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1

Space Weathering of Rocks  

NASA Technical Reports Server (NTRS)

Space weathering discussions have generally centered around soils but exposed rocks will also incur the effects of weathering. On the Moon, rocks make up only a very small percentage of the exposed surface and areas where rocks are exposed, like central peaks, are often among the least space weathered regions we find in remote sensing data. However, our studies of weathered Ap 17 rocks 76015 and 76237 show that significant amounts of weathering products can build up on rock surfaces. Because rocks have much longer surface lifetimes than an individual soil grain, and thus record a longer history of exposure, we can study these products to gain a deeper perspective on the weathering process and better assess the relative impo!1ance of various weathering components on the Moon. In contrast to the lunar case, on small asteroids, like Itokowa, rocks make up a large fraction of the exposed surface. Results from the Hayabusa spacecraft at Itokowa suggest that while the low gravity does not allow for the development of a mature regolith, weathering patinas can and do develop on rock surfaces, in fact, the rocky surfaces were seen to be darker and appear spectrally more weathered than regions with finer materials. To explore how weathering of asteroidal rocks may differ from lunar, a set of ordinary chondrite meteorites (H, L, and LL) which have been subjected to artificial space weathering by nanopulse laser were examined by TEM. NpFe(sup 0) bearing glasses were ubiquitous in both the naturally-weathered lunar and the artificially-weathered meteorite samples.

Noble, Sarah

2011-01-01

2

Sedimentary Rocks and Weathering  

NSDL National Science Digital Library

This site contains 42 questions on the topic of sedimentary rocks and weathering including clast sizes, depositional environments, and products of weathering. This is part of the Principles of Earth Science course at the University of South Dakota. Users select an answer and are provided immediate feedback.

Heaton, Timothy

3

Rocks and Weathering  

NSDL National Science Digital Library

Sedimentary, igneous and metamorphic rocks, weathering, erosion and transport, and the rock cycle are explained in this resource for students through written content, interactive content, audio, video and games. A multiple choice test is included. Students may score their tests and the correct responses will be given.

4

Weathering of rock 'Ginger'  

NASA Technical Reports Server (NTRS)

One of the more unusual rocks at the site is Ginger, located southeast of the lander. Parts of it have the reddest color of any material in view, whereas its rounded lobes are gray and relatively unweathered. These color differences are brought out in the inset, enhanced at the upper right. In the false color image at the lower right, the shape of the visible-wavelength spectrum (related to the abundance of weathered ferric iron minerals) is indicated by the hue of the rocks. Blue indicates relatively unweathered rocks. Typical soils and drift, which are heavily weathered, are shown in green and flesh tones. The very red color in the creases in the rock surface correspond to a crust of ferric minerals. The origin of the rock is uncertain; the ferric crust may have grown underneath the rock, or it may cement pebbles together into a conglomerate. Ginger will be a target of future super-resolution studies to better constrain its origin.

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator. JPL is an operating division of the California Institute of Technology (Caltech).

1997-01-01

5

Rocks, Weathering, and Erosional Landscapes  

NSDL National Science Digital Library

Students will identify principal rock forming silicate minerals and distinguish their relative stability when exposed to weathering; identify sedimentary, igneous and metamorphic rocks and deduce the relative resistance based on mineral composition and texture;and finally relate erosional landscapes to the differential weathering and erosion of rocks of varying strengths. Designed for a geomorphology course

Hanson, Lindley

6

Space Weathering of Lunar Rocks  

NASA Technical Reports Server (NTRS)

All materials exposed at the lunar surface undergo space weathering processes. On the Moon, boulders make up only a small percentage of the exposed surface, and areas where such rocks are exposed, like central peaks, are often among the least space weathered regions identified from remote sensing data. Yet space weathered surfaces (patina) are relatively common on returned rock samples, some of which directly sample the surface of larger boulders. Because, as witness plates to lunar space weathering, rocks and boulders experience longer exposure times compared to lunar soil grains, they allow us to develop a deeper perspective on the relative importance of various weathering processes as a function of time.

Noble, S. K.; Keller, L. P.; Christoffersen, R.; Rahman, Z.

2012-01-01

7

The Weathering of Rocks: Three Activities.  

ERIC Educational Resources Information Center

Integrates science and social studies in several activities that study weathering caused by the freezing and thawing of rocks, wind erosion, and the effects of weathering on tombstones. Cites the possibility of these activities leading to an interdisciplinary exploration of pollution, customs, and populations. (MCO)

McLure, John W.

