Intrusive rocks and plutonic belts of southeastern Alaska, U.S.A.

USGS Publications Warehouse

Brew, David A.; Morrell, Robert P.; Roddick, J.A.

1983-01-01

About 30 percent of the 175,000-km2 area of southeastern Alaska is underlain by intrusive igneous rocks. Compilation of available information on the distribution, composition, and ages of these rocks indicates the presence of six major and six minor plutonic belts. From west to east, the major belts are: the Fairweather-Baranof belt of early to mid-Tertiary granodiorite; the Muir-Chichagof belt of mid-Cretaceous tonalite and granodiorite; the Admiralty-Revillagigedo belt of porphyritic granodiorite, quartz diorite, and diorite of probable Cretaceous age; the Klukwan-Duke belt of concentrically zoned or Alaskan-type ultramafic-mafic plutons of mid-Cretaceous age within the Admiralty-Revillagigedo belt; the Coast Plutonic Complex sill belt of tonalite of unknown, but perhaps mid-Cretaceous, age; and the Coast Plutonic Complex belt I of early to mid-Tertiary granodiorite and quartz monzonite. The minor belts are distributed as follows: the Glacier Bay belt of Cretaceous and(or) Tertiary granodiorite, tonalite, and quartz diorite lies within the Fair-weather-Baranof belt; layered gabbro complexes of inferred mid-Tertiary age lie within and are probably related to the Fairweather-Baranof belt; the Chilkat-Chichagof belt of Jurassic granodiorite and tonalite lies within the Muir-Chichagof belt; the Sitkoh Bay alkaline, the Kendrick Bay pyroxenite to quartz monzonite, and the Annette and Cape Fox trondhjemite plutons, all interpreted to be of Ordovician(?) age, together form the crude southern southeastern Alaska belt within the Muir-Chichagof belt; the Kuiu-Etolin mid-Tertiary belt of volcanic and plutonic rocks extends from the Muir-Chichagof belt eastward into the Admiralty-Revillagigedo belt; and the Behm Canal belt of mid- to late Tertiary granite lies within and next to Coast Plutonic Complex belt II. In addition, scattered mafic-ultramafic bodies occur within the Fairweather-Baranof, Muir-Chichagof, and Coast Plutonic Complex belts I and II. Palinspastic

Deformation of the Eastern Franciscan Belt, northern California

USGS Publications Warehouse

Jayko, A.S.; Blake, M.C.

1989-01-01

The late Jurassic and Cretaceous Eastern Franciscan belt of the northern California Coast Range consists of two multiply deformed, blueschist-facies terranes; the Pickett Peak and Yolla Bolly terranes. Four deformations have been recognized in the Pickett Peak terrane, and three in the Yolla Bolly terrane. The earliest recognized penetrative fabric, D1, occurs only in the Pickett Peak terrane. The later penetrative fabrics, D2 and D3, occur in both the Yolla Bolly and Pickett Peak terranes. D1 and D2 apparently represent fabrics that formed during subduction and accretion of the terranes. Fabrics from both D1 and D2 are consistent with SW-NE movement directions with respect to their present geographic positions. D3 postdates blueschist-facies metamorphism of the terranes and may be related to emplacement of the terranes to higher structural levels. A broad regional warping, D4, is evident from the map pattern and folding of large metamorphosed thrust sheets. D4 folds may be related to deformation associated with oblique convergence along the continental margin in late Cretaceous and (or) early Tertiary time. ?? 1989.

Ultramafic rocks of the western Idaho suture zone: Asbestos Peak and Misery Ridge

DOE Office of Scientific and Technical Information (OSTI.GOV)

Godchaux, M.M.; Bonnichsen, B.

1993-04-01

The Western Idaho Ultramafic Belt extends northward from the town of Weiser to the northern end of Dworshak Reservoir; in its northern portion most of the ultramafic bodies are localized along the suture zone where the Mesozoic oceanic accreted terranes meet the continental craton. Of the twenty bodies investigated, all are small, all are in fault contact with their metavolcanic and metasedimentary host rocks, all have been metamorphosed, and all display deformational fabrics in at least some portion of the outcrop area, suggesting that deformation continued after peak metamorphism. The degree of metamorphism ranges from incipient serpentinization to attainment ofmore » equilibrium in the upper amphibolite facies. Some bodies have been intruded by granitic dikes or pegmatite veins after emplacement, and have locally undergone contact metasomatism. Two particularly complex bodies, Asbestos Peak and Misery Ridge, were chosen for detailed petrographic and chemical study. Asbestos Peak is composed mostly of decussate anthophyllite-talc rock containing isolated patches of harzburgite protolith, and has blackwall border zones. Misery Ridge is composed mostly of coarse-grained sheared tremolite-talc schist without remnant protolith, and lacks true blackwall zones. Both bodies exhibit an unusual and enigmatic hornblende-poikiloblastic garnet-green spinel-skeletal ilmenite assemblage, present in some places as well-defined border zones and in other places as cross-cutting bodies.« less

Mineral potential for nickel, copper, platinum group elements(PGE), and chromium deposits hosted in ultramafic rocks in the Islamic Republic of Mauritania (phase V, deliverable 67): Chapter G in Second projet de renforcement institutionnel du secteur minier de la République Islamique de Mauritanie (PRISM-II)

USGS Publications Warehouse

Taylor, Cliff D.; Marsh, Erin; Anderson, Eric D.

2015-01-01

PRISM-I summary documents mention the presence of mafic-ultramafic igneous intrusive rocks in several areas of Mauritania and a number of chromium (Cr) and copper-nickel (Cu-Ni (±Co, Au)) occurrences associated with them. Permissive geologic settings generally include greenstone belts of any age, layered mafic-ultramafic and unlayered gabbro-anorthosite intrusive complexes in cratonic settings, ophiolite complexes, flood basalt provinces, and fluid-rich shear zones cutting accumulations of mafic-ultramafic rocks. Regions of Mauritania having these characteristics that are discussed in PRISM-I texts include the Mesoarchean greenstone belts of the TasiastTijirit terrane in the southwestern Rgueïbat Shield, two separate layered ultramafic complexes in the Amsaga Complex west of Atar, serpentinized metadunites in Mesoarchean rocks of the Rgueïbat Shield in the Zednes map sheet, several lateritized annular mafic-ultramafic complexes in the Paleoproterozoic northwestern portion of the Rgueïbat Shield, and the serpentinized ophiolitic segments of the Gorgol Noir Complex in the axial portion of the southern Mauritanides. Bureau de Recherches Géologiques et Minières (BRGM) work in the “Extreme Sud” zone also suggests that small copper occurrences associated with the extensive Jurassic microgabbroic intrusive rocks in the Taoudeni Basin of southeastern Mauritania could have potential for magmatic Cu-Ni (PGE, Co, Au) sulfide mineralization. Similarly, Jurassic mafic intrusive rocks in the northeastern Taoudeni Basin may be permissive. Known magmatic Cu-Ni deposits of these types in Mauritania are few in number and some uncertainty exists as to the nature of several of the more important ones.

Juxtaposition of Neoproterozoic units along the Baruda - Tulu Dimtu shear-belt in the East African Orogen of western Ethiopia

USGS Publications Warehouse

Braathen, A.; Grenne, Tor; Selassie, M.G.; Worku, T.

2001-01-01

Amalgamation of East and West Gondwanaland during the Neoproterozoic East African Orogen is recorded by several shear-belts or 'suture zones', some of which are associated with ultramafic and mafic complexes that have been interpreted as ophiolite fragments. The Baruda shear-belt is a major structure of this type that belongs to the N-S trending Barka - Tulu Dimtu zone. The significance of this zone has been studied within a transect in western Ethiopia which covers a variety of metasedimentary and metavolcanic sequences, ultramafic rocks and synkinematic intrusive complexes. All rocks participated in the regional D1 event as reflected in a penetrative steep foliation in supracrustal rocks and marginal parts of the intrusions. Highly strained rocks contain a stretching lineation that plunge to the east. The several-km thick Baruda shear-belt, comprising mylonitic supracrustal and plutonic rocks including mafic-ultramafic mega-lenses, is the most prominent expression of this event. Shear-sense indicators demonstrate top-to-the-west shear. Subsequent D2 deformation is recorded in 2-300 m wide, N-S striking, subvertical shear-zones with subhorizontal stretching lineation relatable to sinistral transcurrent movements. Our data indicate that rock units on either side of the Baruda shear-belt are related, rather than being exotic to each other as implied in suture zone models, since there is no major lithologic or metamorphic difference, geochemical data on metavolcanic rocks and pre-tectonic intrusions suggest a paleotectonic link, and style and extent of deformation is similar across the shear-belt. A tentative model for the transect suggests an arc and back-arc setting which experienced later continental collision and tectonic shortening. The initial setting was that of a shallow marine platform characterised by carbonates and sandstones, which covered extensive areas prior to break-up of a pre-existing supercontinent. Continental convergence is first recorded in high

Sedimentological and stratigraphic evolution of the southern part of the Barberton greenstone belt: A case of changing provenance and stability

NASA Technical Reports Server (NTRS)

Lowe, D. R.; Byerly, G. R.

1986-01-01

The sedimentological and stratigraphic evolution of the 3.5 to 3.3 Ga Barberton Greenstone Belt can be divided into three principal stages: (1) the volcanic platform stage during which at least 8 km of mafic and ultramafic volcanic rocks, minor felsic volcanic units, and thin sedimentary layers (Onverwacht Group) accumulated under generally anorogenic conditions; (2) a transitional stage of developing instability during which widespread dacitic volcanism and associated pyroclastic and volcaniclastic sedimentation was punctuated by the deposition of terrigenous debris derived by uplift and shallow erosion of the belt itself (Fig Tree Group); (3) an orogenic stage involving cessation of active volcanism, extensive thrust faulting, and widespread deposition of clastic sediments representing deep erosion of the greenstone belt sequence as well as sources outside of the belt (Moodies Group).

Platinum-group element geochemistry of zoned ultramafic intrusive suites, Klamath Mountains, California and Oregon.

USGS Publications Warehouse

Gray, F.; Page, N.J.; Carlson, C.A.; Wilson, S.A.; Carlson, R.R.

1986-01-01

Analyses for platinum-group elements of the varied rock suites of three Alaskan-type ultramafic to mafic multi-intrusive bodies are reported. Ir and Ru are less than analytical sensitivities of 100 and 20 ppb; Rh is less than or near 1 ppb. Average Pd assays vary among the rocks within intrusive complexes and between the three complexes (6.3, 13.7, 36.4 ppb); average Pt assays vary little among the same samples (27.9, 60.9, 34.0 ppb). Statistically adjusted Pt/(Pt + Pd) ratios increase in each suite from gabbro through clinopyroxenite to olivine-rich rocks, possibly owing to Pd fractionation.-G.J.N.

Previously unrecognized regional structure of the Coastal Belt of the Franciscan Complex, northern California, revealed by magnetic data

USGS Publications Warehouse

Langenheim, Victoria; Jachens, Robert C.; Wentworth, Carl M.; McLaughlin, Robert J.

2013-01-01

Magnetic anomalies provide surprising structural detail within the previously undivided Coastal Belt, the westernmost, youngest, and least-metamorphosed part of the Franciscan Complex of northern California. Although the Coastal Belt consists almost entirely of arkosic graywacke and shale of mainly Eocene age, new detailed aeromagnetic data show that it is pervasively marked by long, narrow, and regularly spaced anomalies. These anomalies arise from relatively simple tabular bodies composed principally of magnetic basalt or graywacke confi ned mainly to the top couple of kilometers, even though metamorphic grade indicates that these rocks have been more deeply buried, at depths of 5–8 km. If true, this implies surprisingly uniform uplift of these rocks. The basalt (and associated Cretaceous limestone) occurs largely in the northern part of the Coastal Belt; the graywacke is recognized only in the southern Coastal Belt and is magnetic because it contains andesitic grains. The magnetic grains were not derived from the basalt, and thus require a separate source. The anomalies defi ne simple patterns that can be related to folding and faulting within the Coastal Belt. This apparent simplicity belies complex structure mapped at outcrop scale, which can be explained if the relatively simple tabular bodies are internally deformed, fault-bounded slabs. One mechanism that can explain the widespread lateral extent of the thin layers of basalt is peeling up of the uppermost part of the oceanic crust into the accretionary prism, controlled by porosity and permeability contrasts caused by alteration in the upper part of the subducting slab. It is not clear, however, how this mechanism might generate fault-bounded layers containing magnetic graywacke. We propose that structural domains defined by anomaly trend, wavelength, and source reflect imbrication and folding during the accretion process and local plate interactions as the Mendocino triple junction migrated north, a

Previously unrecognized regional structure of the Coastal Belt of the Franciscan Complex, northern California, revealed by magnetic data

USGS Publications Warehouse

Langenheim, V.E.; Jachens, R.C.; Wentworth, C.M.; McLaughlin, R.J.

2013-01-01

Magnetic anomalies provide surprising structural detail within the previously undivided Coastal Belt, the westernmost, youngest, and least-metamorphosed part of the Franciscan Complex of northern California. Although the Coastal Belt consists almost entirely of arkosic graywacke and shale of mainly Eocene age, new detailed aeromagnetic data show that it is pervasively marked by long, narrow, and regularly spaced anomalies. These anomalies arise from relatively simple tabular bodies composed principally of magnetic basalt or graywacke confined mainly to the top couple of kilometers, even though metamorphic grade indicates that these rocks have been more deeply buried, at depths of 5–8 km. If true, this implies surprisingly uniform uplift of these rocks. The basalt (and associated Cretaceous limestone) occurs largely in the northern part of the Coastal Belt; the graywacke is recognized only in the southern Coastal Belt and is magnetic because it contains andesitic grains. The magnetic grains were not derived from the basalt, and thus require a separate source. The anomalies define simple patterns that can be related to folding and faulting within the Coastal Belt. This apparent simplicity belies complex structure mapped at outcrop scale, which can be explained if the relatively simple tabular bodies are internally deformed, fault-bounded slabs. One mechanism that can explain the widespread lateral extent of the thin layers of basalt is peeling up of the uppermost part of the oceanic crust into the accretionary prism, controlled by porosity and permeability contrasts caused by alteration in the upper part of the subducting slab. It is not clear, however, how this mechanism might generate fault-bounded layers containing magnetic graywacke. We propose that structural domains defined by anomaly trend, wavelength, and source reflect imbrication and folding during the accretion process and local plate interactions as the Mendocino triple junction migrated north, a

Metasomatism-induced magnesium isotope fractionation in ultramafic rocks: Evidence from the Franciscan Complex, California

NASA Astrophysics Data System (ADS)

Li, W. Y.; Teng, F. Z.; Xiao, Y.

2016-12-01

To investigate the behaviour of Mg isotopes during metasomatic reactions between peridotites and infiltrating fluids along the slab-mantle interface, we analyzed Mg isotopic compositions of a set of well-characterized samples from the ultramafic blocks in the Franciscan Complex of California [1]. The Group 1 and Group 2 samples that were defined by the initial serpentinization and complete serpentinization of peridotites at temperatures of 450-500 ºC, respectively [1], have δ26Mg values (from -0.26 to -0.14‰) clustered around the mantle value. This suggests that Mg isotope fractionation during serpentinization by slab-derived fluids, if any, is small. By contrast, the Group 3 samples that were defined by the replacement of serpentine by talc [1], are enriched in heavy Mg isotopes (δ26Mg of -0.13 to -0.01‰). This may reflect the loss of light Mg isotopes into fluids during the dehydration reaction that produced talc from serpentine, which is consistent with previous observations that secondary clay minerals preferentially incorporate heavy Mg isotopes during water-rock interactions [2, 3]. The Group 4 samples that were defined by the further replacement of talc by tremolite [1], however, have light Mg isotopic compositions (δ26Mg of -0.50 to -0.41‰). Such a shift towards light Mg isotopic compositions likely results from metasomatism by fluids that derived from isotopically light carbonates, which is supported by the remarkably higher CaO content of Group 4 samples (from 6.9 to 9.2 wt%) than Group 3 ones (from 1.1 to 1.4 wt%). Collectively, significant Mg isotopic variations occur during metasomatism of peridotites in the mantle wedge, which would potentially lead to heterogeneous Mg isotopic compositions in arc lavas [4]. Therefore, Mg isotopes can be used as a powerful tracer of crust-mantle interaction at subduction zones. [1] King et al. (2003) Geol. Soc. Am. Bull. 115, 1097-1109. [2] Teng et al. (2010) Earth Planet. Sci. Lett. 300, 63-71. [3] Wimpenny

Ponderosa pine progenies: differential response to ultramafic and granitic soils

Treesearch

James L. Jenkinson

1974-01-01

Progenies of nine ponderosa pines native to one granitic and several ultramafic soils in the northern Sierra Nevada were grown on both soil types in a greenhouse. The progenies differed markedly in first-year growth on infertile ultramafic soils, but not on a fertile granitic soil. Growth differences between progenies were primarily related to differences in calcium...

Evaluation of California's safety belt law change to primary enforcement

DOT National Transportation Integrated Search

1994-12-01

Some states allow an officer to stop a vehicle for an observed belt law violation alone (primary). Most require that the initial stop be made for some other violation before a belt law citation can be issued (secondary). On January 1, 1993, Californi...

Geophysical delineation of Mg-rich ultramafic rocks for mineral carbon sequestration

USGS Publications Warehouse

McCafferty, Anne E.; Van Gosen, Bradley S.; Krevor, Sam C.; Graves, Chris R.

2009-01-01

This presentation covers three general topics: (1) description of a new geologic compilation of the United States that shows the location of magnesium-rich ultramafic rocks in the conterminous United States; (2) conceptual illustration of the potential ways that ultramafic rocks could be used to sequester carbon dioxide; and (3) description of ways to use geophysical data to refine and extend the geologic mapping of ultramafic rocks and to better characterize their mineralogy.The geophysical focus of this research is twofold. First, we illustrate how airborne magnetic data can be used to map the shallow subsurface geometry of ultramafic rocks for the purpose of estimating the volume of rock material available for mineral CO2 sequestration. Secondly, we explore, on a regional to outcrop scale, how magnetic mineralogy, as expressed in magnetic anomalies, may vary with magnesium minerals, which are the primary minerals of interest for CO2 sequestration. 

SOM guided fuzzy logic prospectivity model for gold in the Häme Belt, southwestern Finland

NASA Astrophysics Data System (ADS)

Leväniemi, Hanna; Hulkki, Helena; Tiainen, Markku

2017-04-01

This study investigated gold prospectivity in the Paleoproterozoic Häme Belt, located in southwestern Finland. The Häme Belt comprises calc-alkaline and tholeitic volcanic rocks, migmatites, granitoids, and mafic to ultramafic intrusions. Mineral exploration in the region has resulted in the discovery of several gold occurrences during recent decades; however, no prospectivity modeling for gold has yet been conducted. This study integrated till geochemical and geophysical data to examine and extract data characteristics critical for gold occurrences. Modeling was guided by self-organizing map (SOM) analysis to define essential data associations and to aid in model input data selection and generation. The final fuzzy logic prospectivity model map yielded high predictability values for most known Au or Cu-Au occurrences, but also highlighted new targets for exploration.

Microscale mapping of alteration conditions and potential biosignatures in basaltic-ultramafic rocks on early Earth and beyond.

PubMed

Grosch, Eugene G; McLoughlin, Nicola; Lanari, Pierre; Erambert, Muriel; Vidal, Olivier

2014-03-01

Subseafloor environments preserved in Archean greenstone belts provide an analogue for investigating potential subsurface habitats on Mars. The c. 3.5-3.4 Ga pillow lava metabasalts of the mid-Archean Barberton greenstone belt, South Africa, have been argued to contain the earliest evidence for microbial subseafloor life. This includes candidate trace fossils in the form of titanite microtextures, and sulfur isotopic signatures of pyrite preserved in metabasaltic glass of the c. 3.472 Ga Hooggenoeg Formation. It has been contended that similar microtextures in altered martian basalts may represent potential extraterrestrial biosignatures of microbe-fluid-rock interaction. But despite numerous studies describing these putative early traces of life, a detailed metamorphic characterization of the microtextures and their host alteration conditions in the ancient pillow lava metabasites is lacking. Here, we present a new nondestructive technique with which to study the in situ metamorphic alteration conditions associated with potential biosignatures in mafic-ultramafic rocks of the Hooggenoeg Formation. Our approach combines quantitative microscale compositional mapping by electron microprobe with inverse thermodynamic modeling to derive low-temperature chlorite crystallization conditions. We found that the titanite microtextures formed under subgreenschist to greenschist facies conditions. Two chlorite temperature groups were identified in the maps surrounding the titanite microtextures and record peak metamorphic conditions at 315 ± 40°C (XFe3+(chlorite) = 25-34%) and lower-temperature chlorite veins/microdomains at T = 210 ± 40°C (lower XFe3+(chlorite) = 40-45%). These results provide the first metamorphic constraints in textural context on the Barberton titanite microtextures and thereby improve our understanding of the local preservation conditions of these potential biosignatures. We suggest that this approach may prove to be an important tool in future

Formation of an Archean tectonic mélange in the Schreiber-Hemlo greenstone belt, Superior Province, Canada: Implications for Archean subduction-accretion process

NASA Astrophysics Data System (ADS)

Polat, Ali; Kerrich, Robert

1999-10-01

The late Archean (circa 2750-2670 Ma) Schreiber-Hemlo greenstone belt, Superior Province, Canada, is composed of tectonically juxtaposed fragments of oceanic plateaus (circa 2750-2700 Ma), oceanic island arcs (circa 2720-2695 Ma), and siliciclastic trench turbidites (circa 2705-2697 Ma). Following juxtaposition, these lithotectonic assemblages were collectively intruded by synkinematic tonalite-trondhjemite-granodiorite (TTG) plutons (circa 2720-2690 Ma) and ultramafic to felsic dikes and sills (circa 2690-2680 Ma), with subduction zone geochemical signatures. Overprinting relations between different sequences of structures suggest that the belt underwent at least three phases of deformation. During D1 (circa 2695-2685 Ma), oceanic plateau basalts and associated komatiites, arc-derived trench turbidites, and oceanic island arc sequences were all tectonically juxtaposed as they were incorporated into an accretionary complex. Fragmentation of these sequences resulted in broken formations and a tectonic mélange in the Schreiber assemblage of the belt. D2 (circa 2685-2680 Ma) is consistent with an intra-arc, right-lateral transpressional deformation. Fragmentation and mixing of D2 synkinematic dikes and sills suggest that mélange formation continued during D2. The D1 to D2 transition is interpreted in terms of a trenchward migration of the magmatic arc axis due to continued accretion and underplating. The D2 intra-arc strike-slip faults may have provided conduits for uprising melts from the descending slab, and they may have induced decompressional partial melting in the subarc mantle wedge, to yield synkinematic ultramafic to felsic intrusions. A similar close relationship between orogen-parallel strike-slip faulting and magmatism has recently been recognized in several Phanerozoic transpressional orogenic belts, suggesting that as in Phanerozoic counterparts, orogen-parallel strike-slip faulting in the Schreiber-Hemlo greenstone belt played an important role in

Experimental Constraints on the Origin of Lunar High-Ti Ultramafic Glasses

NASA Technical Reports Server (NTRS)

Wagner, T. P.; Grove, T. L.

1996-01-01

Phase equilibria and dissolution rate experiments are used to develop a petrogenetic model for the high-Ti lunar ultramafic glasses. Near-liquidus phase relations of the Apollo 14 black glass, the most Ti-rich lunar ultramafic glass, are determined to 2.2-GPa. The liquidus is saturated with Cr-spinel at 1-atm, olivine between approximately 0.5- and 1.5-GPa, and low-Ca pyroxene + Cr-spinel above 1.5-GPa. Ilmenite does not crystallize near the liquidus and implies that high-Ti ultramafic glasses are not produced by melting of an ilmenite-saturated source. We infer that high-Ti ultramafic magmas are derived from low-Ti ultramafic parent magmas by assimilation of ilmenite +/- clinopyroxene +/- urKREEP +/- pigeonite in the shallow lunar interior. Heat is provided by adiabatic ascent of the low-Ti ultramafic primary magmas from the deeper lunar interior and crystallization of olivine during assimilation. The assimilation reaction is modeled by mass balance and requires that ilmenite and high-Ca pyroxene are assimilated in a approximately 3:1 ratio, a much higher ratio than the proportion in which these minerals are thought to exist in the lunar interior. In an effort to understand the kinetic controls on this reaction, the dissolution of ilmenite is examined experimentally in both low- and high-Ti lunar magmas. We find that ilmenite dissolves incongruently to Cr-spinel and a high-Ti melt. The dissolution reaction proceeds by a diffusion-controlled mechanism. An assimilation model for the origin of high-Ti melts is developed that leaves the magma ocean cumulates in their initial stratigraphic positions and obviates source hybridization models that require lunar overturn.

Potential Hydrogen Yields from Ultramafic Rocks of the Coast Range Ophiolite and Zambales Ophiolite: Inferences from Mössbauer Spectroscopy

NASA Astrophysics Data System (ADS)

Stander, A.; Nelms, M.; Wilkinson, K.; Dyar, M. D.; Cardace, D.

2013-12-01

The reduced status of mantle rocks is a possible controller and indicator of deep life habitat, due to interactions between water and ultramafic (Fe, Mg-rich) minerals, which, under reducing conditions, can yield copious free hydrogen, which is an energy source for rock-hosted chemosynthetic life. In this work, Mössbauer spectroscopy was used to parameterize the redox status of Fe in altering peridotites of the Coast Range Ophiolite (CRO) in California, USA and Zambales Ophiolite (ZO) in the Philippines. Fe-bearing minerals were identified and data were collected for the percentages of Fe(III)and Fe(II)and bulk Fe concentration. Thin section analysis shows that relict primary olivines and spinels generally constitute a small percentage of the ZO and CRO rock, and given satisfactory estimates of the volume of the ultramafic units of the ZO and CRO, a stoichiometric H2 production can be estimated. In addition, ZO serpentinites are ~63,000 ppm Fe in bulk samples; they contain ~41-58% Fe(III)and ~23-34% Fe(II) in serpentine and relict minerals along with ~8-30% of the total Fe as magnetite. CRO serpentinites are ~42,000 ppm Fe in bulk samples; they contain ~15-50% Fe(III), ~22-88% Fe(II) in serpentine and relict minerals, and ~0-52% of total Fe is in magnetite (Fe(II)Fe(III)2O4). Assuming stoichiometric production of H2, and given the following representation of serpentinization 2(FeO)rock + H2O → (Fe2O3)rock +H2, we calculated the maximum quantity of hydrogen released and yet to be released through the oxidation of Fe(II). Given that relatively high Fe(III)/Fetotal values can imply higher water:rock ratios during rock alteration (Andreani et al., 2013), we can deduce that ZO ultramafics in this study have experienced a net higher water:rock ratio than CRO ultramafics. We compare possible H2 yields and contrast the tectonic and alteration histories of the selected ultramafic units. (M. Andreani, M. Muñoz, C. Marcaillou, A. Delacour, 2013, μXANES study of iron

Airborne gamma-ray and magnetic anomaly signatures of serpentinite in relation to soil geochemistry, northern California

USGS Publications Warehouse

McCafferty, A.E.; Van Gosen, B. S.

2009-01-01

Serpentinized ultramafic rocks and associated soils in northern California are characterized by high concentrations of Cr and Ni, low levels of radioelements (K, Th, and U) and high amounts of ferrimagnetic minerals (primarily magnetite). Geophysical attributes over ultramafic rocks, which include airborne gamma-ray and magnetic anomaly data, are quantified and provide indirect measurements on the relative abundance of radioelements and magnetic minerals, respectively. Attributes are defined through a statistical modeling approach and the results are portrayed as probabilities in chart and map form. Two predictive models are presented, including one derived from the aeromagnetic anomaly data and one from a combination of the airborne K, Th and U gamma-ray data. Both models distinguish preferential values within the aerogeophysical data that coincide with mapped and potentially unmapped ultramafic rocks. The magnetic predictive model shows positive probabilities associated with magnetic anomaly highs and, to a lesser degree, anomaly lows, which accurately locate many known ultramafic outcrops, but more interestingly, locate potentially unmapped ultramafic rocks, possible extensions of ultramafic bodies that dip into the shallow subsurface, as well as prospective buried ultramafic rocks. The airborne radiometric model shows positive probabilities in association with anomalously low gamma radiation measurements over ultramafic rock, which is similar to that produced by gabbro, metavolcanic rock, and water bodies. All of these features share the characteristic of being depleted in K, Th and U. Gabbro is the only rock type in the study area that shares similar magnetic properties with the ultramafic rock. The aerogeophysical model results are compared to the distribution of ultramafic outcrops and to Cr, Ni, K, Th and U concentrations and magnetic susceptibility measurements from soil samples. Analysis of the soil data indicates high positive correlation between

Komatiite genesis in the Archaean mantle, with implications for the tectonics of Archaean greenstone belts

NASA Technical Reports Server (NTRS)

Elthon, D.

1986-01-01

The presence of ultramafic lavas (komatiites) associated with Archean greenstone belts has been suggested to indicate very high increments (50-80%) of partial melting of the Archean mantle. Such extensive melting of the Earth's mantle during the Archean might have profound effects on the early tectonic and chemical evolution of the planet, although problems associated with keeping the komatiite liquid in equilibrium with the residual mantle at such high increments of melting has cast doubt upon aspects of extensive melting. Two important aspects of the origin of komatiites are discussed below.

Extensional tectonics during the igneous emplacement of the mafic-ultramafic rocks of the Barberton greenstone belt

NASA Technical Reports Server (NTRS)

Dewit, M. J.

1986-01-01

The simatic rocks (Onverwacht Group) of the Barberton greenstone belt are part of the Jamestown ophiolite complex. This ophiolite, together with its thick sedimentary cover occupies a complex thrust belt. Field studies have identified two types of early faults which are entirely confined to the simatic rocks and are deformed by the later thrusts and associated folds. The first type of fault (F1a) is regional and always occurs in the simatic rocks along and parallel to the lower contacts of the ophiolite-related cherts (Middle Marker and equivalent layers). These fault zones have previously been referred to both as flaser-banded gneisses and as weathering horizons. In general the zones range between 1-30m in thickness. Displacements along these zones are difficult to estimate, but may be in the order of 1-100 km. The structures indicate that the faults formed close to horizontal, during extensional shear and were therefore low angle normal faults. F1a zones overlap in age with the formation of the ophiolite complex. The second type of faults (F1b) are vertical brittle-ductile shear zones, which crosscut the complex at variable angles and cannot always be traced from plutonic to overlying extrusive (pillowed) simatic rocks. F1b zones are also apparently of penecontemporaneous origin with the intrusive-extrusive igneous processs. F1b zones may either represent transform fault-type activity or represent root zones (steepened extensions) of F1a zones. Both fault types indicate extensive deformation in the rocks of the greenstone belt prior to compressional overthrust tectonics.

Earthquakes in the Mantle? Insights from Ultramafic Pseudotachylytes

NASA Astrophysics Data System (ADS)

Meado, A.; Ferre, E. C.; Ueda, T.; Ashwal, L. D.; Deseta, N.

2015-12-01

Deep earthquakes in subduction/collision zones may originate from mechanical failure of ultramafic rocks at mantle depths. Fault pseudotachylytes in peridotites have been attributed to seismic slip at depths >30 km. However, the possibility of frictional melting at shallower depths still exist. While pristine mantle rocks typically lack magnetite, postseismic serpentinization would likely involve formation of abundant multi-domain (MD) magnetite. Single-domain (SD) to pseudo-single domain (PSD) magnetite may also form in pseudotachylytes through breakdown of mafic silicates. Magnetite has a large magnetic susceptibility (Km). MD magnetite shows low magnetic remanence / magnetic saturation ratios (Mr/Ms) compared to SD-PSD magnetite. The formation of coseismic magnetite however would depend on fO2. Hence, in unserpentinized ultramafic pseudotachylytes, magnetite would form preferentially under shallow, high fO2 conditions. Coseismically deformed magnetite would result in a high anisotropy of magnetic susceptibility (AMS). Here, we present a predictive model of the magnetic properties and magnetic fabrics of ultramafic pseudotachylytes formed under four conditions: i) deep seismic slip and no syn- or postseismic serpentinization: low Km (<600 . 10^-6 [SI]), low Mr/Ms (<0.1), and low AMS (<1.1) ii) deep seismic slip followed by static serpentinization: high Km (>3,000 . 10^-6 [SI]), low Mr/Ms (<0.1), low AMS (<1.1) iii) deep or shallow seismic slip in previously serpentinized peridotites: high Km (>3,000 . 10^-6 [SI]), moderate Mr/Ms (0.1-0.5), high AMS (>1.5) iv) shallow seismic slip with no serpentinization: moderate Km (600-3,000 . 10^-6 [SI]), high Mr/Ms (>0.5), moderate AMS (1.1-1.5) We test these models using samples from the Balmuccia Massif (Italy) and the Schistes Lustrés (Corsica). These models may provide new constrains for ultramafic pseudotachylytes regarding their depth of formation and the timing of serpentinization.

Tectonic analysis of Baja California and Parras shear belt in Mexico

NASA Technical Reports Server (NTRS)

Abdel-Gawad, M. (Principal Investigator); Tubbesing, L.

1974-01-01

The author has identified the following significant results. Geological correlation of terrain across the Gulf of California using ERTS-1 imagery revealed significant similarities between Isla Tiburon, Isla Angel de la Guarda, and the San Carlos Range in mainland Mexico. ERTS-1 imagery was used to check the validity of the existence of major trans-Baja fault zones. ERTS-1 imagery also shows that high albedo sediments similar to known late Tertiary marine sediments are widespread in southern and middle Baja and extend in places to the eastern side of the Peninsula. Major faults in northern Mexico and across the border in the United States were mapped, and ample evidence was found that the Parras and parts of the Texas lineament are belts of major transverse shear faults in areas outside the supposed limit of the Texas and Parras lineaments. A fundamental concept which may help explain many complexities in the tectonic development is beginning to emerge: The southwestern part of North America was torn by massive left-lateral shear of transverse trend (east-west) during the compressive stage of the late Mesozoic and early Cenozoic. This tectonic style has changed into tensional rifting (Basin and Range) and right-lateral shear later in the Cenozoic and Quaternary.

Weathering and vegetation controls on nickel isotope fractionation in surface ultramafic environments (Albania)

NASA Astrophysics Data System (ADS)

Estrade, Nicolas; Cloquet, Christophe; Echevarria, Guillaume; Sterckeman, Thibault; Deng, Tenghaobo; Tang, YeTao; Morel, Jean-Louis

2015-08-01

The dissolved nickel (Ni) isotopic composition of rivers and oceans presents an apparent paradox. Even though rivers represent a major source of Ni in the oceans, seawater is more enriched in the heavier isotopes than river-water. Additional sources or processes must therefore be invoked to account for the isotopic budget of dissolved Ni in seawater. Weathering of continental rocks is thought to play a major role in determining the magnitude and sign of isotopic fractionation of metals between a rock and the dissolved product. We present a study of Ni isotopes in the rock-soil-plant systems of several ultramafic environments. The results reveal key insights into the magnitude and the control of isotopic fractionation during the weathering of continental ultramafic rocks. This study introduces new constraints on the influence of vegetation during the weathering process, which should be taken into account in interpretations of the variability of Ni isotopes in rivers. The study area is located in a temperate climate zone within the ophiolitic belt area of Albania. The serpentinized peridotites sampled present a narrow range of heavy Ni isotopic compositions (δ60Ni = 0.25 ± 0.16 ‰, 2SD n = 2). At two locations, horizons within two soil profiles affected by different degrees of weathering all presented light isotopic compositions compared to the parent rock (Δ60Nisoil-rock up to - 0.63 ‰). This suggests that the soil pool takes up the light isotopes, while the heavier isotopes remain in the dissolved phase. By combining elemental and mineralogical analyses with the isotope compositions determined for the soils, the extent of fractionation was found to be controlled by the secondary minerals formed in the soil. The types of vegetation growing on ultramafic-derived soils are highly adapted and include both Ni-hyperaccumulating species, which can accumulate several percent per weight of Ni, and non-accumulating species. Whole-plant isotopic compositions were found

The Togo-Benin-Nigeria Shield: evidence of crustal aggregation in the Pan-African belt

NASA Astrophysics Data System (ADS)

Ajibade, A. C.; Wright, J. B.

1989-08-01

The importance of "suspect" or "exotic" (i.e. allochthonous) terranes as a major element in collisional orogenic belts is becoming well established. We propose that the southern Pan-African domain in West Africa is an aggregation or " mosaic" of island arcs, interarc (ensimatic) basins and continental fragments. A fracture zone in northwestern Nigeria, already identified as a possible crustal suture, is shown to separate two contrasted basement terranes. Elsewhere in the shield are flat-lying structures characteristic of those associated with crustal convergence, lying within or near to major fractures. Many small ultramafic/mafic bodies occur in the shield and some of them may be remnants of ophiolites caught up in suture zones. An aggregation of allochthonous terranes (island arcs, sedimentary basins and continental blocks) would help to explain: (a) the great width of the Pan-African belt; (b) the spread of ages within the "Pan-African" range (c. 750-450 Ma), also the relict Liberian and Eburnian ages (c. 2700 and 2000 Ma respectively); and the enigmatic Kibaran "event" (c. 1100 Ma); (c) the contrasted volcano-sedimentary characteristics of the different supracrustal belts.

Accretionary history of the Archean Barberton Greenstone Belt (3.55-3.22 Ga), southern Africa

NASA Technical Reports Server (NTRS)

Lowe, D. R.

1994-01-01

The 3.55-3.22 Ga Barberton Greenstone Belt, South Africa and Swaziland, and surrounding coeval plutons can be divided into four tectono-stratigraphic blocks that become younger toward the northwest. Each block formed through early mafic to ultramafic volcanism (Onverwacht Group), probably in oceanic extensional, island, or plateau settings. Volcanism was followed by magmatic quiescence and deposition of fine-grained sediments, possibly in an intraplate setting. Late evolution involved underplating of the mafic crust by tonalitic intrusions along a subduction-related magmatic arc, yielding a thickened, buoyant protocontinental block. The growth of larger continental domains occurred both through magmatic accretion, as new protocontinental blocks developed along the margins of older blocks, and when previously separate blocks were amalgamated through tectonic accretion. Evolution of the Barberton Belt may reflect an Early Archean plate tectonic cycle that characterized a world with few or no large, stabilized blocks of sialic crust.

The Wenquan ultramafic rocks in the Central East Kunlun Fault zone, Qinghai-Tibet Plateau—crustal relics of the Paleo-Tethys ocean

NASA Astrophysics Data System (ADS)

Jia, Lihui; Meng, Fancong; Feng, Huibin

2018-06-01

The Wenquan ultramafic rocks, located in the East Kunlun Orogenic belt in the northeastern part of the Qinghai-Tibet Plateau, consist of dunite, wehrlite, olivine-clinopyroxenite and clinopyroxenite, and exhibit cumulate textures. Olivine from dunite has high Fo (forsterite, 90.0-91.8 wt%) and NiO content (0.15-0.42 wt%). Cr-spinels from all of the rocks in this suite are characterized by high Cr# (100×[Cr/(Cr + Al)], 67-91), low Mg# (100×[Mg/(Mg + Fe2+)], 17-35) and low TiO2 contents (mostly < 0.5 wt%). Clinopyroxene displays high Mg# (92-98) and low TiO2 content (0.002-0.099 wt%), similar to those in ophiolitic cumulates. Geochemically, the Wenquan ultramafic rocks show enrichment of LILE, Sr, and Ba, and depletion of Nb and Th. High-Mg# (mostly > 80) and low-CaO (< 0.08 wt%) olivine, high-Cr# (up to 91) spinel, and low Ti contents of clinopyroxene and Cr-spinel indicate that the Wenquan cumulates were generated by high-degree partial melting of a depleted oceanic lithosphere mantle. The ultramafic intrusion most likely evolved from high-Mg basaltic magmas (Mg# = 77.5) that underwent fractional crystallization and crustal contamination. Zircon grains from clinopyroxenites yield a U-Pb weighted mean age of 331 ± 2 Ma, which is nearly coeval with the formation age of the A'nyemaqen ophiolites. The Wenquan Carboniferous ophiolites are confirmed to exist in the Central East Kunlun Fault zone, whereas previous studies have considered them to be the Proterozoic ophiolites. The Wenquan ophiolite might be a relict of the Paleotethyan ocean, indicating that there were two cycles of oceanic-continental evolution along the Central East Kunlun Fault zone.

Clumped-isotope thermometry of magnesium carbonates in ultramafic rocks

DOE PAGES

Garcia del Real, Pablo; Maher, Kate; Kluge, Tobias; ...

2016-08-19

Here, magnesium carbonate minerals produced by reaction of H 2O–CO 2 with ultramafic rocks occur in a wide range of paragenetic and tectonic settings and can thus provide insights into a variety of geologic processes, including deposition of ore-grade, massive-vein cryptocrystalline magnesite; formation of hydrous magnesium carbonates in weathering environments; and metamorphic carbonate alteration of ultramafic rocks. However, the application of traditional geochemical and isotopic methods to infer temperatures of mineralization, the nature of mineralizing fluids, and the mechanisms controlling the transformation of dissolved CO 2 into magnesium carbonates in these settings is difficult because the fluids are usually notmore » preserved.« less

Clumped-isotope thermometry of magnesium carbonates in ultramafic rocks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Garcia del Real, Pablo; Maher, Kate; Kluge, Tobias

Here, magnesium carbonate minerals produced by reaction of H 2O–CO 2 with ultramafic rocks occur in a wide range of paragenetic and tectonic settings and can thus provide insights into a variety of geologic processes, including deposition of ore-grade, massive-vein cryptocrystalline magnesite; formation of hydrous magnesium carbonates in weathering environments; and metamorphic carbonate alteration of ultramafic rocks. However, the application of traditional geochemical and isotopic methods to infer temperatures of mineralization, the nature of mineralizing fluids, and the mechanisms controlling the transformation of dissolved CO 2 into magnesium carbonates in these settings is difficult because the fluids are usually notmore » preserved.« less

Compositional variations in the Mesoarchean chromites of the Nuggihalli schist belt, Western Dharwar Craton (India): potential parental melts and implications for tectonic setting

NASA Astrophysics Data System (ADS)

Mukherjee, Ria; Mondal, Sisir K.; Rosing, Minik T.; Frei, Robert

2010-12-01

The chromite deposits in the Archean Nuggihalli schist belt are part of a layered ultramafic-mafic sequence within the Western Dharwar Craton of the Indian shield. The 3.1-Ga ultramafic-mafic units occur as sill-like intrusions within the volcano-sedimentary sequences of the Nuggihalli greenstone belt that are surrounded by the tonalite-trondhjemite-granodiorite (TTG) suite of rocks. The entire succession is exposed in the Tagdur mining district. The succession has been divided into the lower and the upper ultramafic units, separated by a middle gabbro unit. The ultramafic units comprise of deformed massive chromitite bodies that are hosted within chromite-bearing serpentinites. The chromitite bodies occur in the form of pods and elongated lenses (~60-500 m by ~15 m). Detailed electron microprobe studies reveal intense compositional variability of the chromite grains in silicate-rich chromitite (~50% modal chromite) and serpentinite (~2% modal chromite) throughout the entire ultramafic sequence. However, the primary composition of chromite is preserved in the massive chromitites (~60-75% modal chromite) from the Byrapur and the Bhaktarhalli mining district of the Nuggihalli schist belt. These are characterized by high Cr-ratios (Cr/(Cr + Al) = 0.78-0.86) and moderate Mg-ratios (Mg/(Mg + Fe2+) = 0.38-0.58). The compositional variability occurs due to sub-solidus re-equilibration in the accessory chromite in the serpentinite (Mg-ratio = 0.01-0.38; Cr-ratio = 0.02-0.99) and in silicate-rich chromitite (Mg-ratio = 0.06-0.48; Cr-ratio = 0.60-0.99). In the massive chromitites, the sub-solidus re-equilibration for chromite is less or absent. However, the re-equilibration is prominent in the co-existing interstitial and included olivine (Fo96-98) and pyroxene grains (Mg-numbers = 97-99). Compositional variability on the scale of a single chromite grain occurs in the form of zoning, and it is common in the accessory chromite grains in serpentinite and in the altered grains

Linking magnetic fabric and cumulate texture in layered mafic-ultramafic intrusions (Invited)

NASA Astrophysics Data System (ADS)

O Driscoll, B.; Stevenson, C.; Magee, C.

2013-12-01

Research on the magnetic fabrics of igneous rocks, pioneered by Balsley and Buddington[1] and Khan[2], has greatly contributed to our understanding of magma dynamics in lava flows, sheet intrusions and plutons over the past five decades. However, considerably few magnetic fabric studies have focused on layered mafic-ultramafic intrusions, particularly ';lopolithic' intrusions, despite the fact that such rocks may preserve a large range of small-scale kinematic structures potentially related to important magma chamber processes. This may be partly due to the fact that mafic-ultramafic cumulates commonly exhibit visible planar fabrics (mineral lamination), as well as compositional layering, in contrast to the frequent absence of such features in granite bodies or fine-grained mafic lava flows. Indeed, debates in the 1970s and 1980s on the development of layering and mineral fabrics in mafic-ultramafic intrusions, focused around the crystal settling versus in situ crystallisation paradigms, are classic in the subject of igneous petrology. Central to these debates is the notion that a wide range of magma chamber processes occur in layered mafic-ultramafic intrusions that are not frequently considered to occur in their relatively viscous granitic counterparts; in essence, the latter have historically been viewed as much more likely to ';freeze-in' a primary magma flow fabric whilst mafic-ultramafic intrusions are subjected to a more protracted solidification history. This wide array of potential initial sources for layering and mineral fabrics in layered mafic-ultramafic intrusions, together with the possible modification of textures at the postcumulus stage, demands a cautious application of any fabric analysis and presents a problem well-suited to interrogation by the AMS technique. The purpose of this contribution is to provide specific context on the application of AMS to elucidating the formation of cumulates in layered mafic-ultramafic intrusions. Examples of AMS

Ultramafic Terranes and Associated Springs as Analogs for Mars and Early Earth

NASA Technical Reports Server (NTRS)

Blake, David; Schulte, Mitch; Cullings, Ken; DeVincezi, D. (Technical Monitor)

2002-01-01

Putative extinct or extant Martian organisms, like their terrestrial counterparts, must adopt metabolic strategies based on the environments in which they live. In order for organisms to derive metabolic energy from the natural environment (Martian or terrestrial), a state of thermodynamic disequilibrium must exist. The most widespread environment of chemical disequilibrium on present-day Earth results from the interaction of mafic rocks of the ocean crust with liquid water. Such environments were even more pervasive and important on the Archean Earth due to increased geothermal heat flow and the absence of widespread continental crust formation. The composition of the lower crust and upper mantle of the Earth is essentially the-same as that of Mars, and the early histories of these two planets are similar. It follows that a knowledge of the mineralogy, water-rock chemistry and microbial ecology of Earth's oceanic crust could be of great value in devising a search strategy for evidence of past or present life on Mars. In some tectonic regimes, cross-sections of lower oceanic crust and upper mantle are exposed on land as so-called "ophiolite suites." Such is the case in the state of California (USA) as a result of its location adjacent to active plate margins. These mafic and ultramafic rocks contain numerous springs that offer an easily accessible field laboratory for studying water/rock interactions and the microbial communities that are supported by the resulting geochemical energy. A preliminary screen of Archaean biodiversity was conducted in a cold spring located in a presently serpentinizing ultramafic terrane. PCR and phylogenetic analysis of partial 16s rRNA, sequences were performed on water and sediment samples. Archaea of recent phylogenetic origin were detected with sequences nearly identical to those of organisms living in ultra-high pH lakes of Africa.

Extensional faulting in the southern Klamath Mountains, California

USGS Publications Warehouse

Schweickert, R.A.; Irwin, W.P.

1989-01-01

Large northeast striking normal faults in the southern Klamath Mountains may indicate that substantial crustal extension occurred during Tertiary time. Some of these faults form grabens in the Jurassic and older bedrock of the province. The grabens contain continental Oligocene or Miocene deposits (Weaverville Formation), and in two of them the Oligocene or Miocene is underlain by Lower Cretaceous marine formations (Great Valley sequence). At the La Grange gold placer mine the Oligocene or Miocene strata dip northwest into the gently southeast dipping mylonitic footwall surface of the La Grange fault. The large normal displacement required by the relations at the La Grange mine is also suggested by omission of several kilometers of structural thickness of bedrock units across the northeast continuation of the La Grange fault, as well as by significant changes in bedrock across some northeast striking faults elsewhere in the Central Metamorphic and Eastern Klamath belts. The Trinity ultramafic sheet crops out in the Eastern Klamath terrane as part of a broad northeast trending arch that may be structurally analogous to the domed lower plate of metamorphic core complexes found in eastern parts of the Cordillera. The northeast continuation of the La Grange fault bounds the southeastern side of the Trinity arch in the Eastern Klamath terrane and locally cuts out substantial lower parts of adjacent Paleozoic strata of the Redding section. Faults bounding the northwestem side of the Trinity arch generally trend northeast and juxtapose stacked thrust sheets of lower Paleozoic strata of the Yreka terrane against the Trinity ultramafic sheet. Geometric relations suggest that the Tertiary extension of the southern Klamath Mountains was in NW-SE directions and that the Redding section and the southern part of the Central Metamorphic terrane may be a large Tertiary allochthon detached from the Trinity ultramafic sheet. Paleomagnetic data indicate a lack of rotation about a

Field geology, geochronology and geochemistry of mafic-ultramafic rocks from Alxa, China: Implications for Late Permian accretionary tectonics in the southern Altaids

NASA Astrophysics Data System (ADS)

Jianyun, Feng; Wenjiao, Xiao

2013-04-01

The termination of orogenesis for the southern Altaids has been controversial. Systematical investigations of field geology, geochronology and geochemistry on mafic-ultramafic rocks from the northern Alxa of the southern Altaids were conducted to address the termination controversy. The newly discriminated mafic-ultramafic rocks belt is located at Bijiertai, Honggueryulin, and Qinggele areas, stretching from west to east for about 100 km in length. All of the three rock associations contact tectonically with the adjacent metamorphic and deformed Precambrian rocks as tectonic blocks or lenses, and are composed of peridotite, pyroxenite, gabbro, and serpentinite, most of which have subjected to pronounced alteration, i.e., serpentinization and chloritization. Geochemically, the rocks are characterized by a uniform trend of compositional distribution, e.g., with low SiO2-contents (42.51-52.21 wt.%) and alkalinity (Na2O+K2O) (0.01-5.45 wt.%, mostly less than 0.8 wt.%), and enriched in MgO (7.37-43.36 wt.%), with Mg# = 52.75-91.87. As the rocks have had strong alteration and have a wide range of loss-on-ignition (LOI: 0.44-14.07 wt.%), the rocks may be subjected to considerable alteration by either sea-water or metamorphic fluid. The REE and trace element patterns for the rocks show a relatively fractionated trend with LILE enrichment and HFSE depletion, similar to that of T-MORB between N-MORB and E-MORB, indicating that the parental melt resulted from the partial melting of oceanic lithospheric mantle overprinted by fluid alteration of island-arc subsequently. The ultramafic rocks are relics derived from the magma after large degree of partial melting of the oceanic lithospheric mantle with overprinted by island-arc processes under the influence of mid-ocean-ridge magmatism. LA - ICP MS U - Pb zircon ages of gabbros from the three spots are 274 ± 3 Ma (MSWD = 0.35), 306 ± 3 Ma (MSWD = 0.49), 262 ± 5 Ma (MSWD = 1.2), respectively, representing the formation ages of

Torngat ultramafic lamprophyres and their relation to the North Atlantic Alkaline Province

NASA Astrophysics Data System (ADS)

Tappe, Sebastian; Jenner, George A.; Foley, Stephen F.; Heaman, Larry; Besserer, Dean; Kjarsgaard, Bruce A.; Ryan, Bruce

2004-09-01

Geological mapping and diamond exploration in northern Quebec and Labrador has revealed an undeformed ultramafic dyke swarm in the northern Torngat Mountains. The dyke rocks are dominated by an olivine-phlogopite mineralogy and contain varying amounts of primary carbonate. Their mineralogy, mineral compositional trends and the presence of typomorphic minerals (e.g. kimzeyitic garnet), indicate that these dykes comprise an ultramafic lamprophyre suite grading into carbonatite. Recognized rock varieties are aillikite, mela-aillikite and subordinate carbonatite. Carbonatite and aillikite have in common high carbonate content and a lack of clinopyroxene. In contrast, mela-aillikites are richer in mafic silicate minerals, in particular clinopyroxene and amphibole, and contain only small amounts of primary carbonate. The modal mineralogy and textures of the dyke varieties are gradational, indicating that they represent end-members in a compositional continuum. The Torngat ultramafic lamprophyres are characterized by high but variable MgO (10-25 wt.%), CaO (5-20 wt.%), TiO2 (3-10 wt.%) and K2O (1-4 wt.%), but low SiO2 (22-37 wt.%) and Al2O3 (2-6 wt.%). Higher SiO2, Al2O3, Na2O and lower CO2 content distinguish the mela-aillikites from the aillikites. Whereas the bulk rock major and trace element concentrations of the aillikites and mela-aillikites overlap, there is no fractional crystallization relation between them. The major and trace element characteristics imply related parental magmas, with minor olivine and Cr-spinel fractionation accounting for intra-group variation. The Torngat ultramafic lamprophyres have a Neoproterozoic age and are spatially and compositionally closely related with the Neoproterozoic ultramafic lamprophyres from central West Greenland. Ultramafic potassic-to-carbonatitic magmatism occurred in both eastern Laurentia and western Baltica during the Late Neoproterozoic. It can be inferred from the emplacement ages of the alkaline complexes and

Petrogenesis of Late Triassic ultramafic rocks from the Andong Ultramafic Complex, South Korea

NASA Astrophysics Data System (ADS)

Kim, Nak Kyu; Choi, Sung Hi

2016-11-01

To constrain the source and tectonomagmatic processes that gave rise to the Andong Ultramafic Complex (AUC) in South Korea, we determined the clinopyroxene Sr-Nd-Hf-Pb isotope and trace element compositions as well as the whole-rock and mineral compositions for the Late Triassic (ca. 222 Ma) ultramafic rocks from the complex. They are composed of dunites, wehrlites, pyroxene/hornblende peridotites, and pyroxenites. The constituent minerals are olivines, diopsides/augites, bronzites, calcic-amphiboles, and spinels. Clinopyroxenes exhibit a convex-upward rare earth element (REE) pattern, with an apex at Sm. The whole-rock compositions plot away from the residual mantle peridotite trends, with variable but lower Al2O3 and SiO2 contents, and higher CaO, FeO*, and TiO2 contents at a given value of MgO. Estimated equilibrium temperatures for the AUC rocks range from 420 to 780 °C. These observations, together with the absence of reaction or melt impregnation textures, indicate that the AUC ultramafic rocks are magmatic cumulates emplaced within the crust rather than residual mantle or mantle-melt reaction products. The AUC clinopyroxenes have compositions intermediate between the oceanic island basalt- and arc basalt-related cumulate clinopyroxenes. The AUC spinels have lower Cr#s than the arc-related magmatic cumulate spinels. They plot within the field for spinels from mid-ocean ridge basalts (MORB) on a TiO2 vs. Cr# diagram. However, the AUC clinopyroxenes have much more radiogenic Sr ([87Sr/86Sr]i = 0.70554 to 0.70596), unradiogenic Nd ([εNd]i = - 1.0 to - 0.3), and Hf ([εHf]i = + 4.4 to + 6.6) isotopic compositions than those of the MORB or fore-arc basalts (FAB). In the Sr-Nd isotopic correlation diagram, the AUC clinopyroxenes plot in the enriched extension of the "mantle array". They also have more elevated 207Pb/204Pb ratios at a given 206Pb/204Pb than those of the MORB or FAB. In the Nd-Hf isotope space, the AUC clinopyroxenes have somewhat elevated 176Hf

A fossil venting system in the Feragen Ultramafic Body, Norway?

NASA Astrophysics Data System (ADS)

Dunkel, Kristina G.; Jamtveit, Bjørn; Austrheim, Håkon

2017-04-01

Carbonation of ultramafic rocks in ophiolites and on the seafloor has recently been the focus of extensive research, as this alteration reaction not only influences the carbon flux between hydro- and lithosphere, but also provides natural analogues for industrial CO2 sequestration. It is a significant part of the hydrothermal circulation in the oceanic crust, as demonstrated by carbonate precipitation at hydrothermal vents. We provide microstructural and geochemical data from a previously little known ophicarbonate occurrence in the Feragen Ultramafic Body, Sør-Trøndelag, Norway. Along the northern edge of the Feragen Ultramafic Body, strongly serpentinised peridotites are carbonated. In places, the carbonation took place pervasively, leading to the formation of soapstones consisting mainly of talc and magnesite. More common is the carbonation of serpentinite breccias. Within the clasts, some of the serpentine mesh centres are replaced by magnesite, and, subordinately, dolomite or calcium carbonate. Four types of matrix have been identified in different localities: fine-grained magnesite, coarse-grained calcium carbonate, brucite occurring in large fans (up to 1 mm in diameter), and dolomite. Inclusion trails in the coarse-grained calcium carbonates record botryoidal growth, indicating crystallisation from a fluid in open space, and a hexagonal precursor phase, suggesting that aragonite was replaced by calcite. Brucite-cemented serpentinite breccias occur very locally in two outcrops with a size less than 10 m2. Many of the brucite fans have a similar arrangement of inclusions, with an area rich in dolomite inclusions in the centre of the brucite crystals, and magnetite inclusions concentrated in the tips. Dolomite as a matrix phase often grows inwards from hexagonal, rectangular, rhomboidal, or irregular pores. Many dolomite grains are probably cast pseudomorphs after (calcitised) aragonite. Some carbonate crystals are crosscut or replaced by serpentine. The

Aeromagnetic map and interpretation of geophysical data from the Condrey Mountain Roadless Area, Siskiyou County, California

USGS Publications Warehouse

Jachens, R.C.; Elder, W.P.

1983-01-01

The western Paleozoic and Triassic belt that nearly surrounds the Condrey Mountain Schist is a melange of sedimentary, volcanic, and ultramafic rocks metamorphosed to amphibolite facies (Coleman and others, 1983). Only two samples of the metamorphic melange were collected near the Condrcy Mountain Road less Area, but extensive sampling of this unit southwest of the roadless area yielded an average sample density of 2.86±0.15 g/cm3 (112 samples) (Jachens and others, 1983).

Metamorphosed ultramafic rocks in east Greenland

NASA Technical Reports Server (NTRS)

Kays, M. A.; Dorais, M. J.

1986-01-01

The compositional and mineralogical characteristics of Archean ultramafic rocks in Kangerdlugssuaq Fjord are summarized: the first provides information important to understanding the primary character of the rock suite, whereas the latter provides data necessary to determine the conditions of their equilibrium during the latest metamorphism. This information will be of value in determining the affinity of the suite to similar Archean rocks in other areas of the North Atlantic craton.

Petrogenesis of metaultramafic rocks from the Quadrilátero Ferrífero and adjacent terrains, Minas Gerais, Brazil: Two events of ultramafic magmatism?

NASA Astrophysics Data System (ADS)

da Fonseca, Gabriela Magalhães; Jordt-Evangelista, Hanna; Queiroga, Gláucia Nascimento

2018-03-01

In the worldwide known Quadrilátero Ferrífero and the adjacent terrains, southeastern Brazil, many serpentinite and soapstone quarries, and some rare bodies of metaultramafic rocks that partially preserve minerals or textures from the original igneous protolith can be found. It is not known if the protoliths and the ages of the metaultramafic rocks found in the Quadrilátero Ferrífero (and its oriental basement) and Mineiro Belt regions are the same or if they represent distinct magmatic episodes. The petrogenetic investigation, specially concerning the REE contents, aimed to gather informations about the type of magmatism and the mantle source in order to compare the metaultramafic rocks of both regions. The interpretation of the data concerning petrography, mineral chemistry and geochemistry shows that the metaultramafic rocks are similar to komatiitic peridotites, with MgO contents > 22 wt % and TiO2 < 0.9 wt %. The plot of the REE for the lithotypes found in the Quadrilátero Ferrífero shows decrease in LREE possibly reflecting the depletion of the mantle source. On the other hand the samples from the Mineiro Belt are enriched in LREE suggesting a mantle source enriched in these elements. This enrichment may have been caused by mantle metassomatism that occurred during accretion of the Paleoproterozoic magmatic arc that generated the Mineiro belt. In this paper, we therefore suggest two periods of ultramafic magmatism. The first one found in the Archean basement of the Quadrilátero Ferrífero, with a depleted mantle source. The second occurred in the Paleoproterozoic basement of the Mineiro belt, having a metassomatized mantle as source.

Geochemical Analysis for Sedimentary Emerald Mineralization in Western Emerald belt, Colombia

NASA Astrophysics Data System (ADS)

Nino Vasquez, Gabriel Felipe; Song, Sheng-Rong

2017-04-01

1Gabriel Felipe Nino Vasquez and 1Sheng-Rong Song 1Department of Geosciences, National Taiwan University Colombia hosts a large quantity of mineral resources due to its complex tectonic arrangement, and emerald deposits are one of the most representatives for the country. Emeralds in Colombia occur mainly in black shale, and are located in eastern Andes Cordillera with two parallel belts separated by approximately 130 Km: the Western belt (WB) and the Eastern belt (EB). The geological, mineralogical and tectonic features from these belts are quite similar (Buenaventura 2002). Previous researchers concluded that emeralds in Colombia came from hydrothermal sedimentary processes without any magmatic influence, and suggested that the source of Cr, V and Be (which are important components of the beryl) was the host rock. According to their results, the process which allowed the shale to release these cations was the metasomatism (albitization and carbonization), which was resulted from the interaction between the rocks and the alkaline brines. Fractures and fault planes originated by these tectonic movements were fulfilled by enriched fluids, which they allowed emeralds and the other minerals precipitation with decreasing alkalinity and pressure (Giuliani et al. 1994). However, there were several pitfalls of conclusions drawn from previous researches. Firstly, Cr and V were widely distributed and come from mafic and ultramafic rocks, and Be was mostly found in pegmatites, finding these elements in sedimentary rocks suggest that probably the ultramafic rocks occurred not far from the deposits. Secondly, there was an inconsistency in the estimated temperatures of emeralds formation, i.e. temperature of hydrothermal sedimentary deposits was only 200° C, while laboratory analysis showed that the formation of emeralds was higher than 300° C. Therefore, there might still be an allocthonus influence on emerald formation that significantly increases the temperature. This

Community Colleges in California Feel the Heat

ERIC Educational Resources Information Center

Basken, Paul

2008-01-01

More than two years after Education Secretary Margaret Spellings stood on a podium in Washington and announced the formation of her Commission on the Future of Higher Education, some of its most powerful effects so far have been on a belt of community colleges in California. In the past year, at least 14 California community and junior colleges…

Petrogenesis of the Alaskan-type mafic-ultramafic complex in the Makkah quadrangle, western Arabian Shield, Saudi Arabia

NASA Astrophysics Data System (ADS)

Habtoor, Abdelmonem; Ahmed, Ahmed Hassan; Harbi, Hesham

2016-10-01

The Makkah quadrangle is a part of the Jeddah terrane in the Precambrian basement, Western Arabian Shield of Saudi Arabia. Gabal Taftafan mafic-ultramafic complex lies within the central part of the Makkah quadrangle. The Taftafan mafic-ultramafic complex is a well-differentiated rock association which comprises of dunite core, hornblende- and plagioclase-bearing peridotites, troctolite, clinopyroxenite and marginal gabbro, in a distinctive zonal structure. The bulk-rock geochemistry of the Taftafan mafic-ultramafic rocks is characterized by a tholeiitic/sub-alkaline affinity with high Mg in the ultramafic core (0.84) and is systematically decreased towards the marginal gabbro (0.60). The patterns of trace elements show enrichment in the fluid-mobile elements (Sr, Ba) and a pronounced negative Nb anomaly which reflect a hydrous parental magma generated in a subduction tectonic setting. The mafic-ultramafic rocks of the Taftafan complex have low total rare earth elements (REE) displaying sub-parallel patterns leading to the assumption that these rocks are comagmatic and are formed by fractional crystallization from a common magma type. The platinum-group elements (PGE) content of all rock types in the Taftafan complex is very low, with ∑ PPGE > ∑ IPGE; displaying slightly positive slopes of the PGE distribution patterns. The chemistry of ferromagnesian minerals is characterized by a high forsterite (Fo) olivine with wide range (Fo91-67), from ultramafic core to the marginal gabbro, Ca-rich diopsidic clinopyroxene, and calcic hornblende. Orthopyroxene is almost absent from all rock types, or very rare when present. Hornblende and Ca-plagioclase possess the longest crystallization history since they are present in almost all rock types of the complex. Spinels in the dunite and hornblende-bearing peridotite core show homogeneous composition with intermediate Cr# (0.53-0.67). Plagioclase-bearing peridotite and troctolite have two exsolved types of spinel; Al

Ectomycorrhizal fungal diversity associated with endemic Tristaniopsis spp. (Myrtaceae) in ultramafic and volcano-sedimentary soils in New Caledonia.

PubMed

Waseem, Muhammad; Ducousso, Marc; Prin, Yves; Domergue, Odile; Hannibal, Laure; Majorel, Clarisse; Jourand, Philippe; Galiana, Antoine

2017-05-01

New Caledonian serpentine (ultramafic) soils contain high levels of toxic heavy metals, in particular nickel, (up to 20 g kg -1 ) and are deficient in essential elements like carbon, nitrogen and phosphorus while having a high magnesium/calcium ratio. Although previous studies showed that ectomycorrhizal symbioses could play an important role in the adaptation of the endemic plants to ultramafic soils (FEMS Microbiol Ecol 72:238-49, 2010), none of them have compared the diversity of microbial communities from ultramafic vs non-ultramafic soils in New Caledonia. We explored the impact of edaphic characteristics on the diversity of ectomycorrhizal (ECM) fungi associated with different endemic species of Tristaniopsis (Myrtaceae) growing under contrasting soil conditions in the natural ecosystems of New Caledonia. ECM root tips were thus sampled from two different ultramafic sites (Koniambo massif and Desmazures forest) vs two volcano-sedimentary ones (Arama and Mont Ninndo). The molecular characterization of the ECM fungi through partial sequencing of the ITS rRNA gene revealed the presence of different dominant fungal genera including, both soil types combined, Cortinarius (36.1%), Pisolithus (18.5%), Russula (13.4%), Heliotales (8.2%) and Boletellus (7.2%). A high diversity of ECM taxa associated with Tristaniopsis species was found in both ultramafic and volcano-sedimentary soils but no significant differences in ECM genera distribution were observed between both soil types. No link could be established between the phylogenetic clustering of ECM taxa and their soil type origin, thus suggesting a possible functional-rather than taxonomical-adaptation of ECM fungal communities to ultramafic soils.

Geochemistry, Metamorphic Assemblages, and Microstructures in Small Ultramafic Bodies from the Northern Nason Terrane, Washington

NASA Astrophysics Data System (ADS)

Magloughlin, J. F.

2014-12-01

Ultramafic bodies ranging from <1 to 2500 m in length occur in multiple settings across the northern part of the Nason Terrane in the North Cascade Mountains of Washington State. Within the Wenatchee Ridge Orthogneiss (WRO) the bodies are approximately equidimensional, ranging from dm-scale metasomatized lenses up to an exposed diameter of (typically) approximately 40 m. Some bodies are completely serpentinized, but others include dunite, harzburgite, and rare seams of pyroxenite. Many are rimmed by blackwall (talc, phlogopite, tremolite, chlorite, serpentine) coinciding with the Late Cretaceous metamorphism. The Napeequa Ultramafic Body (NUB), cut through and well exposed by the Napeequa River west of Lake Wenatchee, is within the White River Shear Zone (WRSZ, Magloughlin & McEwan, 1988). Though highly variable, it consists of dunite and peridotite and is variably serpentinized with common Mg-amphibole. Assemblages include serp+carb+chl+talc+opq and suggest upper greenschist to low amphibolite facies overprinting. Rare high-strain zones resemble relict pseudotachylyte veins. More common are ultramylonitic zones with olivine grain sizes of <5 microns, suggesting terrane-boundary paleostresses of >250 MPa. The Nine Mile Creek Ultramafic Body (NMCUB) and Grave Ultramafic Body (GUB) are the largest bodies outside of the White River Shear Zone, and are approximately 300 m and 800 long, respectively. Both are characterized by ol+talc+amph along with chlorite pseudomorphs, commonly cut by <40 micron thick ribbons of calcite, and rarely containing Si defined by chromite. These tectonites contain fine-grained olivine, but post-deformational, metamorphic cummingtonite and tremolite. In both bodies, a moderate to strong foliation is developed. It is suggested both bodies are retrogressed garnet peridotites. An interesting problem is why the possible retrogressed garnet peridotite bodies are present south of the WRSZ and surrounded by the metatonalites of the WRO, but none

The Spitzer Survey of Interstellar Clouds in the Gould Belt. VI. The Auriga-California Molecular Cloud Observed with IRAC and MIPS

NASA Technical Reports Server (NTRS)

Broekhoven-Fiene, Hannah; Matthews, Brenda C.; Harvey, Paul M.; Gutermuth, Robert A.; Huard, Tracy L.; Tothill, Nicholas F. H.; Nutter, David; Bourke, Tyler L.; DiFrancesco, James; Jorgensen, Jes K.;

Spinifex-textured komatiites in the south border of the Carajas ridge, Selva Greenstone belt, Carajás Province, Brazil

NASA Astrophysics Data System (ADS)

Siepierski, Lincoln; Ferreira Filho, Cesar Fonseca

2016-03-01

Spinifex-textured komatiites in the Selva greenstone belt are the first unequivocal examples of komatiites in the Transition Subdomain of the Carajás Mineral Province. Outcrops of spinifex-textured komatiites, located ∼1.5 km to the south of the Carajás ridge, were discovered during regional exploration for Ni-Cu-(PGE) sulfide deposits by VALE. They are associated with a 3.8 km long unit consisting of variable types of ultramafic rocks (talc schist, serpentinite and spinifex-textured komatiite). This ultramafic unit follows the steep dipping NW-SE trending Selva greenstone belt composed mainly by quartz-chlorite schists (interpreted as metasediments) and chlorite-actinolite schists (interpreted as metabasalts). Greenschist facies metamorphic parageneses characterize all rock types in the Selva greenstone belt. The komatiitic rocks in the Selva belt comprise a sequence of flows consisting of an upper spinifex-textured layer and a lower olivine cumulate layer. Although the spinifex and cumulus textures are well preserved in the field, the primary mineralogy of the komatiites has been completely replaced by greenschist facies metamorphic minerals. Platy olivine spinifex texture, consisting of an array of roughly parallel olivine plates, and random spinifex texture, consisting of randomly oriented olivine plates, are the most common primary volcanic textures in komatiites in the Selva greenstone belt. Platy and random spinifex texture is defined by former plates of olivine replaced by serpentine with minor actinolite, chlorite and magnetite, alternating with former matrix replaced by abundant actinolite and minor chlorite, talc, serpentine, and magnetite. The domains between olivine plates in both platy and random spinifex-textured rocks contain irregular arrays of fine-grained parallel crystals, representing primary fine-grained "quench" clinopyroxene crystals replaced by actinolite. Spinifex-textured komatiites have MgO contents bracket between 22.8 and 26.9 wt

Devonian alkaline magmatic belt along the northern margin of the North China Block: Petrogenesis and tectonic implications

NASA Astrophysics Data System (ADS)

Zhang, Qi-Qi; Zhang, Shuan-Hong; Zhao, Yue; Liu, Jian-Min

2018-03-01

Some Devonian magmatic rocks have been identified from the northern margin of the North China Block (NCB) in recent years. However, their petrogenesis and tectonic setting are still highly controversial. Here we present new geochronological, Sr-Nd-Hf isotopic and whole-rock chemical data on several newly identified and previously reported Devonian alkaline complexes, including mafic-ultramafic rocks (pyroxenites and gabbros), alkaline rocks (syenites, monzonites) and alkaline granites in the northern NCB. We firstly identified some mafic-ultramafic rocks coeval with monzonite and quartz monzonite in the Sandaogou and Wulanhada alkaline intrusions. New zircon U-Pb dating of 16 samples from the Baicaigou, Gaojiacun, Sandaogou, Wulanhada and Chifeng alkaline intrusions combined with previous geochronological results indicate that the Devonian alkaline rocks emplaced during the early-middle Devonian at around 400-380 Ma and constitute an E-W-trending alkaline magmatic belt that extend ca. 900 km long along the northern margin of the NCB. Whole-rock geochemical and Sr-Nd-Hf isotopic data reveal that the Devonian alkaline rocks were mainly originated from partial melting of a variably enriched lithospheric mantle with different involvement of ancient lower crustal component and fractional crystallization. The Devonian alkaline magmatic belt rocks in the northern NCB are characterized by very weak or no deformations and were most likely related to post-collision extension after arc-continent collision between the Bainaimiao island arc and the northern margin of North China Craton during the latest Silurian. Partial melting of subcontinental lithospheric mantle to produce the Devonian alkaline magmatic rocks suggests that the northern North China Craton has an inhomogeneous, variably enriched subcontinental lithospheric mantle and was characterized by significant vertical crustal growth during the Devonian period.

Pyroclastic rocks: another manifestation of ultramafic volcanism on Gorgona Island, Colombia

NASA Astrophysics Data System (ADS)

Echeverría, Lina M.; Aitken, Bruce G.

1986-04-01

Tertiary ultramafic volcanism on Gorgona Island, Colombia, is manifested not only by komatiite flows, but also by a more voluminous sequence of tuff breccias, which is cut by comagmatic picrite dikes. The ultramafic pyroclastic rocks are chaotic to stratified mixtures of angular to subrounded glassy picritic blocks and a fine grained volcaniclastic matrix that consists primarily of plastically-deformed, glassy globules. The entire deposit is interpreted to have formed by an explosive submarine eruption of phenocryst-laden picritic magma. MgO contents of tuff breccias and picrite dikes range from 21 to 27 wt%. Relative to nearby komatiite flows, these rocks are MgO-rich, and FeO-, TiO2- and Ni-poor. HREE concentrations are very low (ultramafic rock types crystallized from magmas which most likely were extracted from distinct mantle source regions.

Accessory and rock forming minerals monitoring the evolution of zoned mafic ultramafic complexes in the Central Ural Mountains

NASA Astrophysics Data System (ADS)

Krause, J.; Brügmann, G. E.; Pushkarev, E. V.

2007-04-01

This study describes major and trace element compositions of accessory and rock forming minerals from three Uralian-Alaskan-type complexes in the Ural Mountains (Kytlym, Svetley Bor, Nizhnii Tagil) for the purpose of constraining the origin, evolution and composition of their parental melts. The mafic-ultramafic complexes in the Urals are aligned along a narrow, 900 km long belt. They consist of a central dunite body grading outward into clinopyroxenite and gabbro lithologies. Several of these dunite bodies have chromitites with platinum group element mineralization. High Fo contents in olivine (Fo 92-93) and high Cr/(Cr + Al) in spinel (0.67-0.84) suggest a MgO-rich (> 15 wt.%) and Al 2O 3-poor ultramafic parental magma. During its early stages the magma crystallized dominantly olivine, spinel and clinopyroxene forming cumulates of dunite, wehrlite and clinopyroxenite. This stage is monitored by a common decrease in the MgO content in olivine (Fo 93-86) and the Cr/(Cr + Al) value of coexisting accessory chromite (0.81-0.70). Subsequently, at subsolidus conditions, the chromite equilibrated with the surrounding silicates producing Fe-rich spinel while Al-rich spinel exsolved chromian picotite and chromian titanomagnetite. This generated the wide compositional ranges typical for spinel from Uralian-Alaskan-type complexes world wide. Laser ablation analyses (LA-ICPMS) reveal that clinopyroxene from dunites and clinopyroxenite from all three complexes have similar REE patterns with an enrichment of LREE (0.5-5.2 prim. mantle) and other highly incompatible elements (U, Th, Ba, Rb) relative to the HREE (0.25-2.0 prim. mantle). This large concentration range implies the extensive crystallization of olivine and clinopyroxene together with spinel from a continuously replenished, tapped and crystallizing magma chamber. Final crystallization of the melt in the pore spaces of the cooling cumulate pile explains the large variation in REE concentrations on the scale of a thin

Sr and Nd isotope composition of the metamorphic, sedimentary and ultramafic xenoliths of Lanzarote (Canary Islands): Implications for magma sources

NASA Astrophysics Data System (ADS)

Aparicio, Alfredo; Tassinari, Colombo C. G.; García, Roberto; Araña, Vicente

2010-01-01

The lavas produced by the Timanfaya eruption of 1730-1736 (Lanzarote, Canary Islands) contain a great many sedimentary and metamorphic (metasedimentary), and mafic and ultramafic plutonic xenoliths. Among the metamorphosed carbonate rocks (calc-silicate rocks [CSRs]) are monomineral rocks with forsterite or wollastonite, as well as rocks containing olivine ± orthopyroxene ± clinopyroxene ± plagioclase; their mineralogical compositions are identical to those of the mafic (gabbros) and ultramafic (dunite, wherlite and lherzolite) xenoliths. The 87Sr/ 86Sr (around 0.703) and 143Nd/ 144Nd (around 0.512) isotope ratios of the ultramafic and metasedimentary xenoliths are similar, while the 147Sm/ 144Nd ratios show crustal values (0.13-0.16) in the ultramafic xenoliths and mantle values (0.18-0.25) in some CSRs. The apparent isotopic anomaly of the metamorphic xenoliths can be explained in terms of the heat source (basaltic intrusion) inducing strong isotopic exchange ( 87Sr/ 86Sr and 143Nd/ 144Nd) between metasedimentary and basaltic rocks. Petrofabric analysis also showed a possible relationship between the ultramafic and metamorphic xenoliths.

Size and Albedo of Kuiper Belt Object 55636 from a Stellar Occultation

DTIC Science & Technology

2010-06-01

Santa Barbara, California 93117, USA. 10University of Hawai’i, Hilo , Hawai’i 96720-4091, USA. 11Department of Terrestrial Magnetism, Carnegie Institution...Jewitt, D. Hawaii Kuiper belt variability project: an update. Earth Moon Planets 92, 207–219 (2003). 11. Grundy, W., Noll, K. & Stephens, D

Geothermobarometry for ultramafic assemblages from the Emeishan Large Igneous Province, Southwest China and the Nikos and Zulu Kimberlites, Nunavut, Canada

NASA Astrophysics Data System (ADS)

Zhao, D.

2009-05-01

To understand and contrast the origins of ultramafic assemblages from basaltic and kimberlitic rocks and their associated deposits, such as V-Ti magnetite and Ni-Cu-(PGE) sulfide deposits and diamond, applicable thermobarometers were evaluated and applied to the ultramafic assemblages from the Emeishan Large Igneous Province (ELIP), Southwest China and from the Nikos and Zulu Kimberlites of Nunavut, Canada. The ELIP is located in the Yangtze Block, Southwest China and composed of Permian Emeishan Flood basalt (EFB) and associated layered mafic-ultramafic intrusions. Some of these intrusions host V-Ti magnetite deposits; while others contain Ni-Cu-(PGE) sulfide deposits. It is not clear why some intrusions host magnetite deposits and others contain sulfide deposits. The P-T conditions for the ultramafic assemblages from the mafic-ultramafic intrusions in the ELIP were calculated in order to understand the origins and the associated mineral deposits. The ultramafic assemblages are peridotite, olivine pyroxenite, pyroxenite in the layered intrusions and the common minerals include spinel, olivine, clinopyroxene, orthopyroxene, and minor magnetite and ilmenite. Using a two pyroxene thermometer and a Ca-Mg exchange barometer between olivine and clinopyroxene, a spinel-olivine-clinopyroxene-orthopyroxene assemblage from the Xinjie intrusion yields a T-P of 905°C and 17 kbar; and a similar assemblage from the Jinbaoshan intrusion yields a T-P of 1124°C and 31 kbar. The Nikos kimberlite, near Elwin Bay on Somerset Island, is located at the northeast end of the northeast-southwest kimberlite zone; and the Zulu kimberlite is located on the neighboring Brodeur Peninsula of Baffin Island, Nunavut. The ultramafic assemblages from the Canadian Kimberlites include garnet lherzolite, garnet-spinel lherzolite, spinel lherzolite, dunite, garnet websterite, spinel websterite and garnet clinopyroxenite. The calculated P-T conditions are in the range of 760 to 1180°C and 25 to 60

Conodonts of the western Paleozoic and Triassic belt, Klamath Mountains, California and Oregon

USGS Publications Warehouse

Irwin, William P.; Wardlaw, Bruce R.; Kaplan, T.A.

1983-01-01

Conodonts were extracted from 32 samples of limestone and 5 samples of chert obtained from the Western Paleozoic and Triassic belt of the Klamath Mountains province. Triassic conodonts were found in 17 samples, and late Paleozoic conodonts in 7 samples. Conodonts of the remaining 13 samples cannot be dated more closely than early or middle Paleozoic through Triassic. The late Paleozoic conodonts are restricted to the North Fork and Hayfork terranes. The Hayfork terrane also contains Early, Middle, and Late Triassic conodonts; mostly Neogondolella. Conodonts from samples of the Rattlesnake Creek terrane and the northern undivided part of the belt are all Late Triassic and are generally Epigondolella. The conodont data support the concept that many of the limestone bodies are olistoliths or tectonic blocks in melange. Color alteration of the conodonts indicates that the rocks of the Western Paleozoic and Triassic belt have been heated to temperatures between 300 degrees and 500 degrees C during regional tectonism.

Geology and geochemistry of the Middle Proterozoic Eastern Ghat mobile belt and its comparison with the lower crust of the Southern Peninsular shield

NASA Technical Reports Server (NTRS)

Rao, M. V. Subba

1988-01-01

Two prominent rock suites constitute the lithology of the Eastern Ghat mobile belt: (1) the khondalite suite - the metapelites, and (2) the charnockite suite. Later intrusives include ultramafic sequences, anorthosites and granitic gneisses. The chief structural element in the rocks of the Eastern Ghats is a planar fabric (gneissosity), defined by the alignment of platy minerals like flattened quartz, garnet, sillimanite, graphite, etc. The parallelism between the foliation and the lithological layering is related to isoclinal folding. The major structural trend (axial plane foliation trend) observed in the belt is NE-SW. Five major tectonic events have been delineated in the belt. A boundary fault along the western margin of the Eastern Ghats, bordering the low grade terrain has been substantiated by recent gravity and the deep seismic sounding studies. Field evidence shows that the pyroxene granulites (basic granulites) post-date the khondalite suite, but are older than the charnockites as well as the granitic gneisses. Polyphase metamorphism, probably correlatable with different periods of deformation is recorded. The field relations in the Eastern Ghats point to the intense deformation of the terrain, apparently both before, during and after metamorphism.

Rock- and Paleomagnetic Properties and Modeling of a Deep Crustal Volcanic System, the Reinfjord Ultramafic Complex, Seiland Igneous Province, Northern Norway

NASA Astrophysics Data System (ADS)

ter Maat, G. W.; Pastore, Z.; Michels, A.; Church, N. S.; McEnroe, S. A.; Larsen, R. B.

2017-12-01

The Reinfjord Ultramafic Complex is part of the 5000 km2 Seiland Igneous Province (SIP) in Northern Norway. The SIP is argued to be the deep-seated conduit system of a Large Igneous Province and was emplaced at 25-35 km depth in less than 10 Ma (570-560 Ma). The Reinfjord Ultramafic Complex was emplaced during three major successive events at 22-28km depth at pressures of 6-8kb, with associated temperatures 1450-1500°C (Roberts, 2006). The rocks are divided into three formations: the central series (CS) consisting of mainly dunites, upper layered series (ULS) consisting of dunites and wehrlites, a lower layered series (LLS) containing most pyroxene-rich rocks and a marginal zone (MZ) which formed where the ultramafic melts intruded the gabbro-norite and metasedimentary gneisses. Deep exposures such as the Reinfjord Ultramafic Complex are rare, therefore this study gives a unique insight in the rock magnetic properties of a deep ultramafic system. Localised serpentinised zones provide an opportunity to observe the effect of this alteration process on the magnetic properties of deep-seated rocks. Here, we present the results from the rock magnetic properties, a paleomagnetic study and combined potential-fields modeling. The study of the rock magnetic properties provides insight in primary processes associated with the intrusion, and later serpentinization. The paleomagnetic data yields two distinct directions. One direction corresponds to a Laurentia pole at ≈ 532 Ma while the other, though younger, is not yet fully understood. Rock magnetic properties were measured on > 700 specimens and used to constrain the modelling of gravity, high-resolution helicopter, and ground magnetic data. The intrusion is modelled as a cylindrically shaped complex with a dunite core surrounded by wehrlite and gabbro. The ultramafic part of the complex dips to the NE and its maximum vertical extent is modelled to 1400m. Furthermore, modelling allows estimation of relative volumes of

Accreted seamounts in North Tianshan, NW China: Implications for the evolution of the Central Asian Orogenic Belt

NASA Astrophysics Data System (ADS)

Yang, Gaoxue; Li, Yongjun; Kerr, Andrew C.; Tong, Lili

2018-03-01

The Carboniferous Bayingou ophiolitic mélange is exposed in the North Tianshan accretionary complex in the southwestern part of the Central Asian Orogenic Belt (CAOB). The mélange is mainly composed of serpentinised ultramafic rocks (including harzburgite, lherzolite, pyroxenite, dunite and peridotite), pillowed and massive basalts, layered gabbros, radiolarian cherts, pelagic limestones, breccias and tuffs, and displays block-in-matrix structures. The blocks of ultramafic rocks, gabbros, basalts, cherts, and limestones are set in a matrix of serpentinised ultramafic rocks, massive basalts and tuffs. The basaltic rocks in the mélange show significant geochemical heterogeneity, and two compositional groups, one ocean island basalt-like, and the other mid-ocean ridge-like, can be distinguished on the basis of their isotopic compositions and immobile trace element contents (such as light rare earth element enrichment in the former, but depletion in the latter). The more-enriched basaltic rocks are interpreted as remnants/fragments of seamounts, derived from a deep mantle reservoir with low degrees (2-3%) of garnet lherzolite mantle melting. The depleted basalts most likely formed by melting of a shallower spinel lherzolite mantle source with ∼15% partial melting. It is probable that both groups owe their origin to melting of a mixture between plume and depleted MORB mantle. The results from this study, when integrated with previous work, indicate that the Junggar Ocean crust (comprising a significant number of seamounts) was likely to have been subducted southward beneath the Yili-Central Tianshan block in the Late Devonian-Early Carboniferous. The seamounts were scraped-off and accreted along with the oceanic crust in an accretionary wedge to form the Bayingou ophiolitic mélange. We present a model for the tectonomagmatic evolution of this portion of the CAOB involving prolonged intra-oceanic subduction with seamount accretion.

Magnetic exploration of a low-temperature ultramafic-hosted hydrothermal site (Lost City, 30°N, MAR)

NASA Astrophysics Data System (ADS)

Szitkar, Florent; Tivey, Maurice A.; Kelley, Deborah S.; Karson, Jeffrey A.; Früh-Green, Gretchen L.; Denny, Alden R.

2017-03-01

A 2003 high-resolution magnetic survey conducted by the Autonomous Underwater Vehicle ABE over the low-temperature, ultramafic-hosted hydrothermal field Lost City reveals a weak positive magnetic anomaly. This observation is in direct contrast to recent observations of strong positive magnetic anomalies documented over the high-temperature ultramafic-hosted hydrothermal vents fields Rainbow and Ashadze, which indicates that temperature may control the production of magnetization at these sites. The Lost City survey provides a unique opportunity to study a field that is, to date, one of a kind, and is an end member of ultramafic-hosted hydrothermal systems. Our results highlight the key contribution of temperature on magnetite production resulting from serpentinization reactions. Whereas high temperature promotes significant production and partitioning of iron into magnetite, low temperature favors iron partitioning into various alteration phases, resulting in a magnetite-poor rock. Moreover, the distribution of magnetic anomalies confirms results of a previous geological survey indicating the progressive migration of hydrothermal activity upslope. These discoveries contribute to the results of 25 yrs of magnetic exploration of a wide range of hydrothermal sites, from low- to high-temperature and from basalt- to ultramafic-hosted, and thereby validate using high-resolution magnetics as a crucial parameter for locating and characterizing hydrothermal sites hosting unique chemosynthetic-based ecosystems and potentially mineral-rich deposits.

Geochemical constraints on sources of metabolic energy for chemolithoautotrophy in ultramafic-hosted deep-sea hydrothermal systems.

PubMed

McCollom, Thomas M

2007-12-01

Numerical models are employed to investigate sources of chemical energy for autotrophic microbial metabolism that develop during mixing of oxidized seawater with strongly reduced fluids discharged from ultramafic-hosted hydrothermal systems on the seafloor. Hydrothermal fluids in these systems are highly enriched in H(2) and CH(4) as a result of alteration of ultramafic rocks (serpentinization) in the subsurface. Based on the availability of chemical energy sources, inferences are made about the likely metabolic diversity, relative abundance, and spatial distribution of microorganisms within ultramafic-hosted systems. Metabolic reactions involving H(2) and CH(4), particularly hydrogen oxidation, methanotrophy, sulfate reduction, and methanogenesis, represent the predominant sources of chemical energy during fluid mixing. Owing to chemical gradients that develop from fluid mixing, aerobic metabolisms are likely to predominate in low-temperature environments (<20-30 degrees C), while anaerobes will dominate higher-temperature environments. Overall, aerobic metabolic reactions can supply up to approximately 7 kJ of energy per kilogram of hydrothermal fluid, while anaerobic metabolic reactions can supply about 1 kJ, which is sufficient to support a maximum of approximately 120 mg (dry weight) of primary biomass production by aerobic organisms and approximately 20-30 mg biomass by anaerobes. The results indicate that ultramafic-hosted systems are capable of supplying about twice as much chemical energy as analogous deep-sea hydrothermal systems hosted in basaltic rocks.

Generation of Hydrogen and Methane during Experimental Low-Temperature Reaction of Ultramafic Rocks with Water

NASA Astrophysics Data System (ADS)

McCollom, Thomas M.; Donaldson, Christopher

2016-06-01

Serpentinization of ultramafic rocks is widely recognized as a source of molecular hydrogen (H2) and methane (CH4) to support microbial activity, but the extent and rates of formation of these compounds in low-temperature, near-surface environments are poorly understood. Laboratory experiments were conducted to examine the production of H2 and CH4 during low-temperature reaction of water with ultramafic rocks and minerals. Experiments were performed by heating olivine or harzburgite with aqueous solutions at 90°C for up to 213 days in glass bottles sealed with butyl rubber stoppers. Although H2 and CH4 increased steadily throughout the experiments, the levels were very similar to those found in mineral-free controls, indicating that the rubber stoppers were the predominant source of these compounds. Levels of H2 above background were observed only during the first few days of reaction of harzburgite when CO2 was added to the headspace, with no detectable production of H2 or CH4 above background during further heating of the harzburgite or in experiments with other mineral reactants. Consequently, our results indicate that production of H2 and CH4 during low-temperature alteration of ultramafic rocks may be much more limited than some recent experimental studies have suggested. We also found no evidence to support a recent report suggesting that spinels in ultramafic rocks may stimulate H2 production. While secondary silicates were observed to precipitate during the experiments, formation of these deposits was dominated by Si released by dissolution of the glass bottles, and reaction of the primary silicate minerals appeared to be very limited. While use of glass bottles and rubber stoppers has become commonplace in experiments intended to study processes that occur during serpentinization of ultramafic rocks at low temperatures, the high levels of H2, CH4, and SiO2 released during heating indicate that these reactor materials are unsuitable for this purpose.

Generation of Hydrogen and Methane during Experimental Low-Temperature Reaction of Ultramafic Rocks with Water.

PubMed

McCollom, Thomas M; Donaldson, Christopher

2016-06-01

Serpentinization of ultramafic rocks is widely recognized as a source of molecular hydrogen (H2) and methane (CH4) to support microbial activity, but the extent and rates of formation of these compounds in low-temperature, near-surface environments are poorly understood. Laboratory experiments were conducted to examine the production of H2 and CH4 during low-temperature reaction of water with ultramafic rocks and minerals. Experiments were performed by heating olivine or harzburgite with aqueous solutions at 90°C for up to 213 days in glass bottles sealed with butyl rubber stoppers. Although H2 and CH4 increased steadily throughout the experiments, the levels were very similar to those found in mineral-free controls, indicating that the rubber stoppers were the predominant source of these compounds. Levels of H2 above background were observed only during the first few days of reaction of harzburgite when CO2 was added to the headspace, with no detectable production of H2 or CH4 above background during further heating of the harzburgite or in experiments with other mineral reactants. Consequently, our results indicate that production of H2 and CH4 during low-temperature alteration of ultramafic rocks may be much more limited than some recent experimental studies have suggested. We also found no evidence to support a recent report suggesting that spinels in ultramafic rocks may stimulate H2 production. While secondary silicates were observed to precipitate during the experiments, formation of these deposits was dominated by Si released by dissolution of the glass bottles, and reaction of the primary silicate minerals appeared to be very limited. While use of glass bottles and rubber stoppers has become commonplace in experiments intended to study processes that occur during serpentinization of ultramafic rocks at low temperatures, the high levels of H2, CH4, and SiO2 released during heating indicate that these reactor materials are unsuitable for this purpose

Oxygen regime of Siberian alkaline-ultramafic magmas

NASA Astrophysics Data System (ADS)

Ryabchikov, Igor; Kogarko, Liya

2017-04-01

Regimes of S2 and O2 are decisive factors controlling behavior of chalcophile and siderophile elements in magmatic processes. These parameters play important role during magmagenesis and in the course of crystallization and fluid mass transfer in magma chamber. Alkaline-ultramafic magmatism in Maymecha-Kotuy Province (Polar Siberia) is represented by giant intrusive complexes as well as by volcanics and dyke rocks, which include a well-known variety - meimechites. The latter are considered primary magmas of alkaline-ultramafic plutons in the region like for instance Guli intrusive complex. Sulfur content in primitive magmas estimated from the analyses of melt inclusions in olivine megacrysts from meimechites is close to 0.1 %. fO2 values calculated using olivine+clinopyroxene+spinel and spinel+melt oxygen barometers (1, 2) are 2-3 log units above QFM buffer. The relatively high oxygen potential at the early magmatic stage of alkaline-ultramafic Guli pluton provide predominance of sulfates among other forms of sulfur in the melt. This leads to the almost complete absence of sulfides in highly magnesian rocks. The oxidizing conditions exert important effect on behavior of many ore metals. At the stage of magma generation absence of sulfides in mantle materialresults in the presence of siderophile elements in metallic form and saturation of primary magmas in respect of metallic phases at an early stage of injection of the melt into the magma chamber. Later, under favorable circumstances during magma crystallization nuggets of precious metals may be formed. During further evolution of magmatic system fO2 and activity of oxidized sulfur decrease due to intensive crystallization of magnetite during the formation of koswites, then oxygen fugacity becomes even lower as a result serpentinization at a postmagmatic stage. These serpentization processes are caused by the displacement of reactions in the aqueous phase due to cooling towards the formation of methane and other

Unraveling the Alteration History of Serpentinites and Associated Ultramafic Rocks from the Kampos HPLT Subduction Complex, Syros, Greece

NASA Astrophysics Data System (ADS)

Cooperdock, E. H. G.; Stockli, D. F.

2016-12-01

Serpentinization, hydration of peridotite, has a profound effect on fundamental tectonic and petrologic processes such as deformation of the lithosphere, bulk rheology, fluid-mobile element cycling and deep earth carbon cycling. Though numerous studies have investigated the petrology, structure and geochemistry of serpentinites, the absolute chronology of serpentinization remains elusive due to a lack of accessory minerals that can be dated using established geochronological techniques. Magnetite forms as a common secondary mineral in serpentinites from the fluid-induced breakdown reaction of primary peridotite minerals. Magnetite (U-Th)/He chronometry provides the potential to directly date the cooling of exhumed ultramafic bodies and the low-temperature fluid alteration of serpentinites. We present the first application of magnetite (U-Th)/He chronometry to date stages of alteration in ultramafic rocks from the Kampos mélange belt, a high-pressure low-temperature (HP-LT) subduction complex that experienced exhumation in the Miocene on the island of Syros, Greece. Two generations of magnetite are distinguishable by grain size, magnetite trace element geochemistry and (U-Th)/He age. Large magnetite grains (mm) from a chlorite schist and a serpentinite schist have distinct geochemical signatures indicative of formation during blackwall-related fluid alteration and record Mid-Miocene exhumation-related cooling ages, similar to zircon (U-Th)/He ages from northern Syros. Smaller grains (µm) from the serpentinite schist lack blackwall-related fluid signatures and record post-exhumation mineral formation associated with widespread high-angle Pliocene normal faulting. These results reveal evidence for multiple episodes of fluid-rock alteration, which has implications for the cooling history and local geochemical exchanges of this HP-LT terrane. Given the fundamental impact of serpentinizaton on a vast array of tectonic, petrological, and geochemical processes, the

An alkaline spring system within the Del Puerto ophiolite (California USA): A Mars analog site

DOE Office of Scientific and Technical Information (OSTI.GOV)

Blank, J.G.; Green, S.; Blake, D.

2008-10-01

Mars appears to have experienced little compositional differentiation of primitive lithosphere, and thus much of the surface of Mars is covered by mafic lavas. On Earth, mafic and ultramafic rocks present in ophiolites, oceanic crust and upper mantle that have been obducted onto land, are therefore good analogs for Mars. The characteristic mineralogy, aqueous geochemistry, and microbial communities of cold-water alkaline springs associated with these mafic and ultramafic rocks represent a particularly compelling analog for potential life-bearing systems. Serpentinization, the reaction of water with mafic minerals such as olivine and pyroxene, yields fluids with unusual chemistry (Mg-OH and Ca-OH watersmore » with pH values up to {approx}12), as well as heat and hydrogen gas that can sustain subsurface, chemosynthetic ecosystems. The recent observation of seeps from pole-facing crater and canyon walls in the higher Martian latitudes supports the hypothesis that even present conditions might allow for a rockhosted chemosynthetic biosphere in near-surface regions of the Martian crust. The generation of methane within a zone of active serpentinization, through either abiogenic or biogenic processes, could account for the presence of methane detected in the Martian atmosphere. For all of these reasons, studies of terrestrial alkaline springs associated with mafic and ultramafic rocks are particularly timely. This study focuses on the alkaline Adobe Springs, emanating from mafic and ultramafic rocks of the California Coast Range, where a community of novel bacteria is associated with the precipitation of Mg-Ca carbonate cements. The carbonates may serve as a biosignature that could be used in the search for evidence of life on Mars.« less

Clustering of velocities in a GPS network spanning the Sierra Nevada Block, the Northern Walker Lane Belt, and the Central Nevada Seismic Belt, California-Nevada

NASA Astrophysics Data System (ADS)

Savage, J. C.; Simpson, R. W.

2013-09-01

The deformation across the Sierra Nevada Block, the Walker Lane Belt, and the Central Nevada Seismic Belt (CNSB) between 38.5°N and 40.5°N has been analyzed by clustering GPS velocities to identify coherent blocks. Cluster analysis determines the number of clusters required and assigns the GPS stations to the proper clusters. The clusters are shown on a fault map by symbols located at the positions of the GPS stations, each symbol representing the cluster to which the velocity of that GPS station belongs. Fault systems that separate the clusters are readily identified on such a map. Four significant clusters are identified. Those clusters are strips separated by (from west to east) the Mohawk Valley-Genoa fault system, the Pyramid Lake-Wassuk fault system, and the Central Nevada Seismic Belt. The strain rates within the westernmost three clusters approximate simple right-lateral shear (~13 nstrain/a) across vertical planes roughly parallel to the cluster boundaries. Clustering does not recognize the longitudinal segmentation of the Walker Lane Belt into domains dominated by either northwesterly trending, right-lateral faults or northeasterly trending, left-lateral faults.

Clustering of velocities in a GPS network spanning the Sierra Nevada Block, the northern Walker Lane Belt, and the Central Nevada Seismic Belt, California-Nevada

USGS Publications Warehouse

Savage, James C.; Simpson, Robert W.

2013-01-01

The deformation across the Sierra Nevada Block, the Walker Lane Belt, and the Central Nevada Seismic Belt (CNSB) between 38.5°N and 40.5°N has been analyzed by clustering GPS velocities to identify coherent blocks. Cluster analysis determines the number of clusters required and assigns the GPS stations to the proper clusters. The clusters are shown on a fault map by symbols located at the positions of the GPS stations, each symbol representing the cluster to which the velocity of that GPS station belongs. Fault systems that separate the clusters are readily identified on such a map. Four significant clusters are identified. Those clusters are strips separated by (from west to east) the Mohawk Valley-Genoa fault system, the Pyramid Lake-Wassuk fault system, and the Central Nevada Seismic Belt. The strain rates within the westernmost three clusters approximate simple right-lateral shear (~13 nstrain/a) across vertical planes roughly parallel to the cluster boundaries. Clustering does not recognize the longitudinal segmentation of the Walker Lane Belt into domains dominated by either northwesterly trending, right-lateral faults or northeasterly trending, left-lateral faults.

Applications of palynology and kerogen analysis to California Paleogene stratigraphy and paleoenvironment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lucas-Clark, J.

1988-03-01

Paleogene strata of California commonly yield usable preserved organic material. Fossil pollen, spores, and dinoflagellates of chronostratigraphic significance are recovered from Paleogene rocks that contain no other usable fossil material. Palynofacies analysis, which combines data from fossil species with data from kerogen analysis, is used to interpret paleo-environmental aspects such as paleobathymetry, probable upwelling, turbulence, and rates of sedimentation. Examples of applications come from Paleogene submarine canyon deposits, the northern California Franciscan coastal belt, and southern California Transverse Ranges.

Determining baseline element composition of lichens. II. Hypogymnia enteromorpha and Usnea spp. at Redwood National Park, California

USGS Publications Warehouse

Gough, L.P.; Jackson, L.L.; Sacklin, J.A.

1988-01-01

Hypogymnia enteromorpha and Usnea spp. were collected in the Little Bald Hills ultramafic region of Redwood National Park, California, to establish element-concentration norms. Baselines are presented for Ba, Ca, Cu, Mn, Ni, P, Sr, V, and Zn for both lichen species; for Li, Mg, and K for H. enteromorpha; and for Al, Ce, Cr, Co, Fe, Na, and Ti for Usnea. Element concentrations of future collections of this same material can be used to monitor possible air quality changes anticipated from mining activities planned nearby. The variability in the element concentrations was partitioned between geographical distance increments and sample preparation and analysis procedures. In general, most of this variability was found in samples less than a few hundreds of meters apart rather than those at about 1 km apart. Therefore, except for Ba and Co, no large geographical element-concentration trends were observed. Samples of both species contained elevated levels of Ni and Mg, which probably reflect the ultramafic terrain over which they occur.

Three-dimensional model of an ultramafic feeder system to the Nikolai Greenstone mafic large igneous province, central Alaska Range

USGS Publications Warehouse

Glen, J.M.G.; Schmidt, J.M.; Connard, G.G.

2011-01-01

The Amphitheater Mountains and southern central Alaska Range expose a thick sequence of Triassic Nikolai basalts that is underlain by several mafic-ultramafic complexes, the largest and best exposed being the Fish Lake and Tangle (FL-T) mafic-ultramafic sills that flank the Amphitheater Mountains synform. Three-dimensional (3-D) modeling of gravity and magnetic data reveals details of the structure of the Amphitheater Mountains, such as the orientation and thickness of Nikolai basalts, and the geometry of the FL-T intrusions. The 3-D model (50 ?? 70 km) includes the full geographic extent of the FL-T complexes and consists of 11 layers. Layer surfaces and properties (density and magnetic susceptibility) were modified by forward and inverse methods to reduce differences between the observed and calculated gravity and magnetic grids. The model suggests that the outcropping FL-T sills are apparently connected and traceable at depth and reveals variations in thickness, shape, and orientation of the ultramafic bodies that may identify paths of magma flow. The model shows that a significant volume (2000 km3) of ultramafic material occurs in the subsurface, gradually thickening and plunging westward to depths exceeding 4 km. This deep ultramafic material is interpreted as the top of a keel or root system that supplied magma to the Nikolai lavas and controlled emplacement of related magmatic intrusions. The presence of this deep, keel-like structure, and asymmetry of the synform, supports a sag basin model for development of the Amphitheater Mountains structure and reveals that the feeders to the Nikolai are much more extensive than previously known. Copyright 2011 by the American Geophysical Union.

Crustal structure of the Dabie orogenic belt (eastern China) inferred from gravity and magnetic data

NASA Astrophysics Data System (ADS)

Yang, Yu-shan; Li, Yuan-yuan

2018-01-01

In order to better characterize the crustal structure of the Dabie orogen and its tectonic history, we present a crustal structure along a 500 km long profile across the Dabie orogenic belt using various data processing and interpretation of the gravity and magnetic data. Source depth estimations from the spectral analysis by continuous wavelet transform (CWT) provide better constraints for constructing the initial density model. The calculated gravity effects from the initial model show great discrepancy with the observed data, especially at the center of the profile. More practical factors are then incorporated into the gravity modeling. First, we add a high density body right beneath the high pressure metamorphic (HPM) and ultrahigh pressure metamorphic (UHPM) belt considering the exposed HPM and UHPM rocks in the mid of our profile. Then, the anomalous bodies A, B, and C inferred from the CWT-based spectral analysis results are fixed in the model geometry. In the final crustal density structure, two anomalous bodies B and C with high density and low magnetization could possibly be attributed to metasomatised mantle materials by SiO2-rich melt derived from the foundering subducted mafic lower crust. Under the extensional environment in the early Cretaceous, the upwelling metasomatised mantle was partially melted to produce the parental magma of the post-collisional mafic-ultramafic intrusive rocks. As for the low density body A with strong magnetization located in the lower crust right beneath the HP and UHP metamorphic belt, it is more likely to be composed of serpentinized mantle peridotite (SMP). This serpentinized mantle peridotite body (SMPB) represents the emplacement of mantle-derived peridotites in the crust, accompanying the exhumation of the UHP metamorphic rocks.

The Chemical Composition of an Extrasolar Kuiper-Belt-Object

NASA Astrophysics Data System (ADS)

Xu, S.; Zuckerman, B.; Dufour, P.; Young, E. D.; Klein, B.; Jura, M.

2017-02-01

The Kuiper Belt of our solar system is a source of short-period comets that may have delivered water and other volatiles to Earth and the other terrestrial planets. However, the distribution of water and other volatiles in extrasolar planetary systems is largely unknown. We report the discovery of an accretion of a Kuiper-Belt-Object analog onto the atmosphere of the white dwarf WD 1425+540. The heavy elements C, N, O, Mg, Si, S, Ca, Fe, and Ni are detected, with nitrogen observed for the first time in extrasolar planetary debris. The nitrogen mass fraction is ∼2%, comparable to that in comet Halley and higher than in any other known solar system object. The lower limit to the accreted mass is ∼1022 g, which is about one hundred thousand times the typical mass of a short-period comet. In addition, WD 1425+540 has a wide binary companion, which could facilitate perturbing a Kuiper-Belt-Object analog into the white dwarf’s tidal radius. This finding shows that analogs to objects in our Kuiper Belt exist around other stars and could be responsible for the delivery of volatiles to terrestrial planets beyond the solar system. Part of the data presented herein were obtained at the W.M. Keck Observatory, which is operated as a scientific partnership among Caltech, the University of California and NASA. The Observatory was made possible by the generous financial support of the W.M. Keck Foundation.

Lithologic mapping of the Mordor, NT, Australia ultramafic complex by using the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER)

USGS Publications Warehouse

Rowan, L.C.; Mars, J.C.; Simpson, C.J.

2005-01-01

Spectral measurements made in the Mordor Pound, NT, Australia study area using the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), in the laboratory and in situ show dominantly Al-OH and ferric-iron VNIR-SWIR absorption features in felsic rock spectra and ferrous-iron and Fe,Mg-OH features in the mafic-ultramafic rock spectra. ASTER ratio images, matched-filter, and spectral-angle mapper processing (SAM) were evaluated for mapping the lithologies. Matched-filter processing in which VNIR + SWIR image spectra were used for reference resulted in 4 felsic classes and 4 mafic-ultramafic classes based on Al-OH or Fe,Mg-OH absorption features and, in some, subtle reflectance differences related to differential weathering and vegetation. These results were similar to those obtained by match-filter analysis of HyMap data from a previous study, but the units were more clearly demarcated in the HyMap image. ASTER TIR spectral emittance data and laboratory emissivity measurements document a wide wavelength range of Si-O spectral features, which reflect the lithological diversity of the Mordor ultramafic complex and adjacent rocks. SAM processing of the spectral emittance data distinguished 2 classes representing the mafic-ultramafic rocks and 4 classes comprising the quartzose to intermediate composition rocks. Utilization of the complementary attributes of the spectral reflectance and spectral emittance data resulted in discrimination of 4 mafic-ultramafic categories; 3 categories of alluvial-colluvial deposits; and a significantly more completely mapped quartzite unit than could be accomplished by using either data set alone. ?? 2005 Elsevier Inc. All rights reserved.

Delineation of Magnesium-rich Ultramafic Rocks Available for Mineral Carbon Sequestration in the United States

USGS Publications Warehouse

Krevor, S.C.; Graves, C.R.; Van Gosen, B. S.; McCafferty, A.E.

2009-01-01

The 2005 Intergovernmental Panel on Climate Change report on Carbon Dioxide Capture and Storage suggested that a major gap in mineral carbon sequestration is locating the magnesium-silicate bedrock available to sequester CO2. It is generally known that silicate minerals with high concentrations of magnesium are suitable for mineral carbonation. However, no assessment has been made covering the entire United States detailing their geographical distribution and extent, or evaluating their potential for use in mineral carbonation. Researchers at Columbia University and the U.S. Geological Survey have developed a digital geologic database of ultramafic rocks in the continental United States. Data were compiled from varied-scale geologic maps of magnesium-silicate ultramafic rocks. These rock types are potentially suitable as source material for mineral carbon-dioxide sequestration. The focus of the national-scale map is entirely on suitable ultramafic rock types, which typically consist primarily of olivine and serpentine minerals. By combining the map with digital datasets that show non-mineable lands (such as urban areas and National Parks), estimates on potential depth of a surface mine, and the predicted reactivities of the mineral deposits, one can begin to estimate the capacity for CO2 mineral sequestration within the United States. ?? 2009 Elsevier Ltd. All rights reserved.

Laterally bendable belt conveyor

DOEpatents

Peterson, William J.

1985-01-01

An endless, laterally flexible and bendable belt conveyor particularly adapted for coal mining applications in facilitating the transport of the extracted coal up- or downslope and around corners in a continuous manner is disclosed. The conveying means includes a flat rubber belt reinforced along the middle portion thereof along which the major portion of the belt tension is directed so as to cause rotation of the tubular shaped belt when trammed around lateral turns thus preventing excessive belt bulging distortion between adjacent belt supports which would inhibit belt transport. Pretension induced into the fabric reinforced flat rubber belt by conventional belt take-up means supports the load conveyed when the belt conveyor is making lateral turns. The carrying and return portions of the belt are supported and formed into a tubular shape by a plurality of shapers positioned along its length. Each shaper is supported from above by a monorail and includes clusters of idler rollers which support the belt. Additional cluster rollers in each shaper permit the belt supporting roller clusters to rotate in response to the belt's operating tension imposed upon the cluster rollers by induced lateral belt friction forces. The freely rotating roller clusters thus permit the belt to twist on lateral curves without damage to itself while precluding escape of the conveyed material by effectively enclosing it in the tube-shaped, inner belt transport length.

Characterization of the Sukinda and Nausahi ultramafic complexes, Orissa, India by platinum-group element geochemistry

USGS Publications Warehouse

Page, N.J.; Banerji, P.K.; Haffty, J.

1985-01-01

Samples of 20 chromitite, 14 ultramafic and mafic rock, and 9 laterite and soil samples from the Precambrian Sukinda and Nausahi ultramafic complexes, Orissa, India were analyzed for platinum-group elements (PGE). The maximum concentrations are: palladium, 13 parts per billion (ppb); platinum, 120 ppb; rhodium, 21 ppb; iridium, 210 ppb; and ruthenium, 630 ppb. Comparison of chondrite-normalized ratios of PGE for the chromitite samples of lower Proterozoic to Archean age with similar data from Paleozoic and Mesozoic ophiolite complexes strongly implies that these complexes represent Precambrian analogs of ophiolite complexes. This finding is consistent with the geology and petrology of the Indian complexes and suggests that plate-tectonic and ocean basin developement models probably apply to some parts of Precambrian shield areas. ?? 1985.

Mineralization of atmospheric CO2 via fluid reaction with mafic/ultramafic rocks

NASA Astrophysics Data System (ADS)

Westfield, I. T.; Kendall, T. A.; Ries, J. B.

2011-12-01

Atmospheric CO2 has increased nearly 50% since the Industrial Revolution, due primarily to increased fossil fuel combustion, cement production, and deforestation. Although subterranean reservoirs are presently considered the most viable sink for anthropogenically liberated CO2, concerns exist over the stability of these systems and their impacts on regional tectonics, aquifers, and subterranean microbial ecosystems. Direct mineralization of CO2 at the Earth's surface provides an alternative capable of generating useful carbon-negative mineral byproducts that may be used to supplement or replace conventional carbon-positive building materials, like cement. However, mineralization of anthropogenic CO2 requires large sources of alkalinity to convert CO2 to CO32-, and divalent cations (e.g., Mg2+, Ca2+, Fe2+, etc.) to bond with the aqueous CO32-. Ultramafic and mafic rocks, such as peridotites, serpentinites, and basalts, are globally abundant, naturally occurring sources of the divalent cations, and alkalinity required for CO2 mineralization. Here, we present the results of accelerated reactions between ultramafic/mafic rocks, water, and CO2/N2 gases, aimed at quantifying the carbonation potential of mafic/ultramafic rocks. Rock-fluid-gas batch reactions were carried out in vented 4 L borosilicate glass flasks filled with 3 L DI water and 200 g acetone-washed, 49-180μm-diameter grains of four ultramafic/mafic rock types: peridotite, dunite, websterite and basalt. Each of the four rock-water mixtures was reacted under pure CO2 and pure N2 and at 25 and 200 °C, for a total of 16 reactions. Mixtures were continuously heated and stirred for 14 days. Samples (330 mL) were obtained at 0, 1, 6, 24, 48, 96, 168, and 336 hrs and filtered at 0.4 μm. The pH of filtered samples was measured with a single-junction Ag/AgCl glass electrode, salinity was determined with a conductivity probe, total alkalinity (TA) was determined by closed-cell potentiometric Gran titration, and DIC

30 CFR 75.1731 - Maintenance of belt conveyors and belt conveyor entries.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Maintenance of belt conveyors and belt conveyor....1731 Maintenance of belt conveyors and belt conveyor entries. (a) Damaged rollers, or other damaged belt conveyor components, which pose a fire hazard must be immediately repaired or replaced. All other...

The Ultramafic Complex of Reinfjord: from the Magnetic Petrology to the Interpretation of the Magnetic Anomalies

NASA Astrophysics Data System (ADS)

Pastore, Zeudia; McEnroe, Suzanne; Church, Nathan; Fichler, Christine; ter Maat, Geertje W.; Fumagalli, Patrizia; Oda, Hirokuni; Larsen, Rune B.

2017-04-01

A 3D model of the geometry of the Reinfjord complex integrating geological and petrophysical data with high resolution aeromagnetic, ground magnetic and gravity data is developed. The Reinfjord ultramafic complex in northern Norway is one of the major ultramafic complexes of the Neoproterozoic Seiland Igneous Province (SIP). This province, now embedded in the Caledonian orogen, was emplaced deep in the crust (30 km of depth) and is believed to represent a section of the deep plumbing system of a large igneous province. The Reinfjord complex consists of three magmatic series formed during multiple recharging events resulting in the formation of a cylindrically zoned complex with a slightly younger dunite core surrounded by wehrlite and lherzolite units. Gabbros and gneiss form the host rock. The ultramafic complex has several distinct magnetic anomalies which do not match the mapped lithological boundaries, but are correlated with changes in magnetic susceptibilities. In particular, the deviating densities and magnetic susceptibilities at the northern side of the complex are interpreted to be due to serpentinization. Detailed studies of magnetic anomalies and magnetic properties of samples can provide a powerful tool for mapping petrological changes. Samples can have wide range of magnetic properties depending on composition, amount of ferromagnetic minerals, grain sizes and microstructures. Later geological processes such as serpentinization can alter this signal. Therefore a micro-scale study of magnetic anomalies at the thin section scale was carried out to understand better the link between the magnetic petrology and the magnetic anomalies. Serpentinization can significantly enhance the magnetic properties and therefore change the nature of the magnetic anomaly. The detailed gravity and magnetic model here presented shows the subsurface structure of the ultramafic complex refining the geological interpretation of the magnetic sources within it, and the local

Genesis of the Permian Kemozibayi sulfide-bearing mafic-ultramafic intrusion in Altay, NW China: Evidence from zircon geochronology, Hf and O isotopes and mineral chemistry

NASA Astrophysics Data System (ADS)

Tang, Dongmei; Qin, Kezhang; Xue, Shengchao; Mao, Yajing; Evans, Noreen J.; Niu, Yanjie; Chen, Junlu

2017-11-01

The recently discovered Kemozibayi mafic-ultramafic intrusion and its associated magmatic Cu-Ni sulfide deposits are located at the southern margin of the Chinese Altai Mountain, Central Asian Orogenic Belt in north Xinjiang, NW China. The intrusion is composed of olivine websterite, norite, gabbro and diorite. Disseminated and net-textured Ni-Cu sulfide ores are hosted in the center of the gabbro. In this work, new zircon U-Pb ages, Hf-O isotopic and sulfide S isotopic data, and whole rock and mineral chemical analyses are combined in order to elucidate the characteristics of the mantle source, nature of subduction processes, degree of crustal contamination, geodynamic setting of bimodal magmatism in the region, and the metallogenic potential of economic Cu-Ni sulfide deposit at depth. SIMS zircon U-Pb dating of the gabbro yields Permian ages (278.3 ± 1.9 Ma), coeval with the Kalatongke Cu-Ni deposit and with Cu-Ni deposits in the Eastern Tianshan and Beishan areas. Several lines of evidence (positive εHf(t) from + 7.1 to + 13.3, Al2O3, TiO2 and SiO2 contents in clinopyroxene from olivine websterite, high whole rock TiO2 contents) suggest that the primary magma of the Kemozibayi intrusion was a calc-alkaline basaltic magma derived from depleted mantle, and that the degree of partial melting in the magma source was high. The evolution of the Kemozibayi mafic-ultramafic complex was strongly controlled by fractional crystallization and the crystallization sequence was olivine websterite, norite, and then gabbro. This is evidenced by whole rock Fe2O3 contents that are positively correlated with MgO and negatively correlated with Al2O3, CaO and Na2O, similar LREE enrichment and negative Nb, Ta, Hf anomalies in chondrite and primitive mantle-normalized patterns, and a decrease in total REE and trace elements contents and magnetite content from gabbro through to norite and olivine websterite. Varied and low εHf(t) (+ 7.1 to + 13.3) and high δ18O values (+ 6.4‰ to

Effectiveness of Ford's belt reminder system in increasing seat belt use

PubMed Central

Williams, A; Wells, J; Farmer, C

2002-01-01

Objectives: The study investigated the effectiveness in increasing seat belt use of Ford's belt reminder system, a supplementary system that provides intermittent flashing lights and chimes for five minutes if drivers are not belted. Methods: Seat belt use of drivers in relatively new cars with and without the reminder system was unobtrusively observed as vehicles were brought to dealerships for service. Results: Overall use rates were estimated at 71% for drivers in vehicles without the reminder system and 76% for drivers in vehicles with belt reminders (p<0.01). Conclusions: Seat belt use is relatively low in the United States. The present study showed that vehicle based reminder systems can be at least modestly effective in increasing belt use, which may encourage further development of such systems. PMID:12460965

Evaluation of ultramafic deposits in the Eastern United States and Puerto Rico as sources of magnesium for carbon dioxide sequestration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fraser Goff; George Guthrie; Bruce Lipin

2000-04-01

In this report, the authors evaluate the resource potential of extractable magnesium from ultramafic bodies located in Vermont, the Pennsylvania-Maryland-District-of-Columbia (PA-MD-DC) region, western North Carolina, and southwestern Puerto Rico. The first three regions occur in the Appalachian Mountains and contain the most attractive deposits in the eastern United States. They were formed during prograde metamorphism of serpentinized peridotite fragments originating from an ophiolite protolith. The ultramafic rocks consist of variably serpentinized dunite, harzburgite, and minor iherzolite generally containing antigorite and/or lizardite as the major serpentine minor phases. Chrysotile contents vary from minor to major, depending on occurrence. Most bodies containmore » an outer sheath of chlorite-talc-tremolite rock. Larger deposits in Vermont and most deposits in North Carolina contain a core of dunite. Magnesite and other carbonates are common accessories. In these deposits, MgO ranges from 36 to 48 wt % with relatively pure dunite having the highest MgO and lowest H{sub 2}O contents. Ultramafic deposits in southwestern Puerto Rico consist of serpentinized dunite and harzburgite thought to be emplaced as large diapirs or as fragments in tectonic melanges. They consist of nearly pure, low-grade serpentinite in which lizardite and chrysotile are the primary serpentine minerals. Chlorite is ubiquitous in trace amounts. Magnesite is a common accessory. Contents of MgO and H{sub 2}O are rather uniform at roughly 36 and 13 wt %. Dissolution experiments show that all serpentinites and dunite-rich rocks are soluble in 1:1 mixtures of 35% HCl and water by volume. The experiments suggest that low-grade serpentinites from Puerto Rico are slightly more reactive than the higher grade, antigorite-bearing serpentinites of the Appalachian Mountains. The experiments also show that the low-grade serpentinites and relatively pure dunites contain the least amounts of

Plutonism in the central part of the Sierra Nevada Batholith, California

USGS Publications Warehouse

Bateman, Paul C.

1992-01-01

remnants of country rocks within the eastern part of the batholith, although strongly deformed, are autochthonous or have been displaced only short distances, whereas some Mesozoic strata in the western metamorphic belt may be allochthonous. Probably the strata in the western metamorphic belt were deposited in marginal basins and island arcs, but the possibility that they were transported from distant places has not been disproved. All the country rocks have been strongly deformed, most of them more than once. Tectonic disturbances occurred during the Devonian and Mississippian (Antler? orogeny), the Permian and (or) Early Triassic (Sonoman? orogeny), the Late Jurassic (Nevadan orogeny), and at various other times during emplacement of the batholith and uplift that accompanied and followed its emplacement. The strata in the western metamorphic belt probably were deformed in an early Mesozoic subduction complex. The plutonic rocks range in composition from gabbro to leucogranite, but tonalite, granodiorite, and granite are the most common rock types. Most are medium to coarse grained, but some small rock masses are fine grained. Most have hypidiomorphic-granular textures and are equigranular, but some having compositions close to the boundary between granite and granodiorite contain large crystals of alkali feldspar. Serpentinized ultramafic rocks are present locally in the western metamorphic belt within and adjacent to the Melones fault zone. Except for serpentinized ultramafic rocks, trondhjemite, and most granites, all the plutonic rocks contain significant amounts of hornblende. Most of the granitoids are metaluminous or weakly peraluminous; strongly peraluminous granites are present only in the White Mountains. Most of the granitoids are assigned to units of lithodemic rank, and most of these units are assigned to intrusive suites. Plutons assigned to the same lithodeme are composed of rock of similar composition, fabric, and age and are presumed to h

Allochthonous 2.78 Ga oceanic plateau slivers in a 2.72 Ga continental arc sequence: Vizien greenstone belt, northeastern Superior Province, Canada

NASA Astrophysics Data System (ADS)

Skulski, T.; Percival, J. A.

1996-04-01

Embedded within the vast granitoid terrane of the Minto block of northeastern Superior Province are Late Archean greenstone belts of the Goudalie domain that preserve a long-lived record of continent-ocean interaction. The Vizien greenstone belt is one such belt and it contains four fault-bounded structural panels. The 2786 Ma mafic-ultramafic sequence is an allochthonous package of pillowed basaltic andesite, komatiite and volcaniclastic rocks cut by peridotite and gabbro sills. The mafic rocks are LREE-depleted tholeiites which have primitive mantle (PRIM)-normalized abundances of Th < Nb < La, and ɛNd values of +1.5 to + 3.2 reflecting extraction from a depleted mantle source. The 2724 Ma lac Lintelle continental calc-alkaline volcanic sequence consists of massive basalt, plagioclase-porphyritic andesite, dacite, rhyolite, capped by quartz-rich sandstones/conglomerates with 2.97 Ga Nd model ages. Lac Lintelle volcanic rocks are LREE enriched, with low TiO 2 (< 1%) and Zr (< 200 ppm), PRIM-normalized enrichment in Th > La > Nb, and a range of ɛNd values from -0.1 to +1.7. The ~ 2722 Ma lac Serindac bimodal, subaerial tholeiitic volcanic sequence contains andesite (locally with tonalite xenoliths), basalt, gabbro sills, lenses of quartz-rich sedimentary rocks and a thick, upper rhyolite sequence. The lac Serindac tholeiites are LREE-enriched, have PRIM-normalized Th > La > Nb, high Zr (to 300 ppm) and Ti contents, and low ɛNd values from +0.8 in basalt to -1.4 in rhyolite. The < 2718 Ma basement-cover sequence comprises 2.94 Ga tonalitic gneiss unconformably overlain by clastic sediments and a thin upper sequence of 2700 Ma gabbro, siliceous high-Mg basalt (SHMB) and andesite. The SHMB are characterised by LREE depletion and ɛNd values of +2.6, whereas the andesite is LREE-enriched and has ɛNd values of -0.3. The 2786 Ma mafic-ultramafic sequence is interpreted as a sliver of plume-related oceanic plateau crust. The 2724 lac Lintelle sequence represents a

The Hawaii trails project: comet-hunting in the main asteroid belt

NASA Astrophysics Data System (ADS)

Hsieh, H. H.

2009-10-01

Context: The mysterious solar system object 133P/(7968) Elst-Pizarro is dynamically asteroidal, yet displays recurrent comet-like dust emission. Two scenarios were hypothesized to explain this unusual behavior: 1) 133P is a classical comet from the outer solar system that has evolved onto a main-belt orbit or 2) 133P is a dynamically ordinary main-belt asteroid on which subsurface ice has recently been exposed. If 1) is correct, the expected rarity of a dynamical transition onto an asteroidal orbit implies that 133P could be alone in the main belt. In contrast, if 2) is correct, other icy main-belt objects should exist and could also exhibit cometary activity. Aims: Believing 133P to be a dynamically ordinary, yet icy main-belt asteroid, I set out to test the primary prediction of the hypothesis: that 133P-like objects should be common and could be found by an appropriately designed observational survey. Methods: I conducted just such a survey - the Hawaii Trails Project - of selected main-belt asteroids in a search for objects displaying cometary activity. Optical observations were made of targets selected from among the Themis, Koronis, and Veritas asteroid families, the Karin asteroid cluster, and low-inclination, kilometer-scale outer-belt asteroids, using the Lulin 1.0 m, small and moderate aperture research telescope system (SMARTS) 1.0 m, University of Hawaii 2.2 m, southern astrophysical research (SOAR) 4.1 m, Gemini North 8.1 m, Subaru 8.2 m, and Keck I 10 m telescopes. Results: I made 657 observations of 599 asteroids, discovering one active object now known as 176P/LINEAR, leading to the identification of the new cometary class of main-belt comets (MBCs). These results suggest that there could be ~100 currently active MBCs among low-inclination, kilometer-scale outer-belt asteroids. Physically and statistically, MBC activity is consistent with initiation by meter-sized impactors. The estimated rate of impacts and sizes of resulting active sites, however

Condition-Based Conveyor Belt Replacement Strategy in Lignite Mines with Random Belt Deterioration

NASA Astrophysics Data System (ADS)

Blazej, Ryszard; Jurdziak, Leszek

2017-12-01

In Polish lignite surface mines, condition-based belt replacement strategies are applied in order to assure profitable refurbishment of worn out belts performed by external firms specializing in belt maintenance. In two of three lignite mines, staff asses belt condition subjectively during visual inspections. Only one mine applies specialized diagnostic device (HRDS) allowing objective magnetic evaluation of belt core condition in order to choose the most profitable moment for the dismantling of worn out belt segments from conveyors and sending them to the maintenance firm which provides their refurbishment. This article describes the advantages of a new diagnostic device called DiagBelt. It was developed at the Faculty of Geoengineering, Mining and Geology, Wroclaw University of Science and Technology. Economic gains from its application are calculated for the lignite mine and for the belt maintenance firm, taking into account random life (durability) of new and reconditioned belts (after the 1st and the 2nd refurbishment). Recursive calculations for following years allow the estimation of the length and costs of replaced, reconditioned and purchased belts on an annual basis, while the use of the Monte Carlo method allows the estimation of their variability caused by random deterioration of belts. Savings are obtained due to better selection of moments (times) for the replacement of belt segments and die to the possibility to qualify worn out belts for refurbishment without the need to remove their covers. In effect, increased belt durability and lowered share of waste belts (which were not qualified for reconditioning) create savings which can quickly cover expenditures on new diagnostic tools and regular belt inspections in the mine.

Hyperspectral analysis of the ultramafic complex and adjacent lithologies at Mordor, NT, Australia

USGS Publications Warehouse

Rowan, L.C.; Simpson, C.J.; Mars, J.C.

2004-01-01

The Mordor Complex consists of a series of potassic ultramafic rocks which were intruded into Proterozoic felsic gneisses and amphibolite and are overlain by quartzite and unconsolidated deposits. In situ and laboratory 0.4 to 2.5 ??m reflectance spectra show Al-OH absorption features caused by absorption in muscovite, kaolinite, and illite/smectite in syenite, granitic gneiss, quartzite and unconsolidated sedimentary deposits, and Fe,Mg-OH features due to phlogopite, biotite, epidote, and hornblende in the mafic and ultramafic rocks. Ferrous-iron absorption positioned near 1.05 ??m is most intense in peridotite reflectance spectra. Ferric-iron absorption is intense in most of the felsic lithologies. HyMap data were recorded in 126 narrow bands from 0.43 to 2.5 ??m along a 7-km-wide swath with approximately 6-m spatial resolution. Correction of the data to spectral reflectance was accomplished by reference to in situ measurements of an extensive, alluvial plain. Spectral classes for matched filter processing were selected by using the pixel purity index procedure and analysis of in situ and laboratory spectra. Considering the spatial distribution of the resulting 14 classes, some classes were combined, which produced eight classes characterized by Al-OH absorption features, and three Fe,Mg-OH absorption-feature classes. Comparison of the distribution of these 11 spectral classes to a generalized lithologic map of the study area shows that the spectral distinction among the eight Al-OH classes is related to variations in primary lithology, weathering products, and vegetation density. Quartzite is represented in three classes, syenite corresponds to a single scattered class, quartz-muscovite-biotite schist defines a single very coherent class, and unconsolidated sediments are portrayed in four classes. The three mafic-ultramafic classes are distinguished on the basis of generally intense Fe,Mg-OH and ferrous-iron absorption features. A single class represents the

Lower continental crust formation through focused flow in km-scale melt conduits: The zoned ultramafic bodies of the Chilas Complex in the Kohistan island arc (NW Pakistan)

NASA Astrophysics Data System (ADS)

Jagoutz, O.; Müntener, O.; Burg, J.-P.; Ulmer, P.; Jagoutz, E.

2006-02-01

Whole-rock and Sm-Nd isotopic data of the main units of the Chilas zoned ultramafic bodies (Kohistan paleo-island arc, NW Pakistan) indicate that ultramafic rocks and gabbronorite sequences stem from a common magma. However, field observations rule out formation of both ultramafic and mafic sequences in terms of gravitational crystal settling in a large magma chamber. Contacts between ultramafic and gabbronorite sequences show emplacement of the dunitic bodies into a semi-consolidated gabbronoritic crystal-mush, which in turn has intruded and reacted with the ultramafic rocks to produce concentric zoning. Field and petrological observations indicate a replacive origin of the dunite. Bulk Mg#'s of dunitic rocks range from 0.87-0.81 indicating that the dunite-forming melt underwent substantial fractionation-differentiation and that percolative fractional crystallization probably generated the dunitic core. The REE chemistry of clinopyroxene in primitive dunite samples and the Nd isotopic composition of ultramafic rocks are in equilibrium with the surrounding gabbronorite. Accordingly, liquids that formed the dunitic rocks and later the mafic sequence derived from a similar depleted source ( ɛNd˜4.8). We propose a mechanism for the comagmatic emplacement, where km-scale ultramafic bodies represent continuous channels reaching down into the upper mantle. The melt-filled porosity in these melt channels diminishes the mean-depth-integrated density difference to the surrounding rocks. Due to buoyancy forces, melt channels raise into the overlying crustal sequence. In the light of such processes, the ultramafic bodies are interpreted as melt channels through which the Chilas gabbronorite sequence was fed. The estimated basaltic-andesitic, low Mg# (˜0.53) bulk composition of the Chilas gabbronorite sequence closely matches estimates of lower crustal compositions. Since the mafic sequence originated from a primary, high Mg# (> 0.7) basaltic arc magma, differentiation of

Origin of magnetic highs at ultramafic hosted hydrothermal systems: Insights from the Yokoniwa site of Central Indian Ridge

NASA Astrophysics Data System (ADS)

Fujii, Masakazu; Okino, Kyoko; Sato, Taichi; Sato, Hiroshi; Nakamura, Kentaro

2016-05-01

High-resolution vector magnetic measurements were performed on an inactive ultramafic-hosted hydrothermal vent field, called Yokoniwa Hydrothermal Field (YHF), using a deep-sea manned submersible Shinkai6500 and an autonomous underwater vehicle r2D4. The YHF has developed at a non-transform offset massif of the Central Indian Ridge. Dead chimneys were widely observed around the YHF along with a very weak venting of low-temperature fluids so that hydrothermal activity of the YHF was almost finished. The distribution of crustal magnetization from the magnetic anomaly revealed that the YHF is associated with enhanced magnetization, as seen at the ultramafic-hosted Rainbow and Ashadze-1 hydrothermal sites of the Mid-Atlantic Ridge. The results of rock magnetic analysis on seafloor rock samples (including basalt, dolerite, gabbro, serpentinized peridotite, and hydrothermal sulfide) showed that only highly serpentinized peridotite carries high magnetic susceptibility and that the natural remanent magnetization intensity can explain the high magnetization of Yokoniwa. These observations reflect abundant and strongly magnetized magnetite grains within the highly serpentinized peridotite. Comparisons with the Rainbow and Ashadze-1 suggest that in ultramafic-hosted hydrothermal systems, strongly magnetized magnetite and pyrrhotite form during the progression of hydrothermal alteration of peridotite. After the completion of serpentinization and production of hydrogen, pyrrhotites convert into pyrite or nonmagnetic iron sulfides, which considerably reduces their levels of magnetization. Our results revealed origins of the magnetic high and the development of subsurface chemical processes in ultramafic-hosted hydrothermal systems. Furthermore, the results highlight the use of near-seafloor magnetic field measurements as a powerful tool for detecting and characterizing seafloor hydrothermal systems.

Structural correction of paleomagnetic vectors dispersed about two fold axes and application to the Duke Island (Alaska) ultramafic complex

NASA Astrophysics Data System (ADS)

Bogue, Scott W.; Grommé, C. Sherman

2004-11-01

A new analysis of paleomagnetic data from the mid-Cretaceous (˜110 Ma) ultramafic complex at Duke Island (southeast Alaska) supports large poleward transport of the Insular superterrane relative to North America consistent with the Baja British Columbia hypothesis. Previous paleomagnetic work has shown that the characteristic remanence of the ultramafic complex predates kilometer-scale deformation of the very well developed cumulate layering but that the layering was not horizontal everywhere before the folding. It is possible, however, to estimate paleohorizontal for the Duke Island ultramafic complex because the postremanence deformation of the intrusion occurred about two well-defined and spatially separate fold axes. In such a case the tectonically rotated paleomagnetic directions should be distributed along small circles centered on each of the two fold axes. The ancient field direction will lie on both small circles and therefore will be identifiable as one of their two intersection points. Interpreted this way, the tectonically rotated remanence of the Duke Island ultramafic complex defines a mid-Cretaceous (i.e., ancient) field direction that is within 2° of the paleomagnetic direction found by assuming the cumulate layering was initially horizontal (despite the paleomagnetic evidence to the contrary) and performing the standard structure correction. The inferred mid-Cretaceous paleolatitude of Duke Island is 21.2° (2350 km) anomalous with respect to cratonic North America. This result is concordant with southerly paleolatitudes determined by many other workers from bedded rocks of terranes farther inboard in the Insular and Intermontane superterranes.

The JCMT Gould Belt Survey: A First Look at the Auriga–California Molecular Cloud with SCUBA-2

NASA Astrophysics Data System (ADS)

Broekhoven-Fiene, H.; Matthews, B. C.; Harvey, P.; Kirk, H.; Chen, M.; Currie, M. J.; Pattle, K.; Lane, J.; Buckle, J.; Di Francesco, J.; Drabek-Maunder, E.; Johnstone, D.; Berry, D. S.; Fich, M.; Hatchell, J.; Jenness, T.; Mottram, J. C.; Nutter, D.; Pineda, J. E.; Quinn, C.; Salji, C.; Tisi, S.; Hogerheijde, M. R.; Ward-Thompson, D.; Bastien, P.; Bresnahan, D.; Butner, H.; Chrysostomou, A.; Coude, S.; Davis, C. J.; Duarte-Cabral, A.; Fiege, J.; Friberg, P.; Friesen, R.; Fuller, G. A.; Graves, S.; Greaves, J.; Gregson, J.; Holland, W.; Joncas, G.; Kirk, J. M.; Knee, L. B. G.; Mairs, S.; Marsh, K.; Moriarty-Schieven, G.; Mowat, C.; Rawlings, J.; Richer, J.; Robertson, D.; Rosolowsky, E.; Rumble, D.; Sadavoy, S.; Thomas, H.; Tothill, N.; Viti, S.; White, G. J.; Wilson, C. D.; Wouterloot, J.; Yates, J.; Zhu, M.

2018-01-01

We present 850 and 450 μm observations of the dense regions within the Auriga–California molecular cloud using SCUBA-2 as part of the JCMT Gould Belt Legacy Survey to identify candidate protostellar objects, measure the masses of their circumstellar material (disk and envelope), and compare the star formation to that in the Orion A molecular cloud. We identify 59 candidate protostars based on the presence of compact submillimeter emission, complementing these observations with existing Herschel/SPIRE maps. Of our candidate protostars, 24 are associated with young stellar objects (YSOs) in the Spitzer and Herschel/PACS catalogs of 166 and 60 YSOs, respectively (177 unique), confirming their protostellar nature. The remaining 35 candidate protostars are in regions, particularly around LkHα 101, where the background cloud emission is too bright to verify or rule out the presence of the compact 70 μm emission that is expected for a protostellar source. We keep these candidate protostars in our sample but note that they may indeed be prestellar in nature. Our observations are sensitive to the high end of the mass distribution in Auriga–Cal. We find that the disparity between the richness of infrared star-forming objects in Orion A and the sparsity in Auriga–Cal extends to the submillimeter, suggesting that the relative star formation rates have not varied over the Class II lifetime and that Auriga–Cal will maintain a lower star formation efficiency.

Storm-time radiation belt electron dynamics: Repeatability in the outer radiation belt

NASA Astrophysics Data System (ADS)

Murphy, K. R.; Mann, I. R.; Rae, J.; Watt, C.; Boyd, A. J.; Turner, D. L.; Claudepierre, S. G.; Baker, D. N.; Spence, H. E.; Reeves, G. D.; Blake, J. B.; Fennell, J. F.

2017-12-01

During intervals of enhanced solar wind driving the outer radiation belt becomes extremely dynamic leading to geomagnetic storms. During these storms the flux of energetic electrons can vary by over 4 orders of magnitude. Despite recent advances in understanding the nature of competing storm-time electron loss and acceleration processes the dynamic behavior of the outer radiation belt remains poorly understood; the outer radiation belt can exhibit either no change, an enhancement, or depletion in radiation belt electrons. Using a new analysis of the total radiation belt electron content, calculated from the Van Allen probes phase space density (PSD), we statistically analyze the time-dependent and global response of the outer radiation belt during storms. We demonstrate that by removing adiabatic effects there is a clear and repeatable sequence of events in storm-time radiation belt electron dynamics. Namely, the relativistic (μ=1000 MeV/G) and ultra-relativistic (μ=4000 MeV/G) electron populations can be separated into two phases; an initial phase dominated by loss followed by a second phase dominated by acceleration. At lower energies, the radiation belt seed population of electrons (μ=150 MeV/G) shows no evidence of loss but rather a net enhancement during storms. Further, we investigate the dependence of electron dynamics as a function of the second adiabatic invariant, K. These results demonstrate a global coherency in the dynamics of the source, relativistic and ultra-relativistic electron populations as function of the second adiabatic invariant K. This analysis demonstrates two key aspects of storm-time radiation belt electron dynamics. First, the radiation belt responds repeatably to solar wind driving during geomagnetic storms. Second, the response of the radiation belt is energy dependent, relativistic electrons behaving differently than lower energy seed electrons. These results have important implications in radiation belt research. In particular

Belt attachment and system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schneider, Abraham D.; Davidson, Erick M.

Disclosed herein is a belt assembly including a flexible belt with an improved belt attachment. The belt attachment includes two crossbars spaced along the length of the belt. The crossbars retain bearings that allow predetermined movement in six degrees of freedom. The crossbars are connected by a rigid body that attaches to the bearings. Implements that are attached to the rigid body are simply supported but restrained in pitching rotation.

Belt attachment and system

DOEpatents

Schneider, Abraham D.; Davidson, Erick M.

2016-02-02

Disclosed herein is a belt assembly including a flexible belt with an improved belt attachment. The belt attachment includes two crossbars spaced along the length of the belt. The crossbars retain bearings that allow predetermined movement in six degrees of freedom. The crossbars are connected by a rigid body that attaches to the bearings. Implements that are attached to the rigid body are simply supported but restrained in pitching rotation.

Geophysical methods as mapping tools in a strata-bound gold deposit: Haile mine, South Carolina slate belt.

USGS Publications Warehouse

Wynn, J.C.; Luce, R.W.

1984-01-01

The Haile mine is the largest gold producer in the eastern USA. It is postulated to be a strata-bound gold deposit formed by a fumarolic or hot-spring system in felsic tuffs of Cambrian(?) age. Two mineralized zones occur, each composed of a sericitic part overlain by a siliceous part. Au is concentrated in especially silicified horizons and in pyrite horizons in the siliceous part of each mineralized zone. The tuffs are metamorphosed to greenschist facies and intruded by diabase and other mafic dykes. Weathering is deep and the mineralized tuffs are partly covered by coastal-plain sediments. It is suggested that certain geophysical methods may be useful in mapping and exploring Haile-type deposits in the Carolina slate belt. Very low frequency electromagnetic resistivity surveys help define alteration and silicified zones. A magnetic survey found sharp highs that correlate with unexposed mafic and ultramafic dykes. Induced polarization proved useful in giving a two-dimensional view of the structure.-G.J.N.

Chromian spinels in highly altered ultramafic rocks from the Sartohay ophiolitic mélange, Xinjiang, NW China

NASA Astrophysics Data System (ADS)

Qiu, Tian; Zhu, Yongfeng

2018-06-01

The Sartohay ophiolitic mélange is located in western Junggar (Xinjiang province, NW China), which is a major component of the core part of the Central Asian Orogenic Belt (CAOB). Chromian spinels in serpentinite, talc schist, carbonate-talc schist and listwaenite in Sartohay ophiolitic mélange retain primary compositions with Cr# of 0.39-0.65, Mg# = 0.48-0.67, and Fe3+# < 0.08. Chromian spinels in deformed listwaenite were initially transformed into Fe2+-rich chromite during shearing deformation followed by Fe3+-rich chromite at shallow levels. The Cr# and Fe3+# of Fe2+-rich chromite (Cr# = 0.59-0.86, Fe3+# = 0.01-0.12, Mg# = 0.35-0.61) and Fe3+-rich chromite (Cr# = 0.85-1.00, Fe3+# = 0.17-0.38, Mg# < 0.29) increase with decrease of Mg#. We propose a model to illustrate the evolution of chromian spinels in highly altered ultramafic rocks from the Sartohay ophiolitic mélange. Chromian spinels in serpentinite and talc schist were rimmed by Cr-magnetite, which was dissolved completely during transformation from serpentinite/talc schist to listwaenite. Chromian spinels were then transformed into Fe2+-rich chromite in shear zones, which characterized by high fluid/rock ratios. This Fe2+-rich chromite and/or chromian spinels could then be transformed into Fe3+-rich chromite in oxidizing conditions at shallow levels.

49 CFR 393.93 - Seats, seat belt assemblies, and seat belt assembly anchorages.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 5 2012-10-01 2012-10-01 false Seats, seat belt assemblies, and seat belt assembly anchorages. 393.93 Section 393.93 Transportation Other Regulations Relating to Transportation... § 393.93 Seats, seat belt assemblies, and seat belt assembly anchorages. (a) Buses—(1) Buses...

49 CFR 393.93 - Seats, seat belt assemblies, and seat belt assembly anchorages.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 5 2010-10-01 2010-10-01 false Seats, seat belt assemblies, and seat belt assembly anchorages. 393.93 Section 393.93 Transportation Other Regulations Relating to Transportation... § 393.93 Seats, seat belt assemblies, and seat belt assembly anchorages. (a) Buses—(1) Buses...

49 CFR 393.93 - Seats, seat belt assemblies, and seat belt assembly anchorages.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 5 2011-10-01 2011-10-01 false Seats, seat belt assemblies, and seat belt assembly anchorages. 393.93 Section 393.93 Transportation Other Regulations Relating to Transportation... § 393.93 Seats, seat belt assemblies, and seat belt assembly anchorages. (a) Buses—(1) Buses...

49 CFR 393.93 - Seats, seat belt assemblies, and seat belt assembly anchorages.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 5 2014-10-01 2014-10-01 false Seats, seat belt assemblies, and seat belt assembly anchorages. 393.93 Section 393.93 Transportation Other Regulations Relating to Transportation... § 393.93 Seats, seat belt assemblies, and seat belt assembly anchorages. (a) Buses—(1) Buses...

49 CFR 393.93 - Seats, seat belt assemblies, and seat belt assembly anchorages.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 5 2013-10-01 2013-10-01 false Seats, seat belt assemblies, and seat belt assembly anchorages. 393.93 Section 393.93 Transportation Other Regulations Relating to Transportation... § 393.93 Seats, seat belt assemblies, and seat belt assembly anchorages. (a) Buses—(1) Buses...

Geodiversity of hydrothermal processes along the Mid-Atlantic Ridge and ultramafic-hosted mineralization: A new type of oceanic Cu-Zn-Co-Au volcanogenic massive sulfide deposit

NASA Astrophysics Data System (ADS)

Fouquet, Yves; Cambon, Pierre; Etoubleau, Joël; Charlou, Jean Luc; Ondréas, Hélène; Barriga, Fernando J. A. S.; Cherkashov, Georgy; Semkova, Tatiana; Poroshina, Irina; Bohn, M.; Donval, Jean Pierre; Henry, Katell; Murphy, Pamela; Rouxel, Olivier

Several hydrothermal deposits associated with ultramafic rocks have recently been found along slow spreading ridges with a low magmatic budget. Three preferential settings are identified: (1) rift valley walls near the amagmatic ends of ridge segments; (2) nontransform offsets; and (3) ultramafic domes at inside corners of ridge transform-fault intersections. The exposed mantle at these sites is often interpreted to be a detachment fault. Hydrothermal cells in ultramafic rocks may be driven by regional heat flow, cooling gabbroic intrusions, and exothermic heat produced during serpentinization. Along the Mid-Atlantic Ridge (MAR), hydrothermal deposits in ultramafic rocks include the following: (1) sulfide mounds related to high-temperature low-pH fluids (Logatchev, Rainbow, and Ashadze); (2) carbonate chimneys related to low-temperature, high-pH fluids (Lost City); (3) low-temperature diffuse venting and high-methane discharge associated with silica, minor sulfides, manganese oxides, and pervasive alteration (Saldanha); and (4) stockwork quartz veins with sulfides at the base of detachment faults (15°05'N). These settings are closely linked to preferential circulation of fluid along permeable detachment faults. Compared to mineralization in basaltic environments, sulfide deposits associated with ultramafic rocks are enriched in Cu, Zn, Co, Au, and Ni. Gold has a bimodal distribution in low-temperature Zn-rich and in high-temperature Cu-rich mineral assemblages. The Cu-Zn-Co-Au deposits along the MAR seem to be more abundant than in ophiolites on land. This may be because ultramafic-hosted volcanogenic massive sulfide deposits on slow spreading ridges are usually not accreted to continental margins during obduction and may constitute a specific marine type of mineralization.

Conversion of chaparral areas to grassland techniques used in California

Treesearch

Jay R. Bentley

1967-01-01

Chaparral-as the term is used in California-refers to dense stands of evergreen, shrubby vegetation. The information in this handbook applies to the chaparral within the brushland zone that lies below the State's commercial timber belt (fig. 1). This zone includes about 11 million acres of chaparral and associated types and 9 million acres of woodland types.

Synaptic ribbon. Conveyor belt or safety belt?

PubMed

Parsons, T D; Sterling, P

2003-02-06

The synaptic ribbon in neurons that release transmitter via graded potentials has been considered as a conveyor belt that actively moves vesicles toward their release sites. But evidence has accumulated to the contrary, and it now seems plausible that the ribbon serves instead as a safety belt to tether vesicles stably in mutual contact and thus facilitate multivesicular release by compound exocytosis.

Magmatic structure and geochemistry of the Luanga Mafic-Ultramafic Complex: Further constraints for the PGE-mineralized magmatism in Carajás, Brazil

NASA Astrophysics Data System (ADS)

Mansur, Eduardo Teixeira; Ferreira Filho, Cesar Fonseca

2016-12-01

The Luanga Complex is part of the Serra Leste Magmatic Suite, a cluster of PGE-mineralized mafic-ultramafic intrusions located in the northeastern portion of the Carajás Mineral Province. The Luanga Complex is a medium-sized layered intrusion consisting of three main zones: i. the lower Ultramafic Zone comprising ultramafic adcumulates (peridotite), ii. the Transition Zone comprising interlayered ultramafic and mafic cumulates (harzburgite, orthopyroxenite and norite) and iii. the upper Mafic Zone comprising a monotonous sequence of mafic cumulates (norite) with minor orthopyroxenite layers. Several PGE-mineralized zones occur in the Transition Zone but the bulk of the PGE resources are hosted within a 10-50 meter thick interval of disseminated sulfides at the contact of the Ultramafic and Transition Zones. The compositional range of cumulus olivine (Fo78.9-86.4) is comparable to those reported for layered intrusions originated from moderate primitive parental magmas. Mantle normalized alteration-resistant trace element patterns of noritic rocks are fractionated, as indicated by relative enrichment in LREE and Th, with negative Nb and Ta anomalies, suggesting assimilation of older continental crust. Ni contents in olivine in the Luanga Complex (up to 7500 ppm) stand among the highest values reported in layered intrusions globally. The highest Ni contents in olivine in the Luanga Complex occur in distinctively PGE enriched (Pt + Pd > 1 ppm) intervals of the Transition Zone, in both sulfide-poor and sulfide bearing (1-3 vol.%) rocks. The origin of the PGE- and Ni-rich parental magma of the Luanga Complex is discussed considering the upgrading of magmas through dissolution of previously formed Ni-rich sulfide melts. Our results suggest that high Ni contents in olivine and/or orthopyroxene provide an additional exploration tool for Ni-PGE deposits, particularly useful for target selection in large magmatic provinces.

Comfort and convenience specifications for safety belts : shoulder belt fit, pressure and pullout forces

DOT National Transportation Integrated Search

1980-04-30

A three-part study was conducted to further define comfort requirements for seat belt systems with respect to shoulder belt fit, shoulder belt contact pressure, and 3-point restraint system pullout forces. Objective of the belt-fit portion of the stu...

The empty primordial asteroid belt.

PubMed

Raymond, Sean N; Izidoro, Andre

2017-09-01

The asteroid belt contains less than a thousandth of Earth's mass and is radially segregated, with S-types dominating the inner belt and C-types the outer belt. It is generally assumed that the belt formed with far more mass and was later strongly depleted. We show that the present-day asteroid belt is consistent with having formed empty, without any planetesimals between Mars and Jupiter's present-day orbits. This is consistent with models in which drifting dust is concentrated into an isolated annulus of terrestrial planetesimals. Gravitational scattering during terrestrial planet formation causes radial spreading, transporting planetesimals from inside 1 to 1.5 astronomical units out to the belt. Several times the total current mass in S-types is implanted, with a preference for the inner main belt. C-types are implanted from the outside, as the giant planets' gas accretion destabilizes nearby planetesimals and injects a fraction into the asteroid belt, preferentially in the outer main belt. These implantation mechanisms are simple by-products of terrestrial and giant planet formation. The asteroid belt may thus represent a repository for planetary leftovers that accreted across the solar system but not in the belt itself.

The empty primordial asteroid belt

PubMed Central

Raymond, Sean N.; Izidoro, Andre

2017-01-01

The asteroid belt contains less than a thousandth of Earth’s mass and is radially segregated, with S-types dominating the inner belt and C-types the outer belt. It is generally assumed that the belt formed with far more mass and was later strongly depleted. We show that the present-day asteroid belt is consistent with having formed empty, without any planetesimals between Mars and Jupiter’s present-day orbits. This is consistent with models in which drifting dust is concentrated into an isolated annulus of terrestrial planetesimals. Gravitational scattering during terrestrial planet formation causes radial spreading, transporting planetesimals from inside 1 to 1.5 astronomical units out to the belt. Several times the total current mass in S-types is implanted, with a preference for the inner main belt. C-types are implanted from the outside, as the giant planets’ gas accretion destabilizes nearby planetesimals and injects a fraction into the asteroid belt, preferentially in the outer main belt. These implantation mechanisms are simple by-products of terrestrial and giant planet formation. The asteroid belt may thus represent a repository for planetary leftovers that accreted across the solar system but not in the belt itself. PMID:28924609

Soil geochemistry of Mother Lode-type gold deposits in the Hodson mining district, central California, U.S.A.

USGS Publications Warehouse

Chaffee, M.A.; Hill, R.H.

1989-01-01

The Hodson mining district is in the westernmost foothills of the Sierra Nevada in California, about 17 km west of the town of Angels Camp. This district is part of the West Gold Belt, which lies about 12-16 km west of, and generally parallel to, the better known Mother Lode Gold Belt in central California. The district produced several million dollars worth of Au between about 1890 and 1940.The geologic setting and mineral deposits in the West Gold Belt are generally similar to those in the Mother Lode Gold Belt. Rocks in the study area are of Jurassic age and consist of a mixture of (1) fine-grained, generally thin-bedded, clastic sedimentary rocks that have been metamorphosed to slates, schists, and phyllites, and (2) massive volcanic flows and welded tuffs that have been metamorphosed to metabasalts and metatuffs. All rocks were intensely faulted and folded during the Late Cretaceous Nevadan orogeny; northnorthwest- and northwest-trending faults dominate. Mining in the area was of low-grade gold-pyrite ores occurring principally in the carbonatized wall rocks adjacent to the major northwest-trending Hodson fault and its splays. Minor amounts of other sulfide minerals (principally chalcopyrite, arsenopyrite, sphalerite, and galena) are locally associated with the Au deposits. 

Safety belt laws and disparities in safety belt use among US high-school drivers.

PubMed

García-España, J Felipe; Winston, Flaura K; Durbin, Dennis R

2012-06-01

We compared reported safety belt use, for both drivers and passengers, among teenagers with learner's permits, provisional licenses, and unrestricted licenses in states with primary or secondary enforcement of safety belt laws. Our data source was the 2006 National Young Driver Survey, which included a national representative sample of 3126 high-school drivers. We used multivariate, log-linear regression analyses to assess associations between safety belt laws and belt use. Teenaged drivers were 12% less likely to wear a safety belt as drivers and 15% less likely to wear one as passengers in states with a secondary safety belt law than in states with a primary law. The apparent reduction in belt use among teenagers as they progressed from learner to unrestricted license holder occurred in only secondary enforcement states. Groups reporting particularly low use included African American drivers, rural residents, academically challenged students, and those driving pickup trucks. The results provided further evidence for enactment of primary enforcement provisions in safety belt laws because primary laws are associated with higher safety belt use rates and lower crash-related injuries and mortality.

Osmium Isotopic Evolution of the Mantle Sources of Precambrian Ultramafic Rocks

NASA Astrophysics Data System (ADS)

Gangopadhyay, A.; Walker, R. J.

2006-12-01

The Os isotopic composition of the modern mantle, as recorded collectively by ocean island basalts, mid- oceanic ridge basalts (MORB) and abyssal peridotites, is evidently highly heterogeneous (γ Os(I) ranging from <-10 to >+25). One important question, therefore, is how and when the Earth's mantle developed such large-scale Os isotopic heterogeneities. Previous Os isotopic studies of ancient ultramafic systems, including komatiites and picrites, have shown that the Os isotopic heterogeneity of the terrestrial mantle can be traced as far back as the late-Archean (~ 2.7-2.8 Ga). This observation is based on the initial Os isotopic ratios obtained for the mantle sources of some of the ancient ultramafic rocks determined through analyses of numerous Os-rich whole-rock and/or mineral samples. In some cases, the closed-system behavior of these ancient ultramafic rocks was demonstrated via the generation of isochrons of precise ages, consistent with those obtained from other radiogenic isotopic systems. Thus, a compilation of the published initial ^{187}Os/^{188}Os ratios reported for the mantle sources of komatiitic and picritic rocks is now possible that covers a large range of geologic time spanning from the Mesozoic (ca. 89 Ma Gorgona komatiites) to the Mid-Archean (e.g., ca. 3.3 Ga Commondale komatiites), which provides a comprehensive picture of the Os isotopic evolution of their mantle sources through geologic time. Several Precambrian komatiite/picrite systems are characterized by suprachondritic initial ^{187}Os/^{188}Os ratios (e.g., Belingwe, Kostomuksha, Pechenga). Such long-term enrichments in ^{187}Os of the mantle sources for these rocks may be explained via recycling of old mafic oceanic crust or incorporation of putative suprachondritic outer core materials entrained into their mantle sources. The relative importance of the two processes for some modern mantle-derived systems (e.g., Hawaiian picrites) is an issue of substantial debate. Importantly

Redistribution of Iron and Titanium in High-Pressure Ultramafic Rocks

NASA Astrophysics Data System (ADS)

Crossley, Rosalind J.; Evans, Katy A.; Reddy, Steven M.; Lester, Gregory W.

2017-11-01

The redox state of iron in high-pressure serpentinites, which host a significant proportion of Fe3+ in subduction zones, can be used to provide an insight into iron cycling and constrain the composition of subduction zone fluids. In this study, we use oxide and silicate mineral textures, interpretation of mineral parageneses, mineral composition data, and whole rock geochemistry of high-pressure retrogressed ultramafic rocks from the Zermatt-Saas Zone to constrain the distribution of iron and titanium, and iron oxidation state. These data provide an insight on the oxidation state and composition of fluids at depth in subduction zones. Oxide minerals host the bulk of iron, particularly Fe3+. The increase in mode of magnetite and observation of magnetite within antigorite veins in the investigated ultramafic samples during initial retrogression is most consistent with oxidation of existing iron within the samples during the infiltration of an oxidizing fluid since it is difficult to reconcile addition of Fe3+ with the known limited solubility of this species. However, high Ti contents are not typical of serpentinites and also cannot be accounted for by simple mixing of a depleted mantle protolith with the nearby Allalin gabbro. Titanium-rich phases coincide with prograde metamorphism and initial exhumation, implying the early seafloor and/or prograde addition and late mobilization of Ti. If Ti addition has occurred, then the introduction of Fe3+, also generally considered to be immobile, cannot be disregarded. We explore possible transport vectors for Ti and Fe through mineral texture analysis.

Cobalt and scandium partitioning versus iron content for crystalline phases in ultramafic nodules

USGS Publications Warehouse

Glassley, W.E.; Piper, D.Z.

1978-01-01

Fractionation of Co and Sc between garnets, olivines, and clino- and orthopyroxenes, separated from a suite of Salt Lake Crater ultramafic nodules that equilibrated at the same T and P, is strongly dependent on Fe contents. This observation suggests that petrogenetic equilibrium models of partial melting and crystal fractionation must take into account effects of magma composition, if they are to describe quantitatively geochemical evolutionary trends. ?? 1978.

belt law

DOT National Transportation Integrated Search

2007-03-01

A 2003 study estimated that if all States had primary seat belt laws from 1995 to 2002, over 12,000 lives would have been saved. Failure to implement a primary seat belt law creates a real cost to a States budget for Medicaid and other State medic...

Safety Belt Laws and Disparities in Safety Belt Use Among US High-School Drivers

PubMed Central

Winston, Flaura K.; Durbin, Dennis R.

2012-01-01

Objectives. We compared reported safety belt use, for both drivers and passengers, among teenagers with learner’s permits, provisional licenses, and unrestricted licenses in states with primary or secondary enforcement of safety belt laws. Methods. Our data source was the 2006 National Young Driver Survey, which included a national representative sample of 3126 high-school drivers. We used multivariate, log-linear regression analyses to assess associations between safety belt laws and belt use. Results. Teenaged drivers were 12% less likely to wear a safety belt as drivers and 15% less likely to wear one as passengers in states with a secondary safety belt law than in states with a primary law. The apparent reduction in belt use among teenagers as they progressed from learner to unrestricted license holder occurred in only secondary enforcement states. Groups reporting particularly low use included African American drivers, rural residents, academically challenged students, and those driving pickup trucks. Conclusions. The results provided further evidence for enactment of primary enforcement provisions in safety belt laws because primary laws are associated with higher safety belt use rates and lower crash-related injuries and mortality. PMID:22515851

Petrology of the Northern Anabar alkaline-ultramafic rocks (the Siberian Craton, Russia) and the role of metasomatized lithospheric mantle in their genesis

NASA Astrophysics Data System (ADS)

Kargin, Alexey; Golubeva, Yulia; Demonterova, Elena

2017-04-01

The southeastern margin of the Anabar shield (the Siberian Craton) in Mesozoic was characterized by intense alkaline-ultramafic (include diamondiferous kimberlite) magmatism. This zone is located within the Archean-Proterozoic Hapchan terrane and includes several fields of alkaline-ultramafic rocks that formed during three main episodes (Zaytsev and Smelov, 2010; Sun et al., 2014): Late Triassic (235-205 Ma), Middle-Late Jurassic (171-149 Ma), Cretaceous (105 Ma). Following the revised classification scheme of Tappe et al. (2005), the alkaline-ultramafic rocks of the Anabar region were identified, correspondingly, as 1) Late Triassic aillikites, damtjernites, and orangeites; 2) Middle-Late Jurassic silicocarbonatites and 3) Cretaceous carbonatites. According to mineralogical, geochemical and isotopic (Sm-Nd, Rb-Sr) data on the alkaline-ultramafic rocks of the Anabar region, the following scheme of the mantle source evolution is suggested: 1). Ascent of the asthenospheric (or plume) material to the base of the lithospheric mantle containing numerous carbonate- and phlogopite-rich veins in Late Triassic led to the generation of orangeite and aillikite magmas; 2). Evolution of aillikite magmas during their ascent and interaction with the surrounding lithospheric mantle (e.g. mantle-rock assimilation and/or melt differentiation) resulted in the accumulation of Mg-Si components in alkaline-ultramafic magmas and was accompanied by a change in liquidus minerals (from apatite-carbonate to olivine and Ca-silicate). Exsolution of carbonate-rich fluid at this stage was responsible for the formation of damtjernite magmas. 3). The tectonothermal activation within the Anabar region in Jurassic was marked by the generation of silicocarbonatitic magmas. Their geochemical composition suggests decreasing abundance of phlogopite-rich veins in the lithospheric mantle source. 4). In Cretaceous, the alkaline-ultramafic magmatism shifted into the central part of the Hapchan terrane where

Belt conveyor apparatus

DOEpatents

Oakley, David J.; Bogart, Rex L.

1987-01-01

A belt conveyor apparatus according to this invention defines a conveyance path including a first pulley and at least a second pulley. An endless belt member is adapted for continuous travel about the pulleys and comprises a lower portion which engages the pulleys and an integral upper portion adapted to receive objects therein at a first location on said conveyance path and transport the objects to a second location for discharge. The upper belt portion includes an opposed pair of longitudinally disposed crest-like members, biased towards each other in a substantially abutting relationship. The crest-like members define therebetween a continuous, normally biased closed, channel along the upper belt portion. Means are disposed at the first and second locations and operatively associated with the belt member for urging the normally biased together crest-like members apart in order to provide access to the continuous channel whereby objects can be received into, or discharged from the channel. Motors are in communication with the conveyance path for effecting the travel of the endless belt member about the conveyance path. The conveyance path can be configured to include travel through two or more elevations and one or more directional changes in order to convey objects above, below and/or around existing structures.

Peak Metamorphic Temperature Profile across Eastern Belt Franciscan, Northern California Coast Ranges

NASA Astrophysics Data System (ADS)

Schmidt, W. L.; Platt, J. P.

2017-12-01

Previous work done on metamorphic temperatures across the lawsonite-albite to blueschist facies rocks of the Eastern Belt of the Franciscan accretionary complex has relied on a combination of many methods, and suggests that temperature broadly increases from west to east. The Taliaferro Metamorphic Complex is an exception to this pattern and shows higher pressures, and possibly higher temperatures, than its surroundings. The exact location and nature of the faults separating accreted packets in the Eastern Belt is somewhat controversial. A recently calibrated low-temperature laser Raman geothermometer for use on carbonaceous material provides a uniform method of estimating peak metamorphic temperature across the eastern Franciscan and is here used to identify the position of major tectonic boundaries. Temperatures were obtained from exposures in Thomes Creek, Cottonwood Creek, Grindstone Creek, and the middle fork of the Eel River. Peak T in the South Fork Mountain Schist, the highest grade and easternmost unit in the Franciscan, is 310-375°C, whereas in immediately underlying lawsonite-albite facies rocks below the Log Springs thrust, peak T is 270 - 300°C. The Taliaferro Metamorphic Complex reached a peak temperature of 336°C, whereas the surrounding lawsonite-albite facies rocks yield peak temperatures as low as 232°C. Preliminary temperature profiles clearly allow the major faults bounding the Taliaferro Metamorphic Complex and the South Fork Mountain Schist to be located. Extension of the temperature profile has the potential to reveal further detail within these units and the lower grade rocks surrounding them.

Controls on the emplacement and genesis of the MKD5 and Sarah's Find Ni Cu PGE deposits, Mount Keith, Agnew Wiluna Greenstone Belt, Western Australia

NASA Astrophysics Data System (ADS)

Fiorentini, M. L.; Rosengren, N.; Beresford, S. W.; Grguric, B.; Barley, M. E.

2007-11-01

The Mount Keith (MKD5) nickel sulfide deposit is one of the largest komatiite-hosted nickel sulfide deposits in the world; it is hosted by a distinctive spinifex-free, cumulate-rich, ultramafic horizon/unit termed the Mount Keith Ultramafic (MKU). The Mount Keith Ultramafic shows significant variation along its lateral extent. The internal architecture is made up of adcumulate-textured pods and lenses, which are flanked by thinner meso- and orthocumulate-textured units, overlain by pyroxenitic and gabbroic horizons. The lateral and vertical changes in the geometry and internal architecture reflect variations in the lithological association and emplacement conditions along the strike extent of the belt. The chilled margins of the Mount Keith Ultramafic unit contain ˜1,200 ppm Ni. Olivine cumulates average ˜2,500 3,500 ppm Ni, with few exceptions (Ni > 4,500 ppm) reflecting occurrence of minor nickel sulfides, whereas pyroxenites and gabbros generally contain, respectively, ˜1,500 2,000 and ˜100 1,000 ppm Ni. Olivine cumulates generally contain low Cr concentrations (<2,500 ppm Cr), with the rare presence of chromite-rich intervals containing anomalously high values (>5,000 ppm Cr). The internal stratigraphy of the Mount Keith Ultramafic unit may be subdivided into two groups based on rare earth element distribution. The chilled margins and the internal units of the Main Adcumulate domain display LREE-enriched patterns [(La/Sm) n > 1 3] and negative Eu, Hf, Zr, Nb, and Ti anomalies. The internal units in the Western Mineralized Zone generally display flat chondrite-normalized REE patterns and only minor negative Nb anomalies. The pattern of platinum-group element (PGE) distribution varies greatly along the strike extent of the Mount Keith Ultramafic unit. The chilled margins display relatively low absolute concentrations [PGE (excl. Os) ˜16 ppb] and relatively fractionated patterns, with subchondritic Pt/Pd ratios (˜1.5), and superchondritic Pd/Ir ratios (˜3

Moving belt radiator development status

NASA Technical Reports Server (NTRS)

White, K. Alan

1988-01-01

Development of the Moving Belt Radiator (MBR) as an advanced space radiator concept is discussed. The ralative merits of Solid Belt (SBR), Liquid Belt (LBR), and Hybrid Belt (HBR) Radiators are described. Analytical and experimental efforts related to the dynamics of a rotating belt in microgravity are reviewed. The development of methods for transferring heat to the moving belt is discussed, and the results from several experimental investigations are summarized. Limited efforts related to the belt deployment and stowage, and to fabrication of a hybrid belt, are also discussed. Life limiting factors such as seal wear and micrometeroid resistance are identified. The results from various MBR point design studies for several power levels are compared with advanced Heat Pipe Radiator technology. MBR designs are shown to compare favorable at both 300 and 1000 K temperature levels. However, additional effort will be required to resolve critical technology issues and to demonstrate the advantage of MBR systems.

Digital Bedrock Compilation: A Geodatabase Covering Forest Service Lands in California

NASA Astrophysics Data System (ADS)

Elder, D.; de La Fuente, J. A.; Reichert, M.

2010-12-01

This digital database contains bedrock geologic mapping for Forest Service lands within California. This compilation began in 2004 and the first version was completed in 2005. Second publication of this geodatabase was completed in 2010 and filled major gaps in the southern Sierra Nevada and Modoc/Medicine Lake/Warner Mountains areas. This digital map database was compiled from previously published and unpublished geologic mapping, with source mapping and review from California Geological Survey, the U.S. Geological Survey and others. Much of the source data was itself compilation mapping. This geodatabase is huge, containing ~107,000 polygons and ~ 280,000 arcs. Mapping was compiled from more than one thousand individual sources and covers over 41,000,000 acres (~166,000 km2). It was compiled from source maps at various scales - from ~ 1:4,000 to 1:250,000 and represents the best available geologic mapping at largest scale possible. An estimated 70-80% of the source information was digitized from geologic mapping at 1:62,500 scale or better. Forest Service ACT2 Enterprise Team compiled the bedrock mapping and developed a geodatabase to store this information. This geodatabase supports feature classes for polygons (e.g, map units), lines (e.g., contacts, boundaries, faults and structural lines) and points (e.g., orientation data, structural symbology). Lookup tables provide detailed information for feature class items. Lookup/type tables contain legal values and hierarchical groupings for geologic ages and lithologies. Type tables link coded values with descriptions for line and point attributes, such as line type, line location and point type. This digital mapping is at the core of many quantitative analyses and derivative map products. Queries of the database are used to produce maps and to quantify rock types of interest. These include the following: (1) ultramafic rocks - where hazards from naturally occurring asbestos are high, (2) granitic rocks - increased

Petrogenetic implications from ultramafic rocks and pyroxenites in ophiolitic occurrences of East Othris, Greece

NASA Astrophysics Data System (ADS)

Koutsovitis, P.; Magganas, A.

2012-04-01

Ultramafic rocks and pyroxenites in east Othris are included within ophiolitic units near the villages of Vrinena, Karavomilos, Pelasgia, Eretria, Agios Georgios, Aerino and Velestino. The first five ophiolitic occurrences are estimated to have been emplaced between the Oxfordian and Tithonian-Berriasian[1,2,3], while the latter two have been emplaced during the Eocene[4]. Ultramafic rocks include variably serpentinized harzburgites and lherzolites. Pyroxenites are usually found in the form of crosscutting veins within the harzburgites. Ultramafic rocks include depleted lherzolites, with Al2O3 ranging from 1.12 to 1.80 wt% and Cr from 3250 to 3290 ppm, as well as moderate to highly depleted serpentinized harzburgites, with Al2O3 ranging from 0.69 to 1.98 wt% and Cr from 2663 to 5582 ppm. Pyroxenites have generally higher Al2O3 ranging from 1.91 to 3.08 wt% and variable Cr ranging from 1798 to 3611 ppm. Lherzolites mostly include olivines (Fo=87.07-89.23) and clinopyroxenes (Mg#=85.71-90.12). Spinels from Eretria lherzolite (TiO2=0.02-0.08 wt%, Al2O3=36.06-42.45 wt%, Cr#=31.67-36.33) are compositionally similar with those of MORB peridotites[5], while those from Vrinena lherzolite (TiO2=0.16-0.43 wt%, Al2O3=6.90-22.12 wt%, Cr#=57.69-76.88) are similar to SSZ peridotites[5]. Serpentinized harzburgites include few olivines (Fo=90.51-91.15), enstatite porphyroclasts (Mg#=87.42-88.91), as well as fine grained enstatites of similar composition. Harzburgites from Pelasgia, Eretria and Agios Georgios include spinels (TiO2=0.03-0.08 wt%, Al2O3=23.21-31.58 wt%, Cr#=45.21-56.85) which do not clearly show if they are related with MORB or SSZ peridotites[5]. Spinels from Karavomilos harzburgite (TiO2=0.02-0.05 wt%, Al2O3=45.71-50.85 wt%, Cr#=16.84-22.32) are compositionally similar with MORB peridotites[5], whereas spinels from Vrinena harzburgite (TiO2=0.15-0.19 wt%, Al2O3=1.42-1.86 wt% Cr#=91.64-93.47) with SSZ peridotites[5]. Pyroxenites include clinopyroxenes (Mg#=84

Stratigraphy of the late Proterozoic Murdama Group, Saudi Arabia

USGS Publications Warehouse

Greene, Robert C.

1993-01-01

The Murdama group probably was deposited in a back-arc basin on a continental platform bounded on the west by an active volcanic arc above an east-dipping subduction zone. The position of the subduction zone, which was active during most of the deposition in the Afif belt, is marked by a belt of gabbro and ultramafic rocks herein named the jabal Burqah belt. The subduction zone later stepped out to the southwest to the Nabitah belt, and Murdama strata were deposited in the Jabal Hadhah, Mistahjed, and smaller basins.

Placer and lode platinum-group minerals in south Kalimantan, Indonesia: evidence for derivation from Alaskan-type ultramafic intrusions

USGS Publications Warehouse

Zientek, M.L.

1992-01-01

Platinum-group minerals occur in significant proportions in placer deposits in several localities in South Kalimantan. They consist of Pt-Fe alloy that may be intergrown with or contain inclusions of Ir-Os-Ru alloy, laurite and chromite. Alluvial PGM found along Sungai Tambanio are in part derived from chromatite schlieren in dunitic bodies intruded into clinopyroxene cumulates that may be part of an Alaskan-type ultramafic complex. A chromitite schlieren in serpentinite from one of these dunitic bodies is anomalous in PGE. The chondrite-normalized PGE pattern for this rock, pan concentrates from this area, and PGM concentrates from diamond-Au-PGM placer deposits have an "M'-shaped pattern enriched in Ir and Pt that is typical of PGE-mineralization associated with Alaskan-type ultramafic complexes. -Authors

Regional metamorphism in the Condrey Mountain Quadrangle, north-central Klamath Mountains, California

USGS Publications Warehouse

Hotz, Preston Enslow

1979-01-01

A subcircular area of about 650 km 2 in northern California and southwestern Oregon is occupied by rocks of the greenschist metamorphic facies called the Condrey Mountain Schist. This greenschist terrane is bordered on the east and west by rocks belonging to the amphibolite metamorphic facies that structurally overlie and are thrust over the Condrey Mountain Schist. The amphibolite facies is succeeded upward by metavolcanic and metasedimentary rocks belonging to the greenschist metamorphic facies. The Condrey Mountain Schist is composed predominantly of quartz-muscovite schist and lesser amounts of actinolite-chlorite schist formed by the metamorphism of graywacke and spilitic volcanic rocks that may have belonged to the Galice Formation of Late Jurassic age. Potassium-argon age determinations of 141?4 m.y. and 155?5 m.y. obtained on these metamorphic rocks seem to be incompatible with the Late Jurassic age usually assigned the Galice. The rocks that border the amphibolite facies are part of an extensive terrane of metavolcanic and metasedimentary rocks belonging to the western Paleozoic and Triassic belt. The metavolcanic rocks include some unmetamorphosed spilite but are mostly of the greenschist metamorphic facies composed of oligoclase (An15-20) and actinolite with subordinate amounts of chlorite and clinozoisiteepidote. The interbedded sedimentary rocks are predominantly argillite and slaty argillite, less commonly siliceous argillite and chert, and a few lenticular beds of marble. On the south, high-angle faults and a tabular granitic pluton separate the greenschist metavolcanic terrane from the amphibolite facies rocks; on the east, nonfoliated amphibolite is succeeded upward, apparently conformably, by metasedimentary rocks belonging to the greenschist metavolcanic terrane. In the southern part of Condrey Mountain quadrangle, an outlier of a thrust plate composed of the Stuart Fork Formation overlies the metavolcanic and metasedimentary rocks. The Stuart

Assessment of heavy metal contamination in sediment at Sukinda ultramafic complex using HAADF-STEM analysis.

PubMed

Equeenuddin, Sk Md; Pattnaik, Binaya Kumar

2017-10-01

The Sukinda ultramafic complex in Odisha has the largest chromite reserve in India. Sediment derived from ultramafic rocks has been enriched with various metals. Further, mining activities enhance the influx of metals into sediment by dumping mine overburden and tailings in the open area. Metal concentration in sediment is found in order of Cr Total (Cr) > Mn > Ni > Co > Zn > Cu with average concentration 26,778 mg/kg, 3098 mg/kg, 1813 mg/kg, 184 mg/kg, 116 mg/kg and 44 mg/kg respectively. Concentration of Cr(VI) varies from 5.25 to 26.47 mg/L with an average of 12.27 mg/L. Based on various pollution indices, it is confirmed that the area is severely contaminated. Nano-scale goethite, kaolinite, clinochlore and chromite have been identified and have high concentration of Cr, Co and Ni. Goethite has shown maximum metal retention potential as deciphered by high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM). The HAADF-STEM mapping and principal component analysis indicate that Cr and Co mostly derived from chromite whereas Ni and Zn are derived from serpentine. Later, these metals co-precipitate and/or adsorbed onto the goethite and clay minerals. Fractionation study of metals confirms that Cu is the most mobile element followed by Zn. However, at low pH condition Ni is mobilized and likely to be bioavailable. Though Cr mostly occurs in residual fraction but as its concentration is very high, a small proportion of exchangeable fraction contributes significantly in terms of its bioavailability. Thus bioavailable Cr can pose severe threat to the environment in the Sukinda ultramafic complex. Copyright © 2017 Elsevier Ltd. All rights reserved.

Vesta Evolution from Surface Mineralogy: Mafic and Ultramafic Mineral Distribution

NASA Technical Reports Server (NTRS)

DeSanctis, M. C.; Ammannito, E.; Palomba, E.; Longobardo, A.; Mittlefehldt, D. W.; McSween, H. Y; Marchi, S.; Capria, M. T.; Capaccioni, F.; Frigeri, A.;

Seismicity and recent faulting in eastern California and western and central Nevada: A preliminary report

NASA Technical Reports Server (NTRS)

Abdel-Gawad, M. (Principal Investigator); Silverstein, J.; Tubbesing, L.

1973-01-01

The author has identified the following significant results. ERTS-1 imagery covering the eastern California-Nevada seismic belt were utilized to study the fault pattern in relation to the distribution of earthquake epicenters and Quaternary volcanic rocks. Many suspected faults not previously mapped were identified. These include several suspected shear zones in Nevada, faults showing evidence of recent breakage, and major lineaments. Highly seismic areas are generally characterized by Holocene faulting and Quaternary volcanic activity. However, several major fault segments showing evidence of recent breakage are associated with little or no seismicity. The tectonic pattern strongly suggests that the eastern California-Nevada seismic belt coincides with a major crustal rift associated with zones of lateral shear. New data on potentially active fault zones have direct practical applications in national and local earthquake hazard reduction programs. Positive contacts have been made with Kern and Ventura Counties to make results of this investigation available for application to their earthquake hazards definition projects.

Origin of narrow terranes and adjacent major terranes occurring along the denali fault in the eastern and central alaska range, alaska

USGS Publications Warehouse

Nokleberg, W.J.; Richter, D.H.

2007-01-01

Several narrow terranes occur along the Denali fault in the Eastern and Central Alaska Range in Southern Alaska. These terranes are the Aurora Peak, Cottonwood Creek, Maclaren, Pingston, and Windy terranes, and a terrane of ultramafic and associated rocks. Exterior to the narrow terranes to the south is the majorWrangellia island arc composite terrane, and to the north is the major Yukon Tanana metamorphosed continental margin terrane. Overlying mainly the northern margin of the Wrangellia composite terrane are the Kahiltna overlap assemblage to the west, and the Gravina- Nutzotin-Gambier volcanic-plutonic- sedimentary belt to the east and southeast. The various narrow terranes are interpreted as the result of translation of fragments of larger terranes during two major tectonic events: (1) Late Jurassic to mid-Cretaceous accretion of the Wrangellia island arc composite terrane (or superterrane composed of the Wrangellia, Peninsular, and Alexander terranes) and associated subduction zone complexes; and (2) starting in about the Late Cretaceous, dextral transport of the Wrangellia composite terrane along the Denali fault. These two major tectonic events caused: (1) entrapment of a lens of oceanic lithosphere along the suture belt between the Wrangellia composite terrane and the North American Craton Margin and outboard accreted terranes to form the ultramafic and mafic part of the terrane of ultramafic and associated rocks, (2) subsequent dextral translation along the Denali fault of the terrane of ultramafic and associated rocks, (3) dextral translation along the Denali fault of the Aurora Peak, Cottonwood Creek, and Maclaren and continental margin arc terranes from part of the Coast plutonic-metamorphic complex (Coast-North Cascade plutonic belt) in the southwest Yukon Territory or Southeastern Alaska, (4) dextral translation along the Denali fault of the Pingston passive continental margin from a locus along the North American Continental Margin, and (5

Inherited Fe and Ti electron transition spectroscopic features in altered ultramafic-carbonatite intrusives

NASA Astrophysics Data System (ADS)

Shavers, E. J.; Ghulam, A.; Encarnacion, J. P.

2016-12-01

Spectroscopic reflectance in the visible to short-wave infrared region is an important tool for remote geologic mapping and is applied at scales from satellite to field measurements. Remote geologic mapping is challenging in regions subject to significant surficial weathering. Here we identify absorption features found in altered volcanic pipes and dikes in the Avon Volcanic District, Missouri, that are inherited from the original ultramafic and carbonatite lithology. Alteration ranges from small degree hydrothermal alteration to extensive laterization. The absorption features are three broad minima centered near 690, 890, and 1100 nm. Features in this region are recognized to be caused by ferric and ferrous Fe minerals including olivine, carbonates, chlorite, and goethite all of which are found among the Avon pipes and dikes that are in various stages of alteration. Iron-related intervalence charge transfer and crystal field perturbations of ions are the principal causes of the spectroscopic features in the visible to near-infrared region yet spectra are also distorted by factors like texture and the presence of opaque minerals known to reduce overall reflectance. In the Avon samples, Fe oxide content can reach >15 wt% leading to prominent absorption features even in the less altered ultramafics with reflectance curve maxima as low as 5%. The exaggerated minima allow the altered intrusive rocks to stand out among other weathered lithologies that will often have clay features in the region yet have lower iron concentration. The absorption feature centered near 690 nm is particularly noteworthy. Broad mineral-related absorption features centered at this wavelength are rare but have been linked to Ti3+ in octahedral coordination. The reduced form of Ti is not common in surface lithologies. Titanium-rich andradite has Ti3+ in the octahedral position, is resistant to weathering, is found among the Avon lithologies including ultramafic, carbonatite, and carbonated

Mafic/Ultramafic xenoliths from Saurashtra peninsula of Gujarat; northwestern Deccan Trap, India

NASA Astrophysics Data System (ADS)

Naushad, M.; Behera, J. R.; Chakra, M.; Murthy, P. V.

2017-12-01

The crustal growth forming processes at the crust-mantle interface or within the crust due to magma underplating is important for the formation and emplacement of continental flood basalt and large igneous provinces. Mafic/ultramafic xenoliths from lower crust or upper mantle provide clue to characterize the underplated material and magmatic processes. Earlier study of ultramafic xenoliths suggested magma underplating and crustal growth in Kuchchh, Gujarat, northwestern Deccan Trap (NWDT). Absence of such xenoliths in Saurashtra peninsula (SP) of NWDT however could not supplement this. Here, we report the mafic/ultramafic xenoliths entrained in high MgO basaltic lava flows of NWDT of SP in Rajkot district of Gujarat, India. The xenoliths are medium to coarse grained, meso - to melanocratic, elongated to angular pyroxenite (Type-I), two pyroxenes gabbro (Type-II) and anorthosite (Type-III) showing sharp contact with host basalt flows. Type-I xenoliths dominated by clinopyroxene (cpx) (Wo49-45 En49-38) with olivine (ol) (Fo84-78), exhibit cumulate texture, Type-II composed of cpx (core-Wo49-48 En42-41), orthopyroxene (opx) (core- En77-76 Fs23-22) and plagioclase (plag) (Ab35-28 An71-64) and Type-III, composed dominantly of plag (Ab67-29 An68-28) with minor opx (En78-76 Fs20-18) and a grain of hercynite (Al2O3=59%) in close association with plag. The basaltic lavas are porphyritic containing ol (Fo88-75), cpx (Wo50-48 En39-37), plag (Ab43-26 An74-54) and opaques. Whole rock geochemical data of xenolith entrained lava flows indicates high MgO (10-11 wt%) with high Ni (421-430 ppm) and Cr (795-1076 ppm). The equilibration temperature calculated from cpx - opx (adjacent grain of cpx and opx, pair-A; inclusion of cpx within opx, pair-B) for Type-II xenolith indicates 778°C and 789°C (pair-A) and 821°C and 832°C (pair-B) at 5 kbar and 10 kbar pressure respectively. Present study suggests that the possibility of magma underplating at crust-mantle interface or presence

Thermodynamic constraints on hydrogen generation during serpentinization of ultramafic rocks

NASA Astrophysics Data System (ADS)

McCollom, Thomas M.; Bach, Wolfgang

2009-02-01

In recent years, serpentinized ultramafic rocks have received considerable attention as a source of H 2 for hydrogen-based microbial communities and as a potential environment for the abiotic synthesis of methane and other hydrocarbons within the Earth's crust. Both of these processes rely on the development of strongly reducing conditions and the generation of H 2 during serpentinization, which principally results from reaction of water with ferrous iron-rich minerals contained in ultramafic rocks. In this report, numerical models are used to investigate the potential influence of chemical thermodynamics on H 2 production during serpentinization. The results suggest that thermodynamic constraints on mineral stability and on the distribution of Fe among mineral alteration products as a function of temperature are likely to be major factors controlling the extent of H 2 production. At high temperatures (>˜315 °C), rates of serpentinization reactions are fast, but H 2 concentrations may be limited by the attainment of stable thermodynamic equilibrium between olivine and the aqueous fluid. Conversely, at temperatures below ˜150 °C, H 2 generation is severely limited both by slow reaction kinetics and partitioning of Fe(II) into brucite. At 35 MPa, peak temperatures for H 2 production occur at 200-315 °C, indicating that the most strongly reducing conditions will be attained during alteration within this temperature range. Fluids interacting with peridotite in this temperature range are likely to be the most productive sources of H 2 for biology, and should also produce the most favorable environments for abiotic organic synthesis. The results also suggest that thermodynamic constraints on Fe distribution among mineral alteration products have significant implications for the timing of magnetization of the ocean crust, and for the occurrence of native metal alloys and other trace minerals during serpentinization.

Epsilon Eridani Inner Asteroid Belt

NASA Image and Video Library

2017-09-14

SCI2017_0004: Artist's illustration of the Epsilon Eridani system showing Epsilon Eridani b, right foreground, a Jupiter-mass planet orbiting its parent star at the outside edge of an asteroid belt. In the background can be seen another narrow asteroid or comet belt plus an outermost belt similar in size to our solar system's Kuiper Belt. The similarity of the structure of the Epsilon Eridani system to our solar system is remarkable, although Epsilon Eridani is much younger than our sun. SOFIA observations confirmed the existence of the asteroid belt adjacent to the orbit of the Jovian planet. Credit: NASA/SOFIA/Lynette Cook

Continuous Mass Measurement on Conveyor Belt

NASA Astrophysics Data System (ADS)

Tomobe, Yuki; Tasaki, Ryosuke; Yamazaki, Takanori; Ohnishi, Hideo; Kobayashi, Masaaki; Kurosu, Shigeru

The continuous mass measurement of packages on a conveyor belt will become greatly important. In the mass measurement, the sequence of products is generally random. An interesting possibility of raising throughput of the conveyor line without increasing the conveyor belt speed is offered by the use of two or three conveyor belt scales (called a multi-stage conveyor belt scale). The multi-stage conveyor belt scale can be created which will adjust the conveyor belt length to the product length. The conveyor belt scale usually has maximum capacities of less than 80kg and 140cm, and achieves measuring rates of more than 150 packages per minute and more. The output signals from the conveyor belt scale are always contaminated with noises due to vibrations of the conveyor and the product to be measured in motion. In this paper an employed digital filter is of Finite Impulse Response (FIR) type designed under the consideration on the dynamics of the conveyor system. The experimental results on the conveyor belt scale suggest that the filtering algorithms are effective enough to practical applications to some extent.

Safety Belt Use: Traffic Safety Tips

DOT National Transportation Integrated Search

1996-01-01

This fact sheet, NHTSA Facts: Summer 1996, discusses traffic safety tips for wearing seat belts. It describes the correct way to wear a seat belt, how to sit, and differentiates between lap belts and shoulder belts. It points out that air bags provid...

Integration of 3 Consecutive Years of Aqueous Geochemistry Monitoring Serpentinization at the Coast Range Ophiolite Microbial Observatory (CROMO), Northern California, USA

NASA Astrophysics Data System (ADS)

Cardace, D.; Hoehler, T. M.; McCollom, T. M.; Schrenk, M. O.; Kubo, M. D.

2014-12-01

In August 2011, a set of 8 groundwater monitoring wells were established in actively serpentinizing ultramafic rocks of the Coast Range Ophiolite near Lower Lake, CA, as a NASA Astrobiology Institute project (Cardace et al., 2013). These wells have enabled repeated sampling and analysis of aqueous geochemistry, which we now present in an integrated model of the progress of serpentinization at this locality. The Coast Range Ophiolite Microbial Observatory (CROMO) plumbs groundwaters percolating through a tectonic mélange of Jurassic-aged oceanic crust, with blocks of metabasalt and metagabbro, variably serpentinized ultramafics, Great Valley Sequence sedimentary rocks including the Jurassic Knoxville formation and the Cretaceous Crack Canyon formation, as well as rocks resulting from silica-carbonate alteration of serpentinites (marginal listvenites). All of these rock units are accessible in the McLaughlin Natural Reserve (administered by the University of California-Davis). In this work, we report on persistent geochemical trends in CROMO waters, which are gas-rich, high pH (11+), Ca2+-OH- type waters, contrast their characteristics with other continental sites of serpentinization and deep sea serpentinizing vent systems, and place the evolution of these waters in a water-rock reaction context based on geochemical modeling.

Use of seatbelts in cars with automatic belts.

PubMed Central

Williams, A F; Wells, J K; Lund, A K; Teed, N J

1992-01-01

Use of seatbelts in late model cars with automatic or manual belt systems was observed in suburban Washington, DC, Chicago, Los Angeles, and Philadelphia. In cars with automatic two-point belt systems, the use of shoulder belts by drivers was substantially higher than in the same model cars with manual three-point belts. This finding was true in varying degrees whatever the type of automatic belt, including cars with detachable nonmotorized belts, cars with detachable motorized belts, and especially cars with nondetachable motorized belts. Most of these automatic shoulder belts systems include manual lap belts. Use of lap belts was lower in cars with automatic two-point belt systems than in the same model cars with manual three-point belts; precisely how much lower could not be reliably estimated in this survey. Use of shoulder and lap belts was slightly higher in General Motors cars with detachable automatic three-point belts compared with the same model cars with manual three-point belts; in Hondas there was no difference in the rates of use of manual three-point belts and the rates of use of automatic three-point belts. PMID:1561301

Eclogites and garnet clinopyroxenites in the Anrakhai complex, Central Asian Orogenic Belt, Southern Kazakhstan: P-T evolution, protoliths and some geodynamic implications

NASA Astrophysics Data System (ADS)

Pilitsyna, Anfisa V.; Tretyakov, Andrey A.; Degtyarev, Kirill E.; Cuthbert, Simon J.; Batanova, Valentina G.; Kovalchuk, Elena V.

2018-03-01

The Anrakhai Metamorphic Complex (AMC), located in the SE part of the Chu-Ili Mountains of Southern Kazakhstan in the western part of Central Asian Orogenic Belt, exhibits occurrences of HP metamorphic rocks in the form of eclogites and garnet clinopyroxenites with peak metamorphic conditions of 750-850° and 15-19 kbar estimated with both conventional geothermobarometric methods and phase diagram modeling. P-T estimates as well as intimate field relations evidently imply a common metamorphic history for eclogites and garnet clinopyroxenites of the AMC. These high-pressure, medium temperature eclogite facies P-T conditions are indicative of a collision or subduction tectonic setting. Major and trace element geochemistry suggests that they probably had a common magmatic origin as part of a suite of differentiated tholeiitic intrusions. Furthermore, distinctive mineral and chemical compositions of these eclogites and garnet clinopyroxenites correspond to the Fe-Ti type of ultramafic rocks suggesting that they may have been derivatives of intraplate tholeiitic melts, introduced into continental crust before HP metamorphism.

Geology and economic potential for chromite in the Zhob Valley ultramafic rock complex, Hindubagh, Quetta division, West Pakistan

USGS Publications Warehouse

Rossman, D.L.; Ahmad, Zaki; Rahman, Hamidur

1971-01-01

The ultramafic rocks making up the Zhob Valley igneous complex have yielded small amounts of metallurgical-grade chromite since the early part of the century. From 1968-1970 a cooperative study undertaken by the Geological Survey of Pakistan and the U. S. Geological Survey, under the auspices of the Government of Pakistan and the Agency for International Development, evaluated the chromite potential of the Zhob Valley area and provided data for effective exploration. The Jung Tor Ghar ultramafic rock mass, covering an area of about 45 square miles, is a thrust-fault block completely surrounded and underlain (?) by sedimentary rocks as young as Late Cretaceous in age. The igneous rocks were thrust from the northwest along an east-trending, north-dipping fault in Late Cretaceous or Paleocene time and were peneplaned, dissected, and deeply laterized by mid-Eocene time. The ultramafic rocks consist of interlayered harzburgite and dunite and a cross-cutting dunite here called transgressive dunite. Layered structure passes without discernible deviation from the interlayered harzburgite-dunite through the transgressive dunite. The lowest rocks in the mass, composed mainly of transgressive dunite, grade upward into the interlayered rock about 3,000 feet above the fault block base. The upper transgressive dunites tend to form interconnecting linear networks and probably a few pipe-like structures. The transgressive dunite is thought to have formed by action of water derived from the underlying sedimentary rocks; the water heated by the hot ultramafic rock (at the time of emplacement) altered the pyroxene to olivine and talc, and, with lowering temperature, to serpentine. Other interpretations are possible. Virtually all the chromite in the Jung Tor Ghar lies in or immediately above the masses of transgressive dunite. This fact provides a key to chromite exploration: The most favorable zone for prospecting lies in the vicinity of the upper contacts of the transgressive

Belt separation system under slat in fattening pig housing: effect of belt type and extraction frequency.

PubMed

Alonso, F; Vázquez, J; Ovejero, I; Garcimartín, M A; Mateos, A; Sánchez, E

2010-08-01

The efficiency of manure separation by a conveyor belt under a partially slatted floor for fattening pigs was determined for two types of belts, a flat belt with an incline of up to 6 degrees transversely and a concave belt with an incline of up to 1 degrees longitudinally. A 31.20% and 23.75% dry matter content of the solid fraction was obtained for the flat and concave belt, respectively. The flat belt was more efficient at 6 degrees than other slope angles. The residence time of the manure on the two belt types influenced the separation efficiency from a live weight of 63.00 kg upwards. The quantity of residue produced with this system was reduced to 25-40% with respect to a pit system under slat. This could mean a remarkable reduction in costs of storage, transport and application of manure. (c) 2010 Elsevier Ltd. All rights reserved.

Seat belt use on interstate highways.

PubMed Central

Wells, J K; Williams, A F; Lund, A K

1990-01-01

More than 5,000 miles of limited-access highways in the eastern United States and Canada were traveled to observe seat belt use. Overall belt use was 58 percent in the United States and 79 percent in Canada. The data indicate that belt use in the United States follows a different pattern on interstate highways than on other streets and roads, with relatively high belt use rates (over 50 percent) appearing to be somewhat independent of belt use law provisions. PMID:2343969

Microbial life associated with low-temperature alteration of ultramafic rocks in the Leka ophiolite complex.

PubMed

Daae, F L; Økland, I; Dahle, H; Jørgensen, S L; Thorseth, I H; Pedersen, R B

2013-07-01

Water-rock interactions in ultramafic lithosphere generate reduced chemical species such as hydrogen that can fuel subsurface microbial communities. Sampling of this environment is expensive and technically demanding. However, highly accessible, uplifted oceanic lithospheres emplaced onto continental margins (ophiolites) are potential model systems for studies of the subsurface biosphere in ultramafic rocks. Here, we describe a microbiological investigation of partially serpentinized dunite from the Leka ophiolite (Norway). We analysed samples of mineral coatings on subsurface fracture surfaces from different depths (10-160 cm) and groundwater from a 50-m-deep borehole that penetrates several major fracture zones in the rock. The samples are suggested to represent subsurface habitats ranging from highly anaerobic to aerobic conditions. Water from a surface pond was analysed for comparison. To explore the microbial diversity and to make assessments about potential metabolisms, the samples were analysed by microscopy, construction of small subunit ribosomal RNA gene clone libraries, culturing and quantitative-PCR. Different microbial communities were observed in the groundwater, the fracture-coating material and the surface water, indicating that distinct microbial ecosystems exist in the rock. Close relatives of hydrogen-oxidizing Hydrogenophaga dominated (30% of the bacterial clones) in the oxic groundwater, indicating that microbial communities in ultramafic rocks at Leka could partially be driven by H2 produced by low-temperature water-rock reactions. Heterotrophic organisms, including close relatives of hydrocarbon degraders possibly feeding on products from Fischer-Tropsch-type reactions, dominated in the fracture-coating material. Putative hydrogen-, ammonia-, manganese- and iron-oxidizers were also detected in fracture coatings and the groundwater. The microbial communities reflect the existence of different subsurface redox conditions generated by

Drivers' assessment of Ford's belt reminder system.

PubMed

Williams, Allan F; Wells, Joann K

2003-12-01

In recent model years, Ford vehicles have been equipped with a supplementary seat belt reminder system that flashes and chimes intermittently for up to 5 min if the driver is unbelted. Sound- and light-based belt reminder systems of various types are beginning to appear in the market place, and it is important to learn about their acceptance and ability to increase belt use. The present study was designed to ascertain consumer reaction and reported belt use regarding the Ford system. Personal interviews were conducted with 405 drivers of vehicles with the reminder system. Among the drivers, 67% said they had activated the belt reminder one or more times, 73% said that the last time this happened they fastened their belts, 46% said their belt use had increased since driving this vehicle, 78% said they liked the reminder system, and 79% said they wanted a reminder system like this in their next vehicle. Five percent had disabled the system. Part-time users were responsive to the reminder, for example, of those who said they currently used belts usually but not on some occasions, 70% said they fastened their seat belts the last time the reminder was activated and 76% said their belt use had increased. Five percent spontaneously mentioned the belt reminder as an especially disliked feature of their new vehicles, and 2% said their belt use had decreased since having it. The 7% of respondents who reported they used belts never or very occasionally were least responsive to the system. Overall, the Ford belt reminder system is being favorably received.

Oak Ridge fault, Ventura fold belt, and the Sisar decollement, Ventura basin, California

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yeats, R.S.; Huftile, G.J.; Grigsby, F.B.

1988-12-01

The rootless Ventura Avenue, San Miguelito, and Rincon anticlines (Ventura fold belt) in Pliocene -Pleistocene turbidites are fault-propagation folds related to south-dipping reverse faults rising from a decollement in Miocene shale. To the east, the Sulfur Mountain anticlinorium overlies and is cut by the Sisar, Big Canyon, and Lion south-dipping thrusts that merge downward into the Sisar decollement in lower Miocene shale. Shortening of the Miocene and younger sequence is {approximately} 3 km greater than that of underlying competent Paleogens strata in the Ventura fold belt and {approximately} 7 km greater farther east at Sulfur Mountain. Cross-section balancing requires thatmore » this difference be taken up by the Paleogene sequence at the Oak Ridge fault to the south. Convergence is northeast to north-northeast on the base of earthquake focal mechanisms, borehole breakouts, and piercing-point offest of the South Mountain seaknoll by the Oak Ridge fault. A northeast-trending line connecting the west end of Oak Ridge and the east end of Sisar fault separates an eastern domain where late Quaternary displacement is taken up entirely on the Oak Ridge fault and a western domain where displacement is transferred to the Sisar decollement and its overlying rootless folds. This implies that (1) the Oak Ridge fault near the coast presents as much seismic risk as it does farther east, despite negligible near-surface late Quaternary movement; (2) ground-rupture hazard is high for the Sisar fault set in the upper Ojai Valley; and (3) the decollement itself could produce an earthquake analogous to the 1987 Whittier Narrows event in Low Angeles.« less

Pilot tests of a seat belt gearshift delay on the belt use of commercial fleet drivers.

DOT National Transportation Integrated Search

2009-12-01

the seat belt was buckled. Participants, commercial drivers from the United States and Canada who did not consistently wear their seat belts, could avoid the delay by fastening their seat belts. Unbelted participants experienced a delay of either a c...

Normative Misperceptions of Peer Seat Belt Use Among High School Students and Their Relationship to Personal Seat Belt Use

PubMed Central

LITT, DANA M.; LEWIS, MELISSA A.; LINKENBACH, JEFFREY W.; LANDE, GARY; NEIGHBORS, CLAYTON

2016-01-01

Objectives This research examined gender-specific perceptions of peer seat belt use norms among high school students and their relationship with one’s own seat belt use. We expected that students would underestimate the seat belt use of their peers and that these perceptions would be positively associated with their own seat belt use. Methods High school students from 4 schools (N = 3348; 52% male) completed measures assessing perceived seat belt use and personal seat belt use. Results Findings demonstrated that students perceived that others engaged in less seat belt use than they do and that perceived norms were positively associated with one’s own seat belt use. Conclusions Peer influences are a strong predictor of behavior, especially among adolescents. Ironically, adolescents’ behaviors are often influenced by inaccurate perceptions of their peers. This research establishes the presence of a misperception related to seat belt use and suggests that misperception is associated with own behaviors. This research provides a foundation for social norms–based interventions designed to increase seat belt use by correcting normative misperceptions among adolescents. PMID:24628560

Behavior of major and trace elements upon weathering of peridotites in New Caledonia : A possible site on ultramafic rocks for the Critical Zone Exploration Network (CZEN) ?

NASA Astrophysics Data System (ADS)

Juillot, Farid; Fandeur, D.; Fritsch, E.; Morin, G.; Ambrosi, J. P.; Olivi, L.; Cognigni, A.; Hazemann, J. L.; Proux, O.; Webb, S.; Brown, G. E., Jr.

2010-05-01

Ultramafic rocks cover about 1% of the continental surfaces and are related to ophiolitic bodies formed near convergent plate boundaries (Coleman, 1977). The most typical ultramafic rocks are dunite and harzburgite, which are composed of easily weatherable ferromagnesian mineral species (olivines and pyroxenes), but also of more resistant spinels (chromite and magnetite). Oceanic serpentinization of these ultramafic rocks usually lead to partial transformation of these initial mineral assemblages by forming hydrous layer silicates such as serpentine (lizardite, chrysotile and antigorite) talc, chlorite and actinolite (Malpas, 1992). It also lead to the formation of highly sheared textures, which favor meteoric weathering through preferential water flows. Compared to their crystalline rock counterpart that covers most of the continental surfaces, these ultramafic rocks mainly differ by their lower SiO2, Al2O3 and K2O contents (less than 50%, 10% and 1%, respectively) and, on the opposite, much higher MgO content (more than 18%). Moreover, they commonly have higher concentrations in FeO and other trace elements, such as Ni, Cr, Mn and Co. Weathering of these rocks is then at the origin of major geochemical anomalies on continental surfaces, especially when they occur in tropical and subtropical regions. Such conditions are encountered in New Caledonia where one third of the surface is covered with peridotites (mainly harzburgite with small amounts of dunite) obducted about 35 millions years ago during large tectonic events in the Southwest Pacific at the Late Eocene (Cluzel et al., 2001). Tropical weathering of these ultramafic rocks lead to the development of thick lateritic regoliths where almost all Mg and Si have been leached out and Fe, Mn, Ni, Cr and Co have been relatively concentrated. In these oxisols, Ni, Cr and Co can exhibit concentration up to several wt%, which make them good candidates for ore mining (New Caledonia is the third Ni producer in the world

Organics in hydrothermal fluids from ultramafics on the Mid-Atlantic Ridge (MAR) - Abiogenic and/or biogenic origin?

NASA Astrophysics Data System (ADS)

Charlou, J.; Donval, J.; Fouquet, Y.; Jean-Baptiste, P.; Dehairs, F.; Holm, N.; Godfroy, A.

2005-12-01

Between 12°N and the Azores Triple Junction along the MAR, CH4 anomalies over axial ultramafic sites are common and point to the association of high or low temperature hydrothermal activity and mantle degassing indicative of ongoing serpentinization process. The general occurrence of isotopically-heavy methane shows the possible abiogenic synthesis of hydrocarbons in hydrothermal systems. The abiogenic formation of CH4 and more complex organic compounds is related to the process of serpentinization of mantellic rocks. Three sites (Logachev, 14°45'N; Rainbow, 36°14'N; Lost City Field, 30°N) are known on the MAR. New fresh fluids were recently sampled at Rainbow and Lost City by the French ROV-Victor during EXOMAR cruise (July 24 to August 28, 2005). The Rainbow and Lost City fluids issued from contrasted ultramafic environments are both enriched in H2, CH4 and hydrocarbons. Hydrogen gas represents more than 40 per cent total gas volume extracted from fluids. SPME (Solid Phase Micro-Extraction) and SBSE (Stir-Bar Sorptive Extraction) extraction techniques were used on board for organic recovery and the analysis was performed on shore by direct GC/MS or by Thermo-Desorption/GC/MS. The hydration of olivine and pyroxen minerals with conversion of Fe(II) to Fe(III) in magnetite during serpentinization leads to production of H2 and conversion of dissolved CO2 to reduced-C species including methane, ethane, propane. In addition heavier straight chain hydrocarbons as alcohols, aldehydes, ketones, aromatics, and cyclic compounds are identified at Rainbow. These compounds may be generated in ultramafic rocks through catalytic reactions (Fischer-Tropsch type reactions), but a biogenic contribution cannot be excluded. Abiogenic organic compounds may be produced from crystalline basement, from volcanic structures, from riftogenic zones and probably from sedimented margins.

Seat Belt Sign and Its Significance

PubMed Central

Agrawal, Amit; Inamadar, Praveenkumar Ishwarappa; Subrahmanyam, Bhattara Vishweswar

2013-01-01

Safety belts are the most important safety system in motor vehicles and when worn intend to prevent serious injuries. However, in unusual circumstances (high velocity motor vehicle collisions) these safety measures (seat belts) can be the source and cause of serious injuries. The seat belt syndrome was first described as early by Garrett and Braunste in but the term “seat belt sign” was discussed by Doersch and Dozier. Medical personnel's involved in emergency care of trauma patients should be aware of seat belt sign and there should a higher index of suspicion to rule out underlying organ injuries. PMID:24479100

Mineral parageneses, regional architecture, and tectonic evolution of Franciscan metagraywackes, Cape Mendocino-Garberville-Covelo 30' x 60' quadrangles, northwest California

USGS Publications Warehouse

Ernst, W.G.; McLaughlin, Robert J.

2012-01-01

The Franciscan Complex is a classic subduction-zone assemblage. In northwest California, it comprises a stack of west vergent thrust sheets: westernmost Eastern Belt outliers; Central Belt mélange; Coastal Belt Yager terrane; Coastal Belt Coastal terrane; Coastal Belt King Range/False Cape terranes. We collected samples and determined P-T conditions of recrystallization for 88 medium-fine-grained metasandstones to assess their subduction-exhumation histories and assembly of the host allochthons. Feebly recrystallized Yager, Coastal, and King Range strata retain clear detrital features. Scattered neoblastic prehnite occurs in several Coastal terrane metasandstones; traces of possible pumpellyite are present in three Yager metaclastic rocks. Pumpellyite ± lawsonite ± aragonite-bearing Central Belt metasandstones are moderately deformed and reconstituted. Intensely contorted, thoroughly recrystallized Eastern Belt affinity quartzose metagraywackes contain lawsonite + jadeitic pyroxene ± aragonite ± glaucophane. We microprobed neoblastic phases in 23 rocks, documenting mineral parageneses that constrain the tectonic accretion and metamorphic P-T evolution of these sheets. Quasi-stable mineral assemblages typify Eastern Belt metasandstones, but mm-sized domains in the Central and Coastal belt rocks failed to achieve chemical equilibrium. Eastern Belt slabs rose from subduction depths approaching 25–30 km, whereas structurally lower Central Belt mélanges returned from ∼15–18 km. Coastal Belt assemblages suggest burial depths less than 5–8 km. Eastern and Central belt allochthons sequentially decoupled from the downgoing oceanic lithosphere and ascended into the accretionary margin; K-feldspar-rich Coastal Belt rocks were stranded along the continental edge without undergoing appreciable subduction, probably during Paleogene unroofing of the older, deeply subducted units of the Franciscan Complex in east-vergent crustal wedges.

Field geology, geochronology and geochemistry of mafic-ultramafic rocks from Alxa, China: Implications for Late Permian accretionary tectonics in the southern Altaids

NASA Astrophysics Data System (ADS)

Feng, Jianyun; Xiao, Wenjiao; Windley, Brian; Han, Chunming; Wan, Bo; Zhang, Ji'en; Ao, Songjian; Zhang, Zhiyong; Lin, Lina

2013-12-01

The time of termination of orogenesis for the southern Altaids has been controversial. Systematic investigations of field geology, geochronology and geochemistry on newly discriminated mafic-ultramafic rocks from northern Alxa in the southern Altaids were conducted to address the termination problem. The mafic-ultramafic rocks are located in the Bijiertai, Honggueryulin, and Qinggele areas, stretching from west to east for about 100 km. All rocks occur high-grade gneisses as tectonic lenses that are composed of peridotite, pyroxenite, gabbro, and serpentinite, most of which have undergone pronounced alteration, i.e., serpentinization and chloritization. Geochemically, the rocks are characterized by uniform compositional trends, i.e., with low SiO2-contents (42.51-52.21 wt.%) and alkalinity (Na2O + K2O) (0.01-5.45 wt.%, mostly less than 0.8 wt.%), and enrichments in MgO (7.37-43.36 wt.%), with Mg# = 52.75-91.87. As the rocks have been strongly altered and have a wide range of loss-on-ignition (LOI: 0.44-14.07 wt.%) values, they may have been subjected to considerable alteration by either seawater or metamorphic fluids. The REE and trace element patterns show a relatively fractionated trend with LILE enrichment and HFSE depletion, similar to that of T-MORB between N-MORB and E-MORB, indicating that the parental melt resulted from the partial melting of oceanic lithospheric mantle overprinted by fluid alteration of island-arc origin. The ultramafic rocks are relics derived from the magma after a large degree of partial melting of oceanic lithospheric mantle with superposed island arc processes under the influence of mid-ocean-ridge magmatism. LA-ICP MS U-Pb zircon ages of gabbros from three spots are 274 ± 3 Ma (MSWD = 0.35), 306 ± 3 Ma (MSWD = 0.49), 262 ± 5 Ma (MSWD = 1.2), respectively, representing the formation ages of the mafic-ultramafic rocks. Therefore, considering other previously published data, we suggest that the mafic-ultramafic rocks were products of

Bacterially Induced Weathering of Ultramafic Rock and Its Implications for Phytoextraction

PubMed Central

Kidd, Petra; Kuffner, Melanie; Prieto-Fernández, Ángeles; Hann, Stephan; Monterroso, Carmela; Sessitsch, Angela; Wenzel, Walter; Puschenreiter, Markus

2013-01-01

The bioavailability of metals in soil is often cited as a limiting factor of phytoextraction (or phytomining). Bacterial metabolites, such as organic acids, siderophores, or biosurfactants, have been shown to mobilize metals, and their use to improve metal extraction has been proposed. In this study, the weathering capacities of, and Ni mobilization by, bacterial strains were evaluated. Minimal medium containing ground ultramafic rock was inoculated with either of two Arthrobacter strains: LA44 (indole acetic acid [IAA] producer) or SBA82 (siderophore producer, PO4 solubilizer, and IAA producer). Trace elements and organic compounds were determined in aliquots taken at different time intervals after inoculation. Trace metal fractionation was carried out on the remaining rock at the end of the experiment. The results suggest that the strains act upon different mineral phases. LA44 is a more efficient Ni mobilizer, apparently solubilizing Ni associated with Mn oxides, and this appeared to be related to oxalate production. SBA82 also leads to release of Ni and Mn, albeit to a much lower extent. In this case, the concurrent mobilization of Fe and Si indicates preferential weathering of Fe oxides and serpentine minerals, possibly related to the siderophore production capacity of the strain. The same bacterial strains were tested in a soil-plant system: the Ni hyperaccumulator Alyssum serpyllifolium subsp. malacitanum was grown in ultramafic soil in a rhizobox system and inoculated with each bacterial strain. At harvest, biomass production and shoot Ni concentrations were higher in plants from inoculated pots than from noninoculated pots. Ni yield was significantly enhanced in plants inoculated with LA44. These results suggest that Ni-mobilizing inoculants could be useful for improving Ni uptake by hyperaccumulator plants. PMID:23793627

Origin of ultramafic xenoliths containing exsolved pyroxenes from Hualalai Volcano, Hawaii

NASA Astrophysics Data System (ADS)

Bohrson, Wendy A.; Clague, David A.

1988-10-01

Hualalai Volcano, Hawaii, is best known for the abundant and varied xenoliths included in the historic 1800 Kaupulehu alkalic basalt flow. Xenoliths, which range in composition from dunite to anorthosite, are concentrated at 915-m elevation in the flow. Rare cumulate ultramafic xenoliths, which include websterite, olivine websterite, wehrlite, and clinopyroxenite, display complex pyroxene exsolution textures that indicate slow cooling. Websterite, olivine websterite, and one wehrlite are spinel-bearing orthopyroxene +olivine cumulates with intercumulus clinopyroxene +plagioclase. Two wehrlite samples and clinopyroxenite are spinel-bearing olivine cumulates with intercumulus clinopyroxene+orthopyroxene + plagioclase. Two-pyroxene geothermometry calculations, based on reconstructed pyroxene compositions, indicate that crystallization temperatures range from 1225° to 1350° C. Migration or unmixing of clinopyroxene and orthopyroxene stopped between 1045° and 1090° C. Comparisons of the abundance of K2O in plagioclase and the abundances of TiO2 and Fe2O3in spinel of xenoliths and mid-ocean ridge basalt, and a single 87Sr/ 86Sr determination, indicate that these Hualalai xenoliths are unrelated to mid-ocean ridge basalt. Similarity between the crystallization sequence of these xenoliths and the experimental crystallization sequence of a Hawaiian olivine tholeiite suggest that the parental magma of the xenoliths is Hualalai tholeiitic basalt. Xenoliths probably crystallized between about 4.5 and 9 kb. The 155° 230° C of cooling which took place over about 120 ka — the age of the youngest Hualalai tholeiitic basalt — yield maximum cooling rates of 1.3×10-3 1.91×10-3 °C/yr. Hualalai ultramafic xenoliths with exsolved pyroxenes crystallized from Hualalai tholeiitic basalt and accumulated in a magma reservoir located between 13 and 28 km below sealevel. We suspect that this reservoir occurs just below the base of the oceanic crust at about 19 km below sealevel.

Origin of ultramafic xenoliths containing exsolved pyroxenes from Hualalai Volcano, Hawaii

USGS Publications Warehouse

Bohrson, W.A.; Clague, D.A.

1988-01-01

Hualalai Volcano, Hawaii, is best known for the abundant and varied xenoliths included in the historic 1800 Kaupulehu alkalic basalt flow. Xenoliths, which range in composition from dunite to anorthosite, are concentrated at 915-m elevation in the flow. Rare cumulate ultramafic xenoliths, which include websterite, olivine websterite, wehrlite, and clinopyroxenite, display complex pyroxene exsolution textures that indicate slow cooling. Websterite, olivine websterite, and one wehrlite are spinel-bearing orthopyroxene +olivine cumulates with intercumulus clinopyroxene +plagioclase. Two wehrlite samples and clinopyroxenite are spinel-bearing olivine cumulates with intercumulus clinopyroxene+orthopyroxene + plagioclase. Two-pyroxene geothermometry calculations, based on reconstructed pyroxene compositions, indicate that crystallization temperatures range from 1225?? to 1350?? C. Migration or unmixing of clinopyroxene and orthopyroxene stopped between 1045?? and 1090?? C. Comparisons of the abundance of K2O in plagioclase and the abundances of TiO2 and Fe2O3in spinel of xenoliths and mid-ocean ridge basalt, and a single 87Sr/ 86Sr determination, indicate that these Hualalai xenoliths are unrelated to mid-ocean ridge basalt. Similarity between the crystallization sequence of these xenoliths and the experimental crystallization sequence of a Hawaiian olivine tholeiite suggest that the parental magma of the xenoliths is Hualalai tholeiitic basalt. Xenoliths probably crystallized between about 4.5 and 9 kb. The 155??-230?? C of cooling which took place over about 120 ka - the age of the youngest Hualalai tholeiitic basalt - yield maximum cooling rates of 1.3??10-3-1.91??10-3 ??C/yr. Hualalai ultramafic xenoliths with exsolved pyroxenes crystallized from Hualalai tholeiitic basalt and accumulated in a magma reservoir located between 13 and 28 km below sealevel. We suspect that this reservoir occurs just below the base of the oceanic crust at about 19 km below sealevel

Asbestos in the United States, exclusive of Alaska and Hawaii

USGS Publications Warehouse

Chidester, A.H.; Shride, A.F.

1962-01-01

The asbestos deposits in the United States (exclusive of Alaska and Hawaii) are shown on the accompanying map. The principal mineralogic types of asbestos (chrysotile and amphibole) are indicated by the shape of symbols, and the relative importance of the deposit is indicated by the size of symbols. The text lists localities by State by numbers that are keyed to the map. Localities are distinguished by name of mine, prospect, or geographic area; their coordinates are given to the nearest minute of latitude and longitude. Geologic relations of each occurrence, if known, are characterized briefly. The text and map were compiled from published and unpublished information, and at least one reference is given for each locality if reports on it have been published. Chrysotile asbestos, a variety of serpentine, occurs chiefly in serpentinized peridotite and is distributed in the United States in two principal belts, the eastern extending from Maine to Alabama, and the western extending from Washington to California, where numerous masses of ultramafic rocks were intruded in Paleozoic and Mesozoic time, respectively. Domestic production from deposits of this type has not been large compared with that of Canada from the extensively developed deposits in Quebec, Ontario, and British Columbia. The principal mine in the United States is located at Belvidere Mountain, Vt. Minor amounts of asbestos have been produced from other deposits in these belts and from scattered occurrences of chrysotile elsewhe,re in a number of States between them. Increased exploration and development activity for short-fiber chrysotile has recently been reported in California. Chrysotile also occurs in bedded limestone, metamorphosed close to intrusions of diabase. The principal occurrences of this type are in Arizona, where small quantities of long-fiber, low-iron chrysotile have been mined from numerous small deposits. Several species of amphibole occur in fibrous forms; in the United States only

Edaphic interactions in first-year growth of California ponderosa pine

Treesearch

James L. Jenkinson

1977-01-01

To investigate local adaptation to soil fertility, seeds were collected from trees in natural stands selected on one fertile and one nearby ultramafic soil in four geographic areas in the northern Sierra Nevada. Germinants from all seed parents in an area were planted in soils dug from the A horizon of both parent stands. Seedling growth on the fertile and ultramafic...

Early onset of magma ocean crystallization revealed by coupled 146,147Sm-142,143Nd systematics of Nulliak ultramafics (3.78 Ga, Labrador)

NASA Astrophysics Data System (ADS)

Morino, P.; Caro, G.; Reisberg, L. C.

2015-12-01

Early onset of magma ocean crystallization revealed by coupled 146,147Sm-142,143Nd systematics of Nulliak ultramafics (3.78 Ga, Labrador) Precillia Morino1, Guillaume Caro1, Laurie Reisberg 1 1CRPG-CNRS, Université de Lorraine, Nancy, France Coupled 146,147Sm-142,143Nd systematics provides constraints on the timing of magma ocean crystallization on Mars, the Moon and Vesta. Estimates for the Earth's mantle, however, are less accurate owing to the sparsity of Eoarchean mantle-derived rocks with undisturbed 147Sm-143Nd systematics. This study attempts to establish a coherent 142,143Nd dataset for the Eoarchean mantle using well-preserved ultramafic rocks from the Nulliak assemblage (Labrador). Samples include meta-dunites, -pyroxenites and -peridotites exhibiting only minor serpentinization and limited element mobility. The presence of "Barberton type" komatiitic compositions (low Al/Ti, HREE depletion) is suggestive of a deep mantle source. 146,147Sm-142,143Nd and 187Re-187Os analyses yield a crystallization age of 3.78±0.09 Ga with ɛ143Ndi=1.5±0.2 and ɛ142Nd=8.6±2 ppm. This 142,143Nd signature yields a model age of mantle differentiation of 4.43±0.05 Ga (assuming a BSE with chondritic Sm/Nd and ɛ142Nd=0). Superchondritic Sm/Nd compositions for the BSE would translate into older model ages. Irrespective of the choice of primitive mantle composition, Nulliak ultramafics provide differentiation ages 100 Ma older than those estimated from Akilia tonalites but remarkably similar to that estimated from the 2.7 Ga Theo's flow (Abitibi). If Nulliak ultramafics originated from deep melting of a hot plume, their model age could reflect the early onset of magma ocean crystallization in the lowermost mantle.

Pelvic belt effects on sacroiliac joint ligaments: a computational approach to understand therapeutic effects of pelvic belts.

PubMed

Sichting, Freddy; Rossol, Jerome; Soisson, Odette; Klima, Stefan; Milani, Thomas; Hammer, Niels

2014-01-01

The sacroiliac joint is a widely described source of low back pain. Therapeutic approaches to relieve pain include the application of pelvic belts. However, the effects of pelvic belts on sacroiliac joint ligaments as potential pain generators are mostly unknown. The aim of our study was to analyze the influence of pelvic belts on ligament load by means of a computer model. Experimental computer study using a finite element method. A computer model of the human pelvis was created, comprising bones, ligaments, and cartilage. Detailed geometries, material properties of ligaments, and in-vivo pressure distribution patterns of a pelvic belt were implemented. The effects of pelvic belts on ligament strain were computed in the double-leg stance. Pelvic belts increase sacroiliac joint motion around the sagittal axis but decrease motion around the transverse axis. With pelvic belt application, most of the strained sacroiliac joint ligaments were relieved, especially the sacrospinous, sacrotuberous, and the interosseous sacroiliac ligaments. Sacroiliac joint motion and ligament strains were minute. These results agree with validation data from other studies. Assigning homogenous and linear material properties and excluding muscle forces are clear simplifications of the complex reality. Pelvic belts alter sacroiliac joint motion and provide partial relief of ligament strain that is subjectively marked, although minimal in absolute terms. These findings confirm theories that besides being mechanical stabilizers, the sacroiliac joint ligaments are likely involved in neuromuscular feedback mechanisms. The results from our computer model help with unraveling the therapeutic mechanisms of pelvic belts.

Main-belt Comet P/2012 T1 (PANSTARRS)

NASA Astrophysics Data System (ADS)

Hsieh, Henry H.; Kaluna, Heather M.; Novaković, Bojan; Yang, Bin; Haghighipour, Nader; Micheli, Marco; Denneau, Larry; Fitzsimmons, Alan; Jedicke, Robert; Kleyna, Jan; Vereš, Peter; Wainscoat, Richard J.; Ansdell, Megan; Elliott, Garrett T.; Keane, Jacqueline V.; Meech, Karen J.; Moskovitz, Nicholas A.; Riesen, Timm E.; Sheppard, Scott S.; Sonnett, Sarah; Tholen, David J.; Urban, Laurie; Kaiser, Nick; Chambers, K. C.; Burgett, William S.; Magnier, Eugene A.; Morgan, Jeffrey S.; Price, Paul A.

2013-07-01

We present initial results from observations and numerical analyses aimed at characterizing the main-belt comet P/2012 T1 (PANSTARRS). Optical monitoring observations were made between 2012 October and 2013 February using the University of Hawaii 2.2 m telescope, the Keck I telescope, the Baade and Clay Magellan telescopes, Faulkes Telescope South, the Perkins Telescope at Lowell Observatory, and the Southern Astrophysical Research Telescope. The object's intrinsic brightness approximately doubles from the time of its discovery in early October until mid-November and then decreases by ~60% between late December and early February, similar to photometric behavior exhibited by several other main-belt comets and unlike that exhibited by disrupted asteroid (596) Scheila. We also used Keck to conduct spectroscopic searches for CN emission as well as absorption at 0.7 μm that could indicate the presence of hydrated minerals, finding an upper limit CN production rate of Q CN < 1.5 × 1023 mol s-1, from which we infer a water production rate of Q_H_2O<5\\times 10^{25} mol s-1, and no evidence of the presence of hydrated minerals. Numerical simulations indicate that P/2012 T1 is largely dynamically stable for >100 Myr and is unlikely to be a recently implanted interloper from the outer solar system, while a search for potential asteroid family associations reveals that it is dynamically linked to the ~155 Myr old Lixiaohua asteroid family. Some of the data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration, and made possible by the generous financial support of the W. M. Keck Foundation, the Magellan Telescopes located at Las Campanas Observatory, Chile, and the Southern Astrophysical Research (SOAR) telescope, which is a joint project of the Ministério da Ciência, Tecnologia, e Inova

Seat belt use-inducing system effectiveness

DOT National Transportation Integrated Search

1975-04-01

Seat belt use inducing system effectiveness was measured in fleet automobiles of a private business and in rental automobiles at a large airport. There were three parts to the activity: 1. Seat belt use inducing systems and seat belt use counting sys...

Small Main-Belt Asteroid Lightcurve Survey

NASA Technical Reports Server (NTRS)

Binzel, Richard P.; Xu, Shui; Bus, Schelte J.; Bowell, Edward

1992-01-01

The Small Main-Belt Asteroid Lightcurve Survey is the first to measure main-belt asteroid lightcurve properties for bodies with diameters smaller than 5 km. Attention is given to CCD lightcurves for 32 small main-belt asteroids. The objects of this sample have a mean rotational frequency which is faster than that of larger main-belt asteroids. All lightcurves were investigated for nonperiodic variations ascribable to free precession; no conclusive detection of this phenomenon has been made, however.

14 CFR 27.1413 - Safety belts.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Safety belts. 27.1413 Section 27.1413 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Equipment Safety Equipment § 27.1413 Safety belts. Each safety belt...

14 CFR 27.1413 - Safety belts.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Safety belts. 27.1413 Section 27.1413 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Equipment Safety Equipment § 27.1413 Safety belts. Each safety belt...

Persistence of Salmonella on egg conveyor belts is dependent on the belt type but not on the rdar morphotype.

PubMed

Stocki, S L; Annett, C B; Sibley, C D; McLaws, M; Checkley, S L; Singh, N; Surette, M G; White, A P

2007-11-01

Commercial caged layer flocks in Alberta, Canada, are commonly monitored for Salmonella enterica serovar Enteritidis (SE) and S. enterica serovar Typhimurium (ST) by environmental sampling. In one recent case, a SE strain isolated from the egg conveyor belt was a source of persistent infection for the flock. This study was undertaken to examine Salmonella colonization on egg conveyor belts and to determine whether the rdar morphotype, a conserved physiology associated with aggregation and long-term survival, contributed to persistence. Four woven belts constructed of natural or nonnatural fibers and a 1-piece belt made of vinyl were tested with rdar-positive ST and SE strains and a rdar-negative ST DeltaagfD reference strain. The type of egg belt was the most important factor influencing Salmonella colonization and persistence. The vinyl belt, with the least surface area available for colonization, had the fewest Salmonella remaining after washing and disinfection, whereas the hemp-plastic belt, with the greatest surface area, had the most Salmonella remaining. Real-time gene expression indicated that the rdar morphotype was involved in colonizing the egg belt pieces; however, it was not essential for persistence. In addition, rdar-positive and rdar-negative strains were equally similarly to disinfection on the egg belt pieces. The results indicate that Salmonella can persist on a variety of egg belts by mechanisms other than the rdar morphotype, and that using egg conveyer belts with reduced surface area for bacterial colonization can lessen contamination problems.

Granulite belts of Central India with special reference to the Bhopalpatnam Granulite Belt: Significance in crustal evolution and implications for Columbia supercontinent

NASA Astrophysics Data System (ADS)

Vansutre, Sandeep; Hari, K. R.

2010-11-01

The Central Indian collage incorporates the following major granulite belts: (1) the Balaghat-Bhandara Granulite Belt (BBG), (2) the Ramakona-Katangi Granulite Belt (RKG), (3) the Chhatuabhavna Granulite (CBG) of Bilaspur-Raigarh Belt, (4) the Makrohar Granulite Belt (MGB) of Mahakoshal supracrustals, (5) the Kondagaon Granulite Belt (KGGB), (6) the Bhopalpatnam Granulite Belt (BGB), (7) the Konta Granulite Belt (KTGB) and (8) the Karimnagar Granulite Belt (KNGB) of the East Dharwar Craton (EDC). We briefly synthesize the general geologic, petrologic and geochronologic features of these belts and explain the Precambrian crustal evolution in Central India. On the basis of the available data, a collisional relationship between Bastar craton and the EDC during the Paleo-Mesoproterozoic is reiterated as proposed by the earlier workers. The tectonic evolution of only few of the orogenic belts (BGB in particular) of Central India is related to Columbia.

Reduced fatalities related to rear seat shoulder belts

PubMed Central

Robertson, L.

1999-01-01

Methods—During 1988–96, fatalities to rear outboard seat occupants of passenger cars, classified by age of occupant and vehicle curb weight were matched to data on model year in which shoulder belts became standard equipment. The same data were obtained from the same years on back seat occupants in crashes from the Crashworthiness Data System. Weighted regression was performed on death rates per occupants in crashes by belt equipment, occupant age, and vehicle weight for all occupants and occupants who claimed to be restrained. Results—The risk of death is significantly lower in vehicles equipped with shoulder belts, midsized to larger cars, and among children. Claimed child restraint use is higher in cars with shoulder belts and claimed use of shoulder belts is higher among adolescents and young adults but lower among those 35 and older. However, older occupants have lower death rates in shoulder belt equipped cars. Conclusions—Shoulder belts substantially reduce risk of death relative to lap belts at prevalent use rates in each age group. Belt effectiveness when used cannot be estimated precisely because of invalid claimed use, but the lowered rates among vehicles with shoulder belts indicates that effectiveness given prevalent use is far more efficacious than lap belts without shoulder belts. PMID:10323573

Effect of ultramafic intrusions and associated mineralized rocks on the aqueous geochemistry of the Tangle Lakes Area, Alaska: Chapter C in Studies by the U.S. Geological Survey in Alaska, 2011

USGS Publications Warehouse

Wang, Bronwen; Gough, Larry P.; Wanty, Richard B.; Lee, Gregory K.; Vohden, James; O’Neill, J. Michael; Kerin, L. Jack

2013-01-01

Stream water was collected at 30 sites within the Tangle Lakes area of the Delta mineral belt in Alaska. Sampling focused on streams near the ultramafic rocks of the Fish Lake intrusive complex south of Eureka Creek and the Tangle Complex area east of Fourteen Mile Lake, as well as on those within the deformed metasedimentary, metavolcanic, and intrusive rocks of the Specimen Creek drainage and drainages east of Eureka Glacier. Major, minor, and trace elements were analyzed in aqueous samples for this reconnaissance aqueous geochemistry effort. The lithologic differences within the study area are reflected in the major-ion chemistry of the water. The dominant major cation in streams draining mafic and ultramafic rocks is Mg2+; abundant Mg and low Ca in these streams reflect the abundance of Mg-rich minerals in these intrusions. Nickel and Cu are detected in 84 percent and 87 percent of the filtered samples, respectively. Nickel and Cu concentrations ranged from Ni <0.4 to 10.1 micrograms per liter (mg/L), with a median of 4.2 mg/L, and Cu <0.5 to 27 mg/L, with a median of 1.2 mg/L. Trace-element concentrations in water are generally low relative to U.S. Environmental Protection Agency freshwater aquatic-life criteria; however, Cu concentrations exceed the hardness-based criteria for both chronic and acute exposure at some sites. The entire rare earth element (REE) suite is found in samples from the Specimen Creek sites MH5, MH4, and MH6 and, with the exception of Tb and Tm, at site MH14. These samples were all collected within drainages containing or downstream from Tertiary gabbro, diabase, and metagabbro (Trgb) exposures. Chondrite and source rock fractionation profiles for the aqueous samples were light rare earth element depleted, with negative Ce and Eu anomalies, indicating fractionation of the REE during weathering. Fractionation patterns indicate that the REE are primarily in the dissolved, as opposed to colloidal, phase.

Observed use of automatic seat belts in 1987 cars.

PubMed

Williams, A F; Wells, J K; Lund, A K; Teed, N

1989-10-01

Usage of the automatic belt systems supplied by six large-volume automobile manufacturers to meet the federal requirements for automatic restraints were observed in suburban Washington, D.C., Chicago, Los Angeles, and Philadelphia. The different belt systems studied were: Ford and Toyota (motorized, nondetachable automatic shoulder belt), Nissan (motorized, detachable shoulder belt), VW and Chrysler (nonmotorized, detachable shoulder belt), and GM (nonmotorized detachable lap and shoulder belt). Use of automatic belts was significantly greater than manual belt use in otherwise comparable late-model cars for all manufacturers except Chrysler; in Chrysler cars, automatic belt use was significantly lower than manual belt use. The automatic shoulder belts provided by Ford, Nissan, Toyota, and VW increased use rates to about 90%. Because use rates were lower in Ford cars with manual belts, their increase was greater. GM cars had the smallest increase in use rates; however, lap belt use was highest in GM cars. The other manufacturers supply knee bolsters to supplement shoulder belt protection; all--except VW--also provide manual lap belts, which were used by about half of those who used the automatic shoulder belt. The results indicate that some manufacturers have been more successful than others in providing automatic belt systems that result in high use that, in turn, will mean fewer deaths and injuries in those cars.

Igneous and Ore-Forming Processes at the Roots of Giant - Ultra-Mafic Pluming System: the Seiland Igneous Comples, Norway

NASA Astrophysics Data System (ADS)

Larsen, R. B.; Iljina, M.; Schanke, M.

2012-12-01

SIP covers an area of 5500 km2 in N. Norway. 50 % of the volume comprises mafic layered or homogenous plg+px+Fe-Ti±ol gabbros. 25 % of the area comprises ultramafic intrusions, mostly peridotite and subsidiary pyroxenite and hornblendite. 25 % comprises calc-alkaline and alkaline plutons, respectively. Ultramafic plutons intersect gabbros and calc-alkaline plutons. Recent zircon U/Pb geochronology imply that SIP formed at 560-570 Ma, with mafic- and ultramafic rocks being emplaced in <4 Ma (Roberts et al., Geol. Mag, 2007). Geothermobarometry of contact metamorphic mineral assemblages, implies minimum depth of 20-30 kilometres. Accordingly, the Seiland province arguably provides a unique cross section through the deep-seated parts of a huge magmatic plumbing system. Sulphide Cu-Ni-(PGE) deposits are intimately associated with the ultramafic rock suite. One deposit from Stjernøy comprises sulphide dissiminations at the floor of a peridotitic pluton, another deposit occur at the floor of the Reinfjord ultramafic layered complex in the far West of SIP and the third deposit comprises vertical sulphide dykes in the interior of a hornblendite on the Øksfjord peninsula. Currently, only the Reinfjord deposit is studied in detail. The Reinfjord intrusions is layered and develops from olivine clinopyroxenites in the Lower Zone to wherlite in the Middle Zone to wehrlites and dunite in the Upper Zone. Earlier studies suggest parental melts with pyroxenitic compositions whereas the dunites and wherlites formed by fractional crystallization (Bennet et al., Bull. NGU, 405, 1-41). During our fieldwork we observed spectacular examples of cumulus structures, not previously reported, and including modally layered and modally graded dunite/wherlite, cross-bedding, slumping and mush-diapirs. Finally we saw an example of magma-replenishment where an olivine pyroxenitic magma was emplaced in to and mixed with the contemporary olivine/wherlite mushes!. The country rock gabbros were

Al-augite and Cr-diopside ultramafic xenoliths in basaltic rocks from western United States

USGS Publications Warehouse

Wilshire, H.G.; Shervais, J.W.

1975-01-01

Ultramafic xenoliths in basalts from the western United States are divided into Al-augite and Cr-diopside groups. The Al-augite group is characterized by Al, Ti-rich augites, comparatively Fe-rich olivine and orthopyroxene, and Al-rich spinel, the Cr-diopside group by Cr-rich clinopyroxene and spinel and by Mg-rich olivine and pyroxenes. Both groups have a wide range of subtypes, but the Al-augite group is dominated by augite-rich varieties, and the Cr-diopside group by olivine-rich lherzolites. ?? 1975.

14 CFR 31.63 - Safety belts.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Safety belts. 31.63 Section 31.63 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: MANNED FREE BALLOONS Design Construction § 31.63 Safety belts. (a) There must be a safety belt...

14 CFR 31.63 - Safety belts.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Safety belts. 31.63 Section 31.63 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: MANNED FREE BALLOONS Design Construction § 31.63 Safety belts. (a) There must be a safety belt...

Mandatory seat belt use.

DOT National Transportation Integrated Search

1984-01-01

The purposes of this study were to review mandatory seat belt use laws as they have been used around the world, to forecast the impact of such a law in Virginia, and, if appropriate, to propose a mandatory seat belt law for inclusion in the Code of V...

Structure and regional significance of the Late Permian(?) Sierra Nevada - Death Valley thrust system, east-central California

USGS Publications Warehouse

Stevens, C.H.; Stone, P.

2005-01-01

An imbricate system of north-trending, east-directed thrust faults of late Early Permian to middle Early Triassic (most likely Late Permian) age forms a belt in east-central California extending from the Mount Morrison roof pendant in the eastern Sierra Nevada to Death Valley. Six major thrust faults typically with a spacing of 15-20 km, original dips probably of 25-35??, and stratigraphic throws of 2-5 km compose this structural belt, which we call the Sierra Nevada-Death Valley thrust system. These thrusts presumably merge into a de??collement at depth, perhaps at the contact with crystalline basement, the position of which is unknown. We interpret the deformation that produced these thrusts to have been related to the initiation of convergent plate motion along a southeast-trending continental margin segment probably formed by Pennsylvanian transform truncation. This deformation apparently represents a period of tectonic transition to full-scale convergence and arc magmatism along the continental margin beginning in the Late Triassic in central California. ?? 2005 Elsevier B.V. All rights reserved.

46 CFR 169.723 - Safety belts.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 7 2011-10-01 2011-10-01 false Safety belts. 169.723 Section 169.723 Shipping COAST... Control, Miscellaneous Systems, and Equipment § 169.723 Safety belts. Each vessel must carry a harness type safety belt conforming to Offshore Racing Council (ORC) standards for each person on watch or...

46 CFR 169.723 - Safety belts.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 7 2010-10-01 2010-10-01 false Safety belts. 169.723 Section 169.723 Shipping COAST... Control, Miscellaneous Systems, and Equipment § 169.723 Safety belts. Each vessel must carry a harness type safety belt conforming to Offshore Racing Council (ORC) standards for each person on watch or...

30 CFR 77.1107 - Belt conveyors.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Belt conveyors. 77.1107 Section 77.1107 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY... § 77.1107 Belt conveyors. Belt conveyors in locations where fire would create a hazard to personnel...

Petrogenesis of the Dalongkai ultramafic-mafic intrusion and its tectonic implication for the Paleotethyan evolution along the Ailaoshan tectonic zone (SW China)

NASA Astrophysics Data System (ADS)

Liu, Huichuan; Wang, Yuejun; Zi, Jian-Wei

2017-06-01

Layered ultramafic-mafic intrusions are usually formed in an arc/back-arc or intra-plate tectonic environment, or genetically related to a mantle plume. In this paper, we report on an ultramafic-mafic intrusion, the Dalongkai intrusion in the Ailaoshan tectonic zone (SW China), whose occurrence is closely associated with arc/back-arc magmatic rocks. The Dalongkai intrusion is composed of plagioclase-lherzolite, hornblende-peridotite, lherzolite and wehrlite at the bottom, cumulate plagioclase-pyroxenite at the middle part, changing to fine-grained gabbro towards the upper part of the intrusion, forming layering structure. Zircons from the plagioclase-pyroxenites and gabbros yielded U-Pb ages of 272.1 ± 1.7 Ma and 266.4 ± 5.8 Ma, respectively. The plagioclase-pyroxenites show cumulate textures, and are characterized by high MgO (25.0-28.0 wt.%; mg# = 80.6-82.3), Cr (1606-2089 ppm) and Ni (893-1203 ppm) contents, interpreted as early cumulate phases. By contrast, the gabbros have relatively lower mg# values (56.3-62.7), and Cr (157-218 ppm) and Ni (73-114 ppm) concentrations, and may represent frozen liquids. The plagioclase-pyroxenites and gabbros share similar chondrite-normalized REE patterns and primitive mantle-normalized trace element profiles which are analogous to those of typical back-arc basin basalts. The εNd(t) values for both rock types range from +2.20 to +4.22. These geochemical and isotopic signatures suggest that the Dalongkai ultramafic-mafic rocks originated from a MORB-like mantle source metasomatized by subduction-related, sediment-derived fluids. Our data, together with other geological evidence, indicate that the emplacement of the Dalongkai ultramafic-mafic intrusion most likely occurred in a back-arc extensional setting associated with subduction of the Ailaoshan Paleotethyan branch ocean during the Middle Permian, thus ruling out the previously speculated linkage to the Emeishan mantle plume, or to an intra-continental rift.

Seat belt use in cars with air bags.

PubMed Central

Williams, A F; Wells, J K; Lund, A K

1990-01-01

Seat belt use was observed in 1,628 cars with air bags and manual belts and 34,223 cars with manual seat belts only. Sixty-six percent of drivers in cars with air bags wore seat belts compared to 63 percent of drivers in cars with manual belts only. The study found no evidence for the speculation that drivers with air bags will reduce their seat belt use because they believe an air bag alone provides sufficient protection. PMID:2240346

Investigation of Moving Belt Radiator Technology Issues

NASA Technical Reports Server (NTRS)

Teagan, W. Peter; Aguilar, Jerry L.

1994-01-01

The development of an advanced spacecraft radiator technology is reported. The moving belt radiator is a thermal radiator concept with the promise of lower specific mass (per kW rejected) than that afforded by existing technologies. The results of a parametric study to estimate radiator mass for future space power systems is presented. It is shown that this technology can be scaled up to 200 MW for higher rejection temperatures. Several aspects of the design concept are discussed, including the dynamics of a large rotating belt in microgravity. The results of a computer code developed to model the belt dynamics are presented. A series of one-g experiments to investigate the dynamics of small belts is described. A comprehensive test program to investigate belt dynamics in microgravity aboard the NASA KC-135 aircraft is discussed. It was found that the desired circular shape can readily be achieved in microgravity. It is also shown that a rotating belt is stable when subjected to simulated attitude control maneuvers. Heat exchanger design is also investigated. Several sealing concepts were examined experimentally, and are discussed. Overall heat transfer coefficients to the rotating belt are presented. Material properties for various belt materials, including screen meshes, are also presented. The results presented in this report indicate that the moving belt radiator concept is technically feasible.

Aeromagnetic survey map of the central California Coast Ranges

USGS Publications Warehouse

Langenheim, V.E.; Jachens, R.C.; Moussaoui, K.

2009-01-01

This aeromagnetic survey was flown as part of a Cooperative Research and Development Agreement (CRADA) with the Pacific Gas and Electric Company and is intended to promote further understanding of the geology and structure in the central California Coast Ranges by serving as a basis for geophysical interpretations and by supporting geological mapping, mineral and water resource investigations, and other topical studies. Local spatial variations in the Earth's magnetic field (evident as anomalies on aeromagnetic maps) reflect the distribution of magnetic minerals, primarily magnetite, in the underlying rocks. In many cases the volume content of magnetic minerals can be related to rock type, and abrupt spatial changes in the amount of magnetic minerals can commonly mark lithologic or structural boundaries. Bodies of serpentinite and other mafic and ultramafic rocks tend to produce the most intense magnetic anomalies, but such generalizations must be applied with caution because rocks with more felsic compositions, such as the porphyritic granodiorite-granite of the La Panza Range, and even some sedimentary units, also can cause measurable magnetic anomalies.

36 CFR 4.15 - Safety belts.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 36 Parks, Forests, and Public Property 1 2011-07-01 2011-07-01 false Safety belts. 4.15 Section 4... TRAFFIC SAFETY § 4.15 Safety belts. (a) Each operator and passenger occupying any seating position of a motor vehicle in a park area will have the safety belt or child restraint system properly fastened at...

36 CFR 4.15 - Safety belts.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Safety belts. 4.15 Section 4... TRAFFIC SAFETY § 4.15 Safety belts. (a) Each operator and passenger occupying any seating position of a motor vehicle in a park area will have the safety belt or child restraint system properly fastened at...

Experimental evidence for chemo-mechanical coupling during carbon mineralization in ultramafic rocks

NASA Astrophysics Data System (ADS)

Lisabeth, H. P.; Zhu, W.; Kelemen, P. B.; Ilgen, A.

2017-09-01

Storing carbon dioxide in the subsurface as carbonate minerals has the benefit of long-term stability and immobility. Ultramafic rock formations have been suggested as a potential reservoir for this type of storage due to the availability of cations to react with dissolved carbon dioxide and the fast reaction rates associated with minerals common in ultramafic formations; however, the rapid reactions have the potential to couple with the mechanical and hydraulic behavior of the rocks and little is known about the extent and mechanisms of this coupling. In this study, we argue that the dissolution of primary minerals and the precipitation of secondary minerals along pre-existing fractures in samples lead to reductions in both the apparent Young's modulus and shear strength of aggregates, accompanied by reduction in permeability. Hydrostatic and triaxial deformation experiments were run on dunite samples saturated with de-ionized water and carbon dioxide-rich solutions while stress, strain, permeability and pore fluid chemistry were monitored. Sample microstructures were examined after reaction and deformation using scanning electron microscopy (SEM). The results show that channelized dissolution and carbonate mineral precipitation in the samples saturated with carbon dioxide-rich solutions modify the structure of grain boundaries, leading to the observed reductions in stiffness, strength and permeability. A geochemical model was run to help interpret fluid chemical data, and we find that the apparent reaction rates in our experiments are faster than rates calculated from powder reactors, suggesting mechanically enhanced reaction rates. In conclusion, we find that chemo-mechanical coupling during carbon mineralization in dunites leads to substantial modification of mechanical and hydraulic behavior that needs to be accounted for in future modeling efforts of in situ carbon mineralization projects.

Klippen Belt, Flysch Belt and Inner Western Carpathian Paleogene Basin Relations in the Northern Slovakia by Magnetotelluric Imaging

NASA Astrophysics Data System (ADS)

Majcin, Dušan; Bezák, Vladimír; Klanica, Radek; Vozár, Ján; Pek, Josef; Bilčík, Dušan; Telecký, Josef

2018-05-01

The paper presents the interpretation of magnetotelluric measurements along the SW-NE profile near Stará Ľubovňa (Northern Slovakia). The profile passes through the Outer Carpathian Flysch Belt, Klippen Belt and ends in the Inner Western Carpathians Paleogene NW from Ružbachy horst structure. The interpretation of the older measurements from profile Mt4 was utilized and, moreover, the 3-D geoelectrical model of studied region was constructed. The magnetotelluric data interpretations verified the northern inclination of Flysch belt structures and their smaller thickness out of Klippen Belt in direction to the Carpathian electrical conductivity zone axis. We consider this as a consequence of the flower structure—more precisely the southern branch of the suture zone related to mentioned conductivity zone. Northerly from this zone the thickness of the Outer Carpathian Flysch Belt increases and the structures have inclination to the south, i.e. to the subduction zone. The contact of Flysch Belt with Klippen Belt has a fault character and it is subvertical, slightly inclined to the North. The southern boundary between Klippen Belt and Inner Western Carpathians has also fault character and is very steep. We detect the continuation of the Ružbachy horst to the NE in the basement of Inner Western Carpathian Paleogene. The structural discordance between this horst and Klippen Belt direction is a result of younger tectonic processes. According to our results the depth distribution of the pre-Tertiary basement below the Inner Western Carpathian units is non-uniform; the basement is broken to a number of partial blocks—horsts and grabens.

The late Archean Schreiber Hemlo and White River Dayohessarah greenstone belts, Superior Province: collages of oceanic plateaus, oceanic arcs, and subduction accretion complexes

NASA Astrophysics Data System (ADS)

Polat, A.; Kerrich, R.; Wyman, D. A.

1998-04-01

The late Archean (ca. 2.80-2.68 Ga) Schreiber-Hemlo and White River-Dayohessarah greenstone belts of the Superior Province, Canada, are supracrustal lithotectonic assemblages of ultramafic to tholeiitic basalt ocean plateau sequences, and tholeiitic to calc-alkaline volcanic arc sequences, and siliciclastic turbidites, collectively intruded by arc granitoids. The belts have undergone three major phases of deformation; two probably prior to, and one during the assembly of the southern Superior Province. Imbricated lithotectonic assemblages are often disrupted by syn-accretion strike-slip faults, suggesting that strike-slip faulting was an important aspect of greenstone belt evolution. Field relations, structural characteristics, and high-precision ICP-MS trace-element data obtained for representative lithologies of the Schreiber-Hemlo and White River-Dayohessarah greenstone belts suggest that they represent collages of oceanic plateaus, juvenile oceanic island arcs, in subduction-accretion complexes. Stratigraphic relationships, structural, and geochemical data from these Archean greenstone belts are consistent with a geodynamic evolution commencing with the initiation of a subduction zone at the margins of an oceanic plateau, similar to the modern Caribbean oceanic plateau and surrounding subduction-accretion complexes. All supracrustal assemblages include both ocean plateau and island-arc geochemical characteristics. The structural and geochemical characteristics of vertically and laterally dismembered supracrustal units of the Schreiber-Hemlo and White River-Dayohessarah greenstone belts cannot be explained either by a simple tectonic juxtaposition of lithotectonic assemblages with stratified volcanic and sedimentary units, or cyclic mafic to felsic bimodal volcanism models. A combination of out-of-sequence thrusting, and orogen-parallel strike-slip faulting of accreted ocean plateaus, oceanic arcs, and trench turbidites can account for the geological and

Metasomatized and hybrid rocks associated with a Palaeoarchaean layered ultramafic intrusion on the Johannesburg Dome, South Africa

NASA Astrophysics Data System (ADS)

Anhaeusser, Carl R.

2015-02-01

The Johannesburg Dome occurs as an inlier of Palaeoarchaean-Mesoarchaean granitic rocks, gneisses and greenstones in the central part of the Kaapvaal Craton, South Africa. In the west-central part of the dome a large greenstone remnant is surrounded and intruded by ca. 3114 Ma porphyritic granodiorites. Referred to locally as the Zandspruit greenstone remnant, it consists of a shallow-dipping ultramafic complex comprised of a number of alternating layers of harzburgite and pyroxenite. The ultramafic rocks are metamorphosed to greenschist grade and have largely been altered to serpentinite and amphibolite (tremolite-actinolite). In the granite-greenstone contact areas the porphyritic granodiorite has partially assimilated the greenstones producing a variety of hybrid rocks of dioritic composition. The hybrid rocks contain enclaves or xenoliths of greenstone and, in places, orbicular granite structures. Particularly noteworthy is an unusual zone of potash-metasomatized rock, occurring adjacent to the porphyritic granodiorite, consisting dominantly of biotite and lesser amounts of carbonate, quartz and sericite. Large potash-feldspar megacrysts and blotchy aggregated feldspar clusters give the rocks a unique texture. An interpretation placed on these rocks is that they represent metasomatized metapyroxenites of the layered ultramafic complex. Field relationships and geochemical data suggest that the rocks were influenced by hydrothermal fluids emanating from the intrusive porphyritic granodiorite. The adjacent greenstones were most likely transformed largely by the process of infiltration metasomatism, rather than simple diffusion, as CO2, H2O as well as dissolved components were added to the greenstones. Element mobility appears to have been complex as those generally regarded as being immobile, such as Ti, Y, Zr, Hf, Ta, Nb, Th, Sc, Ni, Cr, V, and Co, have undergone addition or depletion from the greenstones. Relative to all the rocks analyzed from the greenstones

Inner Radiation Belt Dynamics and Climatology

NASA Astrophysics Data System (ADS)

Guild, T. B.; O'Brien, P. P.; Looper, M. D.

2012-12-01

We present preliminary results of inner belt proton data assimilation using an augmented version of the Selesnick et al. Inner Zone Model (SIZM). By varying modeled physics parameters and solar particle injection parameters to generate many ensembles of the inner belt, then optimizing the ensemble weights according to inner belt observations from SAMPEX/PET at LEO and HEO/DOS at high altitude, we obtain the best-fit state of the inner belt. We need to fully sample the range of solar proton injection sources among the ensemble members to ensure reasonable agreement between the model ensembles and observations. Once this is accomplished, we find the method is fairly robust. We will demonstrate the data assimilation by presenting an extended interval of solar proton injections and losses, illustrating how these short-term dynamics dominate long-term inner belt climatology.

Stable Isotope Geochemistry of Extremely Well-Preserved 2.45-Billion-Year-Old Hydrothermal Systems in the Vetreny Belt, Baltic Shield: Insights into Paleohydrosphere

NASA Astrophysics Data System (ADS)

Zakharov, D. O.; Bindeman, I. N.

2015-12-01

The early Paleoproterozoic was an eventful period in the Earth's history. The first portions of free oxygen emerged in the atmosphere, Snowball Earth glaciations happened several times and the first supercontinent broke up due to extensive rifting. These events should have affected the stable isotopic composition of the hydrosphere. In this study, we use rocks that were altered in underwater hydrothermal systems to investigate the stable isotopic composition of the hydrosphere 2.39-2.45 billion years ago (hereinafter, Ga). Extremely low-δ18O (down to -27.5‰ SMOW) rocks from 2.39 Ga metamorphosed subglacial hydrothermal systems of the Belomorian belt, Baltic Shield formed at near-equatorial latitudes suggesting a Snowball (or Slushball) Earth glaciation. These results motivated us to look at temporally and geographically close hydrothermal systems from the unmetamorhposed 2.45 Ga Vetreny Belt rift. The length of the rift is 250 km and it is composed of high-Mg basalts, mafic-ultramafic intrusions and sedimentary successions. We examined several localities of high-Mg basalt flows that include astonishingly fresh pillow lavas, often with preserved volcanic glass, eruptive breccias, and hydrothermal alteration zones. Collected samples serve a great textural evidence of water-rock interaction that occurred in situ while basalts were cooling. The preliminary results from coexisting quartz and epidote (T, D18O=311°C), and from coexisting calcite and quartz (T, D18O=190°C) yield values of δ18O of involved water between -1.6 and -0.9 ‰. The values of δ13C in calcites vary between -4.0 and -2.3 ‰. It is likely that hydrothermal fluids operated in the Vetreny Belt rift were derived from seawater that is no different from modern oceanic water in terms of δ18O. Apparently, the rift was a Paleoproterozoic analog of the modern Red Sea, filled with oceanic water. The result is important because the Vetreny Belt rift predates the onset of Snowball Earth glaciation at 2

Seat belt injuries in impact.

DOT National Transportation Integrated Search

1969-03-01

Although the seat belt has been demonstrated to provide effective reduction of injuries and fatalities in automobile accidents by preventing ejection, a pattern of injuries directly attributable to impingement on the belt itself is becoming evident. ...

The dynamic history of the Trans-Mexican Volcanic Belt and the Mexico subduction zone

NASA Astrophysics Data System (ADS)

Ferrari, Luca; Orozco-Esquivel, Teresa; Manea, Vlad; Manea, Marina

2012-02-01

The Trans-Mexican Volcanic Belt (TMVB) is a 1000 km long Neogene continental arc showing a large variation in composition and volcanic style, and an intra-arc extensional tectonics. It overlies the Rivera and Cocos slabs, which display marked changes in geometry. Geophysical studies indicate that lithospheric mantle is very thin or absent beneath the forearc and arc, the fluids from the slab are released in a 40 to 100 km wide belt beneath the frontal part of the arc, and the lower crust beneath the arc is partially molten. East of 101°W the TMVB is built on a Precambrian to Paleozoic crust with thickness of 50-55 km. West of 101°W the TMVB is underlain by Jurassic to Cenozoic marine and continental arcs with a 35-40 km thick crust. The evolution of the TMVB occurred in four stages: 1) from ~ 20 to 10 Ma the initial andesitic arc moved inland showing progressively drier melting and, eventually, slab melting, suggesting flattening of the subducted slab; 2) since ~ 11 Ma a pulse of mafic volcanism migrated from west to east reaching the Gulf of Mexico by 7 Ma. This mafic lavas marks the lateral propagation of a slab tear, triggered by cessation of subduction beneath Baja California; 3) thereafter, the volcanic front started moving trenchward, with a marked phase of silicic volcanism between 7.5 and 3 Ma, local emplacement of small volume intraplate-like basalts since 5 Ma, and development of extensional faulting. These features are related to slab rollback, enhancing asthenophere flux into the mantle wedge and promoting partial melting of the crust; 4) the modern arc consists of a frontal belt dominated by flux and slab melting, and a rear belt characterized by more differentiated rocks or by mafic lavas with little or no evidence of subduction fluids but higher asthenosphere fingerprint.

Effects of mother lode-type gold mineralization on 187Os/188Os and platinum group element concentrations in peridotite: Alleghany District, California

USGS Publications Warehouse

Walker, R.J.; Böhlke, J.K.; McDonough, W.F.; Li, Ji

2007-01-01

Osmium isotope compositions and concentrations of Re, platinum group elements (PGE), and Au were determined for host peridotites (serpentinites and barzburgites) and hydrothermally altered ultramafic wall rocks associated with Mother Lode-type hydrothermal gold-quartz vein mineralization in the Alleghany district, California. The host peridotites have Os isotope compositions and Re, PGE, and Au abundances typical of the upper mantle at their presumed formation age during the late Proterozoic or early Paleozoic. The hydrothermally altered rocks have highly variable initial Os isotope compositions with ??os, values (% deviation of 187OS/188OS from the chondritic average calculated for the approx. 120 Ma time of mineralization) ranging from -1.4 to -8.3. The lowest Os isotope compositions are consistent with Re depletion of a chondritic source (e.g., the upper mantle) at ca. 1.6 Ga. Most of the altered samples are enriched in Au and have depleted and fractionated abundances of Re and PGE relative to their precursor peridotites. Geoehemical characteristics of the altered samples suggest that Re and some PGE were variably removed from the ultramafic rocks during the mineralization event. In addition to Re, the Pt and Pd abundances of the most intensely altered rocks appear to have been most affected by mineralization. The 187Os-depleted isotopic compositions of some altered rocks are interpreted to be a result of preferential 187Os loss via destruction of Re-rich phases during the event. For these rocks, Os evidently is not a useful tracer of the mineralizing fluids. The results do, however, provide evidence for differential mobility of these elements, and mobility of 187Os relative to the initial bulk Os isotope composition during hydrothermal metasomatic alteration of ultramafic rocks. ?? 2007 Society of Economic Geologists, Inc.

Chaos on the conveyor belt.

PubMed

Sándor, Bulcsú; Járai-Szabó, Ferenc; Tél, Tamás; Néda, Zoltán

2013-04-01

The dynamics of a spring-block train placed on a moving conveyor belt is investigated both by simple experiments and computer simulations. The first block is connected by a spring to an external static point and, due to the dragging effect of the belt, the blocks undergo complex stick-slip dynamics. A qualitative agreement with the experimental results can be achieved only by taking into account the spatial inhomogeneity of the friction force on the belt's surface, modeled as noise. As a function of the velocity of the conveyor belt and the noise strength, the system exhibits complex, self-organized critical, sometimes chaotic, dynamics and phase transition-like behavior. Noise-induced chaos and intermittency is also observed. Simulations suggest that the maximum complexity of the dynamical states is achieved for a relatively small number of blocks (around five).

The constitutionality of mandatory seat belt laws.

DOT National Transportation Integrated Search

1986-01-01

Low seat belt usage rates have persisted for years despite efforts to educate people about belts' benefits. There is ample documentation of the contribution of seat belts to saving lives and reducing injury. The emotional and pecuniary toll of the fa...

Safety belt promotion: theory and practice.

PubMed

Nelson, G D; Moffit, P B

1988-02-01

The purpose of this paper is to provide practitioners a rationale and description of selected theoretically based approaches to safety belt promotion. Theory failure is a threat to the integrity and effectiveness of safety belt promotion. The absence of theory driven programs designed to promote safety belt use is a concern of this paper. Six theoretical models from the social and behavioral sciences are reviewed with suggestions for application to promoting safety belt use and include Theory of Reasoned Action, the Health Belief Model, Fear Arousal, Operant Learning, Social Learning Theory, and Diffusion of Innovations. Guidelines for the selection and utilization of theory are discussed.

Petrogenesis of ultramafic rocks and olivine-rich troctolites from the East Taiwan Ophiolite in the Lichi mélange

NASA Astrophysics Data System (ADS)

Morishita, Tomoaki; Ghosh, Biswajit; Soda, Yusuke; Mizukami, Tomoyuki; Tani, Ken-ichiro; Ishizuka, Osamu; Tamura, Akihiro; Komaru, Chihiro; Aari, Shoji; Yang, Hsiao-Chin; Chen, Wen-Shan

2017-12-01

We examine ultramafic and olivine-rich troctolite blocks of the East Taiwan Ophiolite (ETO) in the Lichi Mélange. Although ultramafic rocks are extensively serpentinized, the primary minerals, such as olivine, orthopyroxene, clinopyroxene, spinel and plagioclase can be identified. The ultramafic rocks are classified into harzburgite (± clinopyroxene), dunite, and olivine websterite. Major and trace element compositions of the primary minerals in harzburgites, such as the Cr# [= Cr/(Cr + Al) atomic ratio] of chromian spinel (0.3-0.58) and incompatible elements-depleted trace element patterns of clinopyroxenes, indicate their residue origin after partial melting with less flux components. These compositions are similar to those from mid-ocean ridge peridotites as well as back-arc peridotites from the Philippine Sea Plate. The olivine websterite contains discrete as well as occasional locally concentrated plagioclase grains. Petrological characteristics coupled with similarity in trace element patterns of clinopyroxenes in the harzburgite and olivine websterite samples indicate that the olivine websterite is likely formed by clinopyroxene addition to a lherzolitic/harzburgitic peridotite from a pyroxene-saturated mafic melt. Dunite with medium Cr# spinels indicates cumulus or replacement by melt-peridotite reaction origins. Mineral composition of olivine-rich troctolite cannot be explained by simple crystallization from basaltic magmas, but shows a chemical trend expected for products after melt-peridotite interactions. Mineral compositions of the dunite and olivine-rich troctolite are also within chemical ranges of mid-ocean ridge samples, and are slightly different from back-arc samples from the Philippine Sea Plate. We conclude that peridotites in the ETO are not derived from the northern extension of the Luzon volcanic arc mantle. Further geochronological study is, however, required to constrain the origin of the ETO ophiolite, because peridotites are probably

2003 safety belt usage survey in Kentucky.

DOT National Transportation Integrated Search

2003-08-01

The objective of this study was to establish 2003 safety belt and child safety seat usage rates in Kentucky. The 2003 survey continues to document the results after enactment of a statewide mandatory safety belt law in 1994 and safety belt enforcemen...

2004 safety belt usage survey in Kentucky.

DOT National Transportation Integrated Search

2004-08-01

The objective of this study was to establish 2004 safety belt and child safety seat usage rates in Kentucky. The 2004 survey continues to document the results after enactment of a statewide mandatory safety belt law in 1994 and safety belt enforcemen...

Petrology of ultramafic xenoliths from Loihi Seamount, Hawaii

USGS Publications Warehouse

Clague, D.A.

1988-01-01

Ultramafic xenoliths were recovered in four alkalic lava flows from Loihi Seamount at depths between 2200 and 1400 m. No xenolith bearing flows were sampled near the summit despite a concentrated dredge program. The flows, three of alkalic basalt and one of basanite, contain common olivine megacrysts and small xenoliths of dunite, rarer harzburgite, and a single wehrlite. Olivine megacrysts as large as 8 mm are Fo84-88.6 and contain magnesiochromite inclusions with 1.1-3.5 wt.% TiO2. Dunite contains Fo83.5-88.5 olivine, meganesiochromite with 1.5-6.9 wt.% TiO2 (avg. 3.2 wt.), and extremely rare chrome-rich diopside. The wehrlite contains euhedral Fo85.9 olivine and magnesiochromite with 1.9-4.7 wt.% TiO2, poikilitically enclosed in chrome-rich diposide (Wo45.4En48.0s6.6). Most of the olivine megacrysts, dunite, and the wehrlite are cumulates of Loihi alkalic lavas that accumulated in a magma storage zone located at least 16 km below sea level. The rarity of dunite related to tholeiitic magmas supports the interpretation that the alkalic lavas at Loihi generally predate the tholeiitic lavas. -from Author

Teens and seat belt use: What makes them click?

PubMed

Shults, Ruth A; Haegerich, Tamara M; Bhat, Geeta; Zhang, Xinjian

2016-06-01

Motor vehicle crashes kill more adolescents in the United States than any other cause, and often the teen is not wearing a seat belt. Using data from the 2011 Youth Risk Behavior Surveys from 38 states, we examined teens' self-reported seat belt use while riding as a passenger and identified individual characteristics and environmental factors associated with always wearing a seat belt. Only 51% of high school students living in 38 states reported always wearing a seat belt when riding as a passenger; prevalence varied from 32% in South Dakota to 65% in Delaware. Seat belt use was 11 percentage points lower in states with secondary enforcement seat belt laws compared to states with primary enforcement laws. Racial/ethnic minorities, teens living in states with secondary enforcement seat belt laws, and those engaged in substance use were least likely to always wear their seat belts. The likelihood of always being belted declined steadily as the number of substance use behaviors increased. Seat belt use among teens in the United States remains unacceptably low. Results suggest that environmental influences can compound individual risk factors, contributing to even lower seat belt use among some subgroups. This study provides the most comprehensive state-level estimates to date of seat belt use among U.S. teens. This information can be useful when considering policy options to increase seat belt use and for targeting injury prevention interventions to high-risk teens. States can best increase teen seat belt use by making evidence-informed decisions about state policy options and prevention strategies. Published by Elsevier Ltd.

Effects of safety belt laws on safety belt use by American High School Seniors, 1986-2000.

PubMed

O'Malley, Patrick M; Wagenaar, Alexander C

2004-01-01

This manuscript evaluates the effects of enactment of state laws that required safety belt use in various U.S. states between 1986 and 2000. Safety belt use was assessed using nationally representative cross-sectional samples of high school seniors; evaluation of the effects of laws used data from over 2,000 high school seniors before and about 3,300 after the laws took effect in 20 states. Belt use was found to increase significantly between 1986 and 2000, and the laws contributed significantly to that increase. Increases were similar for students differing by gender, race/ethnicity, parent education, grades, truancy, evenings out per week, miles driven per week, and an index of illicit drug use. The data show that although the laws have increased belt use, use is not universal and continued efforts are needed. This study shows that many teenagers fail to use belts when there is a secondary use law; an implication is that primary laws would be more efficacious in increasing use among this vulnerable population.

Effectiveness of media and enforcement campaigns in increasing seat belt usage rates in a state with a secondary seat belt law.

PubMed

Vasudevan, Vinod; Nambisan, Shashi S; Singh, Ashok K; Pearl, Traci

2009-08-01

In 2005, in terms of seat belt usage rates, Nevada ranked third nationally and first among states with secondary seat belt use enforcement laws in the United States. An effective combination of a media-based education and enforcement campaign helped in this regard. The objective of this article is to document the effectiveness of enforcement and media-based education and outreach campaigns on the seat belt usage rates in Nevada, a state with a secondary seat belt usage law. Observational data on seat belt usage and passenger fatality data are used to evaluate the effectiveness of enforcement campaigns and media-based education and outreach campaigns. Data based on observations of about 40,000 vehicles in each of the years 2003 to 2005 were analyzed. Statistical analyses show that a significant increase in seat belt usage rates among both drivers and passengers for both genders resulted from the accompanying the media and enforcement campaigns. The results from this study indicate that effective and well-planned media/enforcement campaigns can have a significant impact on seat belt usage rates even in a state where the enforcement of seat belt laws can only be as a secondary violation. They validate and expand on findings from other efforts documented in the literature. These results demonstrate that, if coordinated properly, media and enforcement campaigns work very effectively in increasing seat belt usage rates even in states with secondary seat belt laws.

Mandatory seat belt use laws.

DOT National Transportation Integrated Search

1985-01-01

The purposes of this study were to review mandatory seat belt use laws as they have been used around the world, to forecast the impact of such a law in Virginia, and, if appropriate, to propose a mandatory seat belt law for inclusion in the Code of V...

Numerical modeling of fold-and-thrust belts: Applications to Kuqa foreland fold belt, China

NASA Astrophysics Data System (ADS)

Yin, H.; Morgan, J. K.; Zhang, J.; Wang, Z.

2009-12-01

We constructed discrete element models to simulate the evolution of fold-and-thrust belts. The impact of rock competence and decollement strength on the geometric pattern and deformation mechanics of fold-and-thrust belts has been investigated. The models reproduced some characteristic features of fold-and-thrust belts, such as faulted detachment folds, pop-ups, far-traveled thrust sheets, passive-roof duplexes, and back thrusts. In general, deformation propagates farther above a weak decollement than above a strong decollement. Our model results confirm that fold-and-thrust belts with strong frictional decollements develop relatively steep and narrow wedges formed by closely spaced imbricate thrust slices, whereas fold belts with weak decollements form wide low-taper wedges composed of faulted detachment folds, pop-ups, and back thrusts. Far-traveled thrust sheets and passive-roof duplexes are observed in the model with a strong lower decollement and a weak upper detachment. Model results also indicate that the thickness of the weak layer is critical. If it is thick enough, it acts as a ductile layer that is able to flow under differential stress, which helps to partition deformation above and below it. The discrete element modeling results were used to interpret the evolution of Kuqa Cenozoic fold-and-thrust belt along northern Tarim basin, China. Seismic and well data show that the widely distributed Paleogene rock salt has a significant impact on the deformation in this area. Structures beneath salt are closely spaced imbricate thrust and passive-roof duplex systems. Deformation above salt propagates much farther than below the salt. Faults above salt are relatively wide spaced. A huge controversy over the Kuqa fold-and-thrust belt is whether it is thin-skinned or thick-skinned. With the insights from DEM results, we suggest that Kuqa structures are mostly thin-skinned with Paleogene salt as decollement, except for the rear part near the backstop, where the

Pattern of seat belt wearing in Nanjing, China

PubMed Central

Routley, V; Ozanne‐Smith, J; Li, D; Hu, X; Wang, P; Qin, Y

2007-01-01

Objective To describe the patterns of seat belt wearing in Nanjing, China for drivers, front seat passengers, and rear occupants of motor vehicles. Design Roadside observational study. Setting Four sites in central and northern Nanjing during daylight hours over 1 week in April 2005. Subjects Drivers and passengers of 17 147 cars, taxis, goods vans, and pickups, which traveled in the inside traffic lane. Main outcome measures Percentage seat belt wearing for each of seating position, age/sex, time of day, vehicle type, day of week. Results The rate of seat belt wearing was significantly higher in drivers (67.3%, 95% CI 66.6 to 68.0) than front seat passengers (18.9%, 95% CI, 18.0 to 19.8). It was negligible for second front seat passengers (2.6%, 95% CI 0.3 to 4.9) and rear seat passengers (0.5%, 95% CI 0.3 to 0.7). Belt tampering, such that protection would be reduced in the event of a crash, was observed for 18.5% of taxi drivers. Drivers were most likely to wear seat belts in cars and vans and at a city roundabout; front seat passengers were most likely to wear seat belts in non‐taxi vehicles, during the evening rush hour, if the driver was wearing a belt, and on the local north road. Drivers were least likely to wear a belt in the early morning, in pickups and taxis, on Tuesday (or the following week), and on the local north road; front seat passengers were least likely to wear a belt in taxis and if the driver was not wearing a belt. Conclusions Rates of seat belt wearing by passengers were low despite national legislation and provincial regulations coming into effect several months before the survey. Combined education and enforcement are necessary accompaniments to legislation. PMID:18056315

Anatomy of a metamorphic core complex: seismic refraction/wide-angle reflection profiling in southeastern California and western Arizona

USGS Publications Warehouse

McCarthy, J.; Larkin, S.P.; Fuis, G.S.; Simpson, R.W.; Howard, K.A.

1991-01-01

The metamorphic core complex belt in southeastern California and western Arizona is a NW-SE trending zone of unusually large Tertiary extension and uplift. Midcrustal rocks exposed in this belt raise questions about the crustal thickness, crustal structure, and the tectonic evolution of the region. Three seismic refraction/wide-angle reflection profiles were collected to address these issues. The results presented here, which focus on the Whipple and Buckskin-Rawhide mountains, yield a consistent three-dimensiional image of this part of the metamorphic core complex belt. The final model consists of a thin veneer (<2 km) of upper plate and fractured lower plate rocks (1.5-5.5 km s-1) overlying a fairly homogeneous basement (~6.0 km s-1) and a localized high-velocity (6.4 km s -1) body situated beneath the western Whipple Mountains. A prominent midcrustal reflection is identified beneath the Whipple and Buckskin Rawhide mountains between 10 and 20km depth. -from Authors

The development of an electronic system to continually monitor, indicate and control, 'belt slippage' in industrial friction 'V' belt drive transmission systems

NASA Astrophysics Data System (ADS)

Brown, R. E.

2012-05-01

Belts have been used for centuries as a mechanism to transfer power from some form of drive system to a variety of load systems. Within industry today, many designs of belts but particularly friction, trapezoidal shaped 'V' belts are used and generally transfer power generated by electrical motors to numerous forms of driven load systems. It is suggested that belt systems, through their simplicity are sadly neglected by maintenance functions and generally are left unattended until high degrees of 'belt slippage' through loss of friction or 'belt breakage' provokes maintenance attention. These circumstances are most often identified through the reduced or loss of manufacturing production or the occurrence of catastrophic circumstances such as fire caused through excessive friction/ high belt slippage conditions. Obviously, these situations incur financial losses to companies and in some cases the near loss of the company's main manufacturing plant. Consequently, a satisfactory, viable solution is currently sought by industry to improve on current labour intensive maintenance practices. This paper will present an account of the development of an industrially robust, accurate and repeatable electronic system which continually monitors and indicates the degree of 'slippage' in a 'V' belt drive transmission system and in the circumstance of belt breakage or high belt slippage will enable and control the switching off the drive motor.

The mafic-ultramafic complex of Aniyapuram, Cauvery Suture Zone, southern India: Petrological and geochemical constraints for Neoarchean suprasubduction zone tectonics

NASA Astrophysics Data System (ADS)

Yellappa, T.; Venkatasivappa, V.; Koizumi, T.; Chetty, T. R. K.; Santosh, M.; Tsunogae, T.

2014-12-01

Several Precambrian mafic-ultramafic complexes occur along the Cauvery Suture Zone (CSZ) in Southern Granulite Terrain, India. Their origin, magmatic evolution and relationship with the associated high-grade rocks have not been resolved. The Aniyapuram Mafic-Ultramafic Complex (AMUC), the focus of the present study in southern part of the CSZ, is dominantly composed of peridotites, pyroxenites, gabbros, metagabbros/mafic granulites, hornblendites, amphibolites, plagiogranites, felsic granulites and ferruginous cherts. The rock types in the AMUC are structurally emplaced within hornblende gneiss (TTG) basement rocks and are highly deformed. The geochemical signature of the amphibolites indicates tholeiitic affinity for the protolith with magma generation in island arc-setting. N-MORB normalized pattern of the amphibolites show depletion in HFS-elements (P, Zr, Sm, Ti, and Y) and enrichment of LIL-elements (Rb, Ba, Th, Sr) with negative Nb anomalies suggesting involvement of subduction component in the depleted mantle source and formation in a supra-subduction zone tectonic setting. Our new results when correlated with the available age data suggest that the lithological association of AMUC represent the remnants of the Neoarchean oceanic lithosphere.

Grinding Glass Disks On A Belt Sander

NASA Technical Reports Server (NTRS)

Lyons, James J., III

1995-01-01

Small machine attached to table-top belt sander makes possible to use belt sander to grind glass disk quickly to specified diameter within tolerance of about plus or minus 0.002 in. Intended to be used in place of production-shop glass grinder. Held on driveshaft by vacuum, glass disk rotated while periphery ground by continuous sanding belt.

Teaching Science: Seat Belt Science.

ERIC Educational Resources Information Center

Leyden, Michael B.

1994-01-01

Describes activities that will help students understand how car seat belts work, the limited reaction time available to passengers in an automobile accident, and the force of impact in a car collision. These activities will provide students with hands-on experiences that demonstrate the importance of always wearing seat belts while in an…

30 CFR 77.406 - Drive belts.

Code of Federal Regulations, 2010 CFR

2010-07-01

... SAFETY STANDARDS, SURFACE COAL MINES AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES Safeguards for Mechanical Equipment § 77.406 Drive belts. (a) Drive belts shall not be shifted while in motion unless the...

Observational and Dynamical Characterization of Main-belt Comet P/2010 R2 (La Sagra)

NASA Astrophysics Data System (ADS)

Hsieh, Henry H.; Yang, Bin; Haghighipour, Nader; Novaković, Bojan; Jedicke, Robert; Wainscoat, Richard J.; Denneau, Larry; Abe, Shinsuke; Chen, Wen-Ping; Fitzsimmons, Alan; Granvik, Mikael; Grav, Tommy; Ip, Wing; Kaluna, Heather M.; Kinoshita, Daisuke; Kleyna, Jan; Knight, Matthew M.; Lacerda, Pedro; Lisse, Carey M.; Maclennan, Eric; Meech, Karen J.; Micheli, Marco; Milani, Andrea; Pittichová, Jana; Schunova, Eva; Tholen, David J.; Wasserman, Lawrence H.; Burgett, William S.; Chambers, K. C.; Heasley, Jim N.; Kaiser, Nick; Magnier, Eugene A.; Morgan, Jeffrey S.; Price, Paul A.; Jørgensen, Uffe G.; Dominik, Martin; Hinse, Tobias; Sahu, Kailash; Snodgrass, Colin

2012-05-01

likely representative of other objects in the same region of the main belt, though the relatively close proximity of the 13:6 mean-motion resonance with Jupiter and the (3,-2,-1) three-body mean-motion resonance with Jupiter and Saturn mean that dynamical instability on larger timescales cannot be ruled out. Some data presented herein were obtained at the Isaac Newton Group of telescopes on La Palma as part of Program I/2010B/P14, at the Gemini Observatory under program GN-2011B-Q-17, with the Danish 1.54 m telescope at the ESO La Silla Observatory, and at the W. M. Keck Observatory. The Keck Observatory is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration, and was made possible by the generous financial support of the W. M. Keck Foundation.

Effect of a weightlifting belt on spinal shrinkage.

PubMed

Bourne, N D; Reilly, T

1991-12-01

Spinal loading during weightlifting results in a loss of stature which has been attributed to a decrease in height of the intervertebral discs--so-called 'spinal shrinkage'. Belts are often used during the lifting of heavy weights, purportedly to support, stabilize and thereby attenuate the load on the spine. The purpose of this study was to examine the effects of a standard weightlifting belt in attenuating spinal shrinkage. Eight male subjects with a mean age of 24.8 years performed two sequences of circuit weight-training, one without a belt and on a separate occasion with a belt. The circuit training regimen consisted of six common weight-training exercises. These were performed in three sets of ten with a change of exercise after each set of ten repetitions. A stadiometer sensitive to within 0.01 mm was used to record alterations in stature. Measurements of stature were taken before and after completion of the circuit. The absolute visual analogue scale (AVAS) was used to measure the discomfort and pain intensity resulting from each of the two conditions. The circuit weight-training caused stature losses of 3.59mm without the belt and 2.87 mm with the belt (P greater than 0.05). The subjects complained of significantly less discomfort when the belt was worn (P less than 0.05). The degree of shrinkage was significantly correlated (r = 0.752, P less than 0.05) with perceived discomfort but only when the belt was not worn. These results suggest the potential benefits of wearing a weightlifting belt and support the hypothesis that the belt can help in stabilizing the trunk.

Effect of a weightlifting belt on spinal shrinkage.

PubMed Central

Bourne, N D; Reilly, T

1991-01-01

Spinal loading during weightlifting results in a loss of stature which has been attributed to a decrease in height of the intervertebral discs--so-called 'spinal shrinkage'. Belts are often used during the lifting of heavy weights, purportedly to support, stabilize and thereby attenuate the load on the spine. The purpose of this study was to examine the effects of a standard weightlifting belt in attenuating spinal shrinkage. Eight male subjects with a mean age of 24.8 years performed two sequences of circuit weight-training, one without a belt and on a separate occasion with a belt. The circuit training regimen consisted of six common weight-training exercises. These were performed in three sets of ten with a change of exercise after each set of ten repetitions. A stadiometer sensitive to within 0.01 mm was used to record alterations in stature. Measurements of stature were taken before and after completion of the circuit. The absolute visual analogue scale (AVAS) was used to measure the discomfort and pain intensity resulting from each of the two conditions. The circuit weight-training caused stature losses of 3.59mm without the belt and 2.87 mm with the belt (P greater than 0.05). The subjects complained of significantly less discomfort when the belt was worn (P less than 0.05). The degree of shrinkage was significantly correlated (r = 0.752, P less than 0.05) with perceived discomfort but only when the belt was not worn. These results suggest the potential benefits of wearing a weightlifting belt and support the hypothesis that the belt can help in stabilizing the trunk. Images Figure 1 PMID:1810615

Colors of Inner Disk Classical Kuiper Belt Objects

NASA Astrophysics Data System (ADS)

Romanishin, W.; Tegler, S. C.; Consolmagno, G. J.

2010-07-01

We present new optical broadband colors, obtained with the Keck 1 and Vatican Advanced Technology telescopes, for six objects in the inner classical Kuiper Belt. Objects in the inner classical Kuiper Belt are of interest as they may represent the surviving members of the primordial Kuiper Belt that formed interior to the current position of the 3:2 resonance with Neptune, the current position of the plutinos, or, alternatively, they may be objects formed at a different heliocentric distance that were then moved to their present locations. The six new colors, combined with four previously published, show that the ten inner belt objects with known colors form a neutral clump and a reddish clump in B-R color. Nonparametric statistical tests show no significant difference between the B-R color distribution of the inner disk objects compared to the color distributions of Centaurs, plutinos, or scattered disk objects. However, the B-R color distribution of the inner classical Kuiper Belt Objects does differ significantly from the distribution of colors in the cold (low inclination) main classical Kuiper Belt. The cold main classical objects are predominately red, while the inner classical belt objects are a mixture of neutral and red. The color difference may reveal the existence of a gradient in the composition and/or surface processing history in the primordial Kuiper Belt, or indicate that the inner disk objects are not dynamically analogous to the cold main classical belt objects.

COLORS OF INNER DISK CLASSICAL KUIPER BELT OBJECTS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Romanishin, W.; Tegler, S. C.; Consolmagno, G. J., E-mail: wromanishin@ou.ed, E-mail: Stephen.Tegler@nau.ed, E-mail: gjc@specola.v

2010-07-15

We present new optical broadband colors, obtained with the Keck 1 and Vatican Advanced Technology telescopes, for six objects in the inner classical Kuiper Belt. Objects in the inner classical Kuiper Belt are of interest as they may represent the surviving members of the primordial Kuiper Belt that formed interior to the current position of the 3:2 resonance with Neptune, the current position of the plutinos, or, alternatively, they may be objects formed at a different heliocentric distance that were then moved to their present locations. The six new colors, combined with four previously published, show that the ten innermore » belt objects with known colors form a neutral clump and a reddish clump in B-R color. Nonparametric statistical tests show no significant difference between the B-R color distribution of the inner disk objects compared to the color distributions of Centaurs, plutinos, or scattered disk objects. However, the B-R color distribution of the inner classical Kuiper Belt Objects does differ significantly from the distribution of colors in the cold (low inclination) main classical Kuiper Belt. The cold main classical objects are predominately red, while the inner classical belt objects are a mixture of neutral and red. The color difference may reveal the existence of a gradient in the composition and/or surface processing history in the primordial Kuiper Belt, or indicate that the inner disk objects are not dynamically analogous to the cold main classical belt objects.« less

Trace elements in olivine of ultramafic lamprophyres controlled by phlogopite-rich mineral assemblages in the mantle source

NASA Astrophysics Data System (ADS)

Veter, Marina; Foley, Stephen F.; Mertz-Kraus, Regina; Groschopf, Nora

2017-11-01

Carbonate-rich ultramafic lamprophyres (aillikites) and associated rocks characteristically occur during the early stages of thinning and rifting of cratonic mantle lithosphere, prior to the eruption of melilitites, nephelinites and alkali basalts. It is accepted that they require volatile-rich melting conditions, and the presence of phlogopite and carbonate in the source, but the exact source rock assemblages are debated. Melts similar to carbonate-rich ultramafic lamprophyres (aillikites) have been produced by melting of peridotites in the presence of CO2 and H2O, whereas isotopes and trace elements appear to favor distinct phlogopite-bearing rocks. Olivine macrocrysts in aillikites are usually rounded and abraded, so that it is debated whether they are phenocrysts or mantle xenocrysts. We have analyzed minor and trace element composition in olivines from the type aillikites from Aillik Bay in Labrador, Canada. We characterize five groups of olivines: [1] mantle xenocrysts, [2] the main phenocryst population, and [3] reversely zoned crystals interpreted as phenocrysts from earlier, more fractionated, magma batches, [4] rims on the phenocrysts, which delineate aillikite melt fractionation trends, and [5] rims around the reversely zoned olivines. The main phenocryst population is characterized by mantle-like Ni (averaging 3400 μg g- 1) and Ni/Mg at Mg# of 88-90, overlapping with phenocrysts in ocean island basalts and Mediterranean lamproites. However, they also have low 100 Mn/Fe of 0.9-1.3 and no correlation between Ni and other trace elements (Sc, Co, Li) that would indicate recycled oceanic or continental crust in their sources. The low Mn/Fe without high Ni/Mg, and the high V/Sc (2-5) are inherited from phlogopite in the source that originated by solidification of lamproitic melts at the base of the cratonic lithosphere in a previous stage of igneous activity. The olivine phenocryst compositions are interpreted to result from phlogopite and not high modal

OUTER RADIATION BELT AND AURORAS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gorchakov, E.V.

1961-01-01

Data obtained from Sputnik IH were used to determine the high-latitude boundary of the outer radiation belt and to interpret the nature of auroras. At the heights at which the auroras were observed, the outer boundary of the belt (69 deg north geomagnetic latitude) practically coincides with the auroral zone maximum (70 deg north geomagnetic latitude), while the maximum intensity of the outer belt near the earth lies at about 55 deg north geomagnetic latitude, i.e., at latitudes 15 deg below the auroral maximum. Consequently, auroras near the zone of maximum cannot be caused by the penetration into the atmospheremore » of electrons from the outer belt with energies on the order of 0.1 Mev (the mean energy of electrons in the outer belt). Other investigators have reported the detection of lowenergy streams at 55,000 to 75,000 km from the center of the earth in the equatorial plane. Moving toward the surface of the earth along the force lines of the magnetic field, electron streams of this type will reach the earth precisely in the region of the auroral zone maximum. It is considered possible that the electron streams are trapped at these distances from the earth and are at least partially responsible for auroras in the region of maximum. The existence of two maxima in the latitudinal distribution of auroral frequency, which attests to differert mechanisms of aurora formation, favors this hypothesis. In the region of the basic auroral maximum (70 deg north geomagnetic latitude) the auroras are the result of the invasion of belt particles, while in the region of the additional maximum (about 80 deg north geomagnetic latitude) they are caused by the direct penetration of corpuscular streams into the atmosphere. (OTS)« less

ScienceCast 76: The Radiation Belt Storm Probes

NASA Image and Video Library

2012-08-30

This morning NASA launched two heavily-shielded spacecraft directly into the Van Allen Belts. The Radiation Belt Storm Probes are on a two-year mission to study the Van Allen Belts and to unravel the mystery of their unpredictability.

Impacts of ultramafic outcrops in Peninsular Malaysia and Sabah on soil and water quality.

PubMed

Tashakor, Mahsa; Modabberi, Soroush; van der Ent, Antony; Echevarria, Guillaume

2018-05-08

This study focused on the influence of ultramafic terrains on soil and surface water environmental chemistry in Peninsular Malaysia and in the State of Sabah also in Malaysia. The sampling included 27 soils from four isolated outcrops at Cheroh, Bentong, Bukit Rokan, and Petasih from Peninsular Malaysia and sites near Ranau in Sabah. Water samples were also collected from rivers and subsurface waters interacting with the ultramafic bodies in these study sites. Physico-chemical parameters (including pH, EC, CEC) as well as the concentration of major and trace elements were measured in these soils and waters. Geochemical indices (geoaccumulation index, enrichment factor, and concentration factor) were calculated. Al 2 O 3 and Fe 2 O 3 had relatively high concentrations in the samples. A depletion in MgO, CaO, and Na 2 O was observed as a result of leaching in tropical climate, and in relation to weathering and pedogenesis processes. Chromium, Ni, and Co were enriched and confirmed by the significant values obtained for Igeo, EF, and CF, which correspond to the extreme levels of contamination for Cr and high to moderate levels of contamination for Ni and Co. The concentrations of Cr, Ni, and Co in surface waters did not reflect the local geochemistry and were within the permissible ranges according to WHO and INWQS standards. Subsurface waters were strongly enriched by these elements and exceeded these standards. The association between Cr and Ni was confirmed by factor analysis. The unexpected enrichment of Cu in an isolated component can be explained by localized mineralization in Sabah.

Rhizosphere bacteria of Costularia spp. from ultramafic soils in New Caledonia: diversity, tolerance to extreme edaphic conditions, and role in plant growth and mineral nutrition.

PubMed

Gonin, Mathieu; Gensous, Simon; Lagrange, Alexandre; Ducousso, Marc; Amir, Hamid; Jourand, Philippe

2013-03-01

Rhizosphere bacteria were isolated from Costularia spp., pioneer sedges from ultramafic soils in New Caledonia, which is a hotspot of biodiversity in the South Pacific. Genus identification, ability to tolerate edaphic constraints, and plant-growth-promoting (PGP) properties were analysed. We found that 10(5) colony-forming units per gram of root were dominated by Proteobacteria (69%) and comprised 21 genera, including Burkholderia (28%), Curtobacterium (15%), Bradyrhizobium (9%), Sphingomonas (8%), Rhizobium (7%), and Bacillus (5%). High proportions of bacteria tolerated many elements of the extreme edaphic conditions: 82% tolerated 100 μmol·L(-1) chromium, 70% 1 mmol·L(-1) nickel, 63% 10 mmol·L(-1) manganese, 24% 1 mmol·L(-1) cobalt, and 42% an unbalanced calcium/magnesium ratio (1/16). These strains also exhibited multiple PGP properties, including the ability to produce ammonia (65%), indole-3-acetic acid (60%), siderophores (52%), and 1-aminocyclopropane-1-carboxylate (ACC) deaminase (39%); as well as the capacity to solubilize phosphates (19%). The best-performing strains were inoculated with Sorghum sp. grown on ultramafic substrate. Three strains significantly enhanced the shoot biomass by up to 33%. The most successful strains influenced plant nutrition through the mobilization of metals in roots and a reduction of metal transfer to shoots. These results suggest a key role of these bacteria in plant growth, nutrition, and adaptation to the ultramafic constraints.

Si-Metasomatism During Serpentinization of Jurassic Ultramafic Sea-floor: a Comparative Study

NASA Astrophysics Data System (ADS)

Vogel, M.; Frueh-Green, G. L.; Boschi, C.; Schwarzenbach, E. M.

2014-12-01

The Bracco-Levanto ophiolitic complex (northwestern Italy) represents one of the largest and better-exposed ophiolitic successions in the Northern Apennines. It is considered to be a fragment of heterogeneous Jurassic lithosphere that records tectono-magmatic and alteration histories similar to those documented along the Mid-Atlantic Ridge (MAR), such as at the 15°20'N area and the Atlantis Massif at 30°N. Structural and petrological studies on these rocks provide constraints on metamorphic/deformation processes during formation and hydrothermal alteration of the Jurassic oceanic lithosphere. We present a petrological and geochemical study of serpentinization processes and fluid-rock interaction in the Bracco-Levanto ophiolitic complex and compare these to published data from modern oceanic hydrothermal systems, such as the Lost City hydrothermal field hosted in serpentinites on the Atlantis Massif. Major element and mineral compositional data allow us to distinguish a multiphase history of alteration characterized by: (1) widespread Si-metasomatism during progressive serpentinization, and (2) multiple phases of veining and carbonate precipitation associated with circulation of seawater in the shallow ultramafic-dominated portions of the Jurassic seafloor, resulting in the formation of ophicalcites. In detail, regional variations in Si, Mg and Al content are observed in zones of ophicalcite formation, indicating metasomatic reactions and Si-Al transport during long-lived fluid-rock interaction and channelling of hydrothermal fluids. Rare earth element and isotopic analysis indicate that the Si-rich fluids are derived from alteration of pyroxenes to talc and tremolite in ultramafic rocks at depth. Comparison with serpentinites from the Atlantis Massif and 15°20'N indicates a similar degree of Si-enrichment in the modern seafloor and suggests that Si-metasomatism may be a fundamental process associated with serpentinization at slow-spreading ridge environments

Effectiveness of safety belt warning and interlock systems

DOT National Transportation Integrated Search

1973-04-01

Rental cars in Fayetteville, N.C., were equipped with four seat belt and warning systems: (Phase I) detachable shoulder and lap belt, no warning system; (Phase II) detachable shoulder and lap belt, warning system (January 1, 1972 standard); (Phase II...

Structural and lithologic study of northern coast ranges and Sacramento Valley, California

NASA Technical Reports Server (NTRS)

Rich, E. I. (Principal Investigator)

1973-01-01

The author has identified the following significant results. The pattern of linear systems within the project area has been extended into the western foothill belt of the Sierra Nevada. The chief pattern of linear features in the western Sierran foothill belt trends about N. 10 - 15 deg W., but in the vicinity of the Feather River the trend of the features abruptly changes to about N. 50-60 deg W and appears to be contiguous across the Sacramento Valley with a similar system of linear features in the Coast Ranges. The linear features in the Modoc Plateau and Klamath Mt. areas appear unrelated to the systems detected in the Coast Ranges of Sierran foothill belt. Although the change in trend of the Sierran structural features has been previously suggested and the interrelationship of the Klamath Mt. region with the northern Sierra Nevadas has been postulated, the data obtained from the ERTS-1 imagery strengthens these notions and provides for the first time evidence of a direct connection of the structural trends within the alluviated part of the Sacramento Valley. In addition rocks of Pleistocene and Holocene age are offset by some of the linear features seen on ERTS-1 imagery and hence may record the latest episode of geologic deformation in north-central California.

Geochemical behavior of ultramafic waste rocks with carbon sequestration potential: a case study of the Dumont Nickel Project, Amos, Québec.

PubMed

Kandji, El Hadji Babacar; Plante, Benoit; Bussière, Bruno; Beaudoin, Georges; Dupont, Pierre-Philippe

2017-04-01

The geochemical behavior of ultramafic waste rocks and the effect of carbon sequestration by these waste rocks on the water drainage quality were investigated using laboratory-scale kinetic column tests on samples from the Dumont Nickel Project (RNC Minerals, QC, Canada). The test results demonstrated that atmospheric CO 2 dissolution induced the weathering of serpentine and brucite within the ultramafic rocks, generating high concentrations of Mg and HCO 3 - with pH values ranging between 9 and 10 in the leachates that promote the precipitation of secondary Mg carbonates. These alkaline pH values appear to have prevented the mobilization of many metals; Fe, Ni, Cu, and Zn were found at negligible concentrations in the leachates. Posttesting characterization using chemical analyses, diffuse reflectance infrared Fourier transform (DRIFT), and scanning electron microscope (SEM) observations confirmed the precipitation of secondary hydrated Mg carbonates as predicted by thermodynamic calculations. The formation of secondary Mg carbonates induced cementation of the waste particles, resulting in the development of a hardpan.

Origin of Meter-Size Granite Basins in the Southern Sierra Nevada, California

USGS Publications Warehouse

Moore, James G.; Gorden, Mary A.; Robinson, Joel E.; Moring, Barry C.

2008-01-01

Meter-size granite basins are found in a 180-km belt extending south from the South Fork of the Kings River to Lake Isabella on the west slope of the southern Sierra Nevada, California. Their origin has long been debated. A total of 1,033 basins have been inventoried at 221 sites. The basins occur on bedrock granitic outcrops at a median elevation of 1,950 m. Median basin diameter among 30 of the basin sites varies from 89 to 170 cm, median depth is 12 to 63 cm. Eighty percent of the basin sites also contain smaller bedrock mortars (~1-2 liters in capacity) of the type used by Native Americans (American Indians) to grind acorns. Features that suggest a manmade origin for the basins are: restricted size, shape, and elevation range; common association with Indian middens and grinding mortars; a south- and west-facing aspect; presence of differing shapes in distinct localities; and location in a food-rich belt with pleasant summer weather. Volcanic ash (erupted A.D. 1240+-60) in the bottom of several of the basins indicates that they were used shortly before ~760 years ago but not thereafter. Experiments suggest that campfires built on the granite will weaken the bedrock and expedite excavation of the basins. The primary use of the basins was apparently in preparing food, including acorns and pine nuts. The basins are among the largest and most permanent artifacts remaining from the California Indian civilization.

Geologic map of Harrat Hutaymah, with petrologic classification and distribution of ultramafic inclusions, Saudi Arabia

USGS Publications Warehouse

Thornber, Carl R.

1990-01-01

This map shows detailed geology of the Quaternary and Tertiary volcanic deposits that comprise Harrat Hutaymah and an updated and generalized compilation of the underlying Proterozoic and Paleozoic basement rocks. Quaternary alluvial cover and details of basement geology (that is, faults, dikes, and other features) are not shown. Volcanic unit descriptions and contact relations are based upon field investigation by the author and on compilation and revision of mapping Kellogg (1984; northern half of area) and Pallister (1984; southern half of area). A single K-Ar date of 1.80 ± 0.05 Ma for an alkali olivine basalt flow transected by the Al Hutaymah tuff ring (Pallister, 1984) provides the basis for an estimated late Tertiary to Quaternary age range for all harrat volcanic units other than unit Qtr (tuff reworked during Quaternary age time). Contact relations and unit descriptions for the basement rocks were compiled from Pallister (1984), Kellogg (1984 and 1985), DuBray (1984), Johnson and Williams (1984), Vaslet and others (1987), Cole and Hedge (1986), and Richter and others (1984). All rock unit names in this report are informal and capitalization follows Saudi Arabian stratigraphic nomenclature (Fitch, 1980). Geographic information was compiled from Pallister (1984), Kellogg (1984), and Fuller (in Johnson and Williams, 1984) and from field investigation by the author in 1986. The pie diagrams on the map show the distribution and petrology of ultramafic xenoliths of Harrat Hutaymah. The pie diagrams are explained by a detailed classification of ultramafic xenoliths that is introduced in this report.

Biomechanics of 4-point seat belt systems in frontal impacts.

PubMed

Rouhana, Stephen W; Bedewi, Paul G; Kankanala, Sundeep V; Prasad, Priya; Zwolinski, Joseph J; Meduvsky, Alex G; Rupp, Jonathan D; Jeffreys, Thomas A; Schneider, Lawrence W

2003-01-01

The biomechanical behavior of 4-point seat belt systems was investigated through MADYMO modeling, dummy tests and post mortem human subject tests. This study was conducted to assess the effect of 4-point seat belts on the risk of thoracic injury in frontal impacts, to evaluate the ability to prevent submarining under the lap belt using 4-point seat belts, and to examine whether 4-point belts may induce injuries not typically observed with 3-point seat belts. The performance of two types of 4-point seat belts was compared with that of a pretensioned, load-limited, 3-point seat belt. A 3-point belt with an extra shoulder belt that "crisscrossed" the chest (X4) appeared to add constraint to the torso and increased chest deflection and injury risk. Harness style shoulder belts (V4) loaded the body in a different biomechanical manner than 3-point and X4 belts. The V4 belt appeared to shift load to the clavicles and pelvis and to reduce traction of the shoulder belt across the chest, resulting in a reduction in chest deflection by a factor of two. This is associated with a 5 to 500-fold reduction in thoracic injury risk, depending on whether one assumes 4-point belts apply concentrated or distributed load. In four of six post mortem human subjects restrained by V4 belts during 40 km/h sled tests, chest compression was zero or negative and rib fractures were nearly eliminated. Submarining was not observed in any test with post mortem human subjects. Though lumbar, sacral and pelvic injuries were noted, they are believed to be due to the artificial restraint environment (no knee bolsters, instrument panels, steering systems or airbags). While they show significant potential to reduce thoracic injury risk, there are still many issues to be resolved before 4-point belts can be considered for production vehicles. These issues include, among others, potential effects on hard and soft neck tissues, of interaction with inboard shoulder belts in farside impacts and potential

Role of mafic and ultramafic rocks in drinking water quality and its potential health risk assessment, Northern Pakistan.

PubMed

Begum, Shaheen; Shah, Mohammad Tahir; Muhammad, Said; Khan, Sardar

2015-12-01

This study investigates the drinking water (groundwater and surface water) quality and potential risk assessment along mafic and ultramafic rocks in the Swat district of Khyber Pakhtunkhwa Provence, Pakistan. For this purpose, 82 groundwater and 33 surface water samples were collected and analyzed for physico-chemical parameters. Results showed that the majority of the physico-chemical parameters were found to be within the drinking water guidelines set by the World Health Organization. However, major cationic metals such as magnesium (Mg), and trace metals (TM) including iron (Fe), manganese (Mn), nickel (Ni), chromium (Cr) and cobalt (Co) showed exceeded concentrations in 13%, 4%, 2%, 20%, 20% and 55% of water samples, respectively. Health risk assessment revealed that the non-carcinogenic effects or hazard quotient values through the oral ingestion pathway of water consumption for the TM (viz., Fe, Cr and Mn) were found to be greater than 1, could result in chronic risk to the exposed population. Results of statistical analyses revealed that mafic and ultramafic rocks are the main sources of metal contamination in drinking water, especially Ni and Cr. Both Ni and Cr have toxic health effects and therefore this study suggests that contaminated sites should be avoided or treated for drinking and domestic purposes.

Electric filter with movable belt electrode

DOEpatents

Bergman, W.

1983-09-20

A method and apparatus for removing airborne contaminants entrained in a gas or airstream includes an electric filter characterized by a movable endless belt electrode, a grounded electrode, and a filter medium sandwiched there between. Inclusion of the movable, endless belt electrode provides the driving force for advancing the filter medium through the filter, and reduces frictional drag on the filter medium, thereby permitting a wide choice of filter medium materials. Additionally, the belt electrode includes a plurality of pleats in order to provide maximum surface area on which to collect airborne contaminants. 4 figs.

Electric filter with movable belt electrode

DOEpatents

Bergman, Werner

1983-01-01

A method and apparatus for removing airborne contaminants entrained in a gas or airstream includes an electric filter characterized by a movable endless belt electrode, a grounded electrode, and a filter medium sandwiched therebetween. Inclusion of the movable, endless belt electrode provides the driving force for advancing the filter medium through the filter, and reduces frictional drag on the filter medium, thereby permitting a wide choice of filter medium materials. Additionally, the belt electrode includes a plurality of pleats in order to provide maximum surface area on which to collect airborne contaminants.

Sources, dispersal, and fate of fine sediment supplied to coastal California

USGS Publications Warehouse

Farnsworth, Katherine L.; Warrick, Jonathan A.

2007-01-01

were observed to discharge sediment at rates consistent with those of the surrounding Transverse Range rivers, which share the same geologic setting. - Direct observations of fine-sediment dispersal have been limited to the river-mouth settings of the Eel and Santa Clara Rivers, where sediment has been observed to settle quickly from buoyant plumes and be transported along the seabed during periods of storm waves. - After heavy loading of fine sediment onto the continental shelf during river floods, there is increasing evidence that fluid-mud gravity flows occur within a layer 10 to 50 cm above the seabed and efficiently transport fine sediment offshore. - All along the California coast, the timing of river discharge and coastal winds and waves from storm events are strongly coherent; however, of large wave events with the potential for resuspending and transporting fine sediment occur during periods without significant rainfall and therefore no significant river discharge. - Although fine sediment dominates the midshelf mud belts offshore of California river mouths, these mud belts are not the dominant sink of fine sediment, much of which is deposited across the entire continental shelf, including the inner shelf, and offshelf into deeper water depths. - Accumulation rates of fine sediment, which can exceed several millimeters per year, are generally highest near river sources of sediment and along the inner shelf and midshelf. - Sediment-accumulation rates, as summarized from both long-term and recent investigations of continental-shelf geochronology, are generally consistent across California except in southern California, where recently the sediment-accumulation rate has been tenfold greater than the long-term rate, possibly as a result of increased river discharge, wastewater outfall inputs, or other anthropogenic sources. Thus, fine sediment is a natural and dynamic element of the California coastal system because of large, natural sediment sources and dynamic

The effect of a gearshift interlock on seat belt use by drivers who do not always use a belt and its acceptance among those who do.

PubMed

Kidd, David G; Singer, Jeremiah; Huey, Richard; Kerfoot, Laura

2018-06-01

Seat belts reduce the risk of fatal injury in a crash, yet in 2015, nearly 10,000 people killed in passenger vehicles were unrestrained. Enhanced seat belt reminders increase belt use, but a gearshift interlock that prevents the vehicle from being placed into gear unless the seat belt is used may prove more effective. Thirty-two people with a recent seat belt citation and who admitted to not always using a seat belt as a driver were recruited as part-time belt users and asked to evaluate two new vehicles. Sixteen drove two vehicles with an enhanced reminder for one week each, and 16 drove a vehicle with an enhanced reminder for one week and a vehicle with a gearshift interlock the following week. Sixteen full-time belt users who reported always using a seat belt drove a vehicle with a gearshift interlock for one week to evaluate acceptance. Relative to the enhanced reminder, the gearshift interlock significantly increased the likelihood that a part-time belt user used a belt during travel time in a trip by 21%, and increased the rate of belt use by 16%; this effect approached significance. Although every full-time belt user experienced the gearshift interlock, their acceptance of the technology reported in a post-study survey was fairly positive and not significantly different from part-time belt users. Six part-time belt users circumvented the gearshift interlock by sitting on a seat belt, waiting for the system to deactivate, or unbuckling during travel. The gearshift interlock increased the likelihood that part-time belt users buckled up and the rate of belt use during travel relative to the enhanced reminder but could be more effective if it prevented circumvention. An estimated 718-942 lives could be saved annually if the belt use of unbuckled drivers and front passengers increased 16-21%. Copyright © 2018 National Safety Council and Elsevier Ltd. All rights reserved.

Principal sources and dispersal patterns of suspended particulate matter in nearshore surface waters of the northeast Pacific Ocean. [California coastal waters

NASA Technical Reports Server (NTRS)

Carlson, P. R. (Principal Investigator); Janda, R. J.

1973-01-01

The author has identified the following significant results. Release-recovery paths of drift cards released in conjunction with ERTS-1 overflight show that nearshore surface currents along the central and northern California coast flowed southward at an average rate in excess of 10 cm/sec (8.5 km/day) during August and September 1973 (California Current). By the middle of October 1973, the nearshore surface currents had reversed and the dominant flow velocity was northward at an average rate in excess of 20 cm/sec (17 km/ day) (Davidson Current). The August-September data suggested the presence of counterclockwise gyres in Monterey Bay and the Gulf of the Farallones, but by the middle of October, the gyres were no longer evident. Imagery of April 1973 showed well developed plumes of suspended sediment in Monterey Bay from the Salinas River and in the Gulf of the Farallones from San Francisco Bay. ERTS-1 imagery provides an effective means of monitoring timber harvest in the redwood forest along the northern California coast. ERTS-1 imagery also clearly portrays contrasting topographic belts characterized by fluvial erosion and by mass movement. The most visually apparent and most persistent river mouth suspended sediment plumes are associated with those rivers that drain belts of topography that appear to have been eroded primarily by mass movement.

Biomechanical considerations for abdominal loading by seat belt pretensioners.

PubMed

Rouhana, Stephen W; El-Jawahri, Raed E; Laituri, Tony R

2010-11-01

While seat belts are the most effective safety technology in vehicles today, there are continual efforts in the industry to improve their ability to reduce the risk of injury. In this paper, seat belt pretensioners and current trends towards more powerful systems were reviewed and analyzed. These more powerful systems may be, among other things, systems that develop higher belt forces, systems that remove slack from belt webbing at higher retraction speeds, or both. The analysis started with validation of the Ford Human Body Finite Element Model for use in evaluation of abdominal belt loading by pretensioners. The model was then used to show that those studies, done with lap-only belts, can be used to establish injury metrics for tests done with lap-shoulder belts. Then, previously-performed PMHS studies were used to develop AIS 2+ and AIS 3+ injury risk curves for abdominal interaction with seat belts via logistic regression and reliability analysis with interval censoring. Finally, some considerations were developed for a possible laboratory test to evaluate higher-powered pretensioners.

Duplex thrusting in the South Dabashan arcuate belt, central China

NASA Astrophysics Data System (ADS)

Li, Wangpeng; Liu, Shaofeng; Wang, Yi; Qian, Tao; Gao, Tangjun

2017-10-01

Due to later tectonic superpositioning and reworking, the South Dabashan arcuate belt extending NW to SE has experienced several episodes of deformation. The earlier deformational style and formation mechanism of this belt remain controversial. Seismic interpretations and fieldwork show that the curved orogen can be divided into three sub-belts perpendicular to the strike of the orogen, the imbricate thrust fault belt, the detachment fold belt and the frontal belt from NE to SW. The imbricate thrust fault belt is characterized by a series of SW-directed thrust faults and nappes. Two regional detachment layers at different depths have been recognized in the detachment fold and frontal belts, and these detachment layers divide the sub-belts into three structural layers: the lower, middle, and upper structural layers. The middle structural layer is characterized by a passive roof duplex structure, which is composed of a roof thrust at the top of the Sinian units, a floor thrust in the upper Lower Triassic units, and horses in between. Apatite fission track dating results and regional structural analyses indicate that the imbricate thrust fault belt may have formed during the latest Early Cretaceous to earliest Paleogene and that the detachment fold belt may have formed during the latest Late Cretaceous to earliest Neogene. Our findings provide important reference values for researching intra-continental orogenic and deformation mechanisms in foreland fold-thrust belts.

A population of comets in the main asteroid belt.

PubMed

Hsieh, Henry H; Jewitt, David

2006-04-28

Comets are icy bodies that sublimate and become active when close to the Sun. They are believed to originate in two cold reservoirs beyond the orbit of Neptune: the Kuiper Belt (equilibrium temperatures of approximately 40 kelvin) and the Oort Cloud (approximately 10 kelvin). We present optical data showing the existence of a population of comets originating in a third reservoir: the main asteroid belt. The main-belt comets are unlike the Kuiper Belt and Oort Cloud comets in that they likely formed where they currently reside and may be collisionally activated. The existence of the main-belt comets lends new support to the idea that main-belt objects could be a major source of terrestrial water.

Tensioning of a belt around a drum using membrane element

NASA Technical Reports Server (NTRS)

Chen, C. H. S.

1980-01-01

An application of the membrane element to the problem of the tensioning of a conveyer belt which wraps around a drum is presented. Two cases were investigated: (1) belt tension increase due to drum edge wear; and (2) material trapped between the drum and the belt. In both cases it was found that the increase in belt tension was due to the additional stretching of the belt resulting from the drum radius change rather than from the transverse deflection of the belt.

Formation of an ultramafic seafloor at the Southwest Indian Ridge 62°-65°E : internal structure of detachment faults and sparse volcanism documented by sidescan sonar and dredges

NASA Astrophysics Data System (ADS)

Cannat, M.; Sauter, D.; Rouméjon, S.

2012-12-01

In october 2010, the Smoothseafloor cruise (RV Marion Dufresne ) documented the continuous exposure, for the past 10 myrs, of mantle-derived ultramafic rocks in the seafloor of the ultra-slow Southwest Indian Ridge in two 50 to 100 km-wide magma-poor corridors centered respectively at 62°30'E and 64°35'E. The proposed interpretation (Sauter et al., AGU abstract 2011) involves successive large offset normal faults (or detachments) that expose ultramafic rocks alternatively in the southern (Antarctic), then in the northern (African) plates. In this presentation we focus on the most recent, near axis regions in these two ultramafic seafloor corridors. We show details of the sidescan sonar images with smooth, non-corrugated exposed detachment surfaces, and an intriguing pattern of pluridecameter-thick and locally anastomozing reflective and less reflective layers in the detachments footwall. Based on preliminary microstructural observations made on samples dredged in the same region, we tentatively interpret these layers as due to contrasted patterns of deformation in the ultramafics next to the fault. Testing this interpretation would be an attractive goal for future submersible and drilling cruises. Deformation types documented in the dredge samples range from heterogeneous plastic to semi-brittle deformation of the primary peridotite mineralogy, to brittle deformation of serpentinized ultramafic rocks. Magmatic rocks make less than 5% of the overal volume of our near axis dredges. These include variably sheared metagabbros, and unmetamorphosed balsalts. Sidescan sonar images show that these basalts form a thin (<200 m) highly discontinuous carapace over the exposed detachments. We show that these basalts are preferentially located along moderate offset normal faults that cut the detachments, or next to inferred breakaways. This observation leads us to propose a link between axial faulting and volcanism in these magma-poor sections of the ultra-slow spreading

Weathering and transport of chromium and nickel from serpentinite in the Coast Range ophiolite to the Sacramento Valley, California, USA

USGS Publications Warehouse

Morrison, Jean M.; Goldhaber, Martin B.; Mills, Christopher T.; Breit, George N.; Hooper, Robert L.; Holloway, JoAnn M.; Diehl, Sharon F.; Ranville, James F.

2015-01-01

A soil geochemical study in northern California was done to investigate the role that weathering and transport play in the regional distribution and mobility of geogenic Cr and Ni, which are both potentially toxic and carcinogenic. These elements are enriched in ultramafic rocks (primarily serpentinite) and the soils derived from them (1700–10,000 mg Cr per kg soil and 1300–3900 mg Ni per kg soil) in the Coast Range ophiolite. Chromium and Ni have been transported eastward from the Coast Range into the western Sacramento Valley and as a result, valley soil is enriched in Cr (80–1420 mg kg−1) and Ni (65–224 mg kg−1) compared to median values of U.S. soils of 50 and 15 mg kg−1, respectively. Nickel in ultramafic source rocks and soils is present in serpentine minerals (lizardite, antigorite, and chrysotile) and is more easily weathered compared to Cr, which primarily resides in highly refractory chromite ([Mg,Fe2+][Cr3+,Al,Fe3+]2O4). Although the majority of Cr and Ni in soils are in refractory chromite and serpentine minerals, the etching and dissolution of these minerals, presence of Cr- and Ni-enriched clay minerals and development of nanocrystalline Fe (hydr)oxides is evidence that a significant fractions of these elements have been transferred to potentially more labile phases.

Origin of ultramafic-hosted magnesite on Margarita Island, Venezuela

NASA Astrophysics Data System (ADS)

Abu-Jaber, N. S.; Kimberley, M. M.

1992-06-01

Ultramafic-hosted deposits of magnesite (MgCO3) have been studied on Margarita Island, Venezuela, to elucidate the source of carbon and conditions of formation for this type of ore. Petrographic, mineralogic, and δ18O data indicate that magnesite precipitated on Margarita in near-surface environments at low P and T. δ13C ranges from -9 to -16‰ PDB within the magnesite and -8 to -10‰ PDB within some calcite and dolomite elsewhere on the island. The isotopically light dolomite fills karst and the calcite occurs as stock-work veins which resemble the magnesite deposits. These carbon isotopic ratios are consistent with a deep-seated source rather than an overlying source from a zone of surficial weathering. However, there is not much enrichment of precious metals and no enrichment of heavy rare-earth elements, as would be expected if the carbon had migrated upward as aqueous carbonate ions. The carbon probably has risen as a gaseous mixture of CO2 and CH4 which partially dissolved in near-surface water before leaching cations and precipitating as magnesite and other carbonates. The process probably is ongoing, given regional exhalation of carbonaceous gases.

Asteroidal Differentiation Processes Deduced from Ultramafic Achondrite Ureilite Meteorites

NASA Technical Reports Server (NTRS)

Downes, Hilary; Mittlefehldt, David W.; Hudson, Pierre; Romanek, Christopher S.; Franchi, Ian

2006-01-01

Ureilites are the second largest achondrite group. They are ultramafic achondrites that have experienced igneous processing whilst retaining some degree of nebula-derived chemical heterogeneity. They differ from other achondrites in that they contain abundant carbon and their oxygen isotope compositions are very heterogeneous and similar to those of the carbonaceous chondrite anhydrous mineral line. Their carbonaceous nature and some compositional characteristics indicative of nebular origin suggest that they are primitive materials that form a link between nebular processes and early periods of planetesimal accretion. However, despite numerous studies, the exact origin of ureilites remains unclear. Current opinion is that they represent the residual mantle of an asteroid that underwent silicate and Fe-Ni-S partial melting and melt removal. Recent studies of short-lived chronometers indicate that the parent asteroid of the ureilites differentiated very early in the history of the Solar System. Therefore, they contain important information about processes that formed small rocky planetesimals in the early Solar System. In effect, they form a bridge between nebula processes and differentiation in small planetesimals prior to accretion into larger planets and so a correct interpretation of ureilite petrogenesis is essential for understanding this critical step.

The Widespread Distribution of Komatiitic Tuffs in the 3.3 Ga Weltevreden Formation, Barberton Greenstone Belt, South Africa

NASA Astrophysics Data System (ADS)

Thompson, M. E.; Lowe, D. R.; Byerly, G. R.

2007-12-01

The 3.5-3.2 Ga Barberton greenstone belt is a heavily deformed, 10-15 km thick succession of volcanic and sedimentary rocks representing one of the best preserved Paleoarchean supracrustal sequences known. It consists of the basal volcanic-dominated Onverwacht Group and the overlying sedimentary-dominated Fig Tree and Moodies Groups. Major volcanic rocks in the BGB include komatiites, tholeiitic basalts, and dacites. Although flow rocks and fragmental deposits have been identified representing all extrusive magma types, the abundance of komatiitic volcaniclastic units is remarkable considering the mechanical difficulties in explosively erupting low viscosity ultramafic lava. In the Onverwacht Group, most komatiitic tuffs contain 85-95 wt% SiO2, due to early silicification, and very low concentrations of most other elements, making original compositions somewhat uncertain. However, in the northernmost part of the BGB, north of the Inyoka Fault, the ~ 3.3 Ga Weltevreden Formation is composed largely of komatiitic flow rocks, tuffs, layered ultramafic complexes, and subordinate black and banded cherts. Previous studies have established the extrusive nature of the komatiites, but there are also many thick interlayered slaty units, previously interpreted as sheared flow rocks, which show cross-bedding, soft-sediment deformation, and other features indicating an alternate derivation. These units range from 2 to 80 m thick and may represent 10% or more of the overall stratigraphy of the Weltevreden Formation. They are characterized by low-temperature serpentinization that has commonly preserved original elemental abundances, enabling a more precise determination of primary komatiitic liquid composition. These rocks are magnesium rich, with MgO ranging from 23 to 36 wt%, and high Ni (~1500 ppm) and Cr (~2600 ppm) contents typical of komatiites. Several possible mechanisms could have produced these rocks, including (1) erosion and transport of pre-existing komatiitic flow

Depletion of the Outer Asteroid Belt

PubMed

Liou; Malhotra

1997-01-17

During the early history of the solar system, it is likely that the outer planets changed their distance from the sun, and hence, their influence on the asteroid belt evolved with time. The gravitational influence of Jupiter and Saturn on the orbital evolution of asteroids in the outer asteroid belt was calculated. The results show that the sweeping of mean motion resonances associated with planetary migration efficiently destabilizes orbits in the outer asteroid belt on a time scale of 10 million years. This mechanism provides an explanation for the observed depletion of asteroids in that region.

Depletion of the Outer Asteroid Belt

NASA Technical Reports Server (NTRS)

Liou, Jer-Chyi; Malhotra, Renu

1997-01-01

During the early history of the solar system, it is likely that the outer planets changed their distance from the sun, and hence, their influence on the asteroid belt evolved with time. The gravitational influence of Jupiter and Saturn on the orbital evolution of asteroids in the outer asteroid belt was calculated. The results show that the sweeping of mean motion resonances associated with planetary migration efficiently destabilizes orbits in the outer asteroid belt on a time scale of 10 million years. This mechanism provides an explanation for the observed depletion of asteroids in that region.

Geography of the asteroid belt

NASA Technical Reports Server (NTRS)

Zellner, B. H.

1978-01-01

The CSM classification serves as the starting point on the geography of the asteroid belt. Raw data on asteroid types are corrected for observational biases (against dark objects, for instance) to derive the distribution of types throughout the belt. Recent work on family members indicates that dynamical families have a true physical relationship, presumably indicating common origin in the breakup of a parent asteroid.

Phyllosilicate absorption features in main-belt and outer-belt asteroid reflectance spectra.

PubMed

Vilas, F; Gaffey, M J

1989-11-10

Absorption features having depths up to 5% are identified in high-quality, high-resolution reflectance spectra of 16 dark asteroids in the main belt and in the Cybele and Hilda groups. Analogs among the CM2 carbonaceous chondrite meteorites exist for some of these asteroids, suggesting that these absorptions are due to iron oxides in phyllosilicates formed on the asteroidal surfaces by aqueous alteration processes. Spectra of ten additional asteroids, located beyond the outer edge of the main belt, show no discernible absorption features, suggesting that aqueous alteration did not always operate at these heliocentric distances.

Phyllosilicate absorption features in main-belt and outer-belt asteroid reflectance spectra

NASA Technical Reports Server (NTRS)

Vilas, Faith; Gaffey, Michael J.

1989-01-01

Absorption features having depths up to 5 percent are identified in high-quality, high-resolution reflectance spectra of 16 dark asteroids in the main belt and in the Cybele and Hilda groups. Analogs among the CM2 carbonaceous chondrite meteorites exist for some of these asteroids, suggesting that these absorptions are due to iron oxides in phyllosilicates formed on the asteroidal surfaces by aqueous alteration processes. Spectra of ten additional asteroids, located beyond the outer edge of the main belt, show no discernible absorption features, suggesting that aqueous alteration did not always operate at these heliocentric distances.

30 CFR 57.15020 - Life jackets and belts.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Life jackets and belts. 57.15020 Section 57.15020 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... Protection Surface Only § 57.15020 Life jackets and belts. Life jackets or belts shall be worn where there is...

30 CFR 56.15020 - Life jackets and belts.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Life jackets and belts. 56.15020 Section 56.15020 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... § 56.15020 Life jackets and belts. Life jackets or belts shall be worn where there is danger from...

30 CFR 57.15020 - Life jackets and belts.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Life jackets and belts. 57.15020 Section 57.15020 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... Protection Surface Only § 57.15020 Life jackets and belts. Life jackets or belts shall be worn where there is...

30 CFR 56.15020 - Life jackets and belts.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Life jackets and belts. 56.15020 Section 56.15020 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... § 56.15020 Life jackets and belts. Life jackets or belts shall be worn where there is danger from...

30 CFR 57.15020 - Life jackets and belts.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Life jackets and belts. 57.15020 Section 57.15020 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... Protection Surface Only § 57.15020 Life jackets and belts. Life jackets or belts shall be worn where there is...

30 CFR 56.15020 - Life jackets and belts.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Life jackets and belts. 56.15020 Section 56.15020 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... § 56.15020 Life jackets and belts. Life jackets or belts shall be worn where there is danger from...

30 CFR 57.15020 - Life jackets and belts.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Life jackets and belts. 57.15020 Section 57.15020 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... Protection Surface Only § 57.15020 Life jackets and belts. Life jackets or belts shall be worn where there is...

30 CFR 56.15020 - Life jackets and belts.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Life jackets and belts. 56.15020 Section 56.15020 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... § 56.15020 Life jackets and belts. Life jackets or belts shall be worn where there is danger from...

30 CFR 57.15020 - Life jackets and belts.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Life jackets and belts. 57.15020 Section 57.15020 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... Protection Surface Only § 57.15020 Life jackets and belts. Life jackets or belts shall be worn where there is...

30 CFR 56.15020 - Life jackets and belts.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Life jackets and belts. 56.15020 Section 56.15020 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... § 56.15020 Life jackets and belts. Life jackets or belts shall be worn where there is danger from...

Evaluation of the varying Naturally Occurring Asbestos mitigation measures at School and Commercial construction projects in California

NASA Astrophysics Data System (ADS)

Kalika, S.

2012-12-01

In commercial development or K-12 school construction, project sites are often purchased and much of the planning process completed prior to an assessment of the soils proposed for excavation or potential offhaul. Geologic maps, while initially helpful for identifying potential hazards such as landslides and earthquake faults, are less helpful in the identification of naturally occurring hazardous minerals, such as the seven regulated minerals currently classified as asbestos. Geologic maps identify mafic and ultramafic bedrock zones; however, a skilled geologist with knowledge of asbestos hazards will further visualize the earth-shaping processes that may have resulted in the deposition of naturally occurring asbestos in locations outside mapped ultramafic zones including the base of an alluvial fan or within streambed channels. When sampled as an afterthought prior to disposal, property owners are surprised by the budget-crippling costs of waste handling and disposal of NOA, as well as mitigations required to protect the health of construction workers, the public, and future site occupants. The California Air Resources Board (CARB) continues to lead the way in evaluation and regulation of NOA, through development of the CARB 435 preparation and laboratory analytical method, local enforcement of the Asbestos Airborne Toxic Control Measure for Construction, Grading, Quarrying, and Surface Mining Operations (ATCM), and implementation of dust control measures to protect public health. A thorough site evaluation and construction design includes utilization of the sampling methods developed by the California Geological Survey, laboratory analytical methods within CARB 435, and mitigation measures required by CARB, DTSC, and OSHA for the protection of worker and public health after NOA is discovered. The site evaluation should additionally include an assessment of the future site usage, as regulations differ based on potential health affects to future occupants

Early Clearing of the Asteroid Belt

NASA Astrophysics Data System (ADS)

Ward, Wm. R.

2005-03-01

The ensemble of embryos destined to become the Jovian core may have excited the primordial asteroid belt and initiated a fragmentation cascade there. Thus, the majority of the belt mass may have drifted via gas drag into the terrestrial zone prior to the formation of Jupiter.

The Idaho cobalt belt

USGS Publications Warehouse

Bookstrom, Arthur A.

2013-01-01

The Idaho cobalt belt (ICB) is a northwest-trending belt of cobalt (Co) +/- copper (Cu)-bearing deposits and prospects in the Salmon River Mountains of east-central Idaho, U.S.A. The ICB is about 55 km long and 10 km long in its central part, which contains multiple strata-bound ore zones in the Blackbird mine area. The Black Pine and Iron Creek Co-Cu prospects are southeast of Blackbird, and the Tinkers Pride, Bonanza Copper, Elk Creek, and Salmon Canyon Copper prospects are northwest of Blackbird.

30 CFR 75.350 - Belt air course ventilation.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Belt air course ventilation. 75.350 Section 75... HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Ventilation § 75.350 Belt air course ventilation. (a) The belt air course must not be used as a return air course; and except as provided in paragraph...

30 CFR 75.350 - Belt air course ventilation.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Belt air course ventilation. 75.350 Section 75... HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Ventilation § 75.350 Belt air course ventilation. (a) The belt air course must not be used as a return air course; and except as provided in paragraph...

30 CFR 75.350 - Belt air course ventilation.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Belt air course ventilation. 75.350 Section 75... HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Ventilation § 75.350 Belt air course ventilation. (a) The belt air course must not be used as a return air course; and except as provided in paragraph...

30 CFR 75.350 - Belt air course ventilation.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Belt air course ventilation. 75.350 Section 75... HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Ventilation § 75.350 Belt air course ventilation. (a) The belt air course must not be used as a return air course; and except as provided in paragraph...

Metamorphic belts of Anatolia

NASA Astrophysics Data System (ADS)

Oberhänsli, Roland; Prouteau, Amaury; Candan, Osman; Bousquet, Romain

2015-04-01

Investigating metamorphic rocks from high-pressure/low-temperature (HP/LT) belts that formed during the closure of several oceanic branches, building up the present Anatolia continental micro-plate gives insight to the palaeogeography of the Neotethys Ocean in Anatolia. Two coherent HP/LT metamorphic belts, the Tavşanlı Zone (distal Gondwana margin) and the Ören-Afyon-Bolkardağ Zone (proximal Gondwana margin), parallel their non-metamorphosed equivalent (the Tauride Carbonate Platform) from the Aegean coast in NW Anatolia to southern Central Anatolia. P-T conditions and timing of metamorphism in the Ören-Afyon-Bolkardağ Zone (>70?-65 Ma; 0.8-1.2 GPa/330-420°C) contrast those published for the overlying Tavşanlı Zone (88-78 Ma; 2.4 GPa/500 °C). These belts trace the southern Neotethys suture connecting the Vardar suture in the Hellenides to the Inner Tauride suture along the southern border of the Kirşehir Complex in Central Anatolia. Eastwards, these belts are capped by the Oligo-Miocene Sivas Basin. Another HP/LT metamorphic belt, in the Alanya and Bitlis regions, outlines the southern flank of the Tauride Carbonate Platform. In the Alanya Nappes, south of the Taurides, eclogites and blueschists yielded metamorphic ages around 82-80 Ma (zircon U-Pb and phengite Ar-Ar data). The Alanya-Bitlis HP belt testifies an additional suture not comparable to the northerly Tavşanlı and Ören-Afyon belts, thus implying an additional oceanic branch of the Neotethys. The most likely eastern lateral continuation of this HP belt is the Bitlis Massif, in SE Turkey. There, eclogites (1.9-2.4 GPa/480-540°C) occur within calc-arenitic meta-sediments and in gneisses of the metamorphic (Barrovian-type) basement. Zircon U-Pb ages revealed 84.4-82.4 Ma for peak metamorphism. Carpholite-bearing HP/LT metasediments representing the stratigraphic cover of the Bitlis Massif underwent 0.8-1.2 GPa/340-400°C at 79-74 Ma (Ar-Ar on white mica). These conditions compares to the Tav

14 CFR 125.211 - Seat and safety belts.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Seat and safety belts. 125.211 Section 125... Requirements § 125.211 Seat and safety belts. (a) No person may operate an airplane unless there are available... the airplane who is at least 2 years old; and (2) An approved safety belt for separate use by each...

Overrepresentation of seat belt non-users in traffic crashes

DOT National Transportation Integrated Search

1988-04-01

This study used observations of driver belt use linked with driver history information to conclude that non-users of belts are overrepresented in traffic crashes. Examining average numbers of accidents and violations per observed belted and unbelted ...

Thermal implications of metamorphism in greenstone belts and the hot asthenosphere-thick continental lithoshere paradox

NASA Technical Reports Server (NTRS)

Morgan, P.

1986-01-01

From considerations of secular cooling of the Earth and the slow decay of radiogenic heat sources in the Earth with time, the conclusion that global heat loss must have been higher in the Archean than at present seems inescapable. The mechanism by which this additional heat was lost and the implications of higher heat low for crustal temperatures are fundamental unknowns in our current understanding of Archean tectonics and geological processes. Higher heat loss implies that the average global geothermal gradient was higher in the Archean than at present, and the restriction of ultramafic komatiites to the Archean and other considerations suggests that the average temperature of the mantle was several hundred degrees hotter during the Archean than today. In contrast, there is little petrologic evidence that the conditions of metamorphism or crustal thickness (including maximum crustal thickness under mountains) were different in archean continental crust from the Phanerozoic record. Additionally, Archean ages have recently been determined for inclusions in diamonds from Cretaceous kimeberlites in South Africa, indicating temperatures of 900 to 1300 at depths of 150 to 215 km (45 to 65 kbar) in the Archean mantle, again implying relatively low geothermal gradients at least locally in the Archean. The thermal implications of metamorphism are examined, with special reference to greenstone belts, and a new thermal model of the continental lithosphere is suggested which is consistent with thick continental lithosphere and high asthenosphere temperatures in the Archean.

Jupiter's Colorful Cloud Belts

NASA Image and Video Library

2018-01-12

Colorful swirling cloud belts dominate Jupiter's southern hemisphere in this image captured by NASA's Juno spacecraft. Jupiter appears in this color-enhanced image as a tapestry of vibrant cloud bands and storms. The dark region in the far left is called the South Temperate Belt. Intersecting the belt is a ghost-like feature of slithering white clouds. This is the largest feature in Jupiter's low latitudes that's a cyclone (rotating with clockwise motion). This image was taken on Dec. 16, 2017 at 10:12 PST (1:12 p.m. EST), as Juno performed its tenth close flyby of Jupiter. At the time the image was taken, the spacecraft was about 8,453 miles (13,604 kilometers) from the tops of the clouds of the planet at a latitude of 27.9 degrees south. The spatial scale in this image is 5.6 miles/pixel (9.1 kilometers/pixel). Citizen scientist Kevin M. Gill processed this image using data from the JunoCam imager. https://photojournal.jpl.nasa.gov/catalog/PIA21974

Scenarios for the Evolution of Asteroid Belts

NASA Image and Video Library

2012-11-01

This illustration shows three possible scenarios for the evolution of asteroid belts. At the top, a Jupiter-size planet migrates through the asteroid belt, scattering material and inhibiting the formation of life on planets.

Space Weather Effects in the Earth's Radiation Belts

NASA Astrophysics Data System (ADS)

Baker, D. N.; Erickson, P. J.; Fennell, J. F.; Foster, J. C.; Jaynes, A. N.; Verronen, P. T.

2018-02-01

The first major scientific discovery of the Space Age was that the Earth is enshrouded in toroids, or belts, of very high-energy magnetically trapped charged particles. Early observations of the radiation environment clearly indicated that the Van Allen belts could be delineated into an inner zone dominated by high-energy protons and an outer zone dominated by high-energy electrons. The energy distribution, spatial extent and particle species makeup of the Van Allen belts has been subsequently explored by several space missions. Recent observations by the NASA dual-spacecraft Van Allen Probes mission have revealed many novel properties of the radiation belts, especially for electrons at highly relativistic and ultra-relativistic kinetic energies. In this review we summarize the space weather impacts of the radiation belts. We demonstrate that many remarkable features of energetic particle changes are driven by strong solar and solar wind forcings. Recent comprehensive data show broadly and in many ways how high energy particles are accelerated, transported, and lost in the magnetosphere due to interplanetary shock wave interactions, coronal mass ejection impacts, and high-speed solar wind streams. We also discuss how radiation belt particles are intimately tied to other parts of the geospace system through atmosphere, ionosphere, and plasmasphere coupling. The new data have in many ways rewritten the textbooks about the radiation belts as a key space weather threat to human technological systems.

Factors related to nonuse of seat belts in Michigan.

DOT National Transportation Integrated Search

1987-09-01

This study combined direct observation of seat belt use with interview methods to : identify factors related to seat belt use in a state with a mandatory seat belt use law. Trained : observers recorded restraint use for a probability sample of motori...

A study of nighttime seat belt use in Indiana

DOT National Transportation Integrated Search

2007-05-01

Overall belt use rates observed during the daytime and nighttime survey waves are presented in Table 2. Belt use observed during the daytime and nighttime pre-mobilization waves was very similar. During the post-mobilization waves, daytime belt use w...

Effectiveness of high school safety belt instruction

DOT National Transportation Integrated Search

1982-12-01

The Effectiveness of High School Safety Belt Instruction was developed during a two-phased project. In Phase I, Focus Group Activities were conducted to determine whether audiovisual safety belt instructional materials assembled by the National Highw...

Pilot tests of a seat belt gearshift delay on the belt use of commercial fleet drivers : traffic tech.

DOT National Transportation Integrated Search

2010-04-01

Wearing a seat belt has been shown effective in avoiding : or reducing serious injury due to traffic crashes. While : belt use rates in the United States increased from under : 60% in 1994 to 83% in 2008, a substantial number of drivers : still drive...

The Collisional Evolution of the Main Asteroid Belt

NASA Astrophysics Data System (ADS)

Bottke, W. F.; Brož, M.; O'Brien, D. P.; Campo Bagatin, A.; Morbidelli, A.; Marchi, S.

Collisional and dynamical models of the main asteroid belt allow us to glean insights into planetesimal- and planet-formation scenarios as well as how the main belt reached its current state. Here we discuss many of the processes affecting asteroidal evolution and the constraints that can be used to test collisional model results. We argue the main belt's wavy size-frequency distribution for diameter D < 100-km asteroids is increasingly a byproduct of comminution as one goes to smaller sizes, with its shape a fossil-like remnant of a violent early epoch. Most D > 100-km asteroids, however, are primordial, with their physical properties set by planetesimal formation and accretion processes. The main-belt size distribution as a whole has evolved into a collisional steady state, and it has possibly been in that state for billions of years. Asteroid families provide a critical historical record of main-belt collisions. The heavily depleted and largely dispersed "ghost families," however, may hold the key to understanding what happened in the primordial days of the main belt. New asteroidal fragments are steadily created by both collisions and mass shedding events via YORP spinup processes. A fraction of this population, in the form of D < 30 km fragments, go on to escape the main belt via the Yarkovsky/YORP effects and gravitational resonances, thereby creating a quasi-steady-state population of planet-crossing and near-Earth asteroids. These populations go on to bombard all inner solar system worlds. By carefully interpreting the cratering records they produce, it is possible to constrain how portions of the main-belt population have evolved with time.

An Empirical Planetesimal Belt Radius–Stellar Luminosity Relation

NASA Astrophysics Data System (ADS)

Matrà, L.; Marino, S.; Kennedy, G. M.; Wyatt, M. C.; Öberg, K. I.; Wilner, D. J.

2018-05-01

Resolved observations of millimeter-sized dust, tracing larger planetesimals, have pinpointed the location of 26 Edgeworth–Kuiper Belt analogs. We report that a belt’s distance R to its host star correlates with the star’s luminosity L ⋆, following R\\propto {L}\\star 0.19 with a low intrinsic scatter of ∼17%. Remarkably, our Edgeworth–Kuiper Belt in the solar system and the two CO snow lines imaged in protoplanetary disks lie close to this R–L ⋆ relation, suggestive of an intrinsic relationship between protoplanetary disk structures and belt locations. To test the effect of bias on the relation, we use a Monte Carlo approach and simulate uncorrelated model populations of belts. We find that observational bias could produce the slope and intercept of the R–L ⋆ relation but is unable to reproduce its low scatter. We then repeat the simulation taking into account the collisional evolution of belts, following the steady-state model that fits the belt population as observed through infrared excesses. This significantly improves the fit by lowering the scatter of the simulated R–L ⋆ relation; however, this scatter remains only marginally consistent with the one observed. The inability of observational bias and collisional evolution alone to reproduce the tight relationship between belt radius and stellar luminosity could indicate that planetesimal belts form at preferential locations within protoplanetary disks. The similar trend for CO snow line locations would then indicate that the formation of planetesimals or planets in the outer regions of planetary systems is linked to the volatility of their building blocks, as postulated by planet formation models.

Composition of the earth's upper mantle. II - Volatile trace elements in ultramafic xenoliths

NASA Technical Reports Server (NTRS)

Morgan, J. W.; Wandless, G. A.; Petrie, R. K.; Irving, A. J.

1980-01-01

Radiochemical neutron activation analysis was used to determine the nine volatile elements Ag, Bi, Cd, In, Sb, Se, Te, Tl, and Zn in 19 ultramafic rocks, consisting mainly of spinel and garnet lherzolites. A sheared garnet lherzolite, PHN 1611, may approximate undepleted mantle material and tends to have a higher volatile element content than the depleted mantle material represented by spinel lherzolites. Comparisons of continental basalts with PHN 1611 and of oceanic ridge basalts with spinel lherzolites show similar basalt: source material partition factors for eight of the nine volatile elements, Sb being the exception. The strong depletion of Te and Se in the mantle, relative to lithophile elements of similar volatility, suggests that 97% of the earth's S, Se and Te may be in the outer core.

36 CFR 1004.15 - Safety belts.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 36 Parks, Forests, and Public Property 3 2011-07-01 2011-07-01 false Safety belts. 1004.15 Section 1004.15 Parks, Forests, and Public Property PRESIDIO TRUST VEHICLES AND TRAFFIC SAFETY § 1004.15 Safety... administered by the Presidio Trust will have the safety belt or child restraint system properly fastened at all...

36 CFR 1004.15 - Safety belts.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Safety belts. 1004.15 Section 1004.15 Parks, Forests, and Public Property PRESIDIO TRUST VEHICLES AND TRAFFIC SAFETY § 1004.15 Safety... administered by the Presidio Trust will have the safety belt or child restraint system properly fastened at all...

Neptune's Eccentricity and the Nature of the Kuiper Belt

NASA Technical Reports Server (NTRS)

Ward, William R.; Hahn, Joseph M.

1998-01-01

The small eccentricity of Neptune may be a direct consequence of apsidal wave interaction with the trans-Neptune population of debris called the Kuiper belt. The Kuiper belt is subject to resonant perturbations from Neptune, so that the transport of angular momentum by density waves can result in orbital evolution of Neptune as well as changes in the structure of the Kuiper belt. In particular, for a belt eroded out to the vicinity of Neptune's 2:1 resonance at about 48 astronomical units, Neptune's eccentricity can damp to its current value over the age of the solar system if the belt contains slightly more than an earth mass of material out to about 75 astronomical units.

Plains tectonism on Venus: The deformation belts of Lavinia Planitia

NASA Technical Reports Server (NTRS)

Squyres, Steven W.; Jankowski, David G.; Simons, Mark; Solomon, Sean C.; Hager, Bradford H.; Mcgill, George E.

1993-01-01

High-resolution radar images from the Magellan spacecraft have revealed the first details of the morphology of the Lavinia Planitia region of Venus. A number of geologic units can be distinguished, including volcanic plains units with a range of ages. Transecting these plains over much of the Lavinia region are two types of generally orthogonal features that we interpret to be compressional wrinkle ridges and extensional grooves. The dominant tectonic features of Lavinia are broad elevated belts of intense deformation that transect the plains with complex geometry. They are many tens to a few hundred kilometers wide, as much as 1000 km long, and elevated hundreds of meters above the surrounding plains. Two classes of deformation belts are seen in the Lavinia region. 'Ridge belts' are composed of parallel ridges, each a few hundred meters in elevation, that we interpret to be folds. Typical fold spacings are 5-10 km. 'Fracture belts' are dominated instead by intense faulting, with faults in some instances paired to form narrow grabens. There is also some evidence for modest amounts of horizontal shear distributed across both ridge and fracture belts. Crosscutting relationships among the belts show there to be a range in belt ages. In western Lavinia, in particular, many ridge and fracture belts appear to bear a relationship to the much smaller wrinkle ridges and grooves on the surrounding plains: ridge morphology tends to dominate belts that lie more nearly parallel to local plains wrinkle ridges, and fracture morphology tends to dominate belts that lie more nearly parallel to local plains grooves. We use simple models to explore the formation of ridge and fracture belts. We show that convective motions in the mantle can couple to the crust to cause horizontal stresses of a magnitude sufficient to induce the formation of deformation belts like those observed in Lavinia. We also use the small-scale wavelengths of deformation observed within individual ridge belts to

2009 safety belt usage survey in Kentucky.

DOT National Transportation Integrated Search

2009-07-01

The objective of this study was to establish 2009 safety belt and child safety seat usage rates in Kentucky. The 2009 survey continues to document the results after enactment of original "secondary enforcement" statewide mandatory safety belt law in ...

2002 safety belt usage survey in Kentucky.

DOT National Transportation Integrated Search

2002-07-01

The objective of this study was to establish 2002 safety belt and child safety seat usage rates in Kentucky. The 2002 survey continues to document the results after enactment of original "secondary enforcement" statewide mandatory safety belt law in ...

2001 safety belt usage survey in Kentucky.

DOT National Transportation Integrated Search

2001-08-01

The objective of this study was to establish 2001 safety belt and child safety seat usage rates in Kentucky. The 2001 survey continues to document the results after enactment of original "secondary enforcement" statewide mandatory safety belt law in ...

2010 safety belt usage survey in Kentucky.

DOT National Transportation Integrated Search

2010-07-01

The objective of this study was to establish 2010 safety belt and child safety seat usage rates in Kentucky. The 2010 survey continues to document the results after enactment of the original "second enforcement" statewide mandatory safety belt law in...

2007 safety belt usage survey in Kentucky.

DOT National Transportation Integrated Search

2007-08-01

The objective of this study was to establish 2007 safety belt and child safety seat usage rates in Kentucky. The 2007 survey continues to document the results after enactment of the initial "second enforcement" statewide mandatory safety belt law in ...

2006 safety belt usage survey in Kentucky.

DOT National Transportation Integrated Search

2006-08-01

The objective of this study was to establish 2006 safety belt and child safety seat usage rates in Kentucky. The 2006 survey continues to document the results after enactment of the initial "second enforcement" statewide mandatory safety belt law in ...

2008 safety belt usage survey in Kentucky.

DOT National Transportation Integrated Search

2008-08-01

The objective of this study was to establish 2008 safety belt and child safety seat usage rates in Kentucky. The 2008 survey continues to document the results after enactment of the initial "second enforcement" statewide mandatory safety belt law in ...

2005 safety belt usage survey in Kentucky.

DOT National Transportation Integrated Search

2005-08-01

The objective of this study was to establish 2005 safety belt and child safety seat usage rates in Kentucky. The 2005 survey continues to document the results after enactment of the initial "second enforcement" statewide mandatory safety belt law in ...

Wearing an abdominal belt increases diastolic blood pressure.

PubMed

Rafacz, W; McGill, S M

1996-09-01

The purpose of this study was to determine the effect of wearing an abdominal belt on blood pressure (systolic and diastolic) and heart rate during a variety of tasks. The belt was typical of the elastic type with suspenders and Velcro tabs for cinching the belt snug. The tasks performed included sitting at rest, sitting with the torso inclined forward at 45 degrees, standing with the torso inclined forward at 45 degrees (with and without holding an 11-kg weight), a trunk axial rotation task, and squat lifting. Blood pressure was monitored noninvasively with a FINAPRES blood pressure monitor. Twenty healthy men performed each task with and without the abdominal belt. Although no significant increases in mean systolic blood pressure or heart rate were found, there was a significant increase in diastolic blood pressure in all conditions. All people considering wearing an abdominal belt should also consider the risks and liability associated with the additional cardiovascular load, particularly heart attack and stroke.

Survey of current situation in radiation belt modeling

NASA Technical Reports Server (NTRS)

Fung, Shing F.

2004-01-01

The study of Earth's radiation belts is one of the oldest subjects in space physics. Despite the tremendous progress made in the last four decades, we still lack a complete understanding of the radiation belts in terms of their configurations, dynamics, and detailed physical accounts of their sources and sinks. The static nature of early empirical trapped radiation models, for examples, the NASA AP-8 and AE-8 models, renders those models inappropriate for predicting short-term radiation belt behaviors associated with geomagnetic storms and substorms. Due to incomplete data coverage, these models are also inaccurate at low altitudes (e.g., <1000 km) where many robotic and human space flights occur. The availability of radiation data from modern space missions and advancement in physical modeling and data management techniques have now allowed the development of new empirical and physical radiation belt models. In this paper, we will review the status of modern radiation belt modeling. Published by Elsevier Ltd on behalf of COSPAR.

87Sr/86Sr ratios in some eugeosynclinal sedimentary rocks and their bearing on the origin of granitic magma in orogenic belts

USGS Publications Warehouse

Peterman, Z.E.; Hedge, C.E.; Coleman, R.G.; Snavely, P.D.

1967-01-01

Rb and Sr contents and 87Sr/86Sr values were determined for samples of eugeosynclinal sedimentary rocks, mostly graywackes, from Oregon and California. These data are compatible with the theory of anataxis of eugeosynclinal sedimentary rocks in orogenic belts to produce granitic magmas provided that the melting occurs within several hundreds of m.y. after sedimentation. The low (87Sr/86Sr)0 values of the eugeosynclinal sedimentary rocks are related to the significant amounts of volcanogenic detritus present which probably were originally derived from the mantle. ?? 1967.

An Effective Belt Conveyor for Underground Ore Transportation Systems

NASA Astrophysics Data System (ADS)

Krol, Robert; Kawalec, Witold; Gladysiewicz, Lech

2017-12-01

Raw material transportation generates a substantial share of costs in the mining industry. Mining companies are therefore determined to improve the effectiveness of their transportation system, focusing on solutions that increase both its energy efficiency and reliability while keeping maintenance costs low. In the underground copper ore operations in Poland’s KGHM mines vast and complex belt conveyor systems have been used for horizontal haulage of the run-of-mine ore from mining departments to shafts. Basing upon a long-time experience in the field of analysing, testing, designing and computing of belt conveyor equipment with regard to specific operational conditions, the improvements to the standard design of an underground belt conveyor for ore transportation have been proposed. As the key elements of a belt conveyor, the energy-efficient conveyor belt and optimised carrying idlers have been developed for the new generation of underground conveyors. The proposed solutions were tested individually on the specially constructed test stands in the laboratory and in the experimental belt conveyor that was built up with the use of prototype parts and commissioned for the regular ore haulage in a mining department in the KGHM underground mine “Lubin”. Its work was monitored and the recorded operational parameters (loadings, stresses and strains, energy dissipation, belt tracking) were compared with those previously collected on a reference (standard) conveyor. These in-situ measurements have proved that the proposed solutions will return with significant energy savings and lower maintenance costs. Calculations made on the basis of measurement results in the specialized belt conveyor designing software allow to estimate the possible savings if the modernized conveyors supersede the standard ones in a large belt conveying system.

Factors Influencing Occupant-To-Seat Belt Interaction in Far-Side Crashes

PubMed Central

Douglas, C.A.; Fildes, B.N.; Gibson, T.J.; Boström, O.; Pintar, F.A.

2007-01-01

Seat belt interaction with a far-side occupant’s shoulder and thorax is critical to governing excursion towards the struck-side of the vehicle in side impact. In this study, occupant-to-belt interaction was simulated using a modified MADYMO human model and finite element belts. Quasi-static tests with volunteers and dynamic sled tests with PMHS and WorldSID were used for model validation and comparison. Parameter studies were then undertaken to quantify the effect of impact direction, seat belt geometry and pretension on occupant-to-seat belt interaction. Results suggest that lowering the D-ring and increasing pretension reduces the likelihood of the belt slipping off the shoulder. Anthropometry was also shown to influence restraint provided by the shoulder belt. Furthermore, the belt may slip off the occupant’s shoulder at impact angles greater than 40 degrees from frontal when no pretension is used. However, the addition of pretension allowed the shoulder to engage the belt in all impacts from 30 to 90 degrees. PMID:18184500

Estimating seat belt effectiveness using matched-pair cohort methods.

PubMed

Cummings, Peter; Wells, James D; Rivara, Frederick P

2003-01-01

Using US data for 1986-1998 fatal crashes, we employed matched-pair analysis methods to estimate that the relative risk of death among belted compared with unbelted occupants was 0.39 (95% confidence interval (CI) 0.37-0.41). This differs from relative risk estimates of about 0.55 in studies that used crash data collected prior to 1986. Using 1975-1998 data, we examined and rejected three theories that might explain the difference between our estimate and older estimates: (1) differences in the analysis methods; (2) changes related to car model year; (3) changes in crash characteristics over time. A fourth theory, that the introduction of seat belt laws would induce some survivors to claim belt use when they were not restrained, could explain part of the difference in our estimate and older estimates; but even in states without seat belt laws, from 1986 through 1998, the relative risk estimate was 0.45 (95% CI 0.39-0.52). All of the difference between our estimate and older estimates could be explained by some misclassification of seat belt use. Relative risk estimates would move away from 1, toward their true value, if misclassification of both the belted and unbelted decreased over time, or if the degree of misclassification remained constant, as the prevalence of belt use increased. We conclude that estimates of seat belt effects based upon data prior to 1986 may be biased toward 1 by misclassification.

2017 safety belt usage survey in Kentucky.

DOT National Transportation Integrated Search

2017-08-01

The use of safety belts and child safety seats is a proven means of reducing injuries to motor vehicle occupants involved in traffic crashes. There have been various methods used in efforts to increase safety belt and safety seat usage. Past efforts ...

2016 safety belt usage survey in Kentucky.

DOT National Transportation Integrated Search

2016-08-01

The use of safety belts and child safety seats is a proven means of reducing injuries to motor vehicle occupants involved in traffic crashes. There have been various methods used in efforts to increase safety belt and safety seat usage. Past efforts ...

2015 safety belt usage survey in Kentucky.

DOT National Transportation Integrated Search

2015-08-01

The use of safety belts and child safety seats has been shown to be an effective means of : reducing injuries to motor-vehicle occupants involved in traffic crashes. There have been various : methods used in efforts to increase safety belt and safety...

2001 Safety belt usage survey in Kentucky

DOT National Transportation Integrated Search

2001-08-01

The objective of this study was to establish 2001 safety belt and child safety seat usage rates in Kentucky. The 2001 survey continues to document the results after enactment of a statewide mandatory safety belt law in 1994. It also documented the lo...

2002 safety belt usage survey in Kentucky

DOT National Transportation Integrated Search

2002-07-01

The objective of this study was to establish 2002 safety belt and child safety seat usage rates in Kentucky. The 2002 survey continues to document the results after enactment of a statewide mandatory safety belt law in 1994. Data were collected at 20...

2000 Safety belt usage survey in Kentucky

DOT National Transportation Integrated Search

2000-08-01

The objective of this study was to establish 2000 safety belt and child safety seat usage rates in Kentucky. The 2000 survey continues to document the results after enactment of a statewide mandatory safety belt law in 1994. Data were collected at 20...

Seat belt use, especially among low-use drivers, increases as Florida upgrades to primary seat belt enforcement : traffic tech.

DOT National Transportation Integrated Search

2012-08-01

As a secondary seat belt law State, Florida had worked : for many years to encourage more drivers to wear : their seat belts by participating in annual Click It or : Ticket (CIOT) mobilizations, and by conducting special : programs in rural areas of ...

Use of safety restraints by law enforcement officers following safety belt training and passage of a statewide belt law

DOT National Transportation Integrated Search

1988-04-01

The report describes work performed in 1984-1985 to develop and evaluate a safety belt program designed for the Maryland State Police - Belt Use Campaign for Law Enforcement (BUCLE), and an evaluation conducted in 1987 to determine the impact of the ...

Cambrian ophiolite complexes in the Beishan area, China, southern margin of the Central Asian Orogenic Belt

NASA Astrophysics Data System (ADS)

Shi, Yuruo; Zhang, Wei; Kröner, Alfred; Li, Linlin; Jian, Ping

2018-03-01

We present zircon ages and geochemical data for Cambrian ophiolite complexes exposed in the Beishan area at the southern margin of the Central Asian Orogenic Belt (CAOB). The complexes consist of the Xichangjing-Xiaohuangshan and Hongliuhe-Yushishan ophiolites, which both exhibit complete ophiolite stratigraphy: chert, basalt, sheeted dikes, gabbro, mafic and ultramafic cumulates and serpentinized mantle peridotites. Zircon grains of gabbro samples yielded 206Pb/238U ages of 516 ± 8, 521 ± 4, 528 ± 3 and 535 ± 6 Ma that reflect the timing of gabbro emplacement. The geochemical data of the basaltic rocks show enrichment in large-ion lithophile elements and depletion in the high field strength elements relative to normal mid-oceanic ridge basalt (NMORB) in response to aqueous fluids or melts expelled from the subducting slab. The gabbro samples have higher whole-rock initial 87Sr/86Sr ratios and lower positive εNd(t) values than NMORB. These geochemical signatures resulted from processes or conditions that are unique to subduction zones, and the ophiolites are therefore likely to have formed within a supra-subduction zone (SSZ) environment. We suggest that the Cambrian ophiolite complexes in the Beishan area formed within a SSZ setting, reflecting an early Paleozoic subduction of components of the Paleo-Central Asian Ocean and recording an early Paleozoic southward subduction event in the southern CAOB along the northern margin of the Tarim and North China Cratons.

"Abomination"--life as a Bible belt gay.

PubMed

Barton, Bernadette

2010-01-01

Drawing on observation, autoethnography, and audio-taped interviews, this article explores the religious backgrounds and experiences of Bible Belt gays. In the Bible Belt, Christianity is not confined to Sunday worship. Christian crosses, messages, paraphernalia, music, news, and attitudes permeate everyday settings. Consequently, Christian fundamentalist dogma about homosexuality-that homosexuals are bad, diseased, perverse, sinful, other, and inferior-is cumulatively bolstered within a variety of other social institutions and environments in the Bible Belt. Of the 46 lesbians and gay men interviewed for this study (age 18-74 years), most describe living through spirit-crushing experiences of isolation, abuse, and self-loathing. This article argues that the geographic region of the Bible Belt intersects with religious-based homophobia. Informants explained that negative social attitudes about homosexuality caused a range of harmful consequences in their lives including the fear of going to hell, depression, low self-esteem, and feelings of worthlessness.

Age and composition of the UHP garnet peridotites in the Dabie orogenic belt (central China) record complex crust-mantle interaction in continental margin

NASA Astrophysics Data System (ADS)

Zhao, Y.; Zheng, J.; Wang, B.

2017-12-01

The Dabie-Sulu UHP belt was created by the collision between the North and South China cratons in Middle Triassic time (240-225 Ma). There are lots of garnet-bearing ultramafic body occurs as a lens in the belt. Age and composition of the Maowu garnet peridotites in the Dabie orogenic belt are reported. The garnet harzburgites are main moderately refractory (Mg#Ol=92) and minor fertile (Mg#Ol=88) with high Ni (2344-2603 ppm) and low Al2O3 (0.35-0.54 wt.%), CaO (0.76-2.19 wt.%) and TiO2 (˜0.01 wt.%). Zircons in the harzburgites mainly document metamorphism at 230 ± 2 Ma, 275 ± 5 Ma, 357 ± 4 Ma, and complex minor populations of ages including: 1.8 Ga, 1.3 Ga, and Neoproterozic-early Paleozoic ages (901-420 Ma). The early Meszosic and late Paleozoic zircons have similar trace-element patterns and ranges in ɛHf(t) (+0.6 to +3.4), Th/U ratio (0.2-0.7) and Hf depleted-mantle model ages (TDM ) mainly cluster in the interval 1.2-0.9 Ga. In contrast, the Paleo-Mesoproterozoic zircons have negative ɛHf(t) (-24.9 to -2.7) and oldest Hf TDM = 3.4Ga. Zircons of Neoproterozic-early Paleozoic have a wide range of Hf depleted-mantle model ages (2.4-0.7Ga) and ɛHf(t) (-15.3 to +9.5). Above of the all, we suggest that the Maowu garnet harzburgites are interpreted as a fragment of the metasomatized ancient lithospheric mantle beneath the southern margin of the North China Craton. They experienced the Proterozoic thermal event (1.9-1.8Ga), which is coeval with the assembly of the supercontinent Columbia. And then 1.3Ga mantle metasomatism with asthenospheric materials resulted in the final breakup of the Columbia supercontinent. Neoproterozic-early Paleozoic (901-420 Ma), deep parts of the south margin of the craton were metasomatized during the assembly and breakup of the Rodinia supercontinent. Then, the southern margin of the craton occurred oceanic crust subduction ( 357 Ma), subsequent continental deep subduction and final continent-continent collision in Triassic.

47. INTERIOR VIEW, DETAIL OF CONVEYOR BELT SYSTEM SYSTEM WITH ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

47. INTERIOR VIEW, DETAIL OF CONVEYOR BELT SYSTEM SYSTEM WITH BACK BELT DROPPING HARDENED NAILS ON THE FRONT BELT TO BE TEMPERED; MOTION STOPPED - LaBelle Iron Works, Thirtieth & Wood Streets, Wheeling, Ohio County, WV

Using haptic feedback to increase seat belt use : traffic tech.

DOT National Transportation Integrated Search

2011-07-01

The legacy of research on increasing seat belt use has : focused on enactment of seat belt legislation, public education, : high-visibility police enforcement, and seat belt : reminder systems. Several behavioral programs have : produced large, susta...

Factors related to increasing safety belt use in states with safety belt use laws : second annual report to Congress

DOT National Transportation Integrated Search

1989-01-01

This report is the second in a series of four annual reports to the Congress on provisions of state safety belt use laws and other programmatic factors related to increasing safety belt use levels. The first Congressional Report reviewed what was kno...

Serpentinization and carbonation of pristine continental ultramafic rocks and applications to the oceanic crust; H2O-CO2 alteration of dunites and re-distribution of Ni-Cu-PGE in sulphide deposits

NASA Astrophysics Data System (ADS)

Grant, Thomas; McEnroe, Suzanne; Eske Sørensen, Bjørn; Larsen, Rune; Pastore, Zeudia; Rune Grannes, Kim; Nikolaisen, Even

2017-04-01

Here, we document carbonation and serpentinization within a suite of ultramafic rocks from a continental setting. These ultramafic rocks vary from pristine dunites to varying degrees of serpentinization which locally penetrates the ultramafic complex. Hence, it allows us to observe a number of delicate serpentinization and carbonation reactions, otherwise lost during more extensive alteration or tectonic events. We use a multi-disciplinary approach using petrographic, EPMA, thermodynamic modelling and geophysical data to reveal how the initial stages of serpentization and carbonation in dunites affects the distribution of economic to sub-economic deposits of Ni-Cu and PGE. The data can then be applied to oceanic crust. The samples are dunites and poikilitic wehrlites from the Reinfjord Ultramafic complex, Seiland Igneous Province Northern Norway. The complex formed through crystallization of picritic melts in the lower continental crust. The dunites contain small amounts of interstitial clinopyroxene, sulphides and spinel, with local enrichments in Ni, Cu and PGE. Late magmatic CO2-H2O-S fluids reacted with the dunite forming clots of amphibole + dolomite + sulphides + enstatite, reaction rims of enstatite + dolomite, and inclusions trails of dolomite + enstatite + magnetite + CO2 fluid. Thermodynamic modelling reveals that these textures formed at pressures of >12 kbar and temperatures 850-950 °C, which would be consistent with the late magmatic history of the Reinfjord complex. The clots and reactions have local association with enrichments in gold-rich PGMs. A second stage of alteration involved H2O-dominated fluids. These formed predominantly lizardite serpentinization, as is often concentrated within highly localized fracture zones. Thermodynamic modelling shows that these formed <400°C, after the complex had been exhumed towards the surface of the crust. Local and more pervasive serpentinization interacted with the earlier formed carbonate bearing

Petrology and metamorphic evolution of ultramafic rocks and dolerite dykes of the Betic Ophiolitic Association (Mulhacén Complex, SE Spain): evidence of eo-Alpine subduction following an ocean-floor metasomatic process

NASA Astrophysics Data System (ADS)

Puga, E.; Nieto, J. M.; Díaz de Federico, A.; Bodinier, J. L.; Morten, L.

1999-10-01

The Betic Ophiolitic Association, cropping out within the Mulhacén Complex (Betic Cordilleras), is made up of numerous metre- to kilometre-sized lenses of mafic and/or ultramafic and meta-sedimentary rocks. Pre-Alpine oceanic metasomatism and metamorphism caused the first stage of serpentinization in the ultramafic sequence of this association, which is characterized by local clinopyroxene (Cpx) breakdown and Ca-depletion, and complementary rodingitization of the basic dykes intruded in them. Subsequent eo-Alpine orogenic metamorphism developed eclogite facies assemblages in ultramafic and basic lithotypes, which were partly retrograded in Ab-Ep-amphibolite facies conditions during a meso-Alpine event. The heterogeneous development of the oceanic metasomatism in the ultramafic rock-types led to the patchy development of highly serpentinized Ca-depleted domains, without gradual transition to the host, and less serpentinized, Cpx-bearing ultramafites, mainly lherzolitic in composition. The high-pressure eo-Alpine recrystallization of these ultramafites in subduction conditions originated secondary harzburgites in the Ca-depleted domains, consisting of a spinifex-like textured olivine+orthopyroxene paragenesis, and a diopside+Ti-clinohumite paragenesis in the enclosing lherzolitic rocks. During the meso-Alpine event, secondary harzburgites were partly transformed into talc+antigorite serpentinites, whereas the diopside and clinohumite-bearing residual meta-lherzolites were mainly transformed into Cpx-bearing serpentinites. Relics of mantle-derived colourless olivine may be present in the more or less serpentinized secondary harzburgites. These relics are overgrown by the eo-Alpine brown pseudo-spinifex olivine, which contains submicroscopic inclusions of chromite, ilmenite and occasional halite and sylvite, inherited from its parental oceanic serpentine. The same type of mantle-derived olivine relics is also preserved within the Cpx-bearing serpentinites, although it

Structure of possible long-lived asteroid belts

NASA Astrophysics Data System (ADS)

Evans, N. W.; Tabachnik, S. A.

2002-06-01

High-resolution simulations are used to map out the detailed structure of two long-lived stable belts of asteroid orbits in the inner Solar system. The Vulcanoid belt extends from 0.09 to 0.20au, though with a gaps at 0.15 and 0.18au corresponding to de-stabilizing mean motion resonances with Mercury and Venus. As collisional evolution proceeds slower at larger heliocentric distances, km-sized or larger Vulcanoids are most likely to be found in the region between 0.16 and 0.18au. The optimum location to search is at geocentric ecliptic longitudes 9°<=|lg|<=10° and latitudes |βg|<1°. Dynamically speaking, the Earth-Mars belt between 1.08 and 1.28au is a stable repository for asteroids on nearly circular orbits. It is interrupted at 1.21au owing to the 3:4 commensurability with the Earth, while secular resonances with Saturn are troublesome beyond 1.17au. These detailed maps of the fine structure of the belts can be used to plan search methodologies. Strategies for detecting members of the belts are discussed, including the use of infrared wide-field imaging with VISTA, and forthcoming European Space Agency satellite missions such as GAIA and BepiColombo.

Exploring the collisional evolution of the asteroid belt

NASA Astrophysics Data System (ADS)

Bottke, W.; Broz, M.; O'Brien, D.; Campo Bagatin, A.; Morbidelli, A.

2014-07-01

The asteroid belt is a remnant of planet-formation processes. By modeling its collisional and dynamical history, and linking the results to constraints, we can probe how the planets and small bodies formed and evolved. Some key model constraints are: (i) The wavy shape of the main-belt size distribution (SFD), with inflection points near 100-km, 10--20-km, 1 to a few km, and ˜0.1-km diameter; (ii) The number of asteroid families created by the catastrophic breakup of large asteroid bodies over the last ˜ 4 Gy, with the number of disrupted D > 100 km bodies as small as ˜20 or as large as 60; (iii) the flux of small asteroids derived from the main belt that have struck the Moon over the last 3.5 Ga --- crater SFDs on lunar terrains with known ages suggest the D < 0.1 km projectile population has not varied appreciably over this interval; (iv) Vesta has an intact basaltic crust with two very large basins, but only two, on its surface. Fits to these parameters allow us to predict the shape of the initial main-belt SFD after accretion and the approximate asteroid disruption scaling law, with the latter consistent with numerical hydrocode simulations. Overall, we find that the asteroid belt probably experienced the equivalent of ˜6--10 Gy of comminution over its history. This value may seem strange, considering the solar system is only 4.56 Gy old. One way to interpret it is that the main belt once had more mass that was eliminated by early dynamical processes between 4--4.56 Ga. This would allow for more early grinding, and it would suggest the main belt's wavy-shaped SFD is a ''fossil'' from a more violent early epoch. Simulations suggest that most D > 100 km bodies have been significantly battered, but only a fraction have been catastrophically disrupted. Conversely, most small asteroids today are byproducts of fragmentation events. These results are consistent with growing evidence that most of the prominent meteorite classes were produced by young asteroid

Review of GEM Radiation Belt Dropout and Buildup Challenges

NASA Astrophysics Data System (ADS)

Tu, Weichao; Li, Wen; Morley, Steve; Albert, Jay

2017-04-01

In Summer 2015 the US NSF GEM (Geospace Environment Modeling) focus group named "Quantitative Assessment of Radiation Belt Modeling" started the "RB dropout" and "RB buildup" challenges, focused on quantitative modeling of the radiation belt buildups and dropouts. This is a community effort which includes selecting challenge events, gathering model inputs that are required to model the radiation belt dynamics during these events (e.g., various magnetospheric waves, plasmapause and density models, electron phase space density data), simulating the challenge events using different types of radiation belt models, and validating the model results by comparison to in situ observations of radiation belt electrons (from Van Allen Probes, THEMIS, GOES, LANL/GEO, etc). The goal is to quantitatively assess the relative importance of various acceleration, transport, and loss processes in the observed radiation belt dropouts and buildups. Since 2015, the community has selected four "challenge" events under four different categories: "storm-time enhancements", "non-storm enhancements", "storm-time dropouts", and "non-storm dropouts". Model inputs and data for each selected event have been coordinated and shared within the community to establish a common basis for simulations and testing. Modelers within and outside US with different types of radiation belt models (diffusion-type, diffusion-convection-type, test particle codes, etc.) have participated in our challenge and shared their simulation results and comparison with spacecraft measurements. Significant progress has been made in quantitative modeling of the radiation belt buildups and dropouts as well as accessing the modeling with new measures of model performance. In this presentation, I will review the activities from our "RB dropout" and "RB buildup" challenges and the progresses achieved in understanding radiation belt physics and improving model validation and verification.

A comparison of muscle activation between back squats and belt squats.

PubMed

Evans, Thomas W; McLester, Cherilyn N; Howard, Jonathan H; McLester, John R; Calloway, Jimmy P

2017-06-08

A machine belt squat is a piece of equipment designed to allow the performance of squats while loading weight on the lifter's hips using a belt. The purpose of this investigation was to determine if belt squats differ from back squats in activation of the primary movers, and to determine the predictive capabilities of back squat load, training status, and anthropometric data on belt squat load. Thirty-one participants (16 males and 15 females) completed anthropometric measurements, a demographic questionnaire, a familiarization visit, and two testing visits, completing a 5 repetition maximum test for back squat and belt squat. Surface electromyography was used to measure muscle activation for the left and right vastus medialis (VMO), vastus lateralis (VLO), rectus femoris (RF), and gluteus maximus (GM). Comparison of muscle activation between the two exercises showed significant differences in the left GM (back squat: 0.84 ± 0.45, belt squat: 0.69 ± 0.22, p=0.015) and right GM (back squat: 0.86 ± 0.45, belt squat: 0.71 ± 0.29, p=0.004). Regression analysis computed significant prediction equations for belt squat load for general population, males, females, and advanced lifters. Overall, results indicate that belt squats may significantly differ in GM activation from back squats. Back squat load, as well as other variables, may be effective in accurately estimating appropriate belt squat load. These findings may help to more appropriately program for training with machine belt squats as a back squat alternative.

Transition From Archean Plume-Arc Orogens to Phanerozoic Style Convergent Margin Orogens, and Changing Mantle Lithosphere

NASA Astrophysics Data System (ADS)

Kerrich, R.; Jia, Y.; Wyman, D.

2001-12-01

Mantle plume activity was more intense in the Archean and komatiite-basalt volcanic sequences are a major component of many Archean greenstone belts. Tholeiitic basalts compositionally resemble Phanerozoic and Recent ocean plateau basalts, such as those of Ontong Java and Iceland. However, komatiite-basalt sequences are tectonically imbricated with bimodal arc lavas and associated trench turbidites. Interfingering of komatiite flows with boninite series flows, and primitive to evolved arc basalts has recently been identified in the 2.7 Ga Abitibi greenstone belt, demonstrating spatially and temporally associated plume and arc magmatism. These observations are consistent with an intra-oceanic arc migrating and capturing an ocean plateau, where the plateau jams the arc and imbricated plateau-arc crust forms a greenstone belt orogen. Melting of shallowly subducted plateau basalt crust (high Ba, Th, LREE) accounts for the areally extensive and voluminous syntectonic tonalite batholiths. In contrast, the adakite-Mg-andesite-Niobium enriched basalt association found in Archean greenstone belts and Cenozoic arcs are melts of LREE depleted MORB slab. Buoyant residue from anomalously hot mantle plume melting at > 100km rises to couple with the composite plume-arc crust to form the distinctively thick and refractory Archean continental lithospheric mantle. New geochemical data for structurally hosted ultramafic units along the N. American Cordillera, from S. California to the Yukon, show that these are obducted slices of sub-arc lithospheric mantle. Negatively fractionated HREE with high Al2O3/TiO2 ratios signify prior melt extraction, and variably enriched Th and LREE with negative Nb anomalies a subduction component in a convergent margin. A secular decrease of mantle plume activity and temperature results in plume-arc dominated geodynamics in the Archean with shallow subduction and thick CLM, whereas Phanerozoic convergent margins are dominated by arc-continent, arc

States upgrade to primary enforcement seat belt laws : traffic tech.

DOT National Transportation Integrated Search

2011-09-01

States with primary seat belt enforcement laws consistently : have higher observed daytime seat belt use rates than secondary : law States. Secondary belt law States, on the other : hand, consistently have more motor vehicle fatalities who : were not...

Documenting How States Recently Upgraded to Primary Seat Belt Laws

DOT National Transportation Integrated Search

2011-09-01

States with primary seat belt enforcement laws consistently have higher observed daytime belt use rates than : secondary law States. Secondary belt law States, on the other hand, consistently have more occupant fatalities who : were not restrained th...

Asteroid Family Associations of Main-Belt Comets

NASA Astrophysics Data System (ADS)

Hsieh, Henry H.; Novakovic, Bojan; Kim, Yoonyoung; Brasser, Ramon

2016-10-01

We present a population-level analysis of the asteroid family associations of known main-belt comets or main-belt comet candidates (which, to date, have largely just been analyzed on individual bases as they have been discovered). In addition to family associations that have already been reported in the literature, we have identified dynamical relationships between 324P/La Sagra and the Alauda family, P/2015 X6 (PANSTARRS) and the Aeolia family, and P/2016 G1 (PANSTARRS) and the Adeona family. We will discuss the overall implications of these family associations, particularly as they pertain to the hypothesis that members of primitive asteroid family members may be more susceptible to producing observable sublimation-driven dust emission activity, and thus becoming main-belt comets. We will also discuss the significance of other dynamical and physical properties of a family or sub-family as they relate to the likelihood of that family containing one or more currently active main-belt comets.

Metamorphic reactions in ruby corundum amphibolite from the Chunky Gal Mountain mafic-ultramafic complex, Clay County, North Carolina

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ranson, W.A.; Garihan, J.M.; Ulmer, K.E.

1992-01-01

Amphibolite outcrops of unusual mineralogy within the Chunky Gal Mountain mafic-ultramafic complex display cm-scale rhythmic layers with moderate-steep dips. Layers are troctolitic, gabbroic, and anorthositic in composition, locally in contact with dunite of the Buck Creek ultramafic body. Meta-gabbroic layers contain striking bladed, emerald green amphibole as the chief mafic phase and relict bronzite with reacted margins. An additional major phase is plagioclase, [approximately]An 95 based on microprobe analysis. Ruby corundum is a minor (> 5%) constituent, which in some of the gabbroic rocks is mantled by a reaction rim of fibrolite. The clinoamphibole has optical properties resembling magnesio-cummingtonite: colorlessmore » to pale green in plane light with (+) sign and 2V = 60--70[degree]. However, microprobe analysis of the clinoamphibole indicates alumino-magnesio-hornblende. Although the texture of the bronzite shows that it is breaking down, it is clear that the clinoamphibole and corundum could not be the reaction products without the addition of Al, Ca, and Si in an aqueous fluid. Associated meta-troctolitic layers contain plagioclase and coarse, anhedral olivines displaying an inner corona of bladed orthopyroxene, rimmed by symplectite. The granulite facies reactions is: plagioclase + olivine = clinopyroxene + garnet. The mesoscopic-scale proximity of troctolitic and gabbroic rhythmic layers indicates both underwent granulite facies metamorphism. Retrogression to amphibolite grade is apparent only in the gabbroic layers, resulting in assemblages distinguished locally by abundant emerald green clinoamphibole and corundum porphyroblasts rimmed by fibrolite.« less

49 CFR 571.210 - Standard No. 210; Seat belt assembly anchorages.

Code of Federal Regulations, 2010 CFR

2010-10-01

... reference point, shall extend forward from that contact point at an angle with the horizontal of not less... torso belt first contacts the uppermost torso belt anchorage.Seat belt anchorage means any component... line from the seating reference point to the nearest contact point of the belt with the anchorage shall...

The Role of the Dynamic Plasmapause on Outer Radiation Belt Electron Flux Enhancement and Three-Belt Structure Formation

NASA Astrophysics Data System (ADS)

Bruff, M.; Jaynes, A. N.; Zhao, H.; Malaspina, D.

2017-12-01

The plasmasphere is a highly dynamic toroidal region of cold, dense plasma around Earth. Plasma waves exist both inside and outside this region and can contribute to the loss and acceleration of high energy outer radiation belt electrons. Early observational studies found an apparent correlation on long time scales between the observed inner edge of the outer radiation belt and the simulated innermost plasmapause location. More recent work using high resolution Van Allen Probe satellite data has found a more complex relationship. The aim of this project was to provide a systematic study of the location and dynamics of the plasmapause compared to the MeV electrons in the outer radiation belt. We used spin-averaged electron flux data from the Relativistic Electron Proton Telescope (REPT) and density data derived from the EFW instrument on the Van Allen Probe satellites. We analyzed these data to determine the standoff distance of the location of peak electron flux of the outer belt MeV electrons from the plasmapause. We found that the location of peak flux was consistently outside but within ΔL=2.5 from the innermost location of the plasmapause at enhancement times, with an average standoff distance ΔL=1.0 +/- 0.5. This is consistent with the current model of chorus enhancement and previous observations of chorus activity. Finally, we identified "three-belt" structure events where a second outer belt formed and found a repeated pattern of plasmapause dynamics associated with specific changes in electron flux required to generate and sustain these structures. This study is significant to improving our understanding of how the plasmasphere under differing conditions can both shield Earth from or worsen the impacts of geomagnetic activity.

The Southeast Asian Tin Belt

NASA Astrophysics Data System (ADS)

Schwartz, M. O.; Rajah, S. S.; Askury, A. K.; Putthapiban, P.; Djaswadi, S.

1995-07-01

The Southeast Asian Tin Belt is a north-south elongate zone 2800 km long and 400 km wide, extending from Burma (Myanmar) and Thailand to Peninsular Malaysia and the Indonesian Tin Islands. Altogether 9.6 million tonnes of tin, equivalent to 54% of the world's tin production is derived from this region. Most of the granitoids in the region can be grouped geographically into elongate provinces or belts, based on petrographic and geochronological features. - The Main Range Granitoid Province in western Peninsular Malaysia, southern Peninsular Thailand and central Thailand is almost entirely made up of biotite granite (184-230 Ma). Tin deposits associated with these granites contributed 55% of the historic tin production of Southeast Asia. - The Northern Granitoid Province in northern Thailand (0.1% of tin production) also has dominant biotite granite (200-269 Ma) but it is distinguished by abundant post-intrusion deformation. - The Eastern Granitoid Province extends from eastern Peninsular Malaysia to eastern Thailand. The Malaysian part is subdivided into the East Coast Belt (220-263 Ma), Boundary Range Belt (197-257 Ma) and Central Belt (79-219 Ma). The granitoids cover a wide compositional range from biotite granite to hornblende-biotite granite/granodiorite and diorite-gabbro. Tin deposits are associated with biotite granite in the East Coast Belt (3% of tin production). The granitoids in the other areas of the Eastern Granitoid Province are barren. - The Western Granitoid Province (22-149 Ma) in northern Peninsular Thailand, western Thailand and Burma has biotite granite and hornblende-biotite granite/granodiorite. Tin deposits are associated with biotite granite, which probably is the dominant phase (14% of tin production). The granitoids of the Indonesian Tin Islands (193-251 Ma) do not permit grouping into geographically distinct units. Main Range-type and Eastern Province-type plutons occur next to each other. Most of the tin deposits are associated with Main

Seat belts and shoulder harnesses : smart protection in small airplanes.

DOT National Transportation Integrated Search

2004-05-01

Seat belts alone will protect you only in minor impacts. : Using shoulder belts in small aircraft would reduce major injuries by 88% and fatalities by 20%. Shoulder belt kits are now available for most airplanes. : Proper use and installation of chil...

Evolution of strength and physical properties of carbonate and ultramafic rocks under hydrothermal conditions

NASA Astrophysics Data System (ADS)

Lisabeth, Harrison Paul

Interaction of rocks with fluids can significantly change mineral assemblage and structure. This so-called hydrothermal alteration is ubiquitous in the Earth's crust. Though the behavior of hydrothermally altered rocks can have planet-scale consequences, such as facilitating oceanic spreading along slow ridge segments and recycling volatiles into the mantle at subduction zones, the mechanisms involved in the hydrothermal alteration are often microscopic. Fluid-rock interactions take place where the fluid and rock meet. Fluid distribution, flux rate and reactive surface area control the efficiency and extent of hydrothermal alteration. Fluid-rock interactions, such as dissolution, precipitation and fluid mediated fracture and frictional sliding lead to changes in porosity and pore structure that feed back into the hydraulic and mechanical behavior of the bulk rock. Examining the nature of this highly coupled system involves coordinating observations of the mineralogy and structure of naturally altered rocks and laboratory investigation of the fine scale mechanisms of transformation under controlled conditions. In this study, I focus on fluid-rock interactions involving two common lithologies, carbonates and ultramafics, in order to elucidate the coupling between mechanical, hydraulic and chemical processes in these rocks. I perform constant strain-rate triaxial deformation and constant-stress creep tests on several suites of samples while monitoring the evolution of sample strain, permeability and physical properties. Subsequent microstructures are analyzed using optical and scanning electron microscopy. This work yields laboratory-based constraints on the extent and mechanisms of water weakening in carbonates and carbonation reactions in ultramafic rocks. I find that inundation with pore fluid thereby reducing permeability. This effect is sensitive to pore fluid saturation with respect to calcium carbonate. Fluid inundation weakens dunites as well. The addition of

Electron-microprobe study of chromitites associated with alpine ultramafic complexes and some genetic implications

USGS Publications Warehouse

Bird, M.L.

1978-01-01

Electron-microprobe and petrographic studies of alpine chromite deposits from around the world demonstrate that they are bimodal with respect to the chromic oxide content of their chromite. The two modes occur at 54 ? 4 and 37 ? 3 weight per cent chromic oxide corresponding to chromite designated as high-chromium and high-aluminum chromite respectively. The high-chromium chromite occurs exclusively with highly magnesian olivine (Fo92-97) and some interstitial diopside. The high-aluminum chromite is associated with more ferrous olivine (Fo88-92), diopside, enstatite, and feldspar. The plot of the mole ratios Cr/(Cr+Al+Fe3+) vs. Mg/(Mg+Fe2+) usually presented for alpine chromite is shown to have a high-chromium, high-iron to low-chromium, low-iron trend contrary to that shown by stratiform chromite. This trend is characteristic of alpine type chromite and is termed the alpine trend. However, a trend similar to that for startiform chromite is discernable on the graph for the high-chromium chromite data. This latter trend is well-developed at Red Mountain, Seldovia, Alaska. Analysis of the iron-magnesium distribution coefficient, Kd=(Fe/Mg)ol/(Fe/Mg)ch, between olivine and chromite shows that Kd for the high-chromium chromite from all ultramafic complexes has essentially the same constant value of .05 while the distribution coefficient for the high-aluminum chromite varies with composition of the chromite. These distribution coefficients are also characteristic of alpine-type chromites. The constant value for Kd for the high-chromium chromite and associated high-magnesium olivine in all alpine complexes suggests that they all crystallized under similar physico-chemical conditions. The two types of massive chromite and their associations of silicate minerals suggest the possibility of two populations with different origins. Recrystallization textures associated with the high-aluminum chromite together with field relationships between the gabbro and the chromite pods

California State Waters Map Series—Offshore of Santa Cruz, California

USGS Publications Warehouse

Cochrane, Guy R.; Dartnell, Peter; Johnson, Samuel Y.; Erdey, Mercedes D.; Golden, Nadine E.; Greene, H. Gary; Dieter, Bryan E.; Hartwell, Stephen R.; Ritchie, Andrew C.; Finlayson, David P.; Endris, Charles A.; Watt, Janet T.; Davenport, Clifton W.; Sliter, Ray W.; Maier, Katherine L.; Krigsman, Lisa M.; Cochrane, Guy R.; Cochran, Susan A.

2016-03-24

upper Quaternary shelf, estuarine, and fluvial sediments deposited as sea level fluctuated in the late Pleistocene. The inner shelf is characterized by bedrock outcrops that have local thin sediment cover, the result of regional uplift, high wave energy, and limited sediment supply. The midshelf occupies part of an extensive, shore-parallel mud belt. The thickest sediment deposits, inferred to consist mainly of lowstand nearshore deposits, are found in the southeastern and northwestern parts of the map area.Coastal sediment transport in the map area is characterized by northwest-to-southeast littoral transport of sediment that is derived mainly from ephemeral streams in the Santa Cruz Mountains and also from local coastal-bluff erosion. During the last approximately 300 years, as much as 18 million cubic yards (14 million cubic meters) of sand-sized sediment has been eroded from the area between Año Nuevo Island and Point Año Nuevo and transported south; this mass of eroded sand is now enriching beaches in the map area. Sediment transport is within the Santa Cruz littoral cell, which terminates in the submarine Monterey Canyon.Benthic species observed in the Offshore of Santa Cruz map area are natives of the cold-temperate biogeographic zone that is called either the “Oregonian province” or the “northern California ecoregion.” This biogeographic province is maintained by the long-term stability of the southward-flowing California Current, the eastern limb of the North Pacific subtropical gyre that flows from southern British Columbia to Baja California. At its midpoint off central California, the California Current transports subarctic surface (0–500 m deep) waters southward, about 150 to 1,300 km from shore. Seasonal northwesterly winds that are, in part, responsible for the California Current, generate coastal upwelling. The south end of the Oregonian province is at Point Conception (about 300 km south of the map area), although its associated

Factors related to increasing safety belt use in states with safety belt use laws : second annual report to Congress, 1988.

DOT National Transportation Integrated Search

1989-01-01

This report. is the second in a series of four annual reports to the : Congress on provisions of state safety belt use laws and other : programmatic factors related to increasing safety belt use levels. : The first Congressional Report reviewed what ...

Geophysical characterization of transtensional fault systems in the Eastern California Shear Zone-Walker Lane Belt

NASA Astrophysics Data System (ADS)

McGuire, M.; Keranen, K. M.; Stockli, D. F.; Feldman, J. D.; Keller, G. R.

2011-12-01

The Eastern California Shear Zone (ECSZ) and Walker Lane belt (WL) accommodate ~25% of plate motion between the North American and Pacific plates. Faults within the Mina deflection link the ECSZ and the WL, transferring strain from the Owens Valley and Death Valley-Fish Lake Valley fault systems to the transcurrent faults of the central Walker Lane. During the mid to late Miocene the majority of strain between these systems was transferred through the Silver Peak-Lone Mountain (SPLM) extensional complex via a shallowly dipping detachment. Strain transfer has since primarily migrated north to the Mina Deflection; however, high-angle faults bounding sedimentary basins and discrepancies between geodetic and geologic models indicate that the SPLM complex may still actively transfer a portion of the strain from the ECSZ to the WL on a younger set of faults. Establishing the pattern and amount of active strain transfer within the SPLM region is required for a full accounting of strain accommodation, and provides insight into strain partitioning at the basin scale within a broader transtensional zone. To map the active structures in and near Clayton Valley, within the SPLM region, we collected seismic reflection and refraction profiles and a dense grid of gravity readings that were merged with existing gravity data. The primary goals were to determine the geometry of the high-angle fault system, the amount and sense of offset along each fault set, connectivity of the faults, and the relationship of these faults to the Miocene detachment. Seismic reflection profiles imaged the high-angle basin-bounding normal faults and the detachment in both the footwall and hanging wall. The extensional basin is ~1 km deep, with a steep southeastern boundary, a gentle slope to the northwest, and a sharp boundary on the northwest side, suggestive of another fault system. Two subparallel dip-slip faults bound the southeast (deeper) basin margin with a large lateral velocity change (from ~2

Evaluation of safety belt education program for employees

DOT National Transportation Integrated Search

1980-06-01

This research was designed to determine the effectiveness of a nine-month safety belt educational program, utilizing various informational materials developed by NHTSA, in increasing safety belt usage among corporate employees. The materials used inc...

The Role of Rift Obliquity in Formation of the Gulf of California

NASA Astrophysics Data System (ADS)

Bennett, Scott Edmund Kelsey

-constrained ˜50-100 kilometer-wide transtensional belt of focused strike-slip faulting, basin formation, and rotating crustal blocks. This proto-Gulf of California shear zone, embedded within the wider Mexican Basin and Range extensional province and connected to the San Andreas fault in southern California, hosted subsequent localization of the plate boundary and rupture of the continental lithosphere.

The relationship between the plasmapause and outer belt electrons

NASA Astrophysics Data System (ADS)

Goldstein, J.; Baker, D. N.; Blake, J. B.; De Pascuale, S.; Funsten, H. O.; Jaynes, A. N.; Jahn, J.-M.; Kletzing, C. A.; Kurth, W. S.; Li, W.; Reeves, G. D.; Spence, H. E.

2016-09-01

We quantify the spatial relationship between the plasmapause and outer belt electrons for a 5 day period, 15-20 January 2013, by comparing locations of relativistic electron flux peaks to the plasmapause. A peak-finding algorithm is applied to 1.8-7.7 MeV relativistic electron flux data. A plasmapause gradient finder is applied to wave-derived electron number densities >10 cm-3. We identify two outer belts. Outer belt 1 is a stable zone of >3 MeV electrons located 1-2 RE inside the plasmapause. Outer belt 2 is a dynamic zone of <3 MeV electrons within 0.5 RE of the moving plasmapause. Electron fluxes earthward of each belt's peak are anticorrelated with cold plasma density. Belt 1 decayed on hiss timescales prior to a disturbance on 17 January and suffered only a modest dropout, perhaps owing to shielding by the plasmasphere. Afterward, the partially depleted belt 1 continued to decay at the initial rate. Belt 2 was emptied out by strong disturbance-time losses but restored within 24 h. For global context we use a plasmapause test particle simulation and derive a new plasmaspheric index Fp, the fraction of a circular drift orbit inside the plasmapause. We find that the locally measured plasmapause is (for this event) a good proxy for the globally integrated opportunity for losses in cold plasma. Our analysis of the 15-20 January 2013 time interval confirms that high-energy electron storage rings can persist for weeks or even months if prolonged quiet conditions prevail. This case study must be followed up by more general study (not limited to a 5 day period).

An investigation of safety belt usage and effectiveness

DOT National Transportation Integrated Search

1975-03-01

This interim report contains primarily a theoretical discussion of problems of inference in studies on seat belt utilization and effectiveness. Seat belt effectiveness in accidents is initially discussed from a population paramenter point of, view. T...

A new interpretation for the interference zone between the southern Brasília belt and the central Ribeira belt, SE Brazil

NASA Astrophysics Data System (ADS)

Trouw, Rudolph A. J.; Peternel, Rodrigo; Ribeiro, Andre; Heilbron, Mônica; Vinagre, Rodrigo; Duffles, Patrícia; Trouw, Camilo C.; Fontainha, Marcos; Kussama, Hugo H.

2013-12-01

In southeastern Brazil, the Neoproterozoic NNW-SSE trending southern Brasília belt is apparently truncated by the ENE-WSW central Ribeira belt. Different interpretations in the literature of the transition between these two belts motivated detailed mapping and additional age dating along the contact zone. The result is a new interpretation presented in this paper. The southern Brasília belt resulted from E-W collision between the active margin of the Paranapanema paleocontinent, on the western side, now forming the Socorro-Guaxupé Nappe, with the passive margin of the São Francisco paleocontinent on the eastern side. The collision produced an east vergent nappe stack, the Andrelândia Nappe System, along the suture. At its southern extreme the Brasília belt was thought to be cut off by a shear zone, the "Rio Jaguari mylonites", at the contact with the Embu terrane, pertaining to the Central Ribeira belt. Our detailed mapping revealed that the transition between the Socorro-Guaxupé Nappe (Brasília belt) and the Embu terrane (Ribeira belt) is not a fault but rather a gradational transition that does not strictly coincide with the Rio Jaguari mylonites. A typical Cordilleran type magmatic arc batholith of the Socorro-Guaxupé Nappe with an age of ca. 640 Ma intrudes biotite schists of the Embu terrane and the age of zircon grains from three samples of metasedimentary rocks, one to the south, one to the north and one along the mylonite zone, show a similar pattern of derivation from a Rhyacian source area with rims of 670-600 Ma interpreted as metamorphic overgrowth. We dated by LA-MC-ICPMS laser ablation (U-Pb) zircon grains from a calc-alkaline granite, the Serra do Quebra-Cangalha Batholith, located within the Embu terrane at a distance of about 40 km south of the contact with the Socorro Nappe, yielding an age of 680 ± 13 Ma. This age indicates that the Embu terrane was part of the upper plate (Socorro-Guaxupé Nappe) by this time. Detailed mapping

30 CFR 75.1108 - Approved conveyor belts.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Approved conveyor belts. 75.1108 Section 75.1108 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND... December 31, 2018 all conveyor belts used in underground coal mines shall be approved under Part 14. [73 FR...

Radiation Belts Throughout the Solar System

NASA Astrophysics Data System (ADS)

Mauk, B. H.

2008-12-01

The several preceding decades of deep space missions have demonstrated that the generation of planetary radiation belts is a universal phenomenon. All strongly magnetized planets show well developed radiation regions, specifically Earth, Jupiter, Saturn, Uranus, and Neptune. The similarities occur despite the tremendous differences between the planets in size, levels of magnetization, external environments, and most importantly, in the fundamental processes that power them. Some planets like Jupiter are powered overwhelmingly by planetary rotation, much like astrophysical pulsars, whereas others, like Earth and probably Uranus, are powered externally by the interplanetary environment. Uranus is a particularly interesting case in that despite the peculiarities engendered by its ecliptic equatorial spin axis orientation, its magnetosphere shows dynamical behavior similar to that of Earth as well as radiation belt populations and associated wave emissions that are perhaps more intense than expected based on Earth-derived theories. Here I review the similarities and differences between the radiation regions of radiation belts throughout the solar system. I discuss the value of the comparative approach to radiation belt physics as one that allows critical factors to be evaluated in environments that are divorced from the special complex conditions that prevail in any one environment, such as those at Earth.

The Fossilized Size Distribution of the Main Asteroid Belt

NASA Astrophysics Data System (ADS)

Bottke, W. F.; Durda, D.; Nesvorny, D.; Jedicke, R.; Morbidelli, A.

2003-05-01

At present, we do not understand how the main asteroid belt evolved into its current state. During the planet formation epoch, the primordial main belt (PMB) contained several Earth masses of material, enough to allow the asteroids to accrete on relatively short timescales (e.g., Weidenschilling 1977). The present-day main belt, however, only contains 5e-4 Earth masses of material (Petit et al. 2002). Constraints on this evolution come from (i) the observed fragments of differentiated asteroids, (ii) meteorites collected from numerous differentiated parent bodies, (iii) the presence of ˜ 10 prominent asteroid families, (iv) the "wavy" size-frequency distribution of the main belt, which has been shown to be a by-product of substantial collisional evolution (e.g., Durda et al. 1997), and (v) the still-intact crust of (4) Vesta. To explain the contradictions in the above constraints, we suggest the PMB evolved in this fashion: Planetesimals and planetary embryos accreted (and differentiated) in the PMB during the first few Myr of the solar system. Gravitational perturbations from these embryos dynamically stirred the main belt, enough to initiate fragmentation. When Jupiter reached its full size, some 10 Myr after the solar system's birth, its perturbations, together with those of the embryos, dynamically depleted the main belt region of ˜ 99% of its bodies. Much of this material was sent to high (e,i) orbits, where it continued to pummel the surviving main belt bodies at high impact velocities for more than 100 Myr. While some differentiated bodies in the PMB were disrupted, most were instead scattered; only small fragments from this population remain. This period of comminution and dynamical evolution in the PMB created, among other things, the main belt's wavy size distribution, such that it can be considered a "fossil" from this violent early epoch. From this time forward, however, relatively little collisional evolution has taken place in the main belt

The Fossilized Size Distribution of the Main Asteroid Belt

NASA Astrophysics Data System (ADS)

Bottke, W. F.; Durda, D.; Nesvorny, D.; Jedicke, R.; Morbidelli, A.

2004-05-01

The main asteroid belt evolved into its current state via two processes: dynamical depletion and collisional evolution. During the planet formation epoch, the primordial main belt (PMB) contained several Earth masses of material, enough to allow the asteroids to accrete on relatively short timescales (e.g., Weidenschilling 1977). The present-day main belt, however, only contains 5e-4 Earth masses of material (Petit et al. 2002). To explain this mass loss, we suggest the PMB evolved in the following manner: Planetesimals and planetary embryos accreted (and differentiated) in the PMB during the first few Myr of the solar system. Gravitational perturbations from these embryos dynamically stirred the main belt, enough to initiate fragmentation. When Jupiter reached its full size, some 10 Myr after the solar system's birth, its perturbations, together with those of the embryos, dynamically depleted the main belt region of > 99% of its bodies. Much of this material was sent to high (e,i) orbits, where it continued to pummel the surviving main belt bodies at high impact velocities for more than 100 Myr. While some differentiated bodies in the PMB were disrupted, most were instead scattered; only small fragments from this population remain. This period of comminution and dynamical evolution in the PMB created, among other things, the main belt's wavy size-frequency distribution, such that it can be considered a "fossil" from this violent early epoch. From this time forward, however, relatively little collisional evolution has taken place in the main belt, consistent with the surprising paucity of prominent asteroid families. We will show that the constraints provided by asteroid families and the shape of the main belt size distribution are essential to obtaining a unique solution from our model's initial conditions. We also use our model results to solve for the asteroid disruption scaling law Q*D, a critical function needed in all planet formation codes that include

Belt-MRF for large aperture mirrors.

PubMed

Ren, Kai; Luo, Xiao; Zheng, Ligong; Bai, Yang; Li, Longxiang; Hu, Haixiang; Zhang, Xuejun

2014-08-11

With high-determinacy and no subsurface damage, Magnetorheological Finishing (MRF) has become an important tool in fabricating high-precision optics. But for large mirrors, the application of MRF is restricted by its small removal function and low material removal rate. In order to improve the material removal rate, shorten the processing cycle, we proposed a new MRF concept, named Belt-MRF to expand the application of MRF to large mirrors and made a prototype with a large remove function, using a belt instead of a very large polishing wheel to expand the polishing length. A series of experimental results on Silicon carbide (SiC) and BK 7 specimens and fabrication simulation verified that the Belt-MRF has high material removal rates, stable removal function and high convergence efficiency which makes it a promising technology for processing large aperture optical elements.

Preventive Effects of Seat Belt on Clinical Outcomes for Road Traffic Injuries

PubMed Central

2015-01-01

Proper seat belt use saves lives; however, the use rate decreased in Korea. This study aimed to measure the magnitude of the preventive effect of seat belt on case-fatality across drivers and passengers. We used the Emergency Department based Injury In-depth Surveillance (EDIIS) database from 17 EDs between 2011 and 2012. All of adult injured patients from road traffic injuries (RTI) in-vehicle of less than 10-seat van were eligible, excluding cases with unknown seat belt use and outcomes. Primary and secondary endpoints were in-hospital mortality and intracranial injury. We calculated adjusted odds ratios (AORs) of seat belt use and driving status for study outcomes adjusting for potential confounders. Among 23,698 eligible patients, 15,304 (64.6%) wore seat belts. Driver, middle aged (30-44 yr), male, daytime injured patients were more likely to use seat belts (all P < 0.001). In terms of clinical outcome, no seat belt group had higher proportions of case-fatality and intracranial injury compared to seat belt group (both P < 0.001). Compared to seat belt group, AORs (95% CIs) of no seat belt group were 10.43 (7.75-14.04) for case-fatality and 2.68 (2.25-3.19) for intracranial injury respectively. In the interaction model, AORs (95% CIs) of no seat belt use for case-fatality were 11.71 (8.45-16.22) in drivers and 5.52 (2.83-14.76) in non-driving passengers, respectively. Wearing seat belt has significantly preventive effects on case-fatality and intracranial injury. Public health efforts to increase seat belt use are needed to reduce health burden from RTIs. PMID:26713066

Trapped belt variations and their effects on human space flights

NASA Technical Reports Server (NTRS)

Robbins, Donald E.; Badhwar, Gautam D.

1993-01-01

Variations in the Earth's trapped (Van Allen) belts produced by solar flare particle events are not well understood. This paper reports the existence of a second proton belt and its subsequent decay as measured by a tissue-equivalent proportional counter and a particle spectrometer on five Space Shuttle flights covering an 18-month period. The creation of this second belt is attributed to the injection of particles from a solar particle event which occurred at 2246 UT, March 22, 1991. Comparisons with observations onboard the Russian Mir space station and other unmanned satellites are made. Shuttle measurements and data from other spacecraft are used to determine that the e-folding time of the peak of the second proton belt was ten months. Proton populations in the second belt returned to values of quiescent times within 18 months. The increase in absorbed dose attributed to protons in the second belt was approximately 20 percent. Passive dosimeter measurements were in good agreement with this value.

Nickel-tolerant ectomycorrhizal Pisolithus albus ultramafic ecotype isolated from nickel mines in New Caledonia strongly enhance growth of the host plant Eucalyptus globulus at toxic nickel concentrations.

PubMed

Jourand, Philippe; Ducousso, Marc; Reid, Robert; Majorel, Clarisse; Richert, Clément; Riss, Jennifer; Lebrun, Michel

2010-10-01

Ectomycorrhizal (ECM) Pisolithus albus (Cooke & Massee), belonging to the ultramafic ecotype isolated in nickel-rich serpentine soils from New Caledonia (a tropical hotspot of biodiversity) and showing in vitro adaptive nickel tolerance, were inoculated to Eucalyptus globulus Labill used as a Myrtaceae plant-host model to study ectomycorrhizal symbiosis. Plants were then exposed to a nickel (Ni) dose-response experiment with increased Ni treatments up to 60 mg kg( - )(1) soil as extractable Ni content in serpentine soils. Results showed that plants inoculated with ultramafic ECM P. albus were able to tolerate high and toxic concentrations of Ni (up to 60 μg g( - )(1)) while uninoculated controls were not. At the highest Ni concentration tested, root growth was more than 20-fold higher and shoot growth more than 30-fold higher in ECM plants compared with control plants. The improved growth in ECM plants was associated with a 2.4-fold reduction in root Ni concentration but a massive 60-fold reduction in transfer of Ni from root to shoots. In vitro, P. albus strains could withstand high Ni concentrations but accumulated very little Ni in its tissue. The lower Ni uptake by mycorrhizal plants could not be explained by increased release of metal-complexing chelates since these were 5- to 12-fold lower in mycorrhizal plants at high Ni concentrations. It is proposed that the fungal sheath covering the plant roots acts as an effective barrier to limit transfer of Ni from soil into the root tissue. The degree of tolerance conferred by the ultramafic P. albus isolates to growth of the host tree species is considerably greater than previously reported for other ECM. The primary mechanisms underlying this improved growth were identified as reduced Ni uptake into the roots and markedly reduced transfer from root to shoot in mycorrhizal plants. The fact that these positive responses were observed at Ni concentrations commonly observed in serpentinic soils suggests that

Liquid belt radiator design study

NASA Technical Reports Server (NTRS)

Teagan, W. P.; Fitzgerald, K. F.

1986-01-01

The Liquid Belt Radiator (LBR) is an advanced concept developed to meet the needs of anticipated future space missions. A previous study documented the advantages of this concept as a lightweight, easily deployable alternative to present day space heat rejection systems. The technical efforts associated with this study concentrate on refining the concept of the LBR as well as examining the issues of belt dynamics and potential application of the LBR to intermediate and high temperature heat rejection applications. A low temperature point design developed in previous work is updated assuming the use of diffusion pump oil, Santovac-6, as the heat transfer media. Additional analytical and design effort is directed toward determining the impact of interface heat exchanger, fluid bath sealing, and belt drive mechanism designs on system performance and mass. The updated design supports the earlier result by indicating a significant reduction in system specific system mass as compared to heat pipe or pumped fluid radiator concepts currently under consideration (1.3 kg/sq m versus 5 kg/sq m).

Suspended particulate layers and internal waves over the southern Monterey Bay continental shelf: An important control on shelf mud belts?

NASA Astrophysics Data System (ADS)

Cheriton, Olivia M.; McPhee-Shaw, Erika E.; Shaw, William J.; Stanton, Timothy P.; Bellingham, James G.; Storlazzi, Curt D.

2014-01-01

Physical and optical measurements taken over the mud belt on the southern continental shelf of Monterey Bay, California documented the frequent occurrence of suspended particulate matter features, the majority of which were detached from the seafloor, centered 9-33 m above the bed. In fall 2011, an automated profiling mooring and fixed instrumentation, including a thermistor chain and upward-looking acoustic Doppler current profiler, were deployed at 70 m depth for 5 weeks, and from 12 to 16 October a long-range autonomous underwater vehicle performed across-shelf transects. Individual SPM events were uncorrelated with local bed shear stress caused by surface waves and bottom currents. Nearly half of all observed SPM layers occurred during 1 week of the study, 9-16 October 2011, and were advected past the fixed profiling mooring by the onshore phase of semidiurnal internal tide bottom currents. At the start of the 9-16 October period, we observed intense near-bed vertical velocities capable of lifting particulates into the middle of the water column. This "updraft" event appears to have been associated with nonlinear adjustment of high-amplitude internal tides over the mid and outer shelf. These findings suggest that nonlinear internal tidal motions can erode material over the outer shelf and that, once suspended, this SPM can then be transported shoreward to the middle and shallow sections of the mud belt. This represents a fundamental broadening of our understanding of how shelf mud belts may be built up and sustained.

Conveyor belt care.

PubMed

1989-07-08

Nurses, doctors, politicians and public have reacted to the prospect of high-volume hospital bed usage - conveyor belt care - by warning of a future-shock scenario of 'pro[Illegible Word] pea' patients whipped through dehumanising hospital treatment and promptly dumped crutchless into the community.

The binary Kuiper-belt object 1998 WW31.

PubMed

Veillet, Christian; Parker, Joel Wm; Griffin, Ian; Marsden, Brian; Doressoundiram, Alain; Buie, Marc; Tholen, David J; Connelley, Michael; Holman, Matthew J

2002-04-18

The recent discovery of a binary asteroid during a spacecraft fly-by generated keen interest, because the orbital parameters of binaries can provide measures of the masses, and mutual eclipses could allow us to determine individual sizes and bulk densities. Several binary near-Earth, main-belt and Trojan asteroids have subsequently been discovered. The Kuiper belt-the region of space extending from Neptune (at 30 astronomical units) to well over 100 AU and believed to be the source of new short-period comets-has become a fascinating new window onto the formation of our Solar System since the first member object, not counting Pluto, was discovered in 1992 (ref. 13). Here we report that the Kuiper-belt object 1998 WW31 is binary with a highly eccentric orbit (eccentricity e approximately 0.8) and a long period (about 570 days), very different from the Pluto/Charon system, which was hitherto the only previously known binary in the Kuiper belt. Assuming a density in the range of 1 to 2 g cm-3, the albedo of the binary components is between 0.05 and 0.08, close to the value of 0.04 generally assumed for Kuiper-belt objects.

Research on an Active Seat Belt System

NASA Astrophysics Data System (ADS)

Kawashima, Takeshi

In a car crash, permanent injury can be avoided if deformation of an occupant's rib cage is maintained within the allowable value. In order to realize this condition, the occupant's seat belt tension must be instantaneously adjusted by a feedback control system. In this study, a seat belt tension control system based on the active shock control system is proposed. The semi-active control law used is derived from the sliding mode control method. One advantage of this proposed system is that it does not require a large power actuator because the seat belt tension is controlled by a brake mechanism. The effectiveness is confirmed by numerical simulation using general parameters of a human thorax and a passenger car in a collision scenario with a wall at a velocity of 100 km/h. The feasibility is then confirmed with a control experiment using a scale model of about 1/10 scale. The relative displacement of the thorax model approaches the allowable value smoothly along the control reference and settles near this value. Thus, the proposed seat belt tension control system design is established.

Is the Cameron River greenstone belt allochthonous?

NASA Technical Reports Server (NTRS)

Kusky, T. M.

1986-01-01

Many tectonic models for the Slave Province, N.W.T., Canada, and for Archean granite - greenstone terranes in general, are implicitly dependent on the assumption that greenstone belt lithologies rest unconformably upon older gneissic basement. Other models require originally large separations between gneissic terranes and greenstone belts. A key question relating to the tectonics of greenstone belts is therefore the original spatial relationship between the volcanic assemblages and presumed-basement gneisses, and how this relationship has been modified by subsequent deformation. What remains unclear in these examples is the significance of the so-called later faulting of the greenstone - gneiss contacts. Where unconformities between gneisses and overlying sediments are indisputable, such as at Point Lake, the significance of faults which occur below the base of the volcanic succession also needs to be evaluated. As part of an on-going investigation aimed at answering these and other questions, the extremely well-exposed Cameron River Greenstone Belt and the Sleepy Dragon Metamorphic Complex in the vicinity of Webb Lake and Sleepy Dragon Lake was mapped.

Bayesian inference of radiation belt loss timescales.

NASA Astrophysics Data System (ADS)

Camporeale, E.; Chandorkar, M.

2017-12-01

Electron fluxes in the Earth's radiation belts are routinely studied using the classical quasi-linear radial diffusion model. Although this simplified linear equation has proven to be an indispensable tool in understanding the dynamics of the radiation belt, it requires specification of quantities such as the diffusion coefficient and electron loss timescales that are never directly measured. Researchers have so far assumed a-priori parameterisations for radiation belt quantities and derived the best fit using satellite data. The state of the art in this domain lacks a coherent formulation of this problem in a probabilistic framework. We present some recent progress that we have made in performing Bayesian inference of radial diffusion parameters. We achieve this by making extensive use of the theory connecting Gaussian Processes and linear partial differential equations, and performing Markov Chain Monte Carlo sampling of radial diffusion parameters. These results are important for understanding the role and the propagation of uncertainties in radiation belt simulations and, eventually, for providing a probabilistic forecast of energetic electron fluxes in a Space Weather context.

Into the Kuiper Belt: New Horizons Post-Pluto

NASA Astrophysics Data System (ADS)

Harrison Parker, Alex; Spencer, John; Benecchi, Susan; Binzel, Richard; Borncamp, David; Buie, Marc; Fuentes, Cesar; Gwyn, Stephen; Kavelaars, JJ; Noll, Keith; Petit, Jean-Marc; Porter, Simon; Showalter, Mark; Stern, S. Alan; Sterner, Ray; Tholen, David; Verbiscer, Anne; Weaver, Hal; Zangari, Amanda

2015-11-01

New Horizons is now beyond Pluto and flying deeper into the Kuiper Belt. In the summer of 2014, a Hubble Space Telescope Large Program identified two candidate Cold Classical Kuiper Belt Objects (KBOs) that were within reach of New Horizons' remaining fuel budget. Here we present the selection of the Kuiper Belt flyby target for New Horizons' post-Pluto mission, our state of knowledge regarding this target and the potential 2019 flyby, the status of New Horizons' targeting maneuver, and prospects for near-future long-range observations of other KBOs.

The small numbers of large Kuiper Belt objects

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schwamb, Megan E.; Brown, Michael E.; Fraser, Wesley C., E-mail: mschwamb@asiaa.sinica.edu.tw

2014-01-01

We explore the brightness distribution of the largest and brightest (m(R) < 22) Kuiper Belt Objects (KBOs). We construct a luminosity function of the dynamically excited or hot Kuiper Belt (orbits with inclinations >5°) from the very brightest to m(R) = 23. We find for m(R) ≲ 23, a single slope appears to describe the luminosity function. We estimate that ∼12 KBOs brighter than m(R) ∼ 19.5 are present in the Kuiper Belt today. With nine bodies already discovered this suggests that the inventory of bright KBOs is nearly complete.

Can ectomycorrhizal symbiosis and belowground plant traits be used as ecological tools to mitigate erosion on degraded slopes in the ultramafic soils of New Caledonia?

NASA Astrophysics Data System (ADS)

Demenois, Julien; Carriconde, Fabian; Rey, Freddy; Stokes, Alexia

2015-04-01

New Caledonia is an archipelago in the South West Pacific located just above the Tropic of Capricorn. The main island is bisected by a continuous mountain chain whose highest peaks reach more than 1 600 m. With mean annual rainfall above 2 000 mm in the South of the main island, frequent downpours and steep slopes, its soils are prone to water erosion. Deforestation, fires and mining activity are the main drivers of water erosion. Stakes are high to mitigate the phenomenon: extraction of nickel from ultramafic substrates (one third of the whole territory) is the main economic activity; New Caledonia is considered as a biodiversity hotspot. Restoration ecology is seen as a key approach for tackling such environmental challenges. Soil microorganisms could play significant roles in biological processes such as plant nutrition and plant resistance to abiotic and biotic stresses. Microorganisms could increase soil aggregate stability and thus mitigate soil erodibility. Plant roots increase soil cohesion through exudation and decomposition processes. To date, few studies have collected data on the soil aggregate stability of steep slopes affected by erosion and, to our knowledge, interactions between ectomycorrhizas (ECM), roots and erodibility of ultramafic soils have never been considered. The objective of our study is to assess the influence of ECM symbiosis and plant root traits on the erodibility of ultramafic soils of New Caledonia and answer the following questions: 1/ What is the influence of plant root traits of vegetal communities and ECM fungal diversity on soil erodibility? 2/ What are the belowground plant traits of some mycorrhized endemic species used in ecological restoration? 3/ What is the influence of plant root traits and ECM fungal inoculation on soil erodibility? At the scale of plant communities, five types of vegetation have been chosen in the South of the main island: degraded ligno-herbaceous shrubland, ligno-herbaceous shrubland, degraded humid

Greenstone belts: Their boundaries, surrounding rock terrains and interrelationships

NASA Technical Reports Server (NTRS)

Percival, J. A.; Card, K. D.

1986-01-01

Greenstone belts are an important part of the fragmented record of crustal evolution, representing samples of the magmatic activity that formed much of the Earth's crust. Most belts developed rapidly, in less than 100 Ma, leaving large gaps in the geological record. Surrounding terrains provide information on the context of greenstone belts. The effects of tectonic setting, structural geometry and evolution, associated plutonic activity and sedimentation are discussed.

The relationship between the plasmapause and outer belt electrons

DOE PAGES

Goldstein, J.; Baker, D. N.; Blake, J. B.; ...

2016-09-01

Here, we quantify the spatial relationship between the plasmapause and outer belt electrons for a 5 day period, 15–20 January 2013, by comparing locations of relativistic electron flux peaks to the plasmapause. A peak-finding algorithm is applied to 1.8–7.7 MeV relativistic electron flux data. A plasmapause gradient finder is applied to wave-derived electron number densities >10 cm –3. We identify two outer belts. Outer belt 1 is a stable zone of >3 MeV electrons located 1–2 R E inside the plasmapause. Outer belt 2 is a dynamic zone of <3 MeV electrons within 0.5 R E of the moving plasmapause.more » Electron fluxes earthward of each belt's peak are anticorrelated with cold plasma density. Belt 1 decayed on hiss timescales prior to a disturbance on 17 January and suffered only a modest dropout, perhaps owing to shielding by the plasmasphere. Afterward, the partially depleted belt 1 continued to decay at the initial rate. Belt 2 was emptied out by strong disturbance-time losses but restored within 24 h. For global context we use a plasmapause test particle simulation and derive a new plasmaspheric index F p, the fraction of a circular drift orbit inside the plasmapause. We find that the locally measured plasmapause is (for this event) a good proxy for the globally integrated opportunity for losses in cold plasma. Our analysis of the 15–20 January 2013 time interval confirms that high-energy electron storage rings can persist for weeks or even months if prolonged quiet conditions prevail. This case study must be followed up by more general study (not limited to a 5 day period).« less

Compliance with seat belt use in Benin City, Nigeria.

PubMed

Iribhogbe, Pius Ehiawaguan; Osime, Clement Odigie

2008-01-01

Trauma is a major cause of death and disability worldwide. A quarter of all fatalities due to injury occur due to road traffic crashes with 90% of the fatalities occurring in low- and medium-income countries. Poor compliance with the use of seat belts is a problem in many developing countries. The aim of this study was to evaluate the level of seatbelt compliance in motor vehicles in Benin City, Nigeria. A five-day, observational study was conducted in strategic locations in Benin City. The compliance rates of drivers, front seat passengers, and rear seat passengers in the various categories of vehicles were evaluated, and the data were subjected to statistical processing using the Program for Epidemiology. A total of 369 vehicles were observed. This consisted of 172 private cars, 64 taxis, 114 buses, 15 trucks, and four other vehicles. The seat belt compliance rate for drivers was 52.3%, front seat passengers 18.4%, and rear seat passengers 6.1%. Drivers of all categories of vehicles were more likely to use the seat belt compared to front seat passengers (p = 0.000) and rear seat passengers (p = 0.000). Drivers of private cars were more likely to use seat belts compared to taxi drivers (p = 0.000) and bus drivers (p = 0.000). Front seat passengers in private cars were more likely to use the seat belt compared to front seat passengers in taxis (p = 0.000) and buses (p = 0.000). Rear seat passengers in private cars also were more likely to use seat belts compared to rear seat passengers in taxis (p = 0.000) and buses (p = 0.000). Compliance with seat belt use in Benin City is low. Legislation, educational campaigns, and enforcement of seat belt use are needed.

Deconstructing the conveyor belt.

PubMed

Lozier, M Susan

2010-06-18

For the past several decades, oceanographers have embraced the dominant paradigm that the ocean's meridional overturning circulation operates like a conveyor belt, transporting cold waters equatorward at depth and warm waters poleward at the surface. Within this paradigm, the conveyor, driven by changes in deepwater production at high latitudes, moves deep waters and their attendant properties continuously along western boundary currents and returns surface waters unimpeded to deepwater formation sites. A number of studies conducted over the past few years have challenged this paradigm by revealing the vital role of the ocean's eddy and wind fields in establishing the structure and variability of the ocean's overturning. Here, we review those studies and discuss how they have collectively changed our view of the simple conveyor-belt model.

The levantine amber belt

NASA Astrophysics Data System (ADS)

Nissenbaum, A.; Horowitz, A.

1992-02-01

Amber, a fossil resin, is found in Early Cretaceous sanstones and fine clastics in Lebanon, Jordan, and Israel. The term "Levantine amber belt" is coined for this amber-containing sediment belt. The amber occurs as small nodules of various colors and frequently contains inclusions of macro- and microorganisms. The Lebanese amber contains Lepidoptera and the amber from southern Israel is rich in fungal remains. The source of the amber, based on geochemical and palynological evidence, is assumed to be from a conifer belonging to the Araucariaceae. The resins were produced by trees growing in a tropical near shore environment. The amber was transported into small swamps and was preserved there together with lignite. Later reworking of those deposits resulted in redeposition of the amber in oxidized sandstones.

Papers on adult seat belts : effectiveness and use

DOT National Transportation Integrated Search

1988-06-01

The eight papers in this volume describe analyses of the : effectiveness and use of adult seat belts, based on traffic : accident data. All eight were written between January 1984 and : May 1988. The topics addressed include front seat belt : effecti...

Papers on adult seat belts--effectiveness and use

DOT National Transportation Integrated Search

1988-06-01

The eight papers in the volume describe analyses of the effectiveness and use of adult seat belts, based on traffic accident data. All eight were written between January 1984 and May 1988. The topics addressed include front seat belt effectiveness (e...

Understanding Quaternions and the Dirac Belt Trick

ERIC Educational Resources Information Center

Staley, Mark

2010-01-01

The Dirac belt trick is often employed in physics classrooms to show that a 2n rotation is not topologically equivalent to the absence of rotation whereas a 4n rotation is, mirroring a key property of quaternions and their isomorphic cousins, spinors. The belt trick can leave the student wondering if a real understanding of quaternions and spinors…

Driver hand-held mobile phone use and safety belt use.

PubMed

Eby, David W; Vivoda, Jonathon M

2003-11-01

The purposes of the study were to identify hand-held mobile phone use trends for Michigan and to compare safety belt use between users and nonusers. Mobile phone and safety belt use was investigated by a direct observation survey of drivers at intersections in Michigan. Data were weighted to calculate mobile phone use and safety belt use rates statewide. The study showed 2.7% of Michigan drivers were using a mobile phone at any given daylight time. Safety belt use of current mobile phone users was significantly lower than those not using mobile phones.

Ultramafic clasts from the South Chamorro serpentine mud volcano reveal a polyphase serpentinization history of the Mariana forearc mantle

NASA Astrophysics Data System (ADS)

Kahl, Wolf-Achim; Jöns, Niels; Bach, Wolfgang; Klein, Frieder; Alt, Jeffrey C.

2015-06-01

Serpentine seamounts located on the outer half of the pervasively fractured Mariana forearc provide an excellent window into the forearc devolatilization processes, which can strongly influence the cycling of volatiles and trace elements in subduction zones. Serpentinized ultramafic clasts recovered from an active mud volcano in the Mariana forearc reveal microstructures, mineral assemblages and compositions that are indicative of a complex polyphase alteration history. Petrologic phase relations and oxygen isotopes suggest that ultramafic clasts were serpentinized at temperatures below 200 °C. Several successive serpentinization events represented by different vein generations with distinct trace element contents can be recognized. Measured in situ Rb/Cs ratios are fairly uniform ranging between 1 and 10, which is consistent with Cs mobilization from sediments at lower temperatures and lends further credence to the low-temperature conditions proposed in models of the thermal structure in forearc settings. Late veins show lower fluid mobile element (FME) concentrations than early veins, suggesting a decreasing influence of fluid discharge from the subducting slab on the composition of the serpentinizing fluids. The continuous microfabric and mineral chemical evolution observed in the ultramafic clasts may have implications as to the origin and nature of the serpentinizing fluids. We hypothesize that opal and smectite dehydration produce quartz-saturated fluids with high FME contents and Rb/Cs between 1 and 4 that cause the early pervasive serpentinization. The partially serpentinized material may then be eroded from the basal plane of the suprasubduction mantle wedge. Serpentinization continued but the interacting fluids did not carry a pronounced sedimentary signature, either because FMEs were no longer released from the slab, or due to an en route loss of FMEs. Late chrysotile veins that document the increased access of fluids in a now fluid-dominated regime are

14 CFR 121.311 - Seats, safety belts, and shoulder harnesses.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Seats, safety belts, and shoulder harnesses... § 121.311 Seats, safety belts, and shoulder harnesses. (a) No person may operate an airplane unless... belt and shoulder harness that meets the applicable requirements specified in § 25.785 of this chapter...

14 CFR 121.311 - Seats, safety belts, and shoulder harnesses.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Seats, safety belts, and shoulder harnesses... § 121.311 Seats, safety belts, and shoulder harnesses. (a) No person may operate an airplane unless... belt and shoulder harness that meets the applicable requirements specified in § 25.785 of this chapter...

14 CFR 121.311 - Seats, safety belts, and shoulder harnesses.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Seats, safety belts, and shoulder harnesses... § 121.311 Seats, safety belts, and shoulder harnesses. (a) No person may operate an airplane unless... belt and shoulder harness that meets the applicable requirements specified in § 25.785 of this chapter...

14 CFR 121.311 - Seats, safety belts, and shoulder harnesses.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Seats, safety belts, and shoulder harnesses... § 121.311 Seats, safety belts, and shoulder harnesses. (a) No person may operate an airplane unless... belt and shoulder harness that meets the applicable requirements specified in § 25.785 of this chapter...

14 CFR 121.311 - Seats, safety belts, and shoulder harnesses.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Seats, safety belts, and shoulder harnesses... § 121.311 Seats, safety belts, and shoulder harnesses. (a) No person may operate an airplane unless... belt and shoulder harness that meets the applicable requirements specified in § 25.785 of this chapter...

Characteristics and conditions of teenage safety belt use

DOT National Transportation Integrated Search

1997-07-01

Safety belt use was observed for 7,384 vehicle occupants estimated as 15-19 years old in four states - Texas, Virginia, Idaho, and Mississippi. Age and other pertinent information was obtained from 2,330 teen occupants. Belt use ranged from 19.5% in ...

Geological setting, emplacement mechanism and igneous evolution of the Atchiza mafic-ultramafic layered suite in north-west Mozambique

NASA Astrophysics Data System (ADS)

Ibraimo, Daniel Luis; Larsen, Rune B.

2015-11-01

The Atchiza mafic and ultramafic-layered suite (hereafter, "Atchiza Suite) crops out in an area 330 km2 west of the Mozambican Tete province. In an early account of the geology of this intrusion, it was considered the continuation of the Great Dyke of Zimbabwe, an idea that was aborted after detailed studies. Nevertheless, the Ni concentrations in the Atchiza outcrop rocks are considerable. Our investigation used field evidence, hand specimens and petrography descriptions, mineral chemistry studies using electron microprobe analysis and tectonic analysis to arrive at a plausible mineralogical composition and understanding of the tectonic setting for the igneous evolution. The mineral composition from the Atchiza Suite indicates that these are cumulates. The magmatic segregation from the petrographic and mineral composition reasoning indicates that dunite-lherzolitic peridotite-olivine gabbro-gabbronorite-gabbro-pegmatitic gabbro is the rock formation sequence. Olivine and chromite were the first phases formed, followed by pyroxene and plagioclase. In addition, it is shown that these minerals are near-liquidus crystallization products of basaltic magma with olivine Fo: 87.06 in dunite, mean values of clinopyroxene are (Wo: 36.4, En: 48.0, Fs: 15.2), orthopyroxene (Wo: 2.95, En: 73.0, Fs: 24.2) and plagioclase An: 71.3, respectively. Opaque minerals comprise Fe-Ti oxides and (Fe, Cr) spinel up to 4.8 vol.%, but chromitite layers are not present. Most of the opaque minerals are interstitial to pyroxene. Sulphides are common in gabbros, with pyrrhotite, pentlandite, chalcopyrite, pyrite and covellite together comprising 0.4-2.0 vol.%. The whole rock Rare Earth Element (REE) concentrations are mainly a result of differentiation, but slight crustal contamination/assimilation contributed to the REE contents. In addition, they also show Eu enrichment, suggesting that plagioclase fractionation was important in the rock. The Atchiza Suite preserves a deep-seated plumbing

Participative education for children: an effective approach to increase safety belt use.

PubMed Central

Lehman, G R; Geller, E S

1990-01-01

Vehicle license plate numbers and the shoulder belt use of front-seat occupants were recorded unobtrusively when parents delivered and picked up their children at a Montessori school during 5-day baseline, intervention, and follow-up phases. Practicing and presenting a 15-min safety belt skit increased the safety belt use of those 6 kindergarten children who were not consistent belt users 82% above their preintervention baseline belt use mean of 47%. The belt use of these children's parents (who watched the skit) increased to 56% above their baseline mean of 36%. Also, mean safety belt use of 11 primary school children who watched the skit increased to 70% above their baseline of 28%. Mean safety belt use of the older children's parents (who didn't watch the skit) remained at approximately 31% for each phase, regardless of whether children were vehicle occupants. The follow-up observations, taken 3 months after the intervention, revealed 60% belt use for the kindergartners, 48% for the primary school children, and 71% for the kindergartners' parents when the children were vehicle occupants but only 30% when the parents were driving alone. PMID:2373658

The Production of Methane, Hydrogen, and Organic Compounds in Ultramafic-Hosted Hydrothermal Vents of the Mid-Atlantic Ridge

PubMed Central

Charlou, J.L.; Holm, N.G.; Mousis, O.

2015-01-01

Abstract Both hydrogen and methane are consistently discharged in large quantities in hydrothermal fluids issued from ultramafic-hosted hydrothermal fields discovered along the Mid-Atlantic Ridge. Considering the vast number of these fields discovered or inferred, hydrothermal fluxes represent a significant input of H2 and CH4 to the ocean. Although there are lines of evidence of their abiogenic formation from stable C and H isotope results, laboratory experiments, and thermodynamic data, neither their origin nor the reaction pathways generating these gases have been fully constrained yet. Organic compounds detected in the fluids may also be derived from abiotic reactions. Although thermodynamics are favorable and extensive experimental work has been done on Fischer-Tropsch-type reactions, for instance, nothing is clear yet about their origin and formation mechanism from actual data. Since chemolithotrophic microbial communities commonly colonize hydrothermal vents, biogenic and thermogenic processes are likely to contribute to the production of H2, CH4, and other organic compounds. There seems to be a consensus toward a mixed origin (both sources and processes) that is consistent with the ambiguous nature of the isotopic data. But the question that remains is, to what proportions? More systematic experiments as well as integrated geochemical approaches are needed to disentangle hydrothermal geochemistry. This understanding is of prime importance considering the implications of hydrothermal H2, CH4, and organic compounds for the ocean global budget, global cycles, and the origin of life. Key Words: Hydrogen—Methane—Organics—MAR—Abiotic synthesis—Serpentinization—Ultramafic-hosted hydrothermal vents. Astrobiology 15, 381–399. PMID:25984920

Radiation belt seed population and its association with the relativistic electron dynamics: A statistical study: Radiation Belt Seed Population

DOE PAGES

Tang, C. L.; Wang, Y. X.; Ni, B.; ...

2017-05-19

Using the Van Allen Probes data, we study the radiation belt seed population and it associated with the relativistic electron dynamics during 74 geomagnetic storm events. Based on the flux changes of 1 MeV electrons before and after the storm peak, these storm events are divided into two groups of “non-preconditioned” and “preconditioned”. The statistical study shows that the storm intensity is of significant importance for the distribution of the seed population (336 keV electrons) in the outer radiation belt. However, substorm intensity can also be important to the evolution of the seed population for some geomagnetic storm events. Formore » non-preconditioned storm events, the correlation between the peak fluxes and their L-shell locations of the seed population and relativistic electrons (592 keV, 1.0 MeV, 1.8 MeV, and 2.1 MeV) is consistent with the energy-dependent dynamic processes in the outer radiation belt. For preconditioned storm events, the correlation between the features of the seed population and relativistic electrons is not fully consistent with the energy-dependent processes. It is suggested that the good correlation between the radiation belt seed population and ≤1.0 MeV electrons contributes to the prediction of the evolution of ≤1.0 MeV electrons in the Earth’s outer radiation belt during periods of geomagnetic storms.« less

Radiation belt seed population and its association with the relativistic electron dynamics: A statistical study: Radiation Belt Seed Population

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tang, C. L.; Wang, Y. X.; Ni, B.

Using the Van Allen Probes data, we study the radiation belt seed population and it associated with the relativistic electron dynamics during 74 geomagnetic storm events. Based on the flux changes of 1 MeV electrons before and after the storm peak, these storm events are divided into two groups of “non-preconditioned” and “preconditioned”. The statistical study shows that the storm intensity is of significant importance for the distribution of the seed population (336 keV electrons) in the outer radiation belt. However, substorm intensity can also be important to the evolution of the seed population for some geomagnetic storm events. Formore » non-preconditioned storm events, the correlation between the peak fluxes and their L-shell locations of the seed population and relativistic electrons (592 keV, 1.0 MeV, 1.8 MeV, and 2.1 MeV) is consistent with the energy-dependent dynamic processes in the outer radiation belt. For preconditioned storm events, the correlation between the features of the seed population and relativistic electrons is not fully consistent with the energy-dependent processes. It is suggested that the good correlation between the radiation belt seed population and ≤1.0 MeV electrons contributes to the prediction of the evolution of ≤1.0 MeV electrons in the Earth’s outer radiation belt during periods of geomagnetic storms.« less

Soda Lake-Painted Rock(!) Petroleum System in the Cuyama Basin, California, U.S.A.

USGS Publications Warehouse

Lillis, Paul G.

1994-01-01

The Cuyama basin, located in the central California Coast Ranges, was formed by extension during early Miocene time and was filled with a variety of nonmarine, marginal marine, and neritic to bathyal marine sediments. Low sulfur oil is produced primarily from the lower Miocene Painted Rock Sandstone Member of the Vaqueros Formation along a structural trend parallel to the Russell fault, which was active from 23 to 5 Ma. A major fold and thrust belt beginning about 3 Ma formed the Caliente and Sierra Madre ranges and partially obscures the Miocene extensional basin. Stable carbon isotope and biomarker data indicate that the lower Miocene Soda Lake Shale Member of the Vaqueros Formation is the predominant source rock for the oil in the Cuyama area. Burial and thermal history modeling shows that oil generation began in middle-late Miocene time and that oil migrated into existing traps. Younger traps that formed in the overthrust are barren of oil because migration occurred prior to the development of the fold and thrust belt or because subthrust oil was unable to migrate into the overthrust.

Dillon cutoff-Basement-involved tectonic link between the disturbed belt of west-central Montana and the overthrust belt of extreme southwestern Montana

NASA Astrophysics Data System (ADS)

O'Neill, J. Michael; Schmidt, Christopher J.; Genovese, Paul W.

1990-11-01

The front of the Cordilleran fold and thrust belt in western Montana follows the disturbed belt in the north, merges with the southwest Montana transverse zone in the west-central part of the region, and in southwestern Montana is marked by a broad zone characterized by complex interaction between thrust belt structures and basement uplifts. The front margin of the thrust belt in Montana reflects mainly thin-skinned tectonic features in the north, an east-trending lateral ramp that curves southwest in the central part into the Dillon cutoff, an oblique-slip, thick-skinned displacement transfer zone that cuts through basement rocks of the Lima recess, and a zone of overlap between thin- and thick-skinned thrusts in extreme southwestern Montana. The transverse ramp and basement-involved thrust faults are controlled by Proterozoic structures.

Origin of the Uinta recess, Sevier fold thrust belt, Utah: influence of basin architecture on fold thrust belt geometry

NASA Astrophysics Data System (ADS)

Paulsen, Timothy; Marshak, Stephen

1999-11-01

Structural trends in the Sevier fold-thrust belt define a pronounced concave-to-the-foreland map-view curve, the Uinta recess, in north-central Utah. This recess separates two convex-to-the-foreland curves, the Provo salient on the south and the Wyoming salient on the north. The two limbs of the recess comprise transverse zones (fault zones at a high-angle to the regional trend of the orogen) that border the flanks of the east-west-trending Uinta/Cottonwood arch. Our structural analysis indicates that the transverse zones formed during the Sevier orogeny, and that they differ markedly from each other in structural style. The Charleston transverse zone (CTZ), on the south side of the arch, initiated as a complex sinistral strike-slip fault system that defines the abrupt northern boundary of the Provo salient. The Mount Raymond transverse zone (MRTZ), on the north side of the arch, represents the region in which the southeast-verging southern limb of the gently curving Wyoming salient was tilted northwards during the Laramide phase of uplift of the Uinta/Cottonwood arch. In effect, the MRTZ represents an oblique cross section through a thrust belt. The contrasting architecture of these transverse zones demonstrates how pre-deformation basin geometry influences the geometry of a fold-thrust belt. Analysis of isopach maps indicates that, at the time the Sevier fold-thrust belt formed, the area just north of the present site of the Uinta/Cottonwood arch was a basement high, with a gently dipping north flank, and a steeply dipping south flank. Thus, predeformational sediment thickened abruptly to the south of the high and thickened gradually to the north of the high. As illustrated by sandbox models, the distance that a fold-thrust belt propagates into the foreland depends on the thickness of the sedimentary layer being deformed, so the shape of the salient mimics the longitudinal cross-sectional shape of the sedimentary basin. Where basins taper gradually along strike

Vega: Two Belts and the Possibility of Planets

NASA Image and Video Library

2013-01-08

In this diagram, the Vega system, which was already known to have a cooler outer belt of comets orange, is compared to our solar system with its asteroid and Kuiper belts. The ring of warm, rocky debris was detected using NASA Spitzer Space Telescope,

Prioritizing Safety with Seat Belts: The Unanswered Question.

ERIC Educational Resources Information Center

Farrell, Elaine

1987-01-01

Reviews conflicting federal and state developments (including liability lawsuits) involving seat belt installation on school buses. The National Highway Traffic Safety Administration and the National Transportation Safety Board differ on this issue, and several states are considering seat belt legislation or crashworthiness studies. Hints are…

Increasing safety belt use by high risk drivers

DOT National Transportation Integrated Search

1991-04-01

The objectives of this study were to: 1) identify groups of non-belt users who are most likely to become involved in highway crashes and 2) develop and test communication programs designed to increase safety belt use by one or more of these groups. T...

Paleozoic and mesozoic evolution of East-Central California

USGS Publications Warehouse

Stevens, C.H.; Stone, P.; Dunne, G.C.; Greene, D.C.; Walker, J.D.; Swanson, B.J.

1997-01-01

East-central California, which encompasses an area located on the westernmost part of sialic North America, contains a well-preserved record of Paleozoic and Mesozoic tectonic events that reflect the evolving nature of the Cordilleran plate margin to the west. After the plate margin was formed by continental rifting in the Neoproterozoic, sediments comprising the Cordilleran miogeocline began to accumulate on the subsiding passive margin. In east-central California, sedimentation did not keep pace with subsidence, resulting in backstepping of a series of successive carbonate platforms throughout the early and middle Paleozoic. This phase of miogeoclinal development was brought to a close by the Late Devonian-Early Mississippian Antler orogeny, during the final phase of which oceanic rocks were emplaced onto the continental margin. Subsequent Late Mississippian-Pennsylvanian faulting and apparent reorientation of the carbonate platform margin are interpreted to have been associated with truncation of the continental plate on a sinistral transform fault zone. In the Early Permian, contractional deformation in east-central California led to the development of a narrow, uplifted thrust belt flanked by marine basins in which thick sequences of deep-water strata accumulated. A second episode of contractional deformation in late Early Permian to earliest Triassic time widened and further uplifted the thrust belt and produced the recently identified Inyo Crest thrust, which here is correlated with the regionally significant Last Chance thrust. In the Late Permian, about the time of the second contractional episode, extensional faulting created shallow sedimentary basins in the southern Inyo Mountains. In the El Paso Mountains to the south, deformation and plutonism record the onset of subduction and arc magmatism in late Early Permian to earliest Triassic time along this part of the margin. Tectonism had ceased in most of east-central California by middle to late Early

Angle stations in or for endless conveyor belts

DOEpatents

Steel, Alan

1987-04-07

In an angle station for an endless conveyor belt, there are presented to each incoming run of the belt stationary curved guide members (18, 19) of the shape of a major segment of a right-circular cylinder and having in the part-cylindrical portion (16 or 17) thereof rectangular openings (15) arranged in parallel and helical paths and through which project small freely-rotatable rollers (14), the continuously-changing segments of the curved surfaces of which projecting through said openings (15) are in attitude to change the direction of travel of the belt (13) through 90.degree. during passage of the belt about the part-cylindrical portion (16 or 17) of the guide member (18 or 19). The rectangular openings (15) are arranged with their longer edges lengthwise of the diagonals representing the mean of the helix but with those of a plurality of the rows nearest to each end of the part-cylindrical portion (16 or 17) slightly out of axial symmetry with said diagonals, being slightly inclined in a direction about the intersections (40) of the diagonals of the main portion of the openings, to provide a "toe-in" attitude in relation to the line of run of the endless conveyor belt.

Dynamics of the Earth's Radiation Belts and Inner Magnetosphere

NASA Astrophysics Data System (ADS)

Schultz, Colin

2013-12-01

Trapped by Earth's magnetic field far above the planet's surface, the energetic particles that fill the radiation belts are a sign of the Sun's influence and a threat to our technological future. In the AGU monograph Dynamics of the Earth's Radiation Belts and Inner Magnetosphere, editors Danny Summers, Ian R. Mann, Daniel N. Baker, and Michael Schulz explore the inner workings of the magnetosphere. The book reviews current knowledge of the magnetosphere and recent research results and sets the stage for the work currently being done by NASA's Van Allen Probes (formerly known as the Radiation Belt Storm Probes). In this interview, Eos talks to Summers about magnetospheric research, whistler mode waves, solar storms, and the effects of the radiation belts on Earth.

The fossilized size distribution of the main asteroid belt

NASA Astrophysics Data System (ADS)

Bottke, William F.; Durda, Daniel D.; Nesvorný, David; Jedicke, Robert; Morbidelli, Alessandro; Vokrouhlický, David; Levison, Hal

2005-05-01

Planet formation models suggest the primordial main belt experienced a short but intense period of collisional evolution shortly after the formation of planetary embryos. This period is believed to have lasted until Jupiter reached its full size, when dynamical processes (e.g., sweeping resonances, excitation via planetary embryos) ejected most planetesimals from the main belt zone. The few planetesimals left behind continued to undergo comminution at a reduced rate until the present day. We investigated how this scenario affects the main belt size distribution over Solar System history using a collisional evolution model (CoEM) that accounts for these events. CoEM does not explicitly include results from dynamical models, but instead treats the unknown size of the primordial main belt and the nature/timing of its dynamical depletion using innovative but approximate methods. Model constraints were provided by the observed size frequency distribution of the asteroid belt, the observed population of asteroid families, the cratered surface of differentiated Asteroid (4) Vesta, and the relatively constant crater production rate of the Earth and Moon over the last 3 Gyr. Using CoEM, we solved for both the shape of the initial main belt size distribution after accretion and the asteroid disruption scaling law QD∗. In contrast to previous efforts, we find our derived QD∗ function is very similar to results produced by numerical hydrocode simulations of asteroid impacts. Our best fit results suggest the asteroid belt experienced as much comminution over its early history as it has since it reached its low-mass state approximately 3.9-4.5 Ga. These results suggest the main belt's wavy-shaped size-frequency distribution is a "fossil" from this violent early epoch. We find that most diameter D≳120 km asteroids are primordial, with their physical properties likely determined during the accretion epoch. Conversely, most smaller asteroids are byproducts of fragmentation

Seat-belt message and the law?

PubMed

Sengupta, S K; Patil, N G; Law, G

1989-09-01

This paper attempts to draw together available information on the use of seat belts, one of the most important safety devices for a person in a car. Considering the high rate of mortality and morbidity due to road traffic accidents in Papua New Guinea the authors strongly feel that seat-belt usage should be made compulsory. When one looks at the history of the implementation of such a successful countermeasure in other countries it seems that legislation is the only answer.

Magnetic refrigeration apparatus with belt of ferro or paramagnetic material

DOEpatents

Barclay, John A.; Stewart, Walter F.; Henke, Michael D.; Kalash, Kenneth E.

1987-01-01

A magnetic refrigerator operating in the 12 to 77K range utilizes a belt which carries ferromagnetic or paramagnetic material and which is disposed in a loop which passes through the center of a solenoidal magnet to achieve cooling. The magnetic material carried by the belt, which can be blocks in frames of a linked belt, can be a mixture of substances with different Curie temperatures arranged such that the Curie temperatures progressively increase from one edge of the belt to the other. This magnetic refrigerator can be used to cool and liquefy hydrogen or other fluids.

Magnetic refrigeration apparatus with belt of ferro or paramagnetic material

DOEpatents

Barclay, J.A.; Stewart, W.F.; Henke, M.D.; Kalash, K.E.

1986-04-03

A magnetic refrigerator operating in the 12 to 77 K range utilizes a belt which carries ferromagnetic or paramagnetic material and which is disposed in a loop which passes through the center of a solenoidal magnet to achieve cooling. The magnetic material carried by the belt, which can be blocks in frames of a linked belt, can be a mixture of substances with different Curie temperatures arranged such that the Curie temperatures progressively increase from one edge of the belt to the other. This magnetic refrigerator can be used to cool and liquefy hydrogen or other fluids.

A regional soil and sediment geochemical study in northern California

USGS Publications Warehouse

Goldhaber, M.B.; Morrison, J.M.; Holloway, J.M.; Wanty, R.B.; Helsel, D.R.; Smith, D.B.

2009-01-01

Regional-scale variations in soil geochemistry were investigated in a 20,000-km2 study area in northern California that includes the western slope of the Sierra Nevada, the southern Sacramento Valley and the northern Coast Ranges. Over 1300 archival soil samples collected from the late 1970s to 1980 in El Dorado, Placer, Sutter, Sacramento, Yolo and Solano counties were analyzed for 42 elements by inductively coupled plasma-atomic emission spectrometry and inductively coupled plasma-mass spectrometry following a near-total dissolution. These data were supplemented by analysis of more than 500 stream-sediment samples from higher elevations in the Sierra Nevada from the same study site. The relatively high-density data (1 sample per 15 km2 for much of the study area) allows the delineation of regional geochemical patterns and the identification of processes that produced these patterns. The geochemical results segregate broadly into distinct element groupings whose distribution reflects the interplay of geologic, hydrologic, geomorphic and anthropogenic factors. One such group includes elements associated with mafic and ultramafic rocks including Cr, Ni, V, Co, Cu and Mg. Using Cr as an example, elevated concentrations occur in soils overlying ultramafic rocks in the foothills of the Sierra Nevada (median Cr = 160 mg/kg) as well as in the northern Coast Ranges. Low concentrations of these elements occur in soils located further upslope in the Sierra Nevada overlying Tertiary volcanic, metasedimentary and plutonic rocks (granodiorite and diorite). Eastern Sacramento Valley soil samples, defined as those located east of the Sacramento River, are lower in Cr (median Cr = 84 mg/kg), and are systematically lower in this suite compared to soils from the west side of the Sacramento Valley (median Cr = 130 mg/kg). A second group of elements showing a coherent pattern, including Ca, K, Sr and REE, is derived from relatively silicic rocks types. This group occurs at elevated

45. July 1974. BLACKSMITH SHOP, VIEW LOOKING NORTHEAST, SHOWING BELT ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

45. July 1974. BLACKSMITH SHOP, VIEW LOOKING NORTHEAST, SHOWING BELT CHASE FOR TWO BELTS FROM THE BASEMENT, THE W. E. & J. BARNES CO. DRILL PRESS, AND THE DRILL PRESS USED FOR REAMING. THE BELT PASSING THROUGH THE WALL POWERS THE SANDER IN THE WOOD SHOP. - Gruber Wagon Works, Pennsylvania Route 183 & State Hill Road at Red Bridge Park, Bernville, Berks County, PA

New Quality Standards of Testing Idlers for Highly Effective Belt Conveyors

NASA Astrophysics Data System (ADS)

Król, Robert; Gladysiewicz, Lech; Kaszuba, Damian; Kisielewski, Waldemar

2017-12-01

The paper presents result of research and analyses carried out into the belt conveyors idlers’ rotational resistance which is one of the key factor indicating the quality of idlers. Moreover, idlers’ rotational resistance is important factor in total resistance to motion of belt conveyor. The evaluation of the technical condition of belt conveyor idlers is carried out in accordance with actual national and international standards which determine the methodology of measurements and acceptable values of measured idlers’ parameters. Requirements defined by the standards, which determine the suitability of idlers to a specific application, despite the development of knowledge on idlers and quality of presently manufactured idlers maintain the same level of parameters values over long periods of time. Nowadays the need to implement new, efficient and economically justified solution for belt conveyor transportation systems characterized by long routes and energy-efficiency is often discussed as one of goals in belt conveyors’ future. One of the basic conditions for achieving this goal is to use only carefully selected idlers with low rotational resistance under the full range of operational loads and high durability. Due to this it is necessary to develop new guidelines for evaluation of the technical condition of belt conveyor idlers in accordance with actual standards and perfecting of existing and development of new methods of idlers testing. The changes in particular should concern updating of values of parameters used for evaluation of the technical condition of belt conveyor idlers in relation to belt conveyors’ operational challenges and growing demands in terms of belt conveyors’ energy efficiency.

The Harang discontinuity in auroral belt ionospheric currents.

NASA Technical Reports Server (NTRS)

Heppner, J. P.

1972-01-01

Discussion of the nature of a discontinuity in the ionospheric current of the auroral belt whose existence was suggested by Harang in 1946. Convection characteristics, time variability, and current continuity in the auroral belt are considered in a context of observations and arguments supporting the reality of Harang's discontinuity.

Distribution of Dust from Kuiper Belt Objects

NASA Technical Reports Server (NTRS)

Gorkavyi, Nick N.; Ozernoy, Leonid; Taidakova, Tanya; Mather, John C.; Fisher, Richard (Technical Monitor)

2000-01-01

Using an efficient computational approach, we have reconstructed the structure of the dust cloud in the Solar system between 0.5 and 100 AU produced by the Kuiper belt objects. Our simulations offer a 3-D physical model of the 'kuiperoidal' dust cloud based on the distribution of 280 dust particle trajectories produced by 100 known Kuiper belt objects; the resulting 3-D grid consists of 1.9 x 10' cells containing 1.2 x 10" particle positions. The following processes that influence the dust particle dynamics are taken into account: 1) gravitational scattering on the eight planets (neglecting Pluto); 2) planetary resonances; 3) radiation pressure; and 4) the Poynting-Robertson (P-R) and solar wind drags. We find the dust distribution highly non-uniform: there is a minimum in the kuiperoidal dust between Mars and Jupiter, after which both the column and number densities of kuiperoidal dust sharply increase with heliocentric distance between 5 and 10 AU, and then form a plateau between 10 and 50 AU. Between 25 and 45 AU, there is an appreciable concentration of kuiperoidal dust in the form of a broad belt of mostly resonant particles associated with Neptune. In fact, each giant planet possesses its own circumsolar dust belt consisting of both resonant and gravitationally scattered particles. As with the cometary belts simulated in our related papers, we reveal a rich and sophisticated resonant structure of the dust belts containing families of resonant peaks and gaps. An important result is that both the column and number dust density are more or less flat between 10 and 50 AU, which might explain the surprising data obtained by Pioneers 10 & 11 and Voyager that the dust number density remains approximately distance-independent in this region. The simulated kuiperoidal dust, in addition to asteroidal and cometary dust, might represent a third possible source of the zodiacal light in the Solar system.

An Experimental Study on Characterization of Physical Properties of Ultramafic Rocks and Controls on Evolution of Fracture Permeability During Serpentinization at Hydrothermal Conditions

NASA Astrophysics Data System (ADS)

Farough, Aida

Serpentinization is a complex set of hydration reactions, where olivine and pyroxene are replaced by serpentine, magnetite, brucite, talc and carbonate minerals. Serpentinization reactions alter chemical, mechanical, magnetic, seismic, and hydraulic properties of the crust. To understand the complicated nature of serpentinization and the linkages between physical and chemical changes during the reactions, I performed flow-through laboratory experiments on cylindrically cored samples of ultramafic rocks. Each core had a well-mated through-going tensile fracture, to investigate evolution of fracture permeability during serpentinization. The samples were tested in a triaxial loading machine at an effective pressure of 30 MPa, and temperature of 260"aC, simulating a depth of 2 km under hydrostatic conditions. Fracture permeability decreased by one to two orders of magnitude during the 200 to 340 hour experiments. Electron microprobe and SEM data indicated the formation of needle-shaped crystals of serpentine composition along the walls of the fracture, and chemical analyses of sampled pore fluids were consistent with dissolution of ferromagnesian minerals. The rate of transformation of olivine to serpentine in a tensile fracture is calculated using the data on evolution of fracture permeability assuming the fracture permeability could be represented by parallel plates. Assuming the dissolution and precipitation reactions occur simultaneously; the rate of transformation at the beginning of the experiments was 10-8-10-9 (mol/m2s) and decreased monotonically by about an order of magnitude towards the end of the experiment. Results show that dissolution and precipitation is the main mechanism contributing to the reduction in fracture aperture. The experimental results suggest that the fracture network in long-lived hydrothermal circulation systems may be sealed rapidly as a result of mineral precipitation, and generation of new permeability resulting from a combination of

Design and implementation of an intelligent belt system using accelerometer.

PubMed

Liu, Botong; Wang, Duo; Li, Sha; Nie, Xuhui; Xu, Shan; Jiao, Bingli; Duan, Xiaohui; Huang, Anpeng

2015-01-01

Activity monitor systems are increasing used recently. They are important for athletes and casual users to manage physical activity during daily exercises. In this paper, we use a triaxial accelerometer to design and implement an intelligent belt system, which can detect the user's step and flapping motion. In our system, a wearable intelligent belt is worn on the user's waist to collect activity acceleration signals. We present a step detection algorithm to detect real-time human step, which has high accuracy and low complexity. In our system, an Android App is developed to manage the intelligent belt. We also propose a protocol, which can guarantee data transmission between smartphones and wearable belt effectively and efficiently. In addition, when users flap the belt in emergency, the smartphone will receive alarm signal sending by the belt, and then notifies the emergency contact person, which can be really helpful for users in danger. Our experiment results show our system can detect physical activities with high accuracy (overall accuracy of our algorithm is above 95%) and has an effective alarm subsystem, which is significant for the practical use.

Cost-benefit analysis of safety belts in Texas school buses.

PubMed

Begley, C E; Biddle, A K

1988-01-01

Although safety belts have been shown to reduce the risk of serious injury or death in automobile crashes, evidence of their effectiveness in school buses is uncertain. In this paper, the potential costs and benefits of mandatory safety belts in Texas school buses are estimated, based on the assumption that their effectiveness is less than or equal to rear seatbelt effectiveness in autos. Costs are based on both retrofitting old buses with belts and installing them in new buses. Benefits include the direct and indirect (forgone earnings) cost-savings from preventable injuries and fatalities. Results indicate that a law mandating safety belts in Texas school buses would not be cost-beneficial. Annual benefits would exceed the annual costs of installing belts in new school buses. However, the benefits would not be large enough to compensate for the five-year costs associated with retrofitting old buses.

Cost-benefit analysis of safety belts in Texas school buses.

PubMed Central

Begley, C E; Biddle, A K

1988-01-01

Although safety belts have been shown to reduce the risk of serious injury or death in automobile crashes, evidence of their effectiveness in school buses is uncertain. In this paper, the potential costs and benefits of mandatory safety belts in Texas school buses are estimated, based on the assumption that their effectiveness is less than or equal to rear seatbelt effectiveness in autos. Costs are based on both retrofitting old buses with belts and installing them in new buses. Benefits include the direct and indirect (forgone earnings) cost-savings from preventable injuries and fatalities. Results indicate that a law mandating safety belts in Texas school buses would not be cost-beneficial. Annual benefits would exceed the annual costs of installing belts in new school buses. However, the benefits would not be large enough to compensate for the five-year costs associated with retrofitting old buses. PMID:3140273

Kuiper Belt Objects Along the Pluto-Express Path

NASA Technical Reports Server (NTRS)

Jewitt, David (Principal Investigator)

1997-01-01

The science objective of this work is to identify objects in the Kuiper Belt which will, in the 5 years following Pluto encounter, be close to the flight path of NASA's Pluto Express. Our hope is that we will find a Kuiper Belt object or objects close enough that a spacecraft flyby will be possible. If we find a suitable object, the science yield of Pluto Express will be substantially enhanced. The density of objects in the Kuiper Belt is such that we are reasonably likely to find an object close enough to the flight path that on-board gas thrusters can effect a close encounter.

Seat belt and child seat use in Lipetskaya Oblast, Russia: frequencies, attitudes, and perceptions.

PubMed

Ma, Sai; Tran, Nhan; Klyavin, Vladimir E; Zambon, Francesco; Hatcher, Kristin W; Hyder, Adnan A

2012-01-01

Despite the importance of understanding seat belt use patterns among drivers and passengers for the purpose of direct interventions or monitoring improvements, no study has described wearing rates for all seat positions in Russia. This study describes observed seat belt use and knowledge, attitudes, and perceptions of seat belt use in Lipetskaya Oblast, Russia. An observational study on the use of seat belts and child restraints in the Lipetskaya region conducted during October 2010 collected data in 6 districts and on 3 different road types. A roadside survey gathered information on knowledge, attitudes, and perceptions toward the use of seat belts from randomly selected drivers. Frequencies of seat belt use by seat position, gender, and road type were calculated. A multivariable logit model disclosed the associations between seat belt use and sociodemographic factors. The study design permitted comparison of observed seat belt use to self-reported seat belt use. A total of 25,795 vehicles and 39,833 drivers and passengers contributed observations. Overall, 55 percent of drivers were observed to be using seat belts. More than half (58%) of front seat passengers wore seat belts and only 9 percent of back seat passengers were observed to be wearing seat belts; 11 percent of cars with children had any type of child safety measure. Drivers on urban roads were less likely to wear seat belts compared to those on main highways and rural roads. Nearly 60 percent of survey respondents mentioned "seat belts save lives," and more than half mentioned law requirements and fines. Although the observed seat belt use in Lipetskaya Oblast is much higher than previous estimates in Russia, overall wearing rates remain far from universal. Rear seat passengers and children are particularly at risk. Because combined education and enforcement has proven to be effective elsewhere, such interventions are needed to improve seat belt use.

Ultramafic lavas and pyroxene-spinifex high-Mg basaltic dykes from the Othris ophiolite complex, Greece

NASA Astrophysics Data System (ADS)

Baziotis, Ioannis; Economou-Eliopoulos, Maria; Asimow, Paul

2017-04-01

This study aims to constrain the physico-chemical conditions and processes associated with the origin of ultramafic lavas of the Agrilia formation and high-Mg basaltic dykes in the Pournari area within the Othris ophiolite complex, a supra-subduction zone ophiolite of Mesozoic age (Paraskevopoulos & Economou, 1986; Barth et al., 2008). Hand-sample-scale spinifex texture is lacking from the ultramafic lavas and, despite whole-rock MgO contents greater than 31 wt.%, we infer an upper bound of 17 wt.% MgO for the erupted liquid, and thus identify these lavas as picrites containing accumulated olivine. We use textural and compositional criteria to divide the crystals within the Agrilia lavas between pre-eruptive and post-eruptive growth phases. The high-Mg basaltic dyke margins display a distinctive thin-section-scale micro-spinifex texture of skeletal and plumose Al- and Fe-rich clinopyroxene surrounded by large crystals of orthopyroxene. Normally zoned clinopyroxene in the Agrilia lavas and clinopyroxene of various textures (skeletal, needle- and dendritic-like) and sizes in the Pournari dykes display anomalous enrichment in Al2O3 and FeO* with decreasing MgO that require rapid, disequilibrium growth. Quantitative characteristics of the micro-spinifex pyroxene textures (<10 μm in width and 50-100 μm in length) imply a cooling rate for the marginal parts of the Pournari dykes of at least 25 °K/hr and more likely 45-55 °K/hr (Faure et al., 2004) and rapid growth of clinopyroxene crystals at a linear rate of about 10-6 m/s (Welsch et al., 2016). MELTS models of the crystallization sequence of the Pournari dykes indicate that progressive low-pressure (500 bar) fractional crystallization of the ultramafic dyke liquid occurred under oxidized (QFM+2.0) and hydrous (at least 0.5 wt.% H2O) conditions. A hydrous magmatic parent for the Othris ophiolite as a whole is further supported by preliminary investigation of melt inclusions (5-20 μm in diameter) in fresh chromite

46 CFR 169.825 - Wearing of safety belts.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 7 2010-10-01 2010-10-01 false Wearing of safety belts. 169.825 Section 169.825 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Operations § 169.825 Wearing of safety belts. The master of each vessel shall ensure that each person wears...

46 CFR 169.825 - Wearing of safety belts.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 7 2011-10-01 2011-10-01 false Wearing of safety belts. 169.825 Section 169.825 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Operations § 169.825 Wearing of safety belts. The master of each vessel shall ensure that each person wears...

Pattern of seat belt use by drivers in Trinidad and Tobago, West Indies

PubMed Central

2011-01-01

Background In Trinidad and Tobago, the law on the mandatory use of seat belts was passed in 1995, but this law is hardly enforced. The objective of this study was to determine the frequency and predictors of seat belt use by motor vehicle drivers in the country. Findings A cross-sectional study of 959 motor vehicle drivers using a self-administered questionnaire. Data analysis included Pearson Chi square test and multinomial logistic regression analysis in order to determine the possible predictors of seat belt use by the drivers in Trinidad and Tobago. A majority of the drivers sometimes (51.8%) or always (31.6%) use a seat belt. About 16.7%, 29% and 54.2% of the drivers perceived that the other drivers use their seat belts more frequently, with the same frequency and less frequently respectively compared to themselves. The main reason for not using seat belt by the drivers was given as frequent stops (40.7%) and the main motivation to use seat belt by the drivers was given as stiffer penalties for non-compliance with the seat belt law (44.5%). The predictors of seat belt use were male driver, no formal or lower level of education, driving for less than 10 years, and the perception that the other drivers use seat belts with the same or higher frequency compared to the respondents. Conclusion Only a small proportion of the drivers in Trinidad and Tobago always use a seat belt when driving. There is the need to enforce the seat belt legislation in the country. PMID:21679410

Planetary Migration and Kuiper Belt Dynamics

NASA Astrophysics Data System (ADS)

Malhotra, Renu

The Kuiper belt holds memory of the dynamical processes that shaped the architecture of the solar system, including the orbital migration history of the giant planets. We propose studies of the orbital dynamics of the Kuiper Belt in order to understand the origin of its complex dynamical structure and its link to the orbital migration history of the giant planets. By means of numerical simulations, statistical tests, as well as analytical calculations we will (1) investigate the origin of resonant Kuiper belt objects to test alternative scenarios of Neptune's migration history, (2) investigate the long term dynamical evolution of the Haumea family of Kuiper Belt objects in order to improve the age estimate of this family, and (3) investigate resonance-sticking behavior and the Kozai-Lidov mechanism and its role in the origin of the extended scattered disk. These studies directly support the goals of the NASA-OSS program by improving our understanding of the origin of the solar system's architecture. Our results will provide constraints on the nature and timing of the dynamical excitation event that is thought to have occurred in early solar system history and to have determined the architecture of the present-day solar system; our results will also provide deeper theoretical understanding of sticky mean motion resonances which contribute greatly to the longevity of many small bodies, improve our understanding of dynamical transport of planetesimals in planetary systems, and help interpret observations of other planetary systems.

Enrichment of trace elements in garnet amphibolites from a paleo-subduction zone: Catalina Schist, southern California

USGS Publications Warehouse

Sorensen, Sorena S.; Grossman, J.N.

1989-01-01

The abundance, P-T stability, solubility, and element-partitioning behavior of minerals such as rutile, garnet, sphene, apatite, zircon, zoisite, and allanite are critical variables in models for mass transfer from the slab to the mantle wedge in deep regions of subduction zones. The influence of these minerals on the composition of subduction-related magmas has been inferred (and disputed) from inverse modelling of the geochemistry of island-arc basalt, or by experiment. Although direct samples of the dehydration + partial-melting region of a mature subduction zone have not been reported from subduction complexes, garnet amphibolites from melanges of circumpacific and Caribbean blueschist terranes reflect high T (>600??C) conditions in shallower regions. Such rocks record geochemical processes that affected deep-seated, high-T portions of paleo-subduction zones. In the Catalina Schist, a subduction-zone metamorphic terrane of southern California, metasomatized and migmatitic garnet amphibolites occur as blocks in a matrix of meta-ultramafic rocks. This mafic and ultramafic complex may represent either slab-derived material accreted to the mantle wedge of a nascent subduction zone or a portion of a shear zone closely related to the slab-mantle wedge contact, or both. The trace-element geochemistry of the complex and the distribution of trace elements among the minerals of garnet amphibolites were studied by INAA, XRF, electron microprobe, and SEM. In order of increasing alteration from a probable metabasalt protolith, three common types of garnet amphibolite blocks in the Catalina Schist are: (1) non-migmatitic, clinopyroxene-bearing blocks, which are compositionally similar to MORB that has lost an albite component; (2) garnet-amphibolite blocks, which have rinds that reflect local interaction between metabasite, metaperidotite, and fluid; and (3) migmatites that are extremely enriched in Th, HFSE, LREE, and other trace elements. These trace-element enrichments

Potential Jupiter-Family comet contamination of the main asteroid belt

NASA Astrophysics Data System (ADS)

Hsieh, Henry H.; Haghighipour, Nader

2016-10-01

We present the results of "snapshot" numerical integrations of test particles representing comet-like and asteroid-like objects in the inner Solar System aimed at investigating the short-term dynamical evolution of objects close to the dynamical boundary between asteroids and comets as defined by the Tisserand parameter with respect to Jupiter, TJ (i.e., TJ = 3). As expected, we find that TJ for individual test particles is not always a reliable indicator of initial orbit types. Furthermore, we find that a few percent of test particles with comet-like starting elements (i.e., similar to those of Jupiter-family comets) reach main-belt-like orbits (at least temporarily) during our 2 Myr integrations, even without the inclusion of non-gravitational forces, apparently via a combination of gravitational interactions with the terrestrial planets and temporary trapping by mean-motion resonances with Jupiter. We estimate that the fraction of real Jupiter-family comets occasionally reaching main-belt-like orbits on Myr timescales could be on the order of ∼ 0.1-1%, although the fraction that remain on such orbits for appreciable lengths of time is certainly far lower. For this reason, the number of JFC-like interlopers in the main-belt population at any given time is likely to be small, but still non-zero, a finding with significant implications for efforts to use apparently icy yet dynamically asteroidal main-belt comets as tracers of the primordial distribution of volatile material in the inner Solar System. The test particles with comet-like starting orbital elements that transition onto main-belt-like orbits in our integrations appear to be largely prevented from reaching low eccentricity, low inclination orbits, suggesting that the real-world population of main-belt objects with both low eccentricities and inclinations may be largely free of this potential occasional Jupiter-family comet contamination. We therefore find that low-eccentricity, low-inclination main-belt

New features in the structure of the classical Kuiper Belt

NASA Astrophysics Data System (ADS)

Gladman, Brett; Bannister, Michele T.; Alexandersen, Mike; Chen, Ying-Tung; Gwyn, Stephen; Kavelaars, J. J.; Petit, Jean-Marc; Volk, Kathryn; OSSOS Collaboration

2016-10-01

We report fascinating new dynamical structures emerging from a higher precision view of the classical Kuiper belt (the plentiful non-resonant orbits with semimajor axes in roughly the a=35-60 au range). The classical Kuiper Belt divides into multiple sub-populations: an 'inner' classical belt (a small group of non-resonant objects with a<39.4 au where the 3:2 resonance is located), an abundant 'main' classical belt (between the 3:2 and the 2:1 at a=47.4 au), and a difficult to study outer classical belt beyond the 2:1. We examine the dynamical structure, as precisely revealed in the detections from OSSOS (the Outer Solar System Origin's Survey); the data set is of superb quality in terms of orbital element and numbers of detections (Kavelaars et al, this meeting).The previous CFEPS survey showed that the main classical belt requires a complex dynamical substructure that goes beyond a simple 'hot versus cold' division based primarily on orbital inclination; the 'cold' inclination component requires two sub-components in the semimajor axis and perihelion distance q space (Petit et al 2011). CFEPS modelled this as a 'stirred' component present at all a=40-47 AU semimajor axes, with a dense superposed 'kernel' near a=44 AU at low eccentricity; the first OSSOS data release remained consistent with this (Bannister et al 2016). As with the main asteroid belt, as statistics and orbital quality improve we see additional significant substructure emerging in the classical belt's orbital distribution.OSSOS continues to add evidence that the cold stirred component extends smoothly beyond the 2:1 (Bannister et al 2016). Unexpectedly, the data also reveal the clear existence of a paucity of orbits just beyond the outer edge of the kernel; there are significantly fewer TNOs in the narrow semimajor axis band from a=44.5-45.0 AU. This may be related to the kernel population's creation, or it may be an independent feature created by planet migration as resonances moved in the

Evaluation of Heterotrophy in in Serpentinite-Associated Waters from the Coast Range Ophiolite, Northern California, USA and the Zambales Ophiolite, Philippines

NASA Astrophysics Data System (ADS)

Scott, T. J.; Arcilla, C. A.; Cardace, D.; Hoehler, T. M.; McCollom, T. M.; Meyer-Dombard, D. R.; Schrenk, M. O.

2013-12-01

The deep biosphere in cold, dark sub-seafloor ultramafic rocks (i.e., those rocks rich in Fe and Mg) is stressed by exceedingly high pH, transient, if any, inorganic carbon availability, and little known organic carbon inventories. As a test of heterotrophic carbon use, serpentinite-associated waters (from groundwater sampling wells and associated surface seepages in tectonically uplifted mantle units in ophiolites) were tested for differences with respect to aqueous geochemistry and performance in EcoPlates™ - Biolog Inc. .. This work focuses on two field locations for water sampling: the Coast Range Ophiolite, CA, USA, and the Zambales Ophiolite, Philippines. Characteristics of each sampling site are presented (pH, mineral substrate, Ca2+/Mg2+ ratio, aqueous metal loads, etc.). Complementary EcoPlate™ results [prefabricated 96-well plates, seeded with triplicate experiments for determining microbiological community response to difference organic carbon sources; a triplicate control experiment with just water is built in to the plate also] are also presented. We found that waters from selected California [groundwater wells (7 discrete wells) and related surface seeps (5 hydrologically connected sites)] and Philippines [4 Zambales Ophiolite springs/seepages] sourced in serpentinites were analyzed. EcoPlate™ average well-color development (AWCD), which demonstrates microbial activities averaged per plate (as in Garland and Mills, 1991), differs across sites. Correlations of AWCD with environmental data (such as pH, oxidation-reduction potential or ORP, Ca2+/Mg2+ ratio, and Fe contents) are evaluated. Clarifying the geochemical-biological relationships that bear out in these analyses informs discourse on the energetic limits of life in serpentinizing systems, with relevance to ultramafic-hosted life on continents and in the seabed.

49 CFR 571.210 - Standard No. 210; Seat belt assembly anchorages.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 6 2013-10-01 2013-10-01 false Standard No. 210; Seat belt assembly anchorages... STANDARDS Federal Motor Vehicle Safety Standards § 571.210 Standard No. 210; Seat belt assembly anchorages. S1. Purpose and scope. This standard establishes requirements for seat belt assembly anchorages to...

49 CFR 571.210 - Standard No. 210; Seat belt assembly anchorages.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 6 2011-10-01 2011-10-01 false Standard No. 210; Seat belt assembly anchorages... STANDARDS Federal Motor Vehicle Safety Standards § 571.210 Standard No. 210; Seat belt assembly anchorages. S1. Purpose and scope. This standard establishes requirements for seat belt assembly anchorages to...

49 CFR 571.210 - Standard No. 210; Seat belt assembly anchorages.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 6 2014-10-01 2014-10-01 false Standard No. 210; Seat belt assembly anchorages... STANDARDS Federal Motor Vehicle Safety Standards § 571.210 Standard No. 210; Seat belt assembly anchorages. S1. Purpose and scope. This standard establishes requirements for seat belt assembly anchorages to...

49 CFR 571.210 - Standard No. 210; Seat belt assembly anchorages.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 6 2012-10-01 2012-10-01 false Standard No. 210; Seat belt assembly anchorages... STANDARDS Federal Motor Vehicle Safety Standards § 571.210 Standard No. 210; Seat belt assembly anchorages. S1. Purpose and scope. This standard establishes requirements for seat belt assembly anchorages to...

The rock components and structures of Archean greenstone belts: An overview

NASA Technical Reports Server (NTRS)

Lowe, D. R.; Byerly, G. R.

1986-01-01

Knowledge of the character and evolution of the Earth's early crust is derived from the studies of the rocks and structures in Archean greenstone belts. Ability to resolve the petrologic, sedimentological and structural histories of greenstone belts, however, hinges first on an ability to apply the concepts and procedures of classical stratigraphy. Unfortunately, early Precambrian greenstone terrains present particular problems to stratigraphic analysis. Many current controversies of greenstone belt petrogenesis, sedimentology, tectonics and evolution arise more from an inability to develop a clear stratigraphic picture of the belts than from ambiguities in interpretation. Four particular stratigraphic problems that afflict studies of Archean greenstone belts are considered: determination of facing directions, correlation of lithologic units, identification of primary lithologies and discrimination of stratigraphic versus structural contacts.

Compliance with Seat Belt Use in Makurdi, Nigeria: An Observational Study

PubMed Central

Popoola, SO; Oluwadiya, KS; Kortor, JN; Denen-Akaa, P; Onyemaechi, NOC

2013-01-01

Background: Seat belts are designed to reduce injuries due to road crash among vehicle occupants. Aims: This study aims to determine the availability of seat belt in vehicles and compliance with seat belt use among vehicle occupants. Materials and methods: This was a 24-h direct observational study of seat belt usage among vehicle occupants in Makurdi, Benue State, Nigeria. By direct surveillance and using a datasheet, we observed 500 vehicles and their occupants for seat belt availability and compliance with its use. Chi-square test was used for test of significance between variables. Results: Twenty-five (5.0%) of the observed 500 vehicles had no seat belt at all. Overall, compliance was 277/486 (57.0%). Use of seat belt was highest in the afternoon with 124/194 (64.4%), followed by 111/188 (59.0%) in the morning and 42/95 (44.2%) at night. Compliance was highest among car occupants [209/308 (67.9%)] and private vehicles, and lowest among commercial vehicle occupants. Compliance among female drivers was 77.1% compared with 51.4% among male drivers. Among drivers, the mean age of seat belt users was 38.4 (7.7) years, which was significantly younger than the 41.3 (8.7) years mean age of non-users. Similar figures were obtained among other vehicle occupants. Conclusions: Compared with previous studies, seat belt usage has improved among Nigerian road users, but there is still room for improvement, especially early in the mornings and at nights. Since these were times when law enforcement agencies were not likely to be on the roads, we advocate for improved coverage by enforcement agents to enforce better compliance. PMID:24116327

Suspended particulate layers and internal waves over the southern Monterey Bay continental shelf: an important control on shelf mud belts?

USGS Publications Warehouse

Cheriton, Olivia M.; McPhee-Shaw, Erika E.; Shaw, William J.; Stanton, Timothy P.; Bellingham, James G.; Storlazzi, Curt D.

2014-01-01

Physical and optical measurements taken over the mud belt on the southern continental shelf of Monterey Bay, California documented the frequent occurrence of suspended particulate matter features, the majority of which were detached from the seafloor, centered 9–33 m above the bed. In fall 2011, an automated profiling mooring and fixed instrumentation, including a thermistor chain and upward-looking acoustic Doppler current profiler, were deployed at 70 m depth for 5 weeks, and from 12 to 16 October a long-range autonomous underwater vehicle performed across-shelf transects. Individual SPM events were uncorrelated with local bed shear stress caused by surface waves and bottom currents. Nearly half of all observed SPM layers occurred during 1 week of the study, 9–16 October 2011, and were advected past the fixed profiling mooring by the onshore phase of semidiurnal internal tide bottom currents. At the start of the 9–16 October period, we observed intense near-bed vertical velocities capable of lifting particulates into the middle of the water column. This “updraft” event appears to have been associated with nonlinear adjustment of high-amplitude internal tides over the mid and outer shelf. These findings suggest that nonlinear internal tidal motions can erode material over the outer shelf and that, once suspended, this SPM can then be transported shoreward to the middle and shallow sections of the mud belt. This represents a fundamental broadening of our understanding of how shelf mud belts may be built up and sustained.

An Evaluation of the Seat Belt Education Campaign.

ERIC Educational Resources Information Center

Rochon, James

A seat belt education campaign conducted in Canada to dispel myths surrounding seat belts and promote a better understanding of their functions was evaluated. Two telephone surveys, each comprised of 4,000 respondents, were conducted. The first was done immediately before the campaign and the second immediately succeeding the campaign. Also, a…

Seat belt use among rear passengers: validity of self-reported versus observational measures

PubMed Central

Zambon, Francesco; Fedeli, Ugo; Marchesan, Maria; Schievano, Elena; Ferro, Antonio; Spolaore, Paolo

2008-01-01

Background The effects of seat belt laws and public education campaigns on seat belt use are assessed on the basis of observational or self-reported data on seat belt use. Previous studies focusing on front seat occupants have shown that self-reports indicate a greater seat belt usage than observational findings. Whether this over-reporting in self reports applies to rear seat belt usage, and to what extent, have yet to be investigated. We aimed to evaluate the over-reporting factor for rear seat passengers and whether this varies by gender and under different compulsory seat belt use conditions. Methods The study was conducted in the Veneto Region, an area in the North-East of Italy with a population of 4.7 million. The prevalence of seat belt use among rear seat passengers was determined by means of a cross-sectional self-report survey and an observational study. Both investigations were performed in two time periods: in 2003, when rear seat belt use was not enforced by primary legislation, and in 2005, after rear seat belt use had become compulsory (June 2003). Overall, 8138 observations and 7902 interviews were recorded. Gender differences in the prevalence of rear seat belt use were examined using the chi-square test. The over-reporting factor, defined as the ratio of the self-reported to the observed prevalence of rear seat belt use, was calculated by gender before and after the rear seat belt legislation came into effect. Results Among rear seat passengers, self-reported rates were always higher than the observational findings, with an overall over-reporting factor of 1.4. We registered no statistically significant changes over time in the over-reporting factor, nor any major differences between genders. Conclusion Self-reported seat belt usage by rear passengers represents an efficient alternative to observational studies for tracking changes in actual behavior, although the reported figures need to be adjusted using an appropriate over-reporting factor in

14 CFR 137.42 - Fastening of safety belts and shoulder harnesses.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Fastening of safety belts and shoulder... AGRICULTURAL AIRCRAFT OPERATIONS Operating Rules § 137.42 Fastening of safety belts and shoulder harnesses. No... belt and shoulder harness properly secured about that person except that the shoulder harness need not...

14 CFR 137.42 - Fastening of safety belts and shoulder harnesses.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Fastening of safety belts and shoulder... AGRICULTURAL AIRCRAFT OPERATIONS Operating Rules § 137.42 Fastening of safety belts and shoulder harnesses. No... belt and shoulder harness properly secured about that person except that the shoulder harness need not...

14 CFR 137.42 - Fastening of safety belts and shoulder harnesses.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Fastening of safety belts and shoulder... AGRICULTURAL AIRCRAFT OPERATIONS Operating Rules § 137.42 Fastening of safety belts and shoulder harnesses. No... belt and shoulder harness properly secured about that person except that the shoulder harness need not...

14 CFR 137.42 - Fastening of safety belts and shoulder harnesses.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Fastening of safety belts and shoulder... AGRICULTURAL AIRCRAFT OPERATIONS Operating Rules § 137.42 Fastening of safety belts and shoulder harnesses. No... belt and shoulder harness properly secured about that person except that the shoulder harness need not...

14 CFR 137.42 - Fastening of safety belts and shoulder harnesses.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Fastening of safety belts and shoulder... AGRICULTURAL AIRCRAFT OPERATIONS Operating Rules § 137.42 Fastening of safety belts and shoulder harnesses. No... belt and shoulder harness properly secured about that person except that the shoulder harness need not...

Van Allen Probes Observations of the Plasmasphere and Radiation Belts

NASA Astrophysics Data System (ADS)

Goldstein, J.; Jahn, J. M.; De Pascuale, S.; Kletzing, C.; Kurth, W. S.; Genestreti, K. J.; Skoug, R. M.; Larsen, B.; Kistler, L. M.; Mouikis, C.; Spence, H. E.; Reeves, G. D.; Baker, D. N.; Blake, J. B.

2014-12-01

Van Allen Probes (RBSP) observations during 15-20 January 2013 are the basis of this study of the spatial relationship between the plasmasphere and radiation belts, and its influence on energy dependent lifetimes of energetic electrons. We use a convection-driven plasmapause test particle (PTP) simulation to provide contextual information for in situ measurements by RBSP during 15-20 January 2013, and find that the model reproduces the observed plasmapause radial locations to within 0.40 Earth radii (RE). We use analysis of the RBSP data to examine the radial structure of both the plasmasphere and radiation belts for the selected 5-day period, which includes a moderate geomagnetic disturbance on 17 January. RBSP observed three belts (inner, outer, and storage ring) prior to the 17 January disturbance, and two belts (inner and outer) afterward. The plasmapause aligns with the outermost belt. We examine the energy dependence of the radial structure and decay lifetimes of energetic electrons, both inside and outside the plasmasphere.

Cenozoic intracontinental deformation of the Kopeh Dagh Belt, Northeastern Iran

NASA Astrophysics Data System (ADS)

Chu, Yang; Wan, Bo; Chen, Ling; Talebian, Morteza

2016-04-01

Compressional intracontinental orogens represent large tectonic zones far from plate boundaries. Since intracontinental mountain belts cannot be framed in the conventional plate tectonics theory, several hypotheses have been proposed to account for the formations of these mountain belts. The far-field effect of collision/subduction at plate margins is now well accepted for the origin and evolution of the intracontinental crust thickening, as exemplified by the Miocene tectonics of central Asia. In northern Iran, the Binalud-Alborz mountain belt witnessed the Triassic tectonothermal events (Cimmerian orogeny), which are interpreted as the result of the Paleotethys Ocean closure between the Eurasia and Central Iran blocks. The Kopeh Dagh Belt, located to the north of the Binalud-Alborz Belt, has experienced two significant tectonic phases: (1) Jurassic to Eocene rifting with more than 7 km of sediments; and (2) Late Eocene-Early Oligocene to Quaternary continuous compression. Due to the high seismicity, deformation associated with earthquakes has received more and more attention; however, the deformation pattern and architecture of this range remain poorly understood. Detailed field observations on the Cenozoic deformation indicate that the Kopeh Dagh Belt can be divided into a western zone and an eastern zone, separated by a series of dextral strike-slip faults, i.e. the Bakharden-Quchan Fault System. The eastern zone characterized by km-scale box-fold structures, associated with southwest-dipping reverse faults and top-to-the NE kinematics. In contrast, the western zone shows top-to-the SW kinematics, and the deformation intensifies from NE to SW. In the northern part of this zone, large-scale asymmetrical anticlines exhibit SW-directed vergence with subordinate thrusts and folds, whereas symmetrical anticlines are observed in the southern part. In regard to its tectonic feature, the Kopeh Dagh Belt is a typical Cenozoic intracontinental belt without ophiolites or

Seat Belts: 1949-1956

DOT National Transportation Integrated Search

1979-04-01

The study assesses the impact of the consumer misconceptions, the lack of a seat belt standard, corporate attitudes towards safety, and the role of safety advocates. In addition, the study assesses the validity of the oft-stated hypothesis "safety do...

SLH Timing Belt Powertrain

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schneider, Abe

2014-04-09

The main goal of this proposal was to develop and test a novel powertrain solution for the SLH hydroEngine, a low-cost, efficient low-head hydropower technology. Nearly two-thirds of U.S. renewable electricity is produced by hydropower (EIA 2010). According to the U.S. Department of Energy; this amount could be increased by 50% with small hydropower plants, often using already-existing dams (Hall 2004). There are more than 80,000 existing dams, and of these, less than 4% generate power (Blankinship 2009). In addition, there are over 800 irrigation districts in the U.S., many with multiple, non-power, low-head drops. These existing, non-power dams andmore » irrigation drops could be retrofitted to produce distributed, baseload, renewable energy with appropriate technology. The problem is that most existing dams are low-head, or less than 30 feet in height (Ragon 2009). Only about 2% of the available low-head hydropower resource in the U.S. has been developed, leaving more than 70 GW of annual mean potential low-head capacity untapped (Hall 2004). Natel Energy, Inc. is developing a low-head hydropower turbine that operates efficiently at heads less than 6 meters and is cost-effective for deployment across multiple low-head structures. Because of the unique racetrack-like path taken by the prime-movers in the SLH, a flexible powertrain is required. Historically, the only viable technological solution was roller chain. Despite the having the ability to easily attach blades, roller chain is characterized by significant drawbacks, including high cost, wear, and vibration from chordal action. Advanced carbon- fiber-reinforced timing belts have been recently developed which, coupled with a novel belt attachment system developed by Natel Energy, result in a large reduction in moving parts, reduced mass and cost, and elimination of chordal action for increased fatigue life. The work done in this project affirmatively addressed each of the following 3 major uncertainties

Does warm debris dust stem from asteroid belts?

NASA Astrophysics Data System (ADS)

Geiler, Fabian; Krivov, Alexander V.

2017-06-01

Many debris discs reveal a two-component structure, with a cold outer and a warm inner component. While the former are likely massive analogues of the Kuiper belt, the origin of the latter is still a matter of debate. In this work, we investigate whether the warm dust may be a signature of asteroid belt analogues. In the scenario tested here, the current two-belt architecture stems from an originally extended protoplanetary disc, in which planets have opened a gap separating it into the outer and inner discs which, after the gas dispersal, experience a steady-state collisional decay. This idea is explored with an analytic collisional evolution model for a sample of 225 debris discs from a Spitzer/IRS catalogue that are likely to possess a two-component structure. We find that the vast majority of systems (220 out of 225, or 98 per cent) are compatible with this scenario. For their progenitors, original protoplanetary discs, we find an average surface density slope of -0.93 ± 0.06 and an average initial mass of (3.3^{+0.4}_{-0.3})× 10^{-3} solar masses, both of which are in agreement with the values inferred from submillimetre surveys. However, dust production by short-period comets and - more rarely - inward transport from the outer belts may be viable, and not mutually excluding, alternatives to the asteroid belt scenario. The remaining five discs (2 per cent of the sample: HIP 11486, HIP 23497, HIP 57971, HIP 85790, HIP 89770) harbour inner components that appear inconsistent with dust production in an 'asteroid belt.' Warm dust in these systems must either be replenished from cometary sources or represent an aftermath of a recent rare event, such as a major collision or planetary system instability.

Petrology and geochemistry of meta-ultramafic rocks in the Paleozoic Granjeno Schist, northeastern Mexico: Remnants of Pangaea ocean floor

NASA Astrophysics Data System (ADS)

Torres-Sánchez, Sonia Alejandra; Augustsson, Carita; Jenchen, Uwe; Rafael Barboza-Gudiño, J.; Alemán Gallardo, Eduardo; Ramírez Fernández, Juan Alonso; Torres-Sánchez, Darío; Abratis, Michael

2017-08-01

The Granjeno Schist is a meta-volcanosedimentary upper Paleozoic complex in northeastern Mexico. We suggest different tectonic settings for metamorphism of its serpentinite and talc-bearing rocks based on petrographic and geochemical compositions. According to the REE ratios (LaN/YbN = 0.51 -20.0 and LaN/SmN = 0.72-9.1) and the enrichment in the highly incompatible elements Cs (0.1 ppm), U (2.8 ppm), and Zr (60 ppm) as well as depletion in Ba (1 - 15 ppm), Sr (1 -184 ppm), Pb (0.1 -14 ppm), and Ce (0.1 -1.9 ppm) the rocks have mid-ocean ridge and subduction zones characteristics. The serpentinite contains Al-chromite, ferrian chromite and magnetite. The Al-chromite is characterized by Cr# of 0.48 to 0.55 suggesting a MORB origin, and Cr# of 0.93 to 1.00 for the ferrian chromite indicates a prograde metamorphism. We propose at least two serpentinization stages of lithospheric mantle for the ultramafic rock of the Granjeno Schist, (1) a first in an ocean-floor environment at sub-greenschist to greenschist facies conditions and (2) later a serpentinization phase related to the progressive replacement of spinel by ferrian chromite and magnetite at greenschist to low amphibolite facies conditions during regional metamorphism. The second serpentinization phase took place in an active continental margin during the Pennsylvanian. We propose that the origin of the ultramafic rocks is related to an obduction and accretional event at the western margin of Pangea.

Deportment of PGE and semimetals in the Volspruit deposit: the most ultramafic PGE horizon of the Bushveld Complex

NASA Astrophysics Data System (ADS)

Tanner, D.; McDonald, I.; Harmer, R. E. J.; Hughes, H. S. R.; Muir, D. D.

2017-12-01

The Volspruit deposit is a zone of disseminated magmatic sulphides carrying Ni-PGE (platinum-group element) mineralization in the Northern Limb of the Bushveld Complex, South Africa. It is one of the few known PGE prospects hosted by the lower ultramafic portion of a layered intrusion and the only known example in the Bushveld Complex. Volspruit therefore provides a unique insight into the processes governing mineralisation early in the Bushveld magmatic system. This study presents a detailed analysis from the northern portion of the Volspruit orebody combining mineralogical and textural observations with sulphide mineral trace element compositions. Electron microscopy reveals a diverse assemblage of Pt-, Pd- and Rh- dominant platinum-group minerals (PGM), electrum, Ag tellurides, Pb-chlorides, Pb-sulphides, U-oxide and monazite. Laser ablation ICP-MS has demonstrated that the Volspruit base metal sulphides have elevated PGE tenors but a range of S/Se values 1414-19319 - greater than other magmatic sulphide deposits in the northern Bushveld. The S/Se values are typical of crustal S and in agreement with previous S isotope data. These data imply a magma with initially high tenor sulphide liquid experienced local contamination from sedimentary S, leading to reduced tenors and elevated S/Se in sulphides coupled with a propensity of Pb- and Zn-bearing minerals (e.g., Pb-sulphide, Pb-chloride and sphalerite) in association with archetypal orthomagmatic sulphide assemblages. Our data demonstrate that assimilation of sedimentary rocks can modify sulphide melt evolution through the addition of metals such as Pb and Zn, not just contamination by sulphur. The Volspruit deposit illustrates the complexity of multi-stage processes governing mineralisation in the ultramafic portions of layered mafic intrusions.

Comprehensive Pb-Sr-Nd-Hf isotopic, trace element, and mineralogical characterization of mafic to ultramafic rock reference materials

NASA Astrophysics Data System (ADS)

Fourny, Anaïs.; Weis, Dominique; Scoates, James S.

2016-03-01

Controlling the accuracy and precision of geochemical analyses requires the use of characterized reference materials with matrices similar to those of the unknown samples being analyzed. We report a comprehensive Pb-Sr-Nd-Hf isotopic and trace element concentration data set, combined with quantitative phase analysis by XRD Rietveld refinement, for a wide range of mafic to ultramafic rock reference materials analyzed at the Pacific Centre for Isotopic and Geochemical Research, University of British Columbia. The samples include a pyroxenite (NIM-P), five basalts (BHVO-2, BIR-1a, JB-3, BE-N, GSR-3), a diabase (W-2), a dolerite (DNC-1), a norite (NIM-N), and an anorthosite (AN-G); results from a leucogabbro (Stillwater) are also reported. Individual isotopic ratios determined by MC-ICP-MS and TIMS, and multielement analyses by HR-ICP-MS are reported with 4-12 complete analytical duplicates for each sample. The basaltic reference materials have coherent Sr and Nd isotopic ratios with external precision below 50 ppm (2SD) and below 100 ppm for Hf isotopes (except BIR-1a). For Pb isotopic reproducibility, several of the basalts (JB-3, BHVO-2) require acid leaching prior to dissolution. The plutonic reference materials also have coherent Sr and Nd isotopic ratios (<50 ppm), however, obtaining good reproducibility for Pb and Hf isotopic ratios is more challenging for NIM-P, NIM-N, and AN-G due to a variety of factors, including postcrystallization Pb mobility and the presence of accessory zircon. Collectively, these results form a comprehensive new database that can be used by the geochemical community for evaluating the radiogenic isotope and trace element compositions of volcanic and plutonic mafic-ultramafic rocks.

Promoting Automobile Safety Belt Use by Young Children.

ERIC Educational Resources Information Center

Sowers-Hoag, Karen M.; And Others

1987-01-01

A program of behavioral practice, assertiveness training, and social and contrived reinforcers was successful in establishing and maintaining automobile safety belt use by 16 children (ages 4-7) who never used them during a five-day preobservation period. Safety belt use occurred during 76%-90% of follow-up observations after two-three months.…

Security Belt for Wireless Implantable Medical Devices.

PubMed

Kulaç, Selman

2017-09-19

In this study, a new protective design compatible with existing non-secure systems was proposed, since it is focused on the secure communication of wireless IMD systems in all transmissions. This new protector is an external wearable device and appears to be a belt fitted around for the patients IMD implanted. However, in order to provide effective full duplex transmissions and physical layer security, some sophisticated transceiver antennas have been placed on the belt. In this approach, beam-focused multi-antennas in optimal positions on the belt are randomly switched when transmissions to the IMD are performed and multi-jammer switching with MRC combining or majority-rule based receiving techniques are applied when transmissions from the IMD are carried out. This approach can also reduce the power consumption of the IMDs and contribute to the prolongation of the IMD's battery life.

Onshore and offshore apatite fission-track dating from the southern Gulf of California: Insights into the time-space evolution of the rifting

NASA Astrophysics Data System (ADS)

Balestrieri, Maria Laura; Ferrari, Luca; Bonini, Marco; Duque-Trujillo, Jose; Cerca, Mariano; Moratti, Giovanna; Corti, Giacomo

2017-11-01

We present the results of a apatite fission-track (AFT) study on intrusive rocks in the southern Gulf of California, sampled along the eastern margin of Baja California Sur (western rift margin), as well as from islands and submerged rifted blocks within the Gulf of California, and from the conjugate Mexican margin (Nayarit state). For most of the samples U-Pb zircon and 40Ar-39Ar mineral ages were already available (Duque-Trujillo et al., 2015). Coupled with the new AFT data these ages provide a more complete information on cooling after emplacement. Our samples span a wide range of ages between 5.5 ± 1.1 and 73.7 ± 5.8 Ma, and show a general spatial distribution, with late Miocene AFT ages (about 6 Ma) aligned roughly NW-SE along a narrow offshore belt, parallel to Baja California Peninsula, separating older ages on both sides. This pattern suggests that in Late Miocene, deformation due to plate transtension focused at the eastern rheological boundary of the Baja California block. Some Early Miocene AFT ages onshore Baja California could be related to plutons emplaced at shallow depths and thermal resetting associated with the onset of volcanism at 19 Ma in this part of the Peninsula. On the other hand, an early extensional event similar to that documented in the eastern Gulf cannot be ruled out in the westernmost Baja California.

Rb-Sr, K-Ar, and stable isotope evidence for the ages and sources of fluid components of gold-bearing quartz veins in the northern Sierra Nevada foothills metamorphic belt, California

USGS Publications Warehouse

Böhlke, John Karl; Kistler, R. W.

1986-01-01

Gold-bearing quartz veins occur in and near major fault zones in deformed oceanic and island-arc rocks west of the main outcrop of the Sierra Nevada composite batholith. Veins typically occupy minor reverse faults that crosscut blueschist to amphibolite-grade metamorphic rocks whose metamorphic ages range from early Paleozoic to Jurassic. Vein micas and carbonate-quartz-mica assemblages that formed by hydrothermal metasomatism of ultramafic wall rocks in the Alleghany, Grass Valley, Washington, and Mother Lode districts yield concordant K-Ar and Rb-Sr ages. The dated veins are significantly younger than prograde metamorphism, penetrative deformation, and accretion of their host rocks to the continental margin. New and previously published mineralization ages from 13 localities in the Sierra foothills range from about 140 to 110 m.y. ago, with mean and median between 120 and 115 m.y. The age relations suggest that mineralizing fluids were set in motion by deep magmatic activity related to the resumption of east-dipping subduction along the western margin of North America following the Late Jurassic Nevadan collision event.CO 2 -bearing fluids responsible for metasomatism and much of the vein mica, carbonate, albite, and quartz deposition in several northern mines were isotopically heavy (delta 18 O [asymp] 8-14ppm; delta D between about -10 and -50ppm) and do not resemble seawater, magmatic, or meteoric waters. Metasomatic and vein-filling mica, dolomite, magnesite, and quartz in altered ultramafic rocks generally formed from fluids with similar Sr and O isotope ratios at a given locality. Consistent quartz-mica delta 18 O fractionations (delta 18 O (sub Q-M) = 4.5-4.9ppm) from various localities imply uniform equilibration temperatures, probably between 300 degrees and 350 degrees C. On a local (mine) scale, fluids responsible for both carbonate alteration of mafic and ultramafic wall rocks and albitic alteration of felsic and pelitic rocks had similar Sr isotope

Geochemistry of amphibolites from the Kolar Schist Belt

NASA Technical Reports Server (NTRS)

Balakrishnan, S.; Hanson, G. N.; Rajamani, V.

1988-01-01

How the Nd isotope data suggest that the amphibolites from the schist belt were derived from long-term depleted mantle sources at about 2.7 Ga is described. Trace element and Pb isotope data from the amphibolites also suggest that the sources for the amphibolites on the western and eastern sides of the narrow schist belt were derived from different sources. The Pb data from one outcrop of the central tholeiitic amphibolites lies on a 2.7 Ga isochron with a low model. The other amphibolites (W komatiitic, E komatiitic, and E tholeiitic) do not define isochrons, but suggest that they were derived from sources with distinct histories of U/Pb. There is some suggestion that the E komatiitic amphibolites may have been contaminated by fluids carrying Pb from a long-term, high U/Pb source, such as the old granitic crust on the west side of the schist belt. This is consistent with published galena Pb isotope data from the ore lodes within the belt, which also show a history of long-term U/Pb enrichment.

Composition of the earth's upper mantle-I. Siderophile trace elements in ultramafic nodules

USGS Publications Warehouse

Morgan, J.W.; Wandless, G.A.; Petrie, R.K.; Irving, A.J.

1981-01-01

Seven siderophile elements (Au, Ge, Ir, Ni, Pd, Os, Re) were determined by radiochemical neutron activation analysis in 19 ultramafic rocks, which are spinel lherzollites-xenoliths from North and Central America, Hawaii and Australia, and garnet Iherzolitexenoliths from Lesotho. Abundances of the platinum metals are very uniform in spinel lherzolites averaging 3.4 ?? 1.2 ppb Os, 3.7 ?? 1.1 ppb Ir, and 4.6 ?? 2.0 ppb Pd. Sheared garnet lherzolite PHN 1611 has similar abundances of these elements, but in 4 granulated garnet lherzolites, abundances are more variable. In all samples, the Pt metals retain cosmic ( Cl-chondrite) ratios. Abundances of Au and Re vary more than those of Pt metals, but the Au/Re ratio remains close to the cosmic value. The fact that higher values of Au and Re approach cosmic proportions with respect to the Pt metals, suggests that Au and Re have been depleted in some ultramafic rocks from an initially chondrite-like pattern equivalent to about 0.01 of Cl chondrite abundances. The relative enrichment of Au and Re in crustal rocks is apparently the result of crust-mantle fractionation and does not require a special circumstance of core-mantle partitioning. Abundances of moderately volatile elements Ni, Co and Ge are very uniform in all rocks, and are much higher than those of the highly siderophile elements Au, Ir, Pd, Os and Re. When normalized to Cl chondrites, abundances of Ni and Co are nearly identical, averaging 0.20 ?? 0.02 and 0.22 ?? 0.02, respectively; but Ge is only 0.027 ?? 0.004. The low abundance of Ge relative to Ni and Co is apparently a reflection of the general depletion of volatile elements in the Earth. The moderately siderophile elements cannot be derived from the same source as the highly siderophile elements because of the marked difference in Cl chondrite-normalized abundances and patterns. We suggest that most of the Ni, Co and Ge were enriched in the silicate by the partial oxidation of pre-existing volatile-poor Fe

Jupiter's radiation belts: Can Pioneer 10 survive?

NASA Technical Reports Server (NTRS)

Hess, W. N.; Birmingham, T. J.; Mead, G. D.

1973-01-01

Model calculations of Jupiter's electron and proton radiation belts indicate that the Galilean satellites can reduce particle fluxes in certain regions of the inner magnetosphere by as much as six orders of magnitude. Average fluxes should be reduced by a factor of 100 or more along the Pioneer 10 trajectory through the heart of Jupiter's radiation belts in early December. This may be enough to prevent serious radiation damage to the spacecraft.

Jupiter's Radiation Belts: Can Pioneer 10 Survive?

PubMed

Hess, W N; Birmingham, T J; Mead, G D

1973-12-07

Model calculations of Jupiter's electron and proton radiation belts indicate that the Galilean satellites can reduce particle fluxes in certain regions of the inner magnetosphere by as much as six orders of magnitude. Average fluxes should be reduced by a factor of 100 or more along the Pioneer 10 trajectory through the heart of Jupiter's radiation belts in early December. This may be enough to prevent serious radiation damage to the spacecraft.

The evolution of Saturn's radiation belts modulated by changes in radial diffusion

NASA Astrophysics Data System (ADS)

Kollmann, P.; Roussos, E.; Kotova, A.; Paranicas, C.; Krupp, N.

2017-12-01

Globally magnetized planets, such as the Earth1 and Saturn2, are surrounded by radiation belts of protons and electrons with kinetic energies well into the million electronvolt range. The Earth's proton belt is supplied locally from galactic cosmic rays interacting with the atmosphere3, as well as from slow inward radial transport4. Its intensity shows a relationship with the solar cycle4,5 and abrupt dropouts due to geomagnetic storms6,7. Saturn's proton belts are simpler than the Earth's because cosmic rays are the principal source of energetic protons8 with virtually no contribution from inward transport, and these belts can therefore act as a prototype to understand more complex radiation belts. However, the time dependence of Saturn's proton belts had not been observed over sufficiently long timescales to test the driving mechanisms unambiguously. Here we analyse the evolution of Saturn's proton belts over a solar cycle using in-situ measurements from the Cassini Saturn orbiter and a numerical model. We find that the intensity in Saturn's proton radiation belts usually rises over time, interrupted by periods that last over a year for which the intensity is gradually dropping. These observations are inconsistent with predictions based on a modulation in the cosmic-ray source, as could be expected4,9 based on the evolution of the Earth's proton belts. We demonstrate that Saturn's intensity dropouts result instead from losses due to abrupt changes in magnetospheric radial diffusion.

Deformation and kinematics of the central Kirthar Fold Belt, Pakistan

NASA Astrophysics Data System (ADS)

Hinsch, Ralph; Hagedorn, Peter; Asmar, Chloé; Nasim, Muhammad; Aamir Rasheed, Muhammad; Kiely, James M.

2017-04-01

The Kirthar Fold Belt is part of the lateral mountain belts in Pakistan linking the Himalaya orogeny with the Makran accretionary wedge. This region is deforming very oblique/nearly parallel to the regional plate motion vector. The study area is situated between the prominent Chaman strike-slip fault in the West and the un-deformed foreland (Kirthar Foredeep/Middle Indus Basin) in the East. The Kirthar Fold Belt is subdivided into several crustal blocks/units based on structural orientation and deformation style (e.g. Kallat, Khuzdar, frontal Kirthar). This study uses newly acquired and depth-migrated 2D seismic lines, surface geology observations and Google Earth assessments to construct three balanced cross sections for the frontal part of the fold belt. Further work was done in order to insure the coherency of the built cross-sections by taking a closer look at the regional context inferred from published data, simple analogue modelling, and constructed regional sketch sections. The Khuzdar area and the frontal Kirthar Fold Belt are dominated by folding. Large thrusts with major stratigraphic repetitions are not observed. Furthermore, strike-slip faults in the Khuzdar area are scarce and not observed in the frontal Kirthar Fold Belt. The regional structural elevation rises from the foreland across the Kirthar Fold Belt towards the hinterland (Khuzdar area). These observations indicate that basement-involved deformation is present at depth. The domination of folding indicates a weak decollement below the folds (soft-linked deformation). The fold pattern in the Khuzdar area is complex, whereas the large folds of the central Kirthar Fold Belt trend SSW-NNE to N-S and are best described as large detachment folds that have been slightly uplifted by basement involved transpressive deformation underneath. Towards the foreland, the deformation is apparently more hard-linked and involves fault-propagation folding and a small triangle zone in Cretaceous sediments

Explaining the dynamics of the ultra-relativistic third Van Allen radiation belt

DOE PAGES

Mann, I. R.; Ozeke, L. G.; Murphy, K. R.; ...

2016-06-20

Since the discovery of the Van Allen radiation belts over 50 years ago, an explanation for their complete dynamics has remained elusive. Especially challenging is understanding the recently discovered ultra-relativistic third electron radiation belt. Current theory asserts that loss in the heart of the outer belt, essential to the formation of the third belt, must be controlled by high-frequency plasma wave–particle scattering into the atmosphere, via whistler mode chorus, plasmaspheric hiss, or electromagnetic ion cyclotron waves. However, this has failed to accurately reproduce the third belt. In this paper, using a data-driven, time-dependent specification of ultra-low-frequency (ULF) waves we showmore » for the first time how the third radiation belt is established as a simple, elegant consequence of storm-time extremely fast outward ULF wave transport. High-frequency wave–particle scattering loss into the atmosphere is not needed in this case. Finally, when rapid ULF wave transport coupled to a dynamic boundary is accurately specified, the sensitive dynamics controlling the enigmatic ultra-relativistic third radiation belt are naturally explained.« less

Explaining the dynamics of the ultra-relativistic third Van Allen radiation belt

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mann, I. R.; Ozeke, L. G.; Murphy, K. R.

Since the discovery of the Van Allen radiation belts over 50 years ago, an explanation for their complete dynamics has remained elusive. Especially challenging is understanding the recently discovered ultra-relativistic third electron radiation belt. Current theory asserts that loss in the heart of the outer belt, essential to the formation of the third belt, must be controlled by high-frequency plasma wave–particle scattering into the atmosphere, via whistler mode chorus, plasmaspheric hiss, or electromagnetic ion cyclotron waves. However, this has failed to accurately reproduce the third belt. In this paper, using a data-driven, time-dependent specification of ultra-low-frequency (ULF) waves we showmore » for the first time how the third radiation belt is established as a simple, elegant consequence of storm-time extremely fast outward ULF wave transport. High-frequency wave–particle scattering loss into the atmosphere is not needed in this case. Finally, when rapid ULF wave transport coupled to a dynamic boundary is accurately specified, the sensitive dynamics controlling the enigmatic ultra-relativistic third radiation belt are naturally explained.« less

The Radiation Belt Storm Probes (RBSP) Energetic Particle, Composition, and Thermal plasma (ECT) Suite: Upcoming Opportunties for Testing Radiation Belt Acceleration Mechanisms

NASA Astrophysics Data System (ADS)

Spence, Harlan; Reeves, Geoffrey

2012-07-01

The Radiation Belt Storm Probes (RBSP) mission will launch in late summer 2012 and begin its exploration of acceleration and dynamics of energetic particles in the inner magnetosphere. In this presentation, we discuss opportunities afforded by the RBSP Energetic Particle, Composition, and Thermal plasma (ECT) instrument suite to advance our understanding of acceleration processes in the radiation belts. The RBSP-ECT instrument suite comprehensively measures the electron and major ion populations of the inner magnetosphere, from the lowest thermal plasmas of the plasmasphere, to the hot plasma of the ring current, to the relativistic populations of the radiation belts. Collectively, the ECT measurements will reveal the complex cross-energy coupling of these colocated particle populations, which along with concurrent RBSP wave measurements, will permit various wave-particle acceleration mechanisms to be tested. We review the measurement capabilities of the RBSP-ECT instrument suite, and demonstrate several examples of how these measurements will be used to explore candidate acceleration mechanisms and dynamics of radiation belt particles.

30 CFR 75.1403-5 - Criteria-Belt conveyors.

Code of Federal Regulations, 2010 CFR

2010-07-01

.... (g) A clear travelway at least 24 inches wide should be provided on both sides of all belt conveyors installed after March 30, 1970. Where roof supports are installed within 24 inches of a belt conveyor, a... is less than 24 inches, and should not exceed 350 feet per minute when the vertical clearance is 24...

Anorthosite belts, continental drift, and the anorthosite event

USGS Publications Warehouse

Herz, N.

1969-01-01

Most anorthosites lie in two principal belts when plotted on a predrift continental reconstruction. Anorthosite ages in the belts cluster around 1300 ?? 200 million years and range from 1100 to 1700 million years. This suggests that anorthosites are the product of a unique cataclysmic event or a thermal event that was normal only during the earth's early history.

Anorthosite belts, continental drift, and the anorthosite event.

PubMed

Herz, N

1969-05-23

Most anorthosites lie in two principal belts when plotted on a predrift continental reconstruction. Anorthosite ages in the belts cluster around 1300 +/- 200 million years and range from 1100 to 1700 million years. This suggests that anorthosites are the product of a unique cataclysmic event or a thermal event that was normal only during the earth's early history.

Nighttime enforcement of seat belt laws : an evaluation of three community programs

DOT National Transportation Integrated Search

2009-08-01

Programs to enforce seat belt laws at night were conducted in Asheville and Greenville, North Carolina and Charleston, West Virginia. It was concluded that night belt use publicity and enforcement efforts can be effective both for increasing belt use...

The Mid-plane of the Main Asteroid Belt

NASA Astrophysics Data System (ADS)

Cambioni, Saverio; Malhotra, Renu

2018-03-01

We measure the mid-plane of the main asteroid belt by using the observational data of a nearly complete and unbiased sample of asteroids and find that it has inclination \\bar{I}=0\\buildrel{\\circ}\\over{.} 93+/- 0\\buildrel{\\circ}\\over{.} 04 and longitude of ascending node \\bar{{{Ω }}}=87\\buildrel{\\circ}\\over{.} 6+/- 2\\buildrel{\\circ}\\over{.} 6 (in J2000 ecliptic-equinox coordinate system). This plane differs significantly from previously published measurements, and it is also distinctly different than the solar system’s invariable plane as well as Jupiter’s orbit plane. The mid-plane of the asteroid belt is theoretically expected to be a slightly warped sheet whose local normal is controlled by the gravity of the major planets. Specifically, its inclination and longitude of ascending node varies with semimajor axis and time (on secular timescales) and is defined by the forced solution of secular perturbation theory; the ν 16 nodal secular resonance is predicted to cause a significant warp of the mid-plane in the inner asteroid belt. We test the secular theory by measuring the current location of the asteroids’ mid-plane in finer semimajor axis bins. We find that the measured mid-plane in the middle and outer asteroid belt is consistent, within the 3σ confidence level, with the prediction of secular perturbation theory, but a notable discrepancy is present in the inner asteroid belt near ∼2 au.

Evaluation of Maine's seat belt law change from secondary to primary enforcement.

DOT National Transportation Integrated Search

2010-04-01

Maine upgraded its seat belt law to primary enforcement on September 20, 2007. Both daytime and nighttime observed belt use increased in the months following implementation of the law (daytime 77% to 84%; night 69% to 81%). Although daytime belt use ...

Year 1 of the Washington nighttime seat belt enforcement program : traffic tech.

DOT National Transportation Integrated Search

2010-09-01

The first year of the Washington nighttime belt program : ran from May 2007 through May 2008. During this period, WTSC ran three, two-week nighttime seat belt enforcement : campaigns. The primary message of the ad was that extra : seat-belt-focuse...

Daytime and nighttime seat belt use at selected sites in New Mexico

DOT National Transportation Integrated Search

2007-01-01

Observational surveys of seat belt use were conducted at 108 observation sites across New Mexico during both daytime and nighttime hours. Belt use at night measured 6.2 percentage points lower than daytime. Belt use was related to sex, vehicle type, ...

Injury pattern as an indication of seat belt failure in ejected vehicle occupants.

PubMed

Freeman, Michael D; Eriksson, Anders; Leith, Wendy

2014-09-01

Prior authors have suggested that when occupant ejection occurs in association with a seat belt failure, entanglement of the outboard upper extremity (OUE) with the retracting shoulder belt will invariably occur, leaving injury pattern evidence of belt use. In the present investigation, the authors assessed this theory using data accessed from the NASS-CDS for ejected front seat occupants of passenger vehicles. Logistic regression models were used to assess the associations between seat belt failure status and injuries. Injury types associated with seat belt failure were significant OUE and head injuries (OR = 3.87, [95% CI 1.2, 13.0] and 3.1, [95% CI 1.0, 9.7], respectively). The two injury types were found to be a predictor of seat belt use and subsequent failure only if combined with a high (≥0.8) precrash probability of belt use. The injury pattern associated with a seat belt failure-related ejection has limited use in the forensic investigation of crash-related ejections. © 2014 American Academy of Forensic Sciences.

Cortlandtitic enclaves associated with calc-alkaline granites from Tapia-Asturias (Hercynian Belt, northwestern Spain)

NASA Astrophysics Data System (ADS)

Galán, G.; Suárez, O.

1989-10-01

Petrographic and mineralogical characteristics of amphibole-olivine- and pyroxene-bearing ultramafic rocks from Asturias (NW Spain) are dealt with in this paper. These rocks are of cortlandtitic type and occur as small rare enclaves in basic rocks related to Hercynian calc-alkaline, post-tectonic epizonal granites, in the northwest of the Iberian Peninsula. These particular ultramafic enclaves are characterized by poikilitic cumulate microtexture. Olivine (Fo 77-81), spinel, from chromite to pleonaste composition, enstatite, subordinated diopside and sulphides are included in large brown calcic amphibole crystals displaying an irregular zonation. Phlogopite and plagioclase are also found, in a much lower proportion, between the large amphibole crystals. Mineral assemblage and chemical composition of minerals indicate formation conditions of 1150°C, 7-8 kbar of Ptotal and PH 2O < Ptotal. These rocks could represent the earlier products of fractional crystallization from a hydrated high-alumina basalt involved in the genesis of the calc-alkaline granites. This basic magma would start crystallizing at a relatively deep level, carrying up the first products of its crystallization during its ascent.

Detrital zircon U-Pb reconnaissance of the Franciscan subduction complex in northwestern California

USGS Publications Warehouse

Dimitru, Trevor; Ernst, W. Gary; Hourigan, Jeremy K.; McLaughlin, Robert J.

2015-01-01

In northwestern California, the Franciscan subduction complex has been subdivided into seven major tectonostratigraphic units. We report U-Pb ages of ≈2400 detrital zircon grains from 26 sandstone samples from 5 of these units. Here, we tabulate each unit's interpreted predominant sediment source areas and depositional age range, ordered from the oldest to the youngest unit. (1) Yolla Bolly terrane: nearby Sierra Nevada batholith (SNB); ca. 118 to 98 Ma. Rare fossils had indicated that this unit was mostly 151-137 Ma, but it is mostly much younger. (2) Central Belt: SND; ca. 103 too 53 Ma (but poorly constrained), again mostly younger than previously thought. (3) Yager terrane: distant Idaho batholith (IB); ca. 52 to 50 Ma. Much of the Yager's detritus was shed during major core complex extension and erosion in Idaho that started 53 Ma. An eocene Princeton River-Princeton submarine canyon system transported this detritus to the Great Valley forearc basin and thence to the Franciscan trench. (4) Coastal terrane: mostly IB, ±SNB, ±nearby Cascade arc, ±Nevada Cenozoic ignimbrite belt; 52 to <32 Ma. (5) King Range terrane: dominated by IB and SNB zircons; parts 16-14 Ma based on microfossils. Overall, some Franciscan units are younger than previously thought, making them more compatible with models for the growth of subduction complexes by positive accretion. From ca. 118 to 70 Ma, Franciscan sediments were sourced mainly from the nearby Sierra Nevada region and were isolated from southwestern US and Mexican sources. From 53 to 49 Ma, the Franciscan was sourced from both Idaho and the Sierra Nevada. By 37-32 Ma, input from Idaho had ceased. The influx from Idaho probably reflects major tectonism in Idaho, Oregon, and Washington, plus development of a through-going Princeton River to California, rather than radical changes in the subduction system at the Franciscan trench itself.

Structural profile reconstructions and thermal metamorphic evolution in the slate belt of southern Hsuehshan Range in the active Taiwan mountain belt

NASA Astrophysics Data System (ADS)

Wu, Yu; Chen, Chih-Tung; Lee, Jian-Cheng; Shyu, J. Bruce H.

2017-04-01

The fate of passive continental margin in collisional orogens is crucial in understanding tectonic evolution of mountain belts. The active arc-continent collision of Taiwan is considered as a model case in studying mountain building processes, and largely consists of deformed margin basement and cover series. Among the whole orogeny belt, the slate belt of the Hsuehshan Range (HR) is a prominent large-scale pop-up structural on the prowedge part of the orogen, and is composed of metamorphosed Eocene to Miocene sediments which experienced only the Neogene Taiwan orogeny after diagenesis in margin graben. Characterizing the metamorphic history of the HR is essential for reconstructing its geological evolution during the mountain building processes. However, previous studies were mostly focused on northern and central HR, structural investigation coupled with metamorphic documentation in the southern part of HR, which is the most active part of the orogeny belt, is therefore targeted in this work. Since carbonaceous material is common in pelitic protolith of HR slates, the Raman spectrum of carbonaceous material (RSCM) measuring the rock peak temperature is chosen for quantitative thermal metamorphic documentation. In this study, we reconstruct a geological structural profile in western central Taiwan across the prowedge part of the mountain belt containing the southern HR by combining the surface geological data, well log records and published seismic reflection profiles. Although most of the existing data are concentrated in the fold-and-thrust belt, they are now reinforced by new field structural measurements and RSCM samples in the southern HR. In total 27 RSCM samples were collected along 2 transects perpendicular to the average strike with a dense interval about 2 km. The results allow us to map peak temperature distribution across southern HR, and provide new constraints for structural profile reconstruction and reappraisal of the structural evolution of the HR

Searching for Chips of Kuiper Belt Objects in Meteorites

NASA Technical Reports Server (NTRS)

Zolensky, M. E.; Ohsumi, K.; Briani, G.; Gounelle, M.; Mikouchi, T.; Satake, W.; Kurihara, T.; Weisberg, M. K.; Le, L.

2009-01-01

The Nice model [1&2] describes a scenario whereby the Jovian planets experienced a violent reshuffling event approx.3:9 Ga the giant planets moved, existing small body reservoirs were depleted or eliminated, and new reservoirs were created in particular locations. The Nice model quantitatively explains the orbits of the Jovian planets and Neptune [1], the orbits of bodies in several different small body reservoirs in the outer solar system (e.g., Trojans of Jupiter [2], the Kuiper belt and scattered disk [3], the irregular satellites of the giant planets [4], and the late heavy bombardment on the terrestrial planets approx.3:9 Ga [5]. This model is unique in plausibly explaining all of these phenomena. One issue with the Nice model is that it predicts that transported Kuiper Belt Objects (KBOs) (things looking like D class asteroids) should predominate in the outer asteroid belt, but we know only about 10% of the objects in the outer main asteroid belt appear to be D-class objects [6]. However based upon collisional modeling, Bottke et al. [6] argue that more than 90% of the objects captured in the outer main belt could have been eliminated by impacts if they had been weakly-indurated objects. These disrupted objects should have left behind pieces in the ancient regoliths of other, presumably stronger asteroids. Thus, a derived prediction of the Nice model is that ancient regolith samples (regolith-bearing meteorites) should contain fragments of collisionally-destroyed Kuiper belt objects. In fact KBO pieces might be expected to be present in most ancient regolith- bearing meteorites [7&8].

Geochemistry of komatiites and basalts from the Rio das Velhas and Pitangui greenstone belts, São Francisco Craton, Brazil: Implications for the origin, evolution, and tectonic setting

NASA Astrophysics Data System (ADS)

Verma, Sanjeet K.; Oliveira, Elson P.; Silva, Paola M.; Moreno, Juan A.; Amaral, Wagner S.

2017-07-01

The Neoarchean Rio das Velhas and Pitangui greenstone belts are situated in the southern São Francisco Craton, Minas Gerais, Brazil. These greenstone belts were formed between ca. 2.79-2.73 Ga, and consist mostly of mafic to ultramafic volcanics and clastic sediments, with minor chemical sediments and felsic volcanics that were metamorphosed under greenschist facies. Komatiites are found only in the Rio das Velhas greenstone belt, which is composed of high-MgO volcanic rocks that have been identified as komatiites and high-Mg basalts, based on their distinctive geochemical characteristics. The Rio das Velhas komatiites are composed of tremolite + actinolite + serpentine + albite with a relict spinifex-texture. The Rio das Velhas komatiites have a high magnesium content ((MgO)adj ≥ 28 wt.%), an Al-undepleted Munro-type [(Al2O3/TiO2)adj and (CaO/Al2O3)adj] ratio ranging from 27 to 47 and 0.48 to 0.89, relatively low abundances of incompatible elements, a depletion of light rare earth elements (LREE), a pattern of non-fractionated heavy rare- earth elements (HREE), and a low (Gd/Yb)PM ratio (≤ 1.0). Negative Ce anomalies suggest that alteration occurred during greenschist facies metamorphism for the komatiites and high-Mg basalts. The low [(Gd/Yb)PM < 1.0] and [(CaO/Al2O3)adj < 0.9)], high [(Al2O3/TiO2)adj > 18] and high HREE, Y, and Zr content suggest that the Rio das Velhas komatiites were derived from the shallow upper mantle without garnet involvement in the residue. The chemical compositions [(Al2O3/TiO2)adj, (FeO)adj, (MgO)adj, (CaO/Al2O3)adj, Na, Th, Ta, Ni, Cr, Zr, Y, Hf, and REE] indicate that the formation of the komatiites, high-Mg basalts and basalts occurred at different depths and temperatures in a heterogeneous mantle. The komatiites and high-Mg basalts melted at liquidus temperatures of 1450-1550 °C. The Pitangui basalts are enriched in the highly incompatible LILE (large-ion lithophile elements) relative to the moderately incompatible HFS (high

Spatial and temporal relations between coronae and extensional belts, northern Lada Terra, Venus

NASA Astrophysics Data System (ADS)

Baer, G.; Schubert, G.; Bindschadler, D. L.; Stofan, E. R.

1994-04-01

Preliminary studies of the distribution of coronae and volcanic rises on Venus show that many of these features tend to cluster along zones of rifting and extension. The plains north of Lada Terra are crossed by two such extensional belts. Each belt is composed of grabens, ridges, faults, volcanic flows, coronae and coronalike features. The longer and more prominent belt is the NW trending Alpha-Lada extensional belt, which is over 6000 km long and 50-200 km wide, and includes the coronae Eve, Tamfana, Carpo, Selu, Derceto, Otygen, and an unnamed corona south of Otygen. The second belt is the NNE trending Derceto-Quetzalpetlatl extensional belt, which is about 2000 km long and in places over 300 km wide, and includes the coronae Sarpanitum, Eithinoha, and Quetzalpetlatl. The two belts intersect at the 1600 x 600 km wide Derceto volcanic plateau. It is apparent that deformation along the two belts overlapped in time, though deformation along the Alpha-Lada extensional belt probably continued after the deformation along the Derceto-Quetzalpetlatl extensional belt terminated. In certain areas, volcanism originated in grabens within the extensional belts, whereas in other areas, such as in Eve, Selu, Derceto, and Quetzalpetlatl, volcanism originated in the coronae and flowed into the lower parts of the extensional belts. Regional extension has affected the evolution of all the coronae at some stage of their development. Regional deformation occurred before the initiation of Derceto and Eithinoha of their development. Regional deformation occurred before the initiation of Derceto and Eithinoha and after the initiation of Carpo, Tamfana, Otygen, and Sarpanitum. It is thus unlikely that coronae formation along the belts is solely a consequence of the regional extension, and it is also unlikely that regional extension has been caused solely by the coronae. No corona along the belts was formed subsequent to the cessation of the regional extension. We therefore suggest that

The thrust belt in Southwest Montana and east-central Idaho

USGS Publications Warehouse

Ruppel, Edward T.; Lopez, David A.

1984-01-01

The leading edge of the Cordilleran fold and thrust in southwest Montana appears to be a continuation of the edge of the Wyoming thrust belt, projected northward beneath the Snake River Plain. Trces of the thrust faults that form the leading edge of the thrust belts are mostly concealed, but stratigraphic and structural evidence suggests that the belt enters Montana near the middle of the Centennial Mountains, continues west along the Red Rock River valley, and swings north into the Highland Mountains near Butte. The thrust belt in southwest Montana and east-central Idaho includes at least two major plates -- the Medicine Lodge and Grasshopper thrust plates -- each of which contains a distinctive sequence of rocks, different in facies and structural style from those of the cratonic region east of the thrust belt. The thrust plates are characterized by persuasive, open to tight and locally overturned folds, and imbricate thrust faults, structural styles unusual in Phanerozoic cratonic rocks. The basal decollement zones of the plates are composed of intensely sheared, crushed, brecciated, and mylonitized rocks, the decollement at the base of the Medicine Lodge plate is as much as 300 meters thick. The Medicine Lodge and Grasshopper thrust plates are fringed on the east by a 10- to 50-kilometer-wide zone of tightly folded rocks cut by imbricate thrust fauls, a zone that forms the eastern margin of the thrust belt in southwest Montana. The frontal fold and thrust zone includes rocks that are similar to those of the craton, even though they differ in details of thickness, composition, or stratigraphic sequence. The zone is interpreted to be one of terminal folding and thrusting in cratonic rocks overridden by the major thrust plates from farther west. The cratonic rocks were drape-folded over rising basement blocks that formed a foreland bulge in front of the thrust belt. The basement blocks are bounded by steep faults of Proterozoic ancestry, which also moved as tear

A photometric survey of outer belt asteroids

NASA Technical Reports Server (NTRS)

Dimartino, M.; Gonano-Beurer, M.; Mottola, Stefano; Neukum, G.

1992-01-01

Since 1989, we have been conducting a research program devoted to the study of the Trojans and outer belt asteroids (Hilda and Cybele groups), in order to characterize their rotational properties and shapes. As an outcome of several observational campaigns, we determined rotational periods and lightcurve amplitudes for 23 distant asteroids, using both CCD and photoelectric photometry. In this paper, we compare the rotational properties of main belt asteroids and Trojans, based on the preliminary results of this survey.

Circumferential truncal contouring: the belt lipectomy.

PubMed

Aly, Al; Mueller, Melissa

2014-10-01

The primary goal of belt lipectomy surgery is to improve the contour of the inferior truncal circumferential unit and to place the resultant scar in natural junctions. Excessive intra-abdominal content is a contraindication for belt lipectomy. The higher the presenting patient's body mass index (BMI), the higher the risk of postoperative complications and the less impressive the results. The converse is also true: the lower the BMI, the lower the risk of complications and the better the results. The most common complications are small wound separations and seromas. Copyright © 2014 Elsevier Inc. All rights reserved.