in anoxic subducted sediments.

  15. Rare earth element contents and multiple mantle sources of the transform-related Mount Edgecumbe basalts, southeastern Alaska

    USGS Publications Warehouse

    Riehle, J.R.; Budahn, J.R.; Lanphere, M.A.; Brew, D.A.

    1994-01-01

    Pleistocene basalt of the Mount Edgecumbe volcanic field (MEF) is subdivided into a plagioclase type and an olivine type. Th/La ratios of plagioclase basalt are similar to those of mid-ocean-ridge basalt (MORB), whereas those of olivine basalt are of continental affinity. Rare earth element (REE) contents of the olivine basalt, which resemble those of transitional MORB, are modelled by 10-15% partial melting of fertile spinel-plagioclase lherzolite followed by removal of 8-13% olivine. It is concluded that olivine basalt originated in subcontinental spinel lherzolite and that plagioclase basalt may have originated in suboceanic lithosphere of the Pacific plate. -from Authors

  16. Temperature profile around a basaltic sill intruded into wet sediments

    USGS Publications Warehouse

    Baker, Leslie; Bernard, Andrew; Rember, William C.; Milazzo, Moses; Dundas, Colin M.; Abramov, Oleg; Kestay, Laszlo P.

    2015-01-01

    The transfer of heat into wet sediments from magmatic intrusions or lava flows is not well constrained from field data. Such field constraints on numerical models of heat transfer could significantly improve our understanding of water–lava interactions. We use experimentally calibrated pollen darkening to measure the temperature profile around a basaltic sill emplaced into wet lakebed sediments. It is well known that, upon heating, initially transparent palynomorphs darken progressively through golden, brown, and black shades before being destroyed; however, this approach to measuring temperature has not been applied to volcanological questions. We collected sediment samples from established Miocene fossil localities at Clarkia, Idaho. Fossils in the sediments include pollen from numerous tree and shrub species. We experimentally calibrated changes in the color of Clarkia sediment pollen and used this calibration to determine sediment temperatures around a Miocene basaltic sill emplaced in the sediments. Results indicated a flat temperature profile above and below the sill, with T > 325 °C within 1 cm of the basalt-sediment contact, near 300 °C at 1–2 cm from the contact, and ~ 250 °C at 1 m from the sill contact. This profile suggests that heat transport in the sediments was hydrothermally rather than conductively controlled. This information will be used to test numerical models of heat transfer in wet sediments on Earth and Mars.

  17. Interim reclamation report, Basalt Waste Isolation project: Boreholes, 1989

    SciTech Connect

    Brandt, C.A.; Rickard, W.H. Jr.; Hefty, M.G.

    1990-03-01

    In 1968, a program was started to assess the feasibility of storing Hanford Site defense waste in deep caverns constructed in basalt. This program was expanded in 1976 to include investigations of the Hanford Site as a potential location for a mined commercial nuclear waste repository. An extensive site characterization program was begun to determine the feasibility of using the basalts beneath the Hanford Site for the repository. Site research focused primarily on determining the direction and speed of groundwater movement, the uniformity of basalt layers, and tectonic stability. Some 98 boreholes were sited, drilled, deepened, or modified by BWIP between 1977 and 1988 to test the geologic properties of the Site. On December 22, 1987, President Reagan signed into law the Nuclear Waste Policy Amendments Act of 1987, which effectively stopped all repository-related activities except reclamation of disturbed lands at the Hanford Site. This report describes the development of the reclamation program for the BWIP boreholes, its implementation, and preliminary estimates of its success. The goal of the reclamation program is to return sites disturbed by the repository program as nearly as practicable to their original conditions using native plant species. 48 refs., 28 figs., 14 tabs.

  18. High water content in primitive continental flood basalts

    NASA Astrophysics Data System (ADS)

    Xia, Qun-Ke; Bi, Yao; Li, Pei; Tian, Wei; Wei, Xun; Chen, Han-Lin

    2016-05-01

    As the main constituent of large igneous provinces, the generation of continental flood basalts (CFB) that are characterized by huge eruption volume (>105 km3) within short time span (<1–3 Ma) is in principle caused by an abnormally high temperature, extended decompression, a certain amount of mafic source rocks (e.g., pyroxenite), or an elevated H2O content in the mantle source. These four factors are not mutually exclusive. There are growing evidences for high temperature, decompression and mafic source rocks, albeit with hot debate. However, there is currently no convincing evidence of high water content in the source of CFB. We retrieved the initial H2O content of the primitive CFB in the early Permian Tarim large igneous province (NW China), using the H2O content of ten early-formed clinopyroxene (cpx) crystals that recorded the composition of the primitive Tarim basaltic melts and the partition coefficient of H2O between cpx and basaltic melt. The arc-like H2O content (4.82 ± 1.00 wt.%) provides the first clear evidence that H2O plays an important role in the generation of CFB.

  19. Spitzer IRS Spectra of Basaltic Asteroids: Preliminary Results

    NASA Technical Reports Server (NTRS)

    Lim, Lucy F.; Emery, Joshua P.; Moskovitz, Nick; Stewart, Heather; Marchis, Frank

    2008-01-01

    We present preliminary results of a Spitzer program to observe the 5.2--38 micron spectra of small basaltic asteroids using the Spitzer IRS (Infrared Spectrograph). Our targets include members of the dynamical family of the unique large differentiated asteroid 4 Vesta ("Vestoids"), four outer-main-belt basaltic asteroids whose orbits exclude them from originating on 4 Vesta, and the basaltic near-Earth asteroid (NEA) 4055 Magellan. We will compare the compositions and thermophysical properties of the non-Vestoid objects with those of the dynamical vestoids to provide insight on the extent of metal-silicate differentiation on planetsimals during the epoch of planet formation in the early Solar System. As of this writing, spectra of asteroids 10537 (1991 RY16) and 2763 Jeans have been returned. Analysis of these data are ongolng. Observations of 956 Elisa, 2653 Principia, 4215 Kamo, 7472 Kumakiri, and 1459 Magnya have been scheduled and are expected to be available by the time of the DPS meeting. NIR spectra and lightcurves o f the target asteroids are also being observed in support of this program.

  20. The consanguinity of the oldest Apollo 11 mare basalts

    NASA Technical Reports Server (NTRS)

    Gamble, R. P.; Coish, R. A.; Taylor, L. A.

    1978-01-01

    The textural, mineralogical, and chemical relationships between three of the oldest dates lunar mare basalt samples returned by Apollo 11 (10003, 10029 and 10062) were investigated. Very strong resemblances were noted between the modal minerologies of 10003 and 10029. Significantly more modal olivine and cristobalite was observed in 10062 than in the other basalt samples. A detailed examination of mineral-chemical relationships among the samples revealed similarities between 10003 and 10062 and differences between these two rocks and 10029, the most significant of which is the presence of akaganeite in 10029, implying that lawrencite was present in the pristine sample of 10029 but not in 10003 and 10062. Results of a Wright-Doherty mixing program used to test various fractional crystallization schemes show that 10062 can be derived from a liquid with the composition of either 10003 or 10029 by removing 2-5% ilmenite and 5% olivine. By removing about 6% plagioclase, 10003 can be derived from a liquid with the bulk composition of 10062. It is concluded that 10003 and 10029 may have come from different basaltic flows, whereas it is possible that 10003 and 10062 were derived from the same parental magma by near-surface fractionation of olivine plus ilmenite or of plagioclase plus or minus olivine.

  1. Recrystallized microbial trace fossils from metamorphosed Permian basalt, southwestern Japan

    NASA Astrophysics Data System (ADS)

    Sugawara, H.; Sakakibara, M.; Ikehara, M.

    2014-05-01

    Microbial trace fossils on terrestrial basalts can be used as an analogue in the search for traces of life on other terrestrial planets. This study reports on microbial trace fossils within Permian greenstones in the Maizuru Terrane, southwest Japan, which is recognized as back-arc basin oceanic crust that consists mainly of metabasalt and metagabbro. The trace fossils have been studied by means of morphology, mineralogy, elemental mapping, and carbon isotope analysis. Although minute original textures of trace fossils are recrystallized in these rocks, Granulohyalichnus vulgaris isp., Tubulohyalichnus spiralis isp., and Tubulohyalichnus annularis isp. were identified. Significant concentration of C within the trace fossils implies these are organic remnants from microbes. The δ13CPDB values <-7‰ of calcite within the greenstones indicates that the bacterial activity took place prior to the formation of calcite veins. The results support that microbial trace fossils within low-grade metamorphic basalt can be reliably identified based on their morphology and chemical composition, as reveled by elemental mapping. In this context, glassy Martian basalt may be the best rock type to investigate in terms of searching for signs of microbial activity on Earth and other planets.

  2. Carbon dioxide sequestration in deep-sea basalt.

    PubMed

    Goldberg, David S; Takahashi, Taro; Slagle, Angela L

    2008-07-22

    Developing a method for secure sequestration of anthropogenic carbon dioxide in geological formations is one of our most pressing global scientific problems. Injection into deep-sea basalt formations provides unique and significant advantages over other potential geological storage options, including (i) vast reservoir capacities sufficient to accommodate centuries-long U.S. production of fossil fuel CO2 at locations within pipeline distances to populated areas and CO2 sources along the U.S. west coast; (ii) sufficiently closed water-rock circulation pathways for the chemical reaction of CO2 with basalt to produce stable and nontoxic (Ca(2+), Mg(2+), Fe(2+))CO(3) infilling minerals, and (iii) significant risk reduction for post-injection leakage by geological, gravitational, and hydrate-trapping mechanisms. CO2 sequestration in established sediment-covered basalt aquifers on the Juan de Fuca plate offer promising locations to securely accommodate more than a century of future U.S. emissions, warranting energized scientific research, technological assessment, and economic evaluation to establish a viable pilot injection program in the future.

  3. Putative cryptoendolithic life in Devonian pillow basalt, Rheinisches Schiefergebirge, Germany.

    PubMed

    Peckmann, J; Bach, W; Behrens, K; Reitner, J

    2008-03-01

    Middle Devonian (Givetian) pillow basalt and inter-pillow breccia from the Rheinisches Schiefergebirge in Germany were found to contain putative biogenic filaments that indicate that life once proliferated within these volcanic rocks. Mineralized filaments are found in carbonate amygdules (vesicles filled by carbonate cement) in the volcanic rock, where they started to form on the internal surface of the once water-filled vesicles. Biogenicity of the filaments is indicated by (1) their size and shape resembling modern microorganisms including a constant diameter along the length of curved filaments, (2) their independence of crystal faces or cleavage planes, (3) branching patterns reminiscent of modern microorganisms, and (4) their spatial clustering and preferential occurrence close to the margin of pillows and in the inter-pillow breccias. A time lag between the deposition of pillow basalt and the activity of endoliths is revealed by the sequence of carbonate cements filling the amygdules. The putative filamentous microorganisms thrived after the formation of early fibrous rim cement, but before later equant calcite spar filled most of the remaining porosity. Microbial clay authigenesis analogous to the encrustation of prokaryotes in modern iron-rich environments led to the preservation of filaments. The filaments predominantly consist of the clay minerals chamosite and illite. Having dwelled in water-filled vesicles, the Devonian basalt-hosted filaments apparently represent cryptoendoliths. This finding suggests that a previously unrecognized niche for life exists within volcanic rock.

  4. Basalt Pb isotope analysis and the prehistoric settlement of Polynesia.

    PubMed

    Weisler, M I; Woodhead, J D

    1995-03-14

    The prehistoric settlement of the Pacific Ocean has intrigued scholars and stimulated anthropological debate for the past two centuries. Colonized over a few millennia during the mid to late Holocene, the islands of the Pacific--displaying a wide diversity of geological and biotic variability--provided the stage for endless "natural experiments" in human adaptation. Crucial to understanding the evolution and transformation of island societies is documenting the relative degree of interisland contacts after island colonization. In the western Pacific, ideal materials for archaeologically documenting interisland contact--obsidian, pottery, and shell ornaments--are absent or of limited geographic distribution in Polynesia. Consequently, archaeologists have relied increasingly on fine-grained basalt artifacts as a means for documenting colonization routes and subsequent interisland contacts. Routinely used x-ray fluorescence characterization of oceanic island basalt has some problems for discriminating source rocks and artifacts in provenance studies. The variation in trace and major element abundances is largely controlled by near-surface magma-chamber processes and is broadly similar between most oceanic islands. We demonstrate that Pb isotope analysis accurately discriminates rock source and is an excellent technique for charting the scale, frequency, and temporal span of imported fine-grained basalt artifacts found throughout Polynesia. The technique adds another tool for addressing evolutionary models of interaction, isolation, and cultural divergence in the eastern Pacific. PMID:7892194

  5. Radiolytic Hydrogen Production in the South Pacific Subseafloor Basaltic Aquifer

    NASA Astrophysics Data System (ADS)

    Dzaugis, M. E.; Spivack, A. J.; Dunlea, A. G.; Murray, R. W.; D'Hondt, S.

    2015-12-01

    Hydrogen (H2) is produced in geological settings by dissociation of water due to radiation from natural radioactive decay of uranium (238U, 235U), thorium (232Th) and potassium (40K). To quantify the potential significance of radiolytic H2 as an electron donor for microbes within the South Pacific subseafloor basaltic aquifer, we calculate radiolytic H2 production rates in basement fractures utilizing measured radionuclide concentrations in 42 basalt samples from IODP Expedition 329. The samples are from three sites with very different basement ages and a wide range of alteration types. Major and trace element concentrations vary by up to an order of magnitude from sample to sample. Comparison of our samples to each other and to previous studies of fresh East Pacific Rise basalt suggests that between-sample variation in radionuclide concentrations is primarily due to differences in initial (pre-alteration) concentrations (which can vary between eruptive events), rather than to alteration type or extent. Local maxima in radionuclide (U, Th, and K) concentrations produce 'hotspots' of radiolytic H2 production; calculated radiolytic rates differ by up to a factor of 80 from sample to sample. Fracture width also greatly influences H2 production. Due to the low penetration distance of alpha radiation, microfractures are 'hotpots' for radiolytic H2 production. For example, radiolytic H2 production rates normalized to water volume are 170 times higher in 1μm-wide fractures than in 10cm-wide fractures.

  6. High water content in primitive continental flood basalts.

    PubMed

    Xia, Qun-Ke; Bi, Yao; Li, Pei; Tian, Wei; Wei, Xun; Chen, Han-Lin

    2016-01-01

    As the main constituent of large igneous provinces, the generation of continental flood basalts (CFB) that are characterized by huge eruption volume (>10(5) km(3)) within short time span (<1-3 Ma) is in principle caused by an abnormally high temperature, extended decompression, a certain amount of mafic source rocks (e.g., pyroxenite), or an elevated H2O content in the mantle source. These four factors are not mutually exclusive. There are growing evidences for high temperature, decompression and mafic source rocks, albeit with hot debate. However, there is currently no convincing evidence of high water content in the source of CFB. We retrieved the initial H2O content of the primitive CFB in the early Permian Tarim large igneous province (NW China), using the H2O content of ten early-formed clinopyroxene (cpx) crystals that recorded the composition of the primitive Tarim basaltic melts and the partition coefficient of H2O between cpx and basaltic melt. The arc-like H2O content (4.82 ± 1.00 wt.%) provides the first clear evidence that H2O plays an important role in the generation of CFB. PMID:27143196

  7. High water content in primitive continental flood basalts.

    PubMed

    Xia, Qun-Ke; Bi, Yao; Li, Pei; Tian, Wei; Wei, Xun; Chen, Han-Lin

    2016-05-04

    As the main constituent of large igneous provinces, the generation of continental flood basalts (CFB) that are characterized by huge eruption volume (>10(5) km(3)) within short time span (<1-3 Ma) is in principle caused by an abnormally high temperature, extended decompression, a certain amount of mafic source rocks (e.g., pyroxenite), or an elevated H2O content in the mantle source. These four factors are not mutually exclusive. There are growing evidences for high temperature, decompression and mafic source rocks, albeit with hot debate. However, there is currently no convincing evidence of high water content in the source of CFB. We retrieved the initial H2O content of the primitive CFB in the early Permian Tarim large igneous province (NW China), using the H2O content of ten early-formed clinopyroxene (cpx) crystals that recorded the composition of the primitive Tarim basaltic melts and the partition coefficient of H2O between cpx and basaltic melt. The arc-like H2O content (4.82 ± 1.00 wt.%) provides the first clear evidence that H2O plays an important role in the generation of CFB.

  8. Basalt Pb isotope analysis and the prehistoric settlement of Polynesia.

    PubMed

    Weisler, M I; Woodhead, J D

    1995-03-14

    The prehistoric settlement of the Pacific Ocean has intrigued scholars and stimulated anthropological debate for the past two centuries. Colonized over a few millennia during the mid to late Holocene, the islands of the Pacific--displaying a wide diversity of geological and biotic variability--provided the stage for endless "natural experiments" in human adaptation. Crucial to understanding the evolution and transformation of island societies is documenting the relative degree of interisland contacts after island colonization. In the western Pacific, ideal materials for archaeologically documenting interisland contact--obsidian, pottery, and shell ornaments--are absent or of limited geographic distribution in Polynesia. Consequently, archaeologists have relied increasingly on fine-grained basalt artifacts as a means for documenting colonization routes and subsequent interisland contacts. Routinely used x-ray fluorescence characterization of oceanic island basalt has some problems for discriminating source rocks and artifacts in provenance studies. The variation in trace and major element abundances is largely controlled by near-surface magma-chamber processes and is broadly similar between most oceanic islands. We demonstrate that Pb isotope analysis accurately discriminates rock source and is an excellent technique for charting the scale, frequency, and temporal span of imported fine-grained basalt artifacts found throughout Polynesia. The technique adds another tool for addressing evolutionary models of interaction, isolation, and cultural divergence in the eastern Pacific.

  9. Basalt Pb isotope analysis and the prehistoric settlement of Polynesia.

    PubMed Central

    Weisler, M I; Woodhead, J D

    1995-01-01

    The prehistoric settlement of the Pacific Ocean has intrigued scholars and stimulated anthropological debate for the past two centuries. Colonized over a few millennia during the mid to late Holocene, the islands of the Pacific--displaying a wide diversity of geological and biotic variability--provided the stage for endless "natural experiments" in human adaptation. Crucial to understanding the evolution and transformation of island societies is documenting the relative degree of interisland contacts after island colonization. In the western Pacific, ideal materials for archaeologically documenting interisland contact--obsidian, pottery, and shell ornaments--are absent or of limited geographic distribution in Polynesia. Consequently, archaeologists have relied increasingly on fine-grained basalt artifacts as a means for documenting colonization routes and subsequent interisland contacts. Routinely used x-ray fluorescence characterization of oceanic island basalt has some problems for discriminating source rocks and artifacts in provenance studies. The variation in trace and major element abundances is largely controlled by near-surface magma-chamber processes and is broadly similar between most oceanic islands. We demonstrate that Pb isotope analysis accurately discriminates rock source and is an excellent technique for charting the scale, frequency, and temporal span of imported fine-grained basalt artifacts found throughout Polynesia. The technique adds another tool for addressing evolutionary models of interaction, isolation, and cultural divergence in the eastern Pacific. PMID:7892194

  10. Carbon dioxide sequestration in deep-sea basalt

    PubMed Central

    Goldberg, David S.; Takahashi, Taro; Slagle, Angela L.

    2008-01-01

    Developing a method for secure sequestration of anthropogenic carbon dioxide in geological formations is one of our most pressing global scientific problems. Injection into deep-sea basalt formations provides unique and significant advantages over other potential geological storage options, including (i) vast reservoir capacities sufficient to accommodate centuries-long U.S. production of fossil fuel CO2 at locations within pipeline distances to populated areas and CO2 sources along the U.S. west coast; (ii) sufficiently closed water-rock circulation pathways for the chemical reaction of CO2 with basalt to produce stable and nontoxic (Ca2+, Mg2+, Fe2+)CO3 infilling minerals, and (iii) significant risk reduction for post-injection leakage by geological, gravitational, and hydrate-trapping mechanisms. CO2 sequestration in established sediment-covered basalt aquifers on the Juan de Fuca plate offer promising locations to securely accommodate more than a century of future U.S. emissions, warranting energized scientific research, technological assessment, and economic evaluation to establish a viable pilot injection program in the future. PMID:18626013

  11. Basalt Waste Isolation Project. Annual report, fiscal year 1980

    SciTech Connect

    Not Available

    1980-11-01

    During this fiscal year the information available in the fields of geology and hydrology of the Columbia Plateau was consolidated and two reports were issued summarizing this information. In addition, the information on engineered barriers was consolidated and a report summarizing the research to date on waste package development and design of borehole seals was prepared. The waste package studies, when combined with the hydrologic integration, revealed that even under extreme disruptive conditions, a repository in basalt with appropriately designed waste packages can serve as an excellent barrier for containment of radionuclides for the long periods of time required for waste isolation. On July 1, 1980, the first two heater tests at the Near-Surface Test Facility were started and have been successfully operated to this date. The papers on the Near-Surface Test Facility section of this report present the results of the equipment installed and the preliminary results of the testing. In October 1979, the US Department of Energy selected the joint venture of Kaiser Engineers/Parsons Brinckerhoff Quade and Douglas, Inc., to be the architect-engineer to produce a conceptual design of a repository in basalt. During the year, this design has progressed and concept selection has now been completed. This annual report presents a summary of the highlights of the work completed during fiscal year 1980. It is intended to supplement and summarize the nearly 200 papers and reports that have been distributed to date as a part of the Basalt Waste Isolation Project studies.

  12. High water content in primitive continental flood basalts

    PubMed Central

    Xia, Qun-Ke; Bi, Yao; Li, Pei; Tian, Wei; Wei, Xun; Chen, Han-Lin

    2016-01-01

    As the main constituent of large igneous provinces, the generation of continental flood basalts (CFB) that are characterized by huge eruption volume (>105 km3) within short time span (<1–3 Ma) is in principle caused by an abnormally high temperature, extended decompression, a certain amount of mafic source rocks (e.g., pyroxenite), or an elevated H2O content in the mantle source. These four factors are not mutually exclusive. There are growing evidences for high temperature, decompression and mafic source rocks, albeit with hot debate. However, there is currently no convincing evidence of high water content in the source of CFB. We retrieved the initial H2O content of the primitive CFB in the early Permian Tarim large igneous province (NW China), using the H2O content of ten early-formed clinopyroxene (cpx) crystals that recorded the composition of the primitive Tarim basaltic melts and the partition coefficient of H2O between cpx and basaltic melt. The arc-like H2O content (4.82 ± 1.00 wt.%) provides the first clear evidence that H2O plays an important role in the generation of CFB. PMID:27143196

  13. Differentiation mechanism of frontal-arc basalt magmas

    NASA Astrophysics Data System (ADS)

    Kuritani, T.; Yoshida, T.; Kimura, J.; Hirahara, Y.; Takahashi, T.

    2012-04-01

    In a cooling magma chamber, magmatic differentiation can proceed both by fractionation of crystals from the main molten part of the magma body (homogeneous fractionation) and by mixing of the main magma with fractionated melt derived from low-temperature mush zones (boundary layer fractionation) (Jaupart and Tait, 1995, and references therein). The geochemical path caused by boundary layer fractionation can be fairly different from a path resulting from homogeneous fractionation (e.g., Langmuir, 1989). Therefore, it is important to understand the relative contributions of these fractionation mechanisms in magma chambers. Kuritani (2009) examined the relative roles of the two fractionation mechanisms in cooling basaltic magma chambers using a thermodynamics-based mass balance model. However, the basaltic magmas examined in the work were alkali-rich (Na2O+K2O > 4 wt.%). In this study, to explore differentiation mechanisms of frontal-arc basalt magmas that are volumetrically much more important than rear-arc alkali basalt magmas, the relative roles of the two fractionation mechanisms are examined for low-K tholetiitic basalt magma from Iwate Volcano, NE Japan arc, using the same mass balance model. First, the water content and the temperature of the Iwate magma were estimated. The Iwate lavas are moderately porphyritic, consisting of ~8 vol.% olivine and ~20 vol.% plagioclase phenocrysts. The olivine and plagioclase phenocrysts show significant compositional variations, and the Mg# of olivine phenocrysts (Mg#78-81) correlates positively with the An content of coexisting plagioclase phenocrysts (An85-92). The olivine phenocrysts with Mg# > ~82 do not form crystal aggregates with plagioclase. It is inferred from these observations that the phenocrysts with variable compositions were derived from a common magma with variable temperature in a magma chamber, and the plagioclase phenocrysts were all derived from mushy boundary layers along the walls of the magma chamber. By

  14. Assessing Eruption Column Height in Ancient Flood Basalt Eruptions

    NASA Technical Reports Server (NTRS)

    Glaze, Lori S.; Self, Stephen; Schmidt, Anja; Hunter, Stephen J.

    2015-01-01

    A buoyant plume model is used to explore the ability of flood basalt eruptions to inject climate-relevant gases into the stratosphere. An example from the 1986 Izu-Oshima basaltic fissure eruption validates the model's ability to reproduce the observed maximum plume heights of 12-16 km above sea level, sustained above fire-fountains. The model predicts maximum plume heights of 13-17 km for source widths of between 4-16 m when 32% (by mass) of the erupted magma is fragmented and involved in the buoyant plume (effective volatile content of 6 wt%). Assuming that the Miocene-age Roza eruption (part of the Columbia River Basalt Group) sustained fire-fountains of similar height to Izu-Oshima (1.6 km above the vent), we show that the Roza eruption could have sustained buoyant ash and gas plumes that extended into the stratosphere at approximately 45 deg N. Assuming 5 km long active fissure segments and 9000 Mt of SO2 released during explosive phases over a 10-15 year duration, the approximately 180 km of known Roza fissure length could have supported approximately 36 explosive events/phases, each with a duration of 3-4 days. Each 5 km fissure segment could have emitted 62 Mt of SO2 per day into the stratosphere while actively fountaining, the equivalent of about three 1991 Mount Pinatubo eruptions per day. Each fissure segment could have had one to several vents, which subsequently produced lava without significant fountaining for a longer period within the decades-long eruption. Sensitivity of plume rise height to ancient atmospheric conditions is explored. Although eruptions in the Deccan Traps (approximately 66 Ma) may have generated buoyant plumes that rose to altitudes in excess of 18 km, they may not have reached the stratosphere because the tropopause was substantially higher in the late Cretaceous. Our results indicate that some flood basalt eruptions, such as Roza, were capable of repeatedly injecting large masses of SO2 into the stratosphere. Thus sustained

  15. Effects of acid deposition on dissolution of carbonate stone during summer storms in the Adirondack Mountains, New York, 1987-89

    USGS Publications Warehouse

    Schuster, Paul F.; Reddy, Michael M.; Sherwood, S.I.

    1994-01-01

    This study is part of a long-term research program designed to identify and quantify acid rain damage to carbonate stone. Acidic deposition accelerates the dissolution of carbonate-stone monuments and building materials. Sequential sampling of runoff from carbonate-stone (marble) and glass (reference) microcatchments in the Adirondack Mountains in New York State provided a detailed record of the episodic fluctuations in rain rate and runoff chemistry during individual summer storms. Rain rate and chemical concentrations from carbonate-stone and glass runoff fluctuated three to tenfold during storms. Net calcium-ion concentrations from the carbonatestone runoff, a measure of stone dissolution, typically fluctuated twofold during these storms. High net sulfate and net calcium concentrations in the first effective runoff at the start of a storm indicated that atmospheric pollutants deposited on the stone surface during dry periods formed calcium sulfate minerals, an important process in carbonate stone dissolution. Dissolution of the carbonate stone generally increased up to twofold during coincident episodes of low rain rate (less than 5 millimeters per hour) and decreased rainfall (glass runoff) pH (less than 4.0); episodes of high rain rate (cloudbursts) were coincident with a rapid increase in rainfall pH and also a rapid decrease in the dissolution of carbonate-stone. During a storm, it seems the most important factors causing increased dissolution of carbonate stone are coincident periods of low rain rate and decreased rainfall pH. Dissolution of the carbonate stone decreased slightly as the rain rate exceeded about 5 millimeters per hour, probably in response to rapidly increasing rainfall pH during episodes of high rain rate and shorter contact time between the runoff and the stone surface. High runoff rates resulting from cloudbursts remove calcium sulfate minerals formed during dry periods prior to storms and also remove dissolution products formed in large

  16. Influence of dietary carbon on mercury bioaccumulation in streams of the Adirondack Mountains of New York and the Coastal Plain of South Carolina, USA

    USGS Publications Warehouse

    Riva-Murray, Karen; Bradley, Paul M.; Chasar, Lia C.; Button, Daniel T.; Brigham, Mark E.; Eikenberry, Barbara C. Scudder; Journey, Celeste A.; Lutz, Michelle A.

    2013-01-01

    We studied lower food webs in streams of two mercury-sensitive regions to determine whether variations in consumer foraging strategy and resultant dietary carbon signatures accounted for observed within-site and among-site variations in consumer mercury concentration. We collected macroinvertebrates (primary consumers and predators) and selected forage fishes from three sites in the Adirondack Mountains of New York, and three sites in the Coastal Plain of South Carolina, for analysis of mercury (Hg) and stable isotopes of carbon (δ13C) and nitrogen (δ15N). Among primary consumers, scrapers and filterers had higher MeHg and more depleted δ13C than shredders from the same site. Variation in δ13C accounted for up to 34 % of within-site variation in MeHg among primary consumers, beyond that explained by δ15N, an indicator of trophic position. Consumer δ13C accounted for 10 % of the variation in Hg among predatory macroinvertebrates and forage fishes across these six sites, after accounting for environmental aqueous methylmercury (MeHg, 5 % of variation) and base-N adjusted consumer trophic position (Δδ15N, 22 % of variation). The δ13C spatial pattern within consumer taxa groups corresponded to differences in benthic habitat shading among sites. Consumers from relatively more-shaded sites had more enriched δ13C that was more similar to typical detrital δ13C, while those from the relatively more-open sites had more depleted δ13C. Although we could not clearly attribute these differences strictly to differences in assimilation of carbon from terrestrial or in-channel sources, greater potential for benthic primary production at more open sites might play a role. We found significant variation among consumers within and among sites in carbon source; this may be related to within-site differences in diet and foraging habitat, and to among-site differences in environmental conditions that influence primary production. These observations suggest that different

  17. Importance of within-lake processes in affecting the dynamics of dissolved organic carbon and dissolved organic and inorganic nitrogen in an Adirondack forested lake/watershed

    NASA Astrophysics Data System (ADS)

    Kang, Phil-Goo; Mitchell, Myron J.; McHale, Patrick J.; Driscoll, Charles T.; Inamdar, Shreeram; Park, Ji-Hyung

    2016-05-01

    Lakes nested in forested watersheds play an important role in mediating the concentrations and fluxes of dissolved organic matter. We compared long-term patterns of concentrations and fluxes of dissolved organic carbon (DOC) and dissolved organic (DON) and inorganic nitrogen (DIN) in aquatic ecosystems of the Arbutus Lake watershed to evaluate how a lake nested in a forested watershed affects the sources (e.g., production) and sinks (e.g., retention) of DOC and DON in the Adirondack Mountains of New York, USA. We observed no significant long-term changes of DOC and DON in the lake outlet since 1983 and 1994, respectively. However, the temporal patterns of DOC and DON concentrations in the lake inlet showed significant seasonality such as increases during the vegetation-growing season along with notable decreases in the dormant season. A comparison of mass balances between inlet and outlet for the period from 2000 to 2009 suggested that the lake was a sink of DOC (mean of influx minus outflux: +1140 mol C ha-1 yr-1). In contrast, the difference of discharge-weighted DON concentrations (mean of inlet minus outlet: -1.0 µmol N L-1) between inlet and outlet was much smaller than the discharge-weighted DOC concentrations (average of inlet minus outlet: + 87 µmol C L-1). DON fluxes showed considerable variation among years (mean of influx minus outflux: +8 mol N ha-1 yr-1; range of differences: -15 to 27 mol N ha-1 yr-1). DON exhibited low percent retention ((influx-outflux)/influx) (mean: 6.9 %, range: -34.8 to +31.2) compared to DOC (mean: 30.1 %, range: +9.2 to +44.1). The resultant increase of DON within the lake was closely linked with a net decrease of DIN through monthly Pearson correlation analysis, suggesting the importance of biotic factors in mediating lake DON dynamics. Our results show different relative retentions of DOC compared with DON, along with a larger retention of DIN than DON, suggesting that DOC and DON might display substantially different

  18. Trace element partitioning between high-An plagioclase and basaltic to basaltic andesite melt at 1 atmosphere pressure

    NASA Astrophysics Data System (ADS)

    Tepley, Frank J., III; Lundstrom, Craig C.; McDonough, William F.; Thompson, Amy

    2010-07-01

    We determined plagioclase-melt partition coefficients for 18 elements by performing controlled cooling rate, 1-atmosphere experiments using both natural and synthetic basaltic (51 wt.% SiO 2) and basaltic andesite (56 wt.% SiO 2) powders in a vertical quench furnace. The experiments produced An 69 to An 87 composition plagioclase. Three starting powders were Gorda Ridge basalt, synthetic diopside (40%)-albite (28%)-anorthite (32%) mixture, and Arenal volcano (Costa Rica) basaltic andesite. The Gorda and synthetic powders were doped at both low concentrations (20-200 ppm) and high concentration (200-5000 ppm), whereas the Arenal powder was doped only at high concentrations resulting in two doped Gorda powders (low: NP, and high: SDP), two doped diopside/albite/anorthite powders (low: DAD, high: SDD) and one doped Arenal powder (high: AR99-2). Trace elements concentrations in both glass and plagioclase were measured by secondary ion mass spectrometry (SIMS) and/or by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Results for the partitioning of trace elements between plagioclase and melt at different doping levels demonstrate both adherence to Henry's Law and good agreement between the different analytical techniques. In general, plagioclase-melt partition coefficients determined in the An 69-73 range are similar to other published values, however, some of those occurring for plagioclase compositions > An 75 are distinctly lower than those predicted by current regression formulations. We applied a two-lattice melt model to these data to account for differences in melt composition and temperature and found that there were no aberrations associated with partition coefficients. A new set of regression formulations is determined involving the newly determined dataset for plagioclase with An contents between 75 and 87.

  19. Trace-element modelling of mare basalt parental melts: Implications for a heterogeneous lunar mantle

    NASA Astrophysics Data System (ADS)

    Hallis, L. J.; Anand, M.; Strekopytov, S.

    2014-06-01

    The heterogeneous-source model of mare basalt formation indicates that Lunar Magma Ocean (LMO) overturn produced an uneven mixture of early-formed olivine and pyroxene, and late-formed, ilmenite-rich cumulates, which subsequently partially melted to give rise to mare magmas. These heterogeneous cumulate source regions would not only have been characterised by different mineral modal abundances, but also by different trace element compositions. The aim of this work was to investigate the petrology and geochemistry of a diverse suite of Apollo mare basalts, and utilise trace-element modelling in order to understand their petrogenetic history. Chemical modelling confirms that the mare basalts were produced by relatively small degrees of partial melting (<10%) of the LMO cumulates, and that the dominant melting type (batch vs. fractional) varies among different basalt groups. Similarly, single-source mineralogy cannot be applied to all mare basalt types, confirming that the lunar mantle was heterogeneous at the time of generation of mare magmas. Plagioclase is not required in the source of most mare basalts, with the notable exception of the Apollo 14 high-Al basalts. Addition of more than 1% plagioclase to the source of other basalts produces weaker negative Eu anomalies than those observed in the samples. AFC calculations demonstrate the compositional differences between materials assimilated into the Apollo 14 high-Al and Apollo 11 high-K mare basalt partial melts, highlighting the complexities of mare basalt petrogenesis.

  20. Petrology and geochemistry of olivine-normative and quartz-normative basalts from regolith breccia 15498 - New diversity in Apollo 15 mare basalts

    NASA Technical Reports Server (NTRS)

    Vetter, Scott K.; Shervais, John W.; Lindstrom, Marilyn M.

    1988-01-01

    Analysis of mare basalt clasts from Apollo 15 shows a greater diversity than previously recognized and provides new constraints on the petrogenesis of these basalts. The quartz-normative basalts (QNB) from 15498 are divided into four groups based on chemical variations: primitive, intermediate/1, intermediate/2, and evolved. The olivine-normative basalts (ONB) are divided into three groups: low-SiO2, high-SiO2, and olivine-pyroxene cumulates. Least-squares mixing calculations show that the high SiO2 ONBs may be parental to the QNB suite. Variations within the low-SiO2 ONBs are explained by olivine factionation. It is suggested that the presence of these basalt types may result from the position of breccia 15498 near the edge of the mare plain where normal ONBs are scarce, and from its presumed origin as ejecta from Dune Crater.

  1. Class distinction

    NASA Astrophysics Data System (ADS)

    White, M. Catherine

    Typical 101 courses discourage many students from pursuing higher level science and math courses. Introductory classes in science and math serve largely as a filter, screening out all but the most promising students, and leaving the majority of college graduates—including most prospective teachers—with little understanding of how science works, according to a study conducted for the National Science Foundation. Because few teachers, particularly at the elementary level, experience any collegiate science teaching that stresses skills of inquiry and investigation, they simply never learn to use those methods in their teaching, the report states.

  2. Extrinsic controls on inter-basaltic plant ecosystems in the Columbia River Flood Basalt Province, Washington State, USA

    NASA Astrophysics Data System (ADS)

    Ebinghaus, Alena; Jolley, David W.; Hartley, Adrian J.

    2015-04-01

    The impact Large Igneous Province (LIP) volcanism may have had on paleoclimate, fauna and flora is still controversy. Inter-lava field plant ecosystems have the potential to record in detail the effects LIPs had on the environment in the immediate vicinity of volcanic activity. The Miocene Columbia River Flood Basalt Province (CRBP), Washington State, USA, provides excellent exposure of an entire LIP stratigraphy and offers a detailed record of inter-basaltic plant ecosystems throughout LIP evolution. The CRBP lava field comprise numerous basaltic lava flows that are intercalated with fluvial and lacustrine sediments which formed during phases of volcanic quiescence. The LIP volcanic evolution is characterised by an initial phase of high eruption volumes and eruptions rates, which is followed by waning volcanism associated with longer interbed intervals. Inter-lava field plant ecosystems are expected to correlate with phases of volcanic evolution: short interbed intervals should be dominated by early seral succession, while longer intervals should record more mature seral successions. The palynological record of the sedimentary interbeds however indicates a decline in successional status within the long interbed intervals of CRBP stratigraphy. An integrated analysis of sedimentary facies and geochemistry suggests intense volcanic ash fall derived from the adjacent Yellowstone hot spot as a major trigger for repetitive successional re-setting. This implies that inter-lava field ecosystem maturity was controlled by extrinsic forcing, and argues against environmental changes solely driven by LIPs of similar scale and magnitude to that of the CRBP.

  3. Basaltic volcanism, mantle plumes, and the mechanics of rifting: The Paraná flood basalt province of South America

    NASA Astrophysics Data System (ADS)

    Harry, Dennis L.; Sawyer, Dale S.

    1992-03-01

    Dynamic modeling of continental extension between South America and Africa shows that the mechanics of rifting played an important role in determining the pattern of volcanism within the Paraná and Etendeka flood-basalt provinces on the Brazilian and Namibian margins. The key feature of the model is the development of a horizontal pressure gradient in the lower crust during the early stages of extension, which provided a mechanism for transporting magma generated beneath the incipient sea-floor spreading axis into the Paraná province, 100-200 km distant. The horizontal pressure gradient developed as a consequence of the dynamic interaction of preexisting weaknesses in the middle crust and upper mantle during rifting. The model accounts for the large quantity of basalt, the asymmetric distribution of basalt on the conjugate margins, and the northward migration of the eruptive center with time. The rapidity of magma genesis is in agreement with models of decompression melting during rifting. The model indicates that although elevated asthenosphere temperatures associated with the Tristan plume account for the volume of melt generated, the mechanics of rifting control the location and style of emplacement. The model suggests that extension in the region began ca. 150-155 Ma, and lasted about 25 m.y.

  4. Lunar Mare Basalts as Analogues for Martian Volcanic Compositions: Evidence from Visible, Near-IR, and Thermal Emission Spectroscopy

    NASA Technical Reports Server (NTRS)

    Graff, T. G.; Morris, R. V.; Christensen, P. R.

    2003-01-01

    The lunar mare basalts potentially provide a unique sample suite for understanding the nature of basalts on the martian surface. Our current knowledge of the mineralogical and chemical composition of the basaltic material on Mars comes from studies of the basaltic martian meteorites and from orbital and surface remote sensing observations. Petrographic observations of basaltic martian meteorites (e.g., Shergotty, Zagami, and EETA79001) show that the dominant phases are pyroxene (primarily pigeonite and augite), maskelynite (a diaplectic glass formed from plagioclase by shock), and olivine [1,2]. Pigeonite, a low calcium pyroxene, is generally not found in abundance in terrestrial basalts, but does often occur on the Moon [3]. Lunar samples thus provide a means to examine a variety of pigeonite-rich basalts that also have bulk elemental compositions (particularly low-Ti Apollo 15 mare basalts) that are comparable to basaltic SNC meteorites [4,5]. Furthermore, lunar basalts may be mineralogically better suited as analogues of the martian surface basalts than the basaltic martian meteorites because the plagioclase feldspar in the basaltic Martian meteorites, but not in the lunar surface basalts, is largely present as maskelynite [1,2]. Analysis of lunar mare basalts my also lead to additional endmember spectra for spectral libraries. This is particularly important analysis of martian thermal emission spectra, because the spectral library apparently contains a single pigeonite spectrum derived from a synthetic sample [6].

  5. Is formation segregation melts in basaltic lava flows a viable analogue to melt generation in basaltic systems?

    NASA Astrophysics Data System (ADS)

    Thordarson, Thorvaldur; Sigmarsson, Olgeir; Hartley, Margaret E.; Miller, Jay

    2010-05-01

    Pahoehoe sheet lobes commonly exhibit a three-fold structural division into upper crust, core and lower crust, where the core corresponds to the liquid portion of an active lobe sealed by crust. Segregations are common in pahoehoe lavas and are confined to the core of individual lobes. Field relations and volume considerations indicate that segregation is initiated by generation of volatile-rich melt at or near the lower crust to core boundary via in-situ crystallization. Once buoyant, the segregated melt rises through the core during last stages of flow emplacement and accumulates at the base of the upper crust. The segregated melt is preserved as vesicular and aphyric, material within well-defined vesicle cylinders and horizontal vesicle sheets that make up 1-4% of the total lobe volume. We have undertaken a detailed sampling and chemical analysis of segregations and their host lava from three pahoehoe flow fields; two in Iceland and one in the Columbia River Basalt Group (CRBG). The Icelandic examples are: the olivine-tholeiite Thjorsa lava (24 cubic km) of the Bardarbunga-Veidivotn volcanic system and mildly alkalic Surtsey lavas (1.2 cubic km) of the Vestmannaeyjar volcanic system. The CRBG example is the tholeiitic ‘high-MgO group' Levering lava (>100? cubic km) of the N2 Grande Ronde Basalt. The thicknesses of the sampled lobes ranges from 2.3 to 14 m and each lobe feature well developed network of segregation structures [1,2,3]. Our whole-rock analyses show that the segregated melt is significantly more evolved than the host lava, with enrichment factors of 1.25 (Thjorsa) to 2.25 (Surtsey) for incompatible trace elements (Ba, Zr). Calculations indicate that the segregation melt was formed by 20 to 50% closed-system fractional crystallization of plagioclase (plus minor pyroxene and/or olivine). A more striking feature is the whole-rock composition of the segregations. In the olivine-tholeiite Thjorsa lava the segregations exhibit quartz tholeiite

  6. Recycled dehydrated lithosphere observed in plume-influenced mid-ocean-ridge basalt.

    PubMed

    Dixon, Jacqueline Eaby; Leist, Loretta; Langmuir, Charles; Schilling, Jean-Guy

    2002-11-28

    A substantial uncertainty in the Earth's global geochemical water cycle is the amount of water that enters the deep mantle through the subduction and recycling of hydrated oceanic lithosphere. Here we address the question of recycling of water into the deep mantle by characterizing the volatile contents of different mantle components as sampled by ocean island basalts and mid-ocean-ridge basalts. Although all mantle plume (ocean island) basalts seem to contain more water than mid-ocean-ridge basalts, we demonstrate that basalts associated with mantle plume components containing subducted lithosphere--'enriched-mantle' or 'EM-type' basalts--contain less water than those associated with a common mantle source. We interpret this depletion as indicating that water is extracted from the lithosphere during the subduction process, with greater than 92 per cent efficiency.

  7. Petrology of basalt and single-mineral fragments in the soil of the Sea of Fertility

    NASA Technical Reports Server (NTRS)

    Bence, A. E.; Holzwarth, W.; Papike, J. J.

    1974-01-01

    Basalt and single-mineral particles, ranging from 150 to 425 microns, from the Luna-16 sample are studied by electron microanalysis, X-ray fluorescence analysis, and petrographic techniques. Three basalt species of different structure are identified. The structure and composition of the individual minerals (in particular of pyroxenes) indicate that the basalts have crystallized under conditions similar to those established for Apollo-11 samples.

  8. Engineered barrier development for a nuclear waste repository in basalt: an integration of current knowledge

    SciTech Connect

    Smith, M.J.

    1980-05-01

    This document represents a compilation of data and interpretive studies conducted as part of the engineered barriers program of the Basalt Waste Isolation Project. The overall objective of these studies is to provide information on barrier system designs, emplacement and isolation techniques, and chemical reactions expected in a nuclear waste repository located in the basalts underlying the Hanford Site within the state of Washington. Backfills, waste-basalt interactions, sorption, borehole plugging, etc., are among the topics discussed.

  9. Rates of mineral dissolution and carbonation in peridotite and basalt

    NASA Astrophysics Data System (ADS)

    Kelemen, P. B.; Matter, J. M.

    2009-12-01

    We study natural rates and processes of mineral carbonation in peridotite (olivine-rich rock) in mantle rocks exposed to weathering in northern Oman to learn effective mechanisms from natural processes, and seek ways to accelerate them to achieve significant CO2 capture and storage via mineral carbonation at the lowest possible cost. In our first paper (1), we fit data on mantle olivine carbonation from the DOE Albany Research Center (2,3, ARC). These data, and data from Arizona State University (4, ASU) suggest that a peridotite rock volume heated to 185°C and infused with H2O+CO2 at PCO2 > 75 bars could consume ~ 1 ton CO2 per cubic meter of rock per year. Because it is more abundant than peridotite, other workers focus on carbonation of the most common type of lava on Earth, basalt, whose main mineral constituent is generally labradorite, part of the plagioclase feldspar solid solution series. Our intuition is that labradorite carbonation is much slower than mantle olivine carbonation. To quantify this, we compiled data on dissolution of mantle olivine, labradorite, crystalline basalt, and basaltic glass in aqueous fluids, as well as data on mantle olivine carbonation. The dissolution data are calibrated as a function of surface area (i.e., grain size and shape) and pH, as well as temperature, whereas most of the ARC and ASU experiments were done at a single pH and grain size. Thus, for comparison, we calculated dissolution rates for 70 micron spheres at pH 8, close to the ARC and ASU experimental conditions. At these conditions, olivine carbonation observed by ARC and ASU is 100 to 1000 times faster than labradorite and crystalline basalt, and faster than conventionally measured olivine dissolution rates. The ARC and ASU experiments were different from conventional dissolution experiments in several ways that could lead to an enhancement in olivine reaction rates: (a) they may have lower a(Mg) in fluid due to solid MgCO3 (magnesite) precipitation, (b) they

  10. A field investigation of the basaltic ring structures of the Channeled Scabland and the relevance to Mars

    USGS Publications Warehouse

    Kestay, Laszlo P.; Jaeger, Windy L.

    2015-01-01

    The basaltic ring structure (BRS) is a class of peculiar features only reported in the Channeled Scabland of eastern Washington State. They have been suggested to be good analogs, however, for some circular features on Mars. BRSs are found where Pleistocene floods scoured the Columbia River Basin, stripping off the uppermost part of the Miocene Columbia River Basalt Group and exposing structures that were previously embedded in the lava. The “Odessa Craters,” near Odessa, WA, are 50–500-m-wide BRSs that are comprised of discontinuous, concentric outcrops of subvertically-jointed basalt and autointrusive dikes. Detailed field investigation of the Odessa Craters in planform and a cross-sectional exposure of a similar structure above Banks Lake, WA, lead us to propose that BRSs formed by concurrent phreatovolcanism and lava flow inflation. In this model, phreatovolcanic (a.k.a., “rootless”) cones formed on a relatively thin, active lava flow; the lava flow inflated around the cones, locally inverting topography; tensile stresses caused concentric fracturing of the lava crust; lava from within the molten interior of the flow exploited the fractures and buried the phreatovolcanic cones; and subsequent erosive floods excavated the structures. Another population of BRSs near Tokio Station, WA, consists of single-ringed, raised-rimmed structures that are smaller and more randomly distributed than the Odessa Craters. We find evidence for a phreatovolcanic component to the origin as well, and hypothesize that they are either flood-eroded phreatovolcanic cones or Odessa Crater-like BRSs. This work indicates that BRSs are not good analogs to the features on Mars because the martian features are found on the uneroded surfaces. Despite this, the now superseded concepts for BRS formation are useful for understanding the formation of the martian features.

  11. A field investigation of the basaltic ring structures of the Channeled Scabland and the relevance to Mars

    NASA Astrophysics Data System (ADS)

    Keszthelyi, Laszlo P.; Jaeger, Windy L.

    2015-07-01

    The basaltic ring structure (BRS) is a class of peculiar features only reported in the Channeled Scabland of eastern Washington State. They have been suggested to be good analogs, however, for some circular features on Mars. BRSs are found where Pleistocene floods scoured the Columbia River Basin, stripping off the uppermost part of the Miocene Columbia River Basalt Group and exposing structures that were previously embedded in the lava. The "Odessa Craters," near Odessa, WA, are 50-500-m-wide BRSs that are comprised of discontinuous, concentric outcrops of subvertically-jointed basalt and autointrusive dikes. Detailed field investigation of the Odessa Craters in planform and a cross-sectional exposure of a similar structure above Banks Lake, WA, lead us to propose that BRSs formed by concurrent phreatovolcanism and lava flow inflation. In this model, phreatovolcanic (a.k.a., "rootless") cones formed on a relatively thin, active lava flow; the lava flow inflated around the cones, locally inverting topography; tensile stresses caused concentric fracturing of the lava crust; lava from within the molten interior of the flow exploited the fractures and buried the phreatovolcanic cones; and subsequent erosive floods excavated the structures. Another population of BRSs near Tokio Station, WA, consists of single-ringed, raised-rimmed structures that are smaller and more randomly distributed than the Odessa Craters. We find evidence for a phreatovolcanic component to the origin as well, and hypothesize that they are either flood-eroded phreatovolcanic cones or Odessa Crater-like BRSs. This work indicates that BRSs are not good analogs to the features on Mars because the martian features are found on the uneroded surfaces. Despite this, the now superseded concepts for BRS formation are useful for understanding the formation of the martian features.

  12. Rb-Sr and Sm-Nd chronology and genealogy of mare basalts from the Sea of Tranquility

    NASA Technical Reports Server (NTRS)

    Papanastassiou, D. A.; Depaolo, D. J.; Wasserburg, G. J.

    1977-01-01

    Rb-Sr and Sm-Nd ages of two Apollo 11 mare basalts, high-K basalt 10072 and low-K basalt 10062, are reported. Rb-Sr, Sm-Nd, and Ar-40-Ar-39 ages are in good agreement and indicate an extensive time interval for filling of the Sea of Tranquility, presumably by thin lava flows, in agreement with similar observations for the Ocean of Storms. Initial Sr and Nd isotopic compositions on Apollo 11 basalts reveal at least two parent sources producing basalts. The Sm-Nd isotopic data demonstrate that low-K and high-Ti basalts from Apollo 11 and 17 derived from distinct reservoirs, while low-Ti Apollo 15 mare basalt sources have Sm/Nd similar to the sources of Apollo 11 basalts. Groupings of mare basalt based on Ti content and on isotopic data do not coincide.

  13. Diffusive fractionation of trace elements in basaltic melt

    NASA Astrophysics Data System (ADS)

    Holycross, Megan E.; Bruce Watson, E.

    2016-10-01

    The chemical diffusivities of 25 trace elements (Sc, V, Rb, Sr, Y, Zr, Nb, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Yb, Lu, Hf, Ta, Th, and U) in basaltic melt were measured in diffusion couple experiments performed at 1 GPa pressure and temperatures from 1250 to 1500 °C. Trace element concentration gradients developed in the glasses were simultaneously characterized using laser ablation ICP/MS to create an internally consistent data set. A ratio-fitting technique was employed to accurately determine the relative diffusivities of the rare earth elements (REE). All diffusion coefficients conform to the expected Arrhenius relation D = D 0exp(- E a /RT), where the constant log( D 0, m2/s) ranges from -3.81 to -5.11 and E a ranges from 161.73 to 223.81 kJ/mol. The slowest diffusivities are obtained for the high-field-strength elements; the fastest diffusivities are obtained for the low-field-strength elements. Trace element diffusion in MORB follows the compensation law, where log D 0 is linearly correlated with E a. Arrhenius parameters for diffusion of trivalent REE monotonically increase from La to Lu and are near-linear functions of bond strength (the variation in Arrhenius parameters means that the diffusivities decrease monotonically from La to Lu at a given T). The new data for trace element diffusion in basaltic melt can be used to explore the potential for diffusive fractionation of trace elements using kinetic models. Concentrations of the slower-diffusing heavy REE may be altered relative to those of the faster-diffusing light REE as a diffusive boundary layer develops in melt-melt and crystal-melt systems. The results indicate that diffusion in basalt can be an effective mechanism to fractionate trace elements from one another.

  14. Evidence of biological activity in Hawaiian subsurface basalts

    NASA Astrophysics Data System (ADS)

    Fisk, M. R.; Storrie-Lombardi, M. C.; Douglas, S.; Popa, R.; McDonald, G.; di Meo-Savoie, C.

    2003-12-01

    The Hawaii Scientific Drilling Program (HSDP) cored and recovered igneous rock from the surface to a depth of 3109 m near Hilo, Hawaii. Much of the deeper parts of the hole is composed of hyaloclastite (fractured basalt glass that has been cemented in situ with secondary minerals). Some hyaloclastite units have been altered in a manner attributed to microorganisms in volcanic rocks. Samples from one such unit (1336 m to 1404 m below sea level) were examined to test the hypothesis that the alteration was associated with microorganisms. Deep ultraviolet native fluorescence and resonance Raman spectroscopy indicate that nucleic acids and aromatic amino acids are present in clay inside spherical cavities (vesicles) within basalt glass. Chemical mapping shows that phosphorus and carbon were enriched at the boundary between the clay and volcanic glass of the vesicles. Environmental scanning electron microscopy (ESEM) reveals two to three micrometer coccoid structures in these same boundaries. ESEM-linked energy dispersive spectroscopy demonstrated carbon, phosphorous, chloride, and magnesium in these bodies significantly differing from unoccupied neighboring regions of basalt. These observations taken together indicate the presence of microorganisms at the boundary between primary volcanic glass and secondary clays. Amino acids and nucleic acids were extracted from bulk samples of the hyaloclastite unit. Amino acid abundance was low, and if the amino acids are derived from microorganisms in the rock, then there are less than 100,000 cells per gram of rock. Most nucleic acid sequences extracted from the unit were closely related to sequences of Crenarchaeota collected from the subsurface of the ocean floor.

  15. Preliminary potentiometric map and flow dynamic characteristics for the upper-basalt confined aquifer system

    SciTech Connect

    Spane, F.A. Jr.; Raymond, R.G.

    1993-09-01

    This report presents the first comprehensive Hanford Site-wide potentiometric map for the upper-basalt confined aquifer system (i.e., the upper Saddle Mountains Basalt). In constructing the potentiometric map, over forty on-site and off-site monitoring wells and boreholes were used. The potentiometric map developed for the upper-basalt confined aquifer is consistent with the areal head pattern indicated for the Mabton interbed, which is a deeper and more areally extensive confined aquifer underlying the Hanford Site. Salient features for the upper-basalt confined aquifer system potentiometric map are described.

  16. Petrography, Geochemistry, and Pairing Relationships of Basaltic Lunar Meteorite Miller Range 13317

    NASA Astrophysics Data System (ADS)

    Zeigler, R. A.; Korotev, R. L.

    2016-08-01

    A petrographic and geochemical description of "new" lunar meteorite MIL 13317, an evolved lunar basaltic regolith breccia. The pairing relationships with previously described lunar meteorites are also explored.

  17. Concentrations and isotope ratios of carbon, nitrogen and sulfur in ocean-floor basalts

    NASA Technical Reports Server (NTRS)

    Sakai, H.; Ueda, A.; Des Marais, D. J.; Moore, J. G.

    1984-01-01

    Ocean floor basalts studied from the Galapagos Ridge, FAMOUS area, Cayman Trough and Kilauea east rift contain 20-200 ppm carbon and 0.3-2.8 ppn nitrogen as sums of the vesicle-filling gases CO2 and N2 and dissolved species. The wide range of carbon contents found is due partly to the different extent of outgassing of vesicle-filling gases and partly to depth dependency of dissolved CO2 in the basalts. Sulfate commonly exists with sulfide in these basalts, and the sulfate/sulfide ratio increases with increasing water content, perhaps reflecting the higher oxidation potential in basalt melt of the higher water content.

  18. Chemical and isotopic constraints on the petrogenesis of the large mare basalt clast in breccia 15459

    NASA Technical Reports Server (NTRS)

    Nyquist, L.; Lindstrom, M.; Bansal, B.; Mittlefehldt, D.; Shih, C.-Y.

    1989-01-01

    Results are presented that demonstrate that the large mare basalt clast in Apollo 15 breccia 15459 may represent one or more independent magma types. The complex nonequilibrium pyroxene and plagioclase compositions and relatively abundant mesostasis suggest that the 15459 clast is not a slowly cooled crystal cumulate. The addition of about 40 percent olivine to an olivine-normative basalt parental magma is found to be necessary to explain the high MgO abundances of picritic basalts by the accumulation of olivine in the magma. The present clast has a slightly younger age and a slightly higher Sr-87/Sr-86 ratio than most Apollo 15 basalts.

  19. Basalt fiber manufacturing technology and the possibility of its use in dentistry

    NASA Astrophysics Data System (ADS)

    Karavaeva, E.; Rogozhnikov, A.; Nikitin, V.; Cherepennikov, Yu; Lysakov, A.

    2015-11-01

    The article touches upon the technology of basalt fiber manufacturing and prospects of its use in dental practice. Two kinds of construction using basalt fiber have been proposed. The first one is a splinting construction for mobile teeth and the second one is the reinforced base for removable plate-denture. The work presents the results of the investigation of physical and mechanical properties of the constructions based on basalt fiber. It also describes the aspects of biomechanical modeling of such constructions in the ANSYS software package. The results of the investigation have proved that applying constructions using basalt fiber is highly promising for prosthetic dentistry practice.

  20. Nd-Sr isotopes, petrochemistry, and origin of the Siberian flood basalts, USSR

    SciTech Connect

    Sharma, M.; Basu, A.R. ); Nesterenko, G.V. )

    1991-04-01

    The Siberian Flood Basalt Province (SFBP) of Permo-Triassic age is one of the largest flood basalt provinces with an estimated area of exposure of 337 000 km{sup 2}, average thickness of 1 km, and a magma volume of 337 000 km{sup 3}. Forty-seven basaltic rocks from two main subprovinces, Norilsk (5-10{percent} of area, thickness up to 3 km) and Putorana (90-95{percent} of area, thickness of more than 2 km), were selected, on the basis of petrography and volcano-stratigraphic relation, for major-element analysis. Twenty-six of these basalts, twelve from Norilsk and fourteen from Putorana, were analyzed for Nd- and Sr-isotopic compositions. The Norilsk and Putorana basalts show some contrasting behavior in terms of the ratios of the highly incompatible elements of Ti, P, and K as a function of their Mg. The Norilsk basalts are more variable, suggesting the role of fractional crystallization-assimilation in their evolution. In contrast, the Putorana basalts show remarkable uniformity in their bulk chemical compositions. In Nd- and Sr-isotopic space, most of the Siberian basalts also fall within the field defined by the ocean island basalts data, implying common mantle sources. It is concluded that the SFBP originated by hotspot volcanism due to the rise of a large and relatively primitive lower mantle-derived plume beneath the Siberian continent.

  1. Reclamation report, Basalt Waste Isolation Project, boreholes 1990

    SciTech Connect

    Brandt, C.A.; Rickard, W.H. Jr.; Cadoret, N.A.

    1991-01-01

    The restoration of areas disturbed activities of the Basalt Waste Isolation Project (BWIP) has been undertaken by the US Department of Energy (DOE) in fulfillment of obligations and commitments made under the National Environmental Policy Act and the Nuclear Waste Policy Act. This restoration program comprises three separate projects: borehole reclamation, Near Surface Test Facility reclamation, and Exploratory Shaft Facility reclamation. Detailed descriptions of these reclamation projects may be found in a number of previous reports. This report describes the second phase of the reclamation program for the BWIP boreholes and analyzes its success relative to the reclamation objective. 6 refs., 14 figs., 13 tabs.

  2. Lonar Lake, India: An impact Crater in basalt

    USGS Publications Warehouse

    Fredriksson, K.; Dube, A.; Milton, D.J.; Balasundaram, M.S.

    1973-01-01

    Discovery of shock-metamorphosed material establishes the impact origin of Lonar Crater. Coarse breccia with shatter coning and microbreccia with moderately shocked fragments containing maskelynite were found in drill holes through the crater floor. Trenches on the rim yield strongly shocked fragments in which plagioclase has melted and vesiculated, and bombs and spherules of homogeneous rock melt. As the only known terrestrial impact crater in basalt, Lonar Crater provides unique opportunities for comparison with lunar craters. In particular, microbreccias and glass spherules from Lonar Crater have close analogs among the Apollo specimens.

  3. Lonar lake, India: an impact crater in basalt.

    PubMed

    Fredriksson, K; Dube, A; Milton, D J; Balasundaram, M S

    1973-05-25

    Discovery of shock-metamorphosed material establishes the impact origin of Lonar Crater. Coarse breccia with shatter coning and microbreccia with moderately shocked fragments containing maskelynite were found in drill holes through the crater floor. Trenches on the rim yield strongly shocked fragments in which plagioclase has melted and vesiculated, and bombs and spherules of homogeneous rock melt. As the only known terrestrial impact crater in basalt, Lonar Crater provides unique opportunities for comparison with lunar craters. In particular, microbreccias and glass spherules from Lonar Crater have close analogs among the Apollo specimens.

  4. Basalt weathering in an Arctic Mars-analog site

    NASA Astrophysics Data System (ADS)

    Yesavage, Tiffany; Thompson, Aaron; Hausrath, Elisabeth M.; Brantley, Susan L.

    2015-07-01

    The martian surface has undergone chemical and physical weathering in the past, and these processes may continue intermittently today. To explore whether martian rocks are likely to retain features indicative of weathering, we investigated how basaltic material weathers on Earth. Specifically, we investigated weathering of a Quaternary-aged basaltic flow at the Sverrefjell volcano in Svalbard, above the Arctic Circle. This flow weathered since deglaciation under cold, dry (<400 mm/yr) conditions. We analyzed a ∼75-cm core of regolith for chemical loss and then characterized the mineralogical and morphological properties using electron microscopy (EM), X-ray diffraction (XRD), infrared (IR) spectroscopy and selective chemical dissolution. In addition, we ran colloidal dispersion, wetting/drying, and freeze/thaw experiments. In the regolith, we observed concentrations of short-range ordered (SRO) phases similar to those observed in warmer, wetter volcanic ash soils. IR and EM analyses of the clay-sized fraction were consistent with allophane as the predominant secondary phase. Selective chemical extractions targeting SRO phases indicated lower Al/Si ratios than those observed in volcanic soils reported in warmer localities, which we attribute to Si-rich allophane and/or abundant Si-rich rock coatings. The oxic circumneutral-pH colloidal dispersion experiments mobilized Al, Fe and Ti primarily as 260-415 nm particles and Ca, Mg and Na as solutes. Si was lost both in the colloidal and dissolved forms. Dispersed colloids likely contain allophane and ferrihydrite. Under anoxic conditions, dissolution of Fe oxide cements also released fines. The experiments help to explain elemental loss from the clay-sized regolith fraction at Svalbard: observed depletions in Ca, K, Mg and Na were likely due to solute loss, while particle-reactive Al, Fe, Si and Ti were mostly retained. Wetting/drying was observed to be as effective as freeze/thaw in driving material loss. It is thus

  5. Dissolved hydrogen and methane in the oceanic basaltic biosphere

    NASA Astrophysics Data System (ADS)

    Lin, Huei-Ting; Cowen, James P.; Olson, Eric J.; Lilley, Marvin D.; Jungbluth, Sean P.; Wilson, Samuel T.; Rappé, Michael S.

    2014-11-01

    The oceanic basaltic crust is the largest aquifer on Earth and has the potential to harbor substantial subsurface microbial ecosystems, which hitherto remains largely uncharacterized and is analogous to extraterrestrial subsurface habitats. Within the sediment-buried 3.5 Myr old basaltic crust of the eastern Juan de Fuca Ridge flank, the circulating basement fluids have moderate temperature (∼65 °C) and low to undetectable dissolved oxygen and nitrate concentrations. Sulfate, present in high concentrations, is therefore expected to serve as the major electron acceptor in this subsurface environment. This study focused on the availability and potential sources of two important electron donors, methane (CH4) and hydrogen (H2), for the subseafloor biosphere. High integrity basement fluids were collected via fluid delivery lines associated with Integrated Ocean Drilling Program (IODP) Circulation Obviation Retrofit Kits (CORKs) that extend from basement depths to outlet ports at the seafloor. Two new CORKs installed during IODP 327 in 2010, 1362A and 1362B, were sampled in 2011 and 2013. The two CORKs are superior than earlier style CORKs in that they are equipped with coated casing and polytetrafluoroethylene fluid delivery lines, reducing the interaction between casing materials with the environment. Additional samples were collected from an earlier style CORK at Borehole 1301A. The basement fluids are enriched in H2 (0.05-1.8 μmol/kg), suggesting that the ocean basaltic aquifer can support H2-driven metabolism. The basement fluids also contain significant amount of CH4 (5-32 μmol/kg), revealing CH4 as an available substrate for subseafloor basaltic habitats. The δ13C values of CH4 from the three boreholes ranged from -22.5 to -58‰, while the δ2H values ranged from -316 to 57‰. The isotopic compositions of CH4 and the molecular compositions of hydrocarbons suggest that CH4 in the basement fluids is of both biogenic and abiotic origins, varying among sites

  6. Carbon and its isotopes in mid-oceanic basaltic glasses

    NASA Technical Reports Server (NTRS)

    Des Marais, D. J.; Moore, J. G.

    1984-01-01

    Sample surface carbon, mantle carbon dioxide in vesicles, and mantle carbon dissolved in glasses, are the three carbon components evident in the 11 mid-oceanic basalts presently analyzed. The total carbon content may be controlled by the depth of the shallowest ridge magma chamber, and carbon isotopic fractionation accompanies magma degassing. Using He-3 and carbon data for submarine hydrothermal fluids, the present day midoceanic ridge carbon flux is approximately estimated to be 1.0 x 10 to the 13th g C/yr, requiring 8 Gyr to accumulate the earth's present crustal carbon inventory.

  7. The petrology of basalts from Surtla (Surtsey), Iceland

    NASA Astrophysics Data System (ADS)

    Kokelaar, B. Peter; Durant, Graham P.

    1983-12-01

    Surtla is the entirely submarine volcanic pile of a satellite vent which was active shortly after initiation of the main Surtsey eruption. Blocks of lava and glassy elastic deposits collected from Surtla are of mildly alkaline olivine basalt and are compositionally the most evolved material determined from the Surtsey volcano. Petrographical and chemical analyses confirm the previously postulated continuum between the evolved (derivative) and more primitive (parental) compositions widely occurring in the Vestmannaeyjar volcanic system but not hitherto found in a single eruption. A compositionally zoned magma chamber is invoked.

  8. Final Reclamation Report: Basalt Waste Isolation Project exploratory shaft site

    SciTech Connect

    Brandt, C.A.; Rickard, W.H. Jr.

    1990-06-01

    The restoration of areas disturbed by activities of the Basalt Waste Isolation Project (BWIP) constitutes a unique operation at the US Department of Energy's (DOE) Hanford Site, both from the standpoint of restoration objectives and the time frame for accomplishing these objectives. The BWIP reclamation program comprises three separate projects: borehole reclamation, Near Surface Test Facility (NSTF) reclamation, and Exploratory Shaft Facility (ESF) reclamation. The main focus of this report is on determining the success of the revegetation effort 1 year after work was completed. This report also provides a brief overview of the ESF reclamation program. 21 refs., 7 figs., 14 tabs.

  9. Ilmenite exsolution schemes in Apollo-17 high-Ti basalts

    SciTech Connect

    Vaniman, D.; Heiken, G. ); Muhich, T. . Dept. of Geology)

    1990-01-01

    Combined electron microprobe and scanning electron microscope (SEM) x-ray image analyses are used to obtain semiquantitative data on the relations between ilmenite grains and their exsolved chromite and rutile. Comparisons of these data for ilmenites in four Apollo-17 high-Ti basalts with a database of electron microprobe analyses from the literature indicates that Cr expulsion from ilmenite can be as important as Fe{sup 2+} reduction in causing subsolidus exsolution of chromite and rutile from ilmenite. 12 refs., 4 figs., 5 tabs.

  10. Geochemical characterization of tubular alteration features in subseafloor basalt glass

    NASA Astrophysics Data System (ADS)

    Knowles, Emily; Staudigel, Hubert; Templeton, Alexis

    2013-07-01

    There are numerous indications that subseafloor basalts may currently host a huge quantity of active microbial cells and contain biosignatures of ancient life in the form of physical and chemical basalt glass alteration. Unfortunately, technological challenges prevent us from observing the formation and mineralization of these alteration features in situ, or reproducing tubular basalt alteration processes in the laboratory. Therefore, comprehensive analysis of the physical and chemical traces retained in mineralized tubules is currently the best approach for deciphering a record of glass alteration. We have used a number of high-resolution spectroscopic and microscopic methods to probe the geochemical and mineralogical characteristics of tubular alteration features in basalt glasses obtained from a suite of subseafloor drill cores that covers a range of different collection locations and ages. By combining three different synchrotron-based X-ray measurements - X-ray fluorescence microprobe mapping, XANES spectroscopy, and μ-XRD - with focused ion beam milling and transmission electron microscopy, we have spatially resolved the major and trace element distributions, as well as the oxidation state of Fe, determined the coordination chemistry of Fe, Mn and Ti at the micron-scale, and constrained the secondary minerals within these features. The tubular alteration features are characterized by strong losses of Fe2+, Mn2+, and Ca2+ compared to fresh glass, oxidation of the residual Fe, and the accumulation of Ti and Cu. The predominant phases infilling the alteration regions are Fe3+-bearing silicates dominated by 2:1 clays, with secondary Fe- and Ti-oxides, and a partially oxidized Mn-silicate phase. These geochemical patterns observed within the tubular alteration features are comparable across a diverse suite of samples formed over the past 5-100 Ma, which shows that the microscale mineralization processes are common and consistent throughout the ocean basins and

  11. Basalt features observed in outcrops, cores, borehole video imagery and geophysical logs, and basalt hydrogeologic study at the Idaho National Engineering Laboratory, Eastern Idaho

    SciTech Connect

    Bennecke, W.M.

    1996-10-01

    A study was undertaken to examine permeable zones identified in boreholes open to the underlying basalt and to describe the vertical cross flows present in the boreholes. To understand the permeable zones in the boreholes detailed descriptions and measurements of three outcrops in the Snake River Plain, three cores at the Idaho Chemical Processing Plant (ICPP) at the INEL, and over fifty borehole TV logs from the INEL were carried out. Based on the observations made on the three outcrops an idealized basalt lava flow model was generated that used a set of nomenclature that would be standard for the basalt lava flows studied. An upper vesicular zone, a sometimes absent columnar zone, central zone, and lower vesicular zone make up the basalt lava flow model. The overall distinction between the different zones are based on the vesicle shape size, vesicularity, and fractures present. The results of the studies also indicated that the basalt lava flows at the INEL are distal to medial facies pahoehoe lava flows with close fitting contacts. The most permeable zones identified in these basalts are fractured vesiculated portions of the top of the lava flow, the columnar areas, and basalt-flow contacts in order of importance. This was determined from impeller flowmeter logging at the INEL. Having this information a detailed stratigraphy of individual basalt lava flows and the corresponding permeable units were generated. From this it was concluded that groundwater flow at the ICPP prefers to travel along thin basalt lava flows or flow-units. Flow direction and velocity of intrawell flows detected by flowmeter is controlled by a nearby pumping well.

  12. Regional assessment of the response of the acid-base status of lake watersheds in the Adirondack region of New York to changes in atmospheric deposition using PnET-BGC.

    PubMed

    Chen, Limin; Driscoll, Charles T

    2005-02-01

    Understanding the response of soil and surface waters to changes in atmospheric deposition is critical for guiding future legislation on air pollution. The Adirondack region of New York experiences among the most severe ecological impacts from acidic deposition. The region is characterized by considerable variability in atmospheric deposition, surficial and bedrock geology, hydrologic flow paths, and vegetation resulting in variability in effects of acidic deposition. In this study, an integrated biogeochemical model (PnET-BGC) was applied to 37 forest lake watersheds to assess the response of soil and surface waters of the Adirondacks to changes in atmospheric deposition at a regional scale. Model-simulated surface water chemistry was validated against data from two synoptic surveys conducted in 1984 and 2001. Results indicate that the model is able to capture the observed changes in surface water chemistry during this period. The model was further used to forecast the response of soil and surface waters to three future emission control scenarios. Results indicate that under the Clean Air Act, surface water SO4(2-) concentrations will continue to decrease at a median rate of -0.38 microeq/L-yr, and surface water ANC is predicted to increase at a median rate of 0.11 microeq/L-yr. More aggressive emission reductions will accelerate the rate of recovery. Under an aggressive control scenario, which represents an additional 75% reduction in SO2 emissions beyond the implementation of the Clean Air Act, surface water SO4(2-) concentrations are predicted to decrease at a median rate of -0.88 microeq/L-yr, and surface water ANC is predicted to increase at a median rate of 0.43 microeq/L-yr. Model predictions of several biologically relevant chemical indicators are also reported.

  13. Spirit Discovers New Class of Igneous Rocks

    NASA Technical Reports Server (NTRS)

    2006-01-01

    . %' indicates that the numbers tell what percentage of the total weight of each rock is silica (on the horizontal scale) and what percentage is oxides of sodium and potassium (on the vertical scale). The thin lines separate volcanic rock types identified on Earth by different scientific names such as foidite and picrobasalt. Various classes of Gusev rocks (see box in upper right) all plot either on or to the left of the green lines, which define 'alkaline' and 'subalkaline' categories (subalkaline rocks have more silica than alkaline rocks).

    Members of the rover team have named different classes of rocks after specimens examined by Spirit that represent their overall character. During the rover's travels, Spirit discovered that Adirondack-class rocks littered the Gusev plains; that Backstay, Irvine, and Wishstone-class rocks occurred as loose blocks on the northwest slope of 'Husband Hill'; and that outcrops of Algonquin-class rocks protruded in several places on the southeast face.

    These rocks have less silica than all previously analyzed Mars samples, which are subalkaline. The previously analyzed Mars samples include Martian meteorites found on Earth and rocks analyzed by the Mars Pathfinder rover in 1997. Gusev is the first documented example of an alkaline igneous province on Mars.

  14. High Mg basalts and basaltic andesites from pyroxenite melts(?) in a continental arc: Tatara-San Pedro, Chilean Andes

    NASA Astrophysics Data System (ADS)

    Jweda, J.; Goldstein, S. L.; Dungan, M. A.; Langmuir, C. H.; Davidson, J. P.

    2011-12-01

    A primary challenge for understanding magma generation at continental arc volcanoes is to distinguish subducted slab and upper mantle contributions from crustal contamination. High-density sampling at the Quaternary frontal arc Tatara-San Pedro complex (TSPC) of the Southern Volcanic Zone (SVZ) in Chile has yielded one of the most complete eruptive chrono-stratigraphies of any arc volcano on Earth, providing a unique opportunity to elucidate magma source heterogeneity and the effects of slab, upper mantle, and crustal inputs. While most TSPC lavas are impacted by crustal contamination, these effects can be distinguished. Beyond them, we have recognized three distinct mantle-derived magma types: (1) the "background SVZ" mantle, which is the subduction-modified depleted mantle wedge, (2) a fluid-rich component derived from fluxing of the "background SVZ" mantle wedge by slab-derived hydrous fluids, and (3) an "enriched mantle" component, with much higher incompatible element and HFSE abundances, LREE/HREE, and Sr isotopes, but lower Nd and Hf isotopes, than the other two endmembers. Lavas containing the "fluid-rich" and "enriched" components are generated in separate regions of the subduction regime, as both lava types show mixing with the "background SVZ" but never with each other. While the loss of fluids from subducted ocean crust and melting of the subduction-modified mantle wedge reflect classic processes associated with convergent plate boundaries, the origin of the "enriched mantle" component is not part of the subduction paradigm. In the SVZ, the presence of the "enriched mantle" was observed in basaltic cones behind the arc front near Villarica by Hickey et al. (1989) and interpreted as either derived from continued input of subduction components into the mantle wedge behind the main frontal arc, or from melting of the subcontinental lithospheric mantle. At TSPC, the inferred parent magmas of basalts and basaltic andesites of the enriched component have

  15. Basalt generation at the Apollo 12 site. Part 1: New data, classification, and re-evaluation

    NASA Technical Reports Server (NTRS)

    Neal, Clive R.; Hacker, Matthew D.; Snyder, Gregory A.; Taylor, Lawrence A.; Liu, Yun-Gang; Schmitt, Roman A.

    1994-01-01

    New data are reported from five previously unanalyzed Apollo 12 mare basalts that are incorporated into an evaluation of previous petrogenetic models and classification schemes for these basalts. This paper proposes a classification for Apollo 12 mare basalts on the basis of whole-rock Mg# (molar 100*(Mg/(Mg+Fe))) and Rb/Sr ratio (analyzed by isotope dilution), whereby the ilmenite, olivine, and pigeonite basalt groups are readily distinguished from each other. Scrutiny of the Apollo 12 feldspathic 'suite' demonstrates that two of the three basalts previously assigned to this group (12031, 12038, 12072) can be reclassified: 12031 is a plagioclase-rich pigeonite basalt; and 12072 is an olivine basalt. Only basalt 12038 stands out as a unique sample to the Apollo 12 site, but whether this represents a single sample from another flow at the Apollo 12 site or is exotic to this site is equivocal. The question of whether the olivine and pigeonite basalt suites are co-magmatic is addressed by incompatible trace-element chemistry: the trends defined by these two suites when Co/Sm and Sm/Eu ratios are plotted against Rb/Sr ratio demonstrate that these two basaltic types cannot be co-magmatic. Crystal fractionation/accumulation paths have been calculated and show that neither the pigeonite, olivine, or ilmenite basalts are related by this process. Each suite requires a distinct and separate source region. This study also examines sample heterogeneity and the degree to which whole-rock analyses are representative, which is critical when petrogenetic interpretation is undertaken. Sample heterogeneity has been investigated petrographically (inhomogeneous mineral distribution) with consideration of duplicate analyses, and whether a specific sample (using average data) plots consistently upon a fractionation trend when a number of different compostional parameters are considered. Using these criteria, four basalts have been identified where reported analyses are not

  16. Lead isotopes and the sources of the Columbia River Basalt Group

    NASA Astrophysics Data System (ADS)

    Chamberlain, V. E.; Lambert, R. St. J.

    1994-06-01

    A detailed study of Pb-208/Pb-204, Pb-207/Pb-204, and Pb-206/Pb-204 ratios suggests that the number of Pb isotopic reservoirs required for the Columbia River Basalt Group (CRBG) (as currently defined) must be increased from the presently accepted four to at least six. The identities of the six reservoirs are two of mid-ocean ridge basalt (MORB) slightly contaminated with sediment (R1 and R2, R1 being 'Cascades' PB); one a probable plume component (R3); two of unspecified mantle material but probably of R1 type, contaminated with local crustal Pb (R4 and R5); and the sixth a complex enriched reservoir of 2150 Ma age (R6). R1 is an end-member for all CRBG, except the Saddle Mountains Basalts. R2 is a second end-member for the Picture Gorge Basalt and CRBG, except the Saddle Mountains Basalts. R2 is a second end-member for the Picture Gorge Basalt and appears to be unique to it. R3 is the principal source for most of the Wanapum Basalt, as well as for most of the chemically evolved portions of the Grande Ronde Basalt. Volumetric and tectonic considerations require that one source of the CRBG be a plume or, at least, a nonlocal crustal or uppermost mantle source, and R3 is the ideal candidate for that role. R4 is the second source for the Imnaha Basalt, and R5 is the source for the (206)Pb-rich varieties of the Grande Ronde Basalt. R4 and R5 are identified with contamination by local Phanerozoic crust because of their similarity to local crustal Pb and because the rocks which contain them also have Cu contents correlated with their Pb isotopic compositions. R6 is the parent for Pb in all the Saddle Mountain Basalts. This last source appears to have been homogeneous 2150 m.y. ago but has since split into a number of separate, discrete pockets, each with its own characteristic Pb isotopic signature. Some of these appear in individual Saddle Mountain Basalt flows, while other sources have mixed with R4 to produce individual Saddle Mountain Basalt flows of the Ice Harbor

  17. Fungal colonies in open fractures of subseafloor basalt

    NASA Astrophysics Data System (ADS)

    Ivarsson, Magnus; Bengtson, Stefan; Skogby, Henrik; Belivanova, Veneta; Marone, Federica

    2013-08-01

    The deep subseafloor crust is one of the few great frontiers of unknown biology on Earth and, still today, the notion of the deep biosphere is commonly based on the fossil record. Interpretation of palaeobiological information is thus central in the exploration of this hidden biosphere and, for each new discovery, criteria used to establish biogenicity are challenged and need careful consideration. In this paper networks of fossilized filamentous structures are for the first time described in open fractures of subseafloor basalts collected at the Emperor Seamounts, Pacific Ocean. These structures have been investigated with optical microscopy, environmental scanning electron microscope, energy dispersive spectrometer, X-ray powder diffraction as well as synchrotron-radiation X-ray tomographic microscopy, and interpreted as fossilized fungal mycelia. Morphological features such as hyphae, yeast-like growth and sclerotia were observed. The fossilized fungi are mineralized by montmorillonite, a process that probably began while the fungi were alive. It seems plausible that the fungi produced mucilaginous polysaccharides and/or extracellular polymeric substances that attracted minerals or clay particles, resulting in complete fossilization by montmorillonite. The findings are in agreement with previous observations of fossilized fungi in subseafloor basalts and establish fungi as regular inhabitants of such settings. They further show that fossilized microorganisms are not restricted to pore spaces filled by secondary mineralizations but can be found in open pore spaces as well. This challenges standard protocols for establishing biogenicity and calls for extra care in data interpretation.

  18. CO2-filled vesicles in mid-ocean basalt

    USGS Publications Warehouse

    Moore, J.G.; Batchelder, J.N.; Cunningham, C.G.

    1977-01-01

    Volatile-filled vesicles are present in minor amounts in all samples of mid-ocean basalt yet collected (and presumably erupted) down to depths of 4.8 km. When such vesicles are pierced in liquid under standard conditions, the volume expansion of the gas is 0.2 ?? 0.05 times the eruption pressure in bars or 20 ?? 5 times the eruption depth in km. Such expansion could be used as a measure of eruption depth. A variety of techniques: (1) vacuum crushing and gas chromatographic, freezing separation, and mass spectrographic analyses; (2) measurements of p