1991-01-01

8

Modeling rock weathering in small watersheds  

NASA Astrophysics Data System (ADS)

Many mountainous watersheds are conceived as aquifer media where multiple groundwater flow systems have developed (Tóth, 1963), and as bimodal landscapes where differential weathering of bare and soil-mantled rock has occurred (Wahrhaftig, 1965). The results of a weathering algorithm (Pacheco and Van der Weijden, 2012a, 2014), which integrates topographic, hydrologic, rock structure and chemical data to calculate weathering rates at the watershed scale, validated the conceptual models in the River Sordo basin, a small watershed located in the Marão cordillera (North of Portugal). The coupling of weathering, groundwater flow and landscape evolution analyses, as accomplished in this study, is innovative and represents a remarkable achievement towards regionalization of rock weathering at the watershed scale. The River Sordo basin occupies an area of approximately 51.2 km2 and was shaped on granite and metassediment terrains between the altitudes 185-1300 m. The groundwater flow system is composed of recharge areas located at elevations >700 m, identified on the basis of ?18O data. Discharge cells comprehend terminations of local, intermediate and regional flow systems, identified on the basis of spring density patterns, infiltration depth estimates based on 87Sr/86Sr data, and spatial distributions of groundwater pH and natural mineralization. Intermediate and regional flow systems, defined where infiltration depths >125 m, develop solely along the contact zone between granites and metassediments, because fractures in this region are profound and their density is very large. Weathering is accelerated where rocks are covered by thick soils, being five times faster relative to sectors of the basin where rocks are covered by thin soils. Differential weathering of bare and soil-mantled rock is also revealed by the spatial distribution of calculated aquifer hydraulic diffusivities and groundwater travel times.

Pacheco, Fernando A. L.; Van der Weijden, Cornelis H.

2014-05-01

9

Building Stone and Its Use in Rock Weathering Studies.  

ERIC Educational Resources Information Center

Building stone provides opportunities for geological study of weathering of different rocks in a particular environment and similar rocks in different environment. The principle studied can be applied on a large scale from the observation of small-scale weathering. Examples of weathering are drawn mainly from the Sydney region of Australia. (RE)

Dragovich, Deirdre

1979-01-01

10

Take a Tumble: Weathering and Erosion Using a Rock Tumbler  

ERIC Educational Resources Information Center

Weathering--the physical and chemical breakdown of geologic materials--and erosion--the transport of materials by wind, water, or ice--can be subtle, yet powerful forces. For example, shale, a rock made of mud-sized particles, is by far the most common sedimentary rock, a testament to the ability of weathering and erosion to take a rock and reduce…

Coffey, Patrick; Mattox, Steve

2006-01-01

11

Water Rock Interaction [WRI 14] Chemical weathering of granitic rocks: experimental approach and Pb-Li  

E-print Network

Water Rock Interaction [WRI 14] Chemical weathering of granitic rocks: experimental approach and Pb of water/rock interactions both in terms of source and extent of weathering, by measuring major and trace elements as well as Pb and Li isotope signatures. Keywords: weathering; granite; Pb isotopes; Li isotopes 1

Paris-Sud XI, Université de

12

Draft Genome Sequence of Rhizobium sp. H41, a Rock-Weathering Bacterium from a Weathered Rock Surface.  

PubMed

Rhizobium sp. H41 isolated from weathered tuff can weather tuff and release Fe, Si, and Al from the rock under nutrient-poor conditions. Here, we report the draft genome sequence of strain H41, which may facilitate a better understanding of the molecular mechanism involved in rock weathering by the bacterium. PMID:25377707

Xi, Jun; Sheng, Xiafang; He, Linyan

2014-01-01

13

Draft Genome Sequence of Rhizobium sp. H41, a Rock-Weathering Bacterium from a Weathered Rock Surface  

PubMed Central

Rhizobium sp. H41 isolated from weathered tuff can weather tuff and release Fe, Si, and Al from the rock under nutrient-poor conditions. Here, we report the draft genome sequence of strain H41, which may facilitate a better understanding of the molecular mechanism involved in rock weathering by the bacterium. PMID:25377707

Xi, Jun; He, Linyan

2014-01-01

14

Science Sampler: Chemical weathering--Where did the rocks go?  

NSDL National Science Digital Library

This lesson is part of a larger Earth science unit that combines the concepts of the rock cycle and the water cycle and how they interact to change landforms. The authors refer to it as the "make it and then break it" unit. They spend half the unit making metamorphic, sedimentary, and igneous rock models, and the second half of the unit weathering and eroding their models and other rocks. Students use the lessons learned to answer an open-ended question describing the process of weathering. They also make decisions regarding the chemical and mechanical weathering on monuments and buildings.

Carolyn Wallace

2008-10-01

15

Physical and chemical weathering. [of Martian surface and rocks  

NASA Technical Reports Server (NTRS)

Physical and chemical weathering processes that might be important on Mars are reviewed, and the limited observations, including relevant Viking results and laboratory simulations, are summarized. Physical weathering may have included rock splitting through growth of ice, salt or secondary silicate crystals in voids. Chemical weathering probably involved reactions of minerals with water, oxygen, and carbon dioxide, although predicted products vary sensitively with the abundance and physical form postulated for the water. On the basis of kinetics data for hydration of rock glass on earth, the fate of weathering-rind formation on glass-bearing Martian volcanic rocks is tentatively estimated to have been on the order of 0.1 to 4.5 cm/Gyr; lower rates would be expected for crystalline rocks.

Gooding, James L.; Arvidson, Raymond E.; Zolotov, Mikhail IU.

1992-01-01

16

Weathering  

NSDL National Science Digital Library

This course handout covers the processes and effects of weathering. The purpose of this handout is to contrast weathering and erosion, contrast and discuss chemical and mechanical weathering, list the products resulting from the chemical weathering of igneous rocks, and list and discuss the factors that influence the type and rate of rock weathering. Many photographs accompany this summary which depict weathered landscapes. Links are provided to the online Physical Geology resources at Georgia Perimeter College.

Pamela Gore

1995-08-29

17

Take a Tumble: Weathering and Erosion Using a Rock Tumbler  

NSDL National Science Digital Library

The subtle effects of weathering and erosion are difficult to convey to students. However, through this activity, students can use a rock tumbler to gain a personal and scientific perspective on weather and erosion. Students have the opportunity to demonstrate their understanding of these concepts and work with geologic materials as they make predictions and measurements, record data, and do simple calculations (McKnight 1989).

Patrick Coffey

2006-03-01

18

Weathering and Erosion: Simulating Rock Attack in the Lab  

NSDL National Science Digital Library

These activities examine the ways in which water can weather rocks. Simulations of erosion by running water, solution, freezeâthaw and by wind are investigated. Several class laboratory and demonstration activities simulate some of the processes occurring in weathering and erosion. They include a look at the effect of pouring water onto brown sugar to simulate the effect of water on soluble rock, observing the residue left after water samples have evaporated to show that water can dissolve minerals, showing that water expands on freezing by placing a sealed jar of water in the freezer overnight, and inspection of the effect of freezing on a water-soaked sample of porous rock. In addition, an activity simulates the effect of water impact on rocks by pouring water on sand and another uses a hair dryer to simulate wind erosion by sandblasting copper sulfate crystals.

19

Confined groundwater zone and slope instability in weathered igneous rocks in Hong Kong  

E-print Network

Confined groundwater zone and slope instability in weathered igneous rocks in Hong Kong Jiu J conductivity (K) of weathered igneous rocks decreases with depth or as the rock mass becomes less weathered igneous rocks, if significantly kaolinized, may have low permeability and behave as a confining zone

Jiao, Jiu Jimmy

20

Subsurface Weathering of Rocks and Soils at Gusev Crater  

NASA Technical Reports Server (NTRS)

Data collected by the Mars Exploration Rover (MER) Spirit at Gusev Crater suggest that enhanced weathering of rocks and soils occurs beneath the immediate surface. We suggest that this alteration occurs over geological timescales under present climatic conditions and is a result of diurnal condensation of thin-films of water on subsurface materials. Additional information is included in the original extended abstract.

Yen, A. S.; Ming, D. W.; Gellert, R.; Clark, B. C.; Morris, R. V.; Rodionov, D.; Schroeder, C.

2005-01-01

21

Association of trace elements with iron oxides during rock weathering  

SciTech Connect

The association of trace elements with Fe oxides during the early stages of rock weathering was determined by analysis of fresh diabase and granite rocks, their associated whole and size-separated saprolites, and goethite by neutron activation and X-ray fluorescence. The same elements are found to be associated with Fe oxides when the results are interpreted by analysis of correlation, by the distribution of elements in the various size fractions by the effects of removing free Fe oxides, and by direct analysis of geothite from the saprolite. The elements Co, Cr, Mn, Sc, Th, U, Zn, and the heavy rare-earth elements during the weathering of diabase, and As, Co, Cr, Sc, Th, U, Zn, and the heavy rare-earth elements during the weathering of granite are associated with Fe oxides. The concentrations of Mn are too low in this system to separate the effects of Mn oxides from those of Fe oxides.

Koons, R.D.; Helmke, P.A.; Jackson, M.L.

1980-01-01

22

Cracks in desert pavement rocks: Further insights into mechanical weathering by directional insolation  

E-print Network

Cracks in desert pavement rocks: Further insights into mechanical weathering by directional August 2010 Keywords: Desert pavements Physical weathering Desert geomorphology Insolation weathering Fractures The formation of cracks is a fundamental first step in the physical weathering of rocks in desert

Ahmad, Sajjad

23

Rock Rinds at Meridiani and Surface Weathering Phenomena  

NASA Astrophysics Data System (ADS)

The Rock Abrasion Tool (RAT) on the Mars rover Opportunity can brush away surface dust and grind away outcrop surface, exposing presumably less altered rock at depths of several mm. Alpha particle X-ray spectrometer (APXS) and Moessbauer spectrometer (MB) analyses of pre- and post-RAT targets, thus, provide information on the chemical nature of weathering of Meridiani outcrop rocks. To date, Opportunity has analyzed some 25 undisturbed rock surfaces, brushed and then analyzed 7 more, and ground 23 targets for IDD analysis. Panoramic camera images show that outcrop surfaces are typically either buff or purple (as viewed in bands centered at 673, 535, and 432 nm, Farrand et al., JGR, in press). Relatively flat surfaces that are approximately parallel to the ground are typically buff, whereas those that slope steeply tend to be purple. Surfaces of rock interiors ground by the RAT are also commonly purple. Spectrally, these color differences correspond to more oxidized (buff) and less oxidized (purple), and appear to relate to the degree of eolian abrasion. Flat-lying surfaces are not eroded as quickly, thus surfaces chemically weathered by exposure to tenuous atmospheric vapor may be preserved. These observations are consistent with in-situ analyses of rock surfaces and interiors. Compared to interiors, rock surfaces have about 1/3 less S, and in general, surface compositions lie between those of rock interiors and average surface soil. In detail, they differ from soil-rock mixtures as follows: surfaces are relatively depleted in Mg, Fe, Mn, Ti, and Cr, and they are enriched in Al, Na, K, P, Cl, and Si. From MB analyses, surfaces are richer (compared to soil-rock mixtures) in oxidized Fe phases and poorer in magnetite, olivine, and pyroxene. Morphologically, numerous flat-lying rocks and outcrop surfaces that are at or near the ground surface have a rind of erosionally resistant material. Such rinds are also chemically distinct from outcrop interiors. A rind/subjacent rock pair analyzed in detail was "Lemon Rind" and "Strawberry," ca. sols 555-560. The rind is depleted in S (balanced mainly by increased Si and Al) and, compared to a soil-rock mixture, it is depleted in Mg, Ti, Cr, Mn, and slightly in Fe, and it is enriched in Na, Cl, K, and P. Differences between rock surfaces and interiors, and between hardened weathering rinds and rock interiors, are consistent with loss of Mg-sulfate, oxidation of mafic minerals, enrichment of siliciclastic material, e.g., feldspar, and enrichment in chloride. These changes are consistent with slow rates of chemical weathering via interaction with small amounts of atmospheric water vapor or condensation. Erosionally resistant rinds may be related to preservation of aqueous condensate by a thin cover of soil on flat, near-surface rocks.

Jolliff, B.; Knoll, A.; Farrand, W.; Sullivan, R.

2006-12-01

24

Weathered stony meteorites from Victoria Land, Antarctica, as possible guides to rock weathering on Mars  

NASA Technical Reports Server (NTRS)

Parallel studies of Martian geomorphic features and their analogs on Earth continue to be fruitful in deciphering the geologic history of Mars. In the context of rock weathering, the Earth-analog approach is admirably served by the study of meteorites recovered from ice sheets in Antarctica. The weathering environment of Victoria Land possesses several Mars-like attributes. Four of the five Antarctic meteorites being studied contain rust and EETA79005 further possesses a conspicuous, dark, weathering rind on one side. Secondary minerals (rust and salts) occur both on the surfaces and interiors of some of the samples and textural evidence indicates that such secondary mineralization contributed to physical weathering (by salt riving) of the rocks. Several different rust morphologies occur and emphasis is being placed on identifying the phase compositions of the various rust occurrances. A thorough understanding of terrestrial weathering features of the meteorites is a prerequisite for identifying possible Martian weathering features (if such features exist) that might be postulated to occur in some meteorites.

Gooding, J. L.

1984-01-01

25

Space Weathering of Lunar Rocks and Regolith Grains  

NASA Technical Reports Server (NTRS)

The exposed surfaces of lunar soil grains and lunar rocks become modified and coated over time with a thin rind of material (patina) through complex interactions with the space environment. These interactions encompass many processes including micrometeorite impacts, vapor and melt deposition, and solar wind implantation/sputtering effects that collectively are referred to as "space weathering". Studies of space weathering effects in lunar soils and rocks provide important clues to understanding the origin and evolution of the lunar regolith as well as aiding in the interpretation of global chemical and mineralogical datasets obtained by remote-sensing missions. The interpretation of reflectance spectra obtained by these missions is complicated because the patina coatings obscure the underlying rock mineralogy and compositions. Much of our understanding of these processes and products comes from decades of work on remote-sensing observations of the Moon, the analysis of lunar samples, and laboratory experiments. Space weathering effects collectively result in a reddened continuum slope, lowered albedo, and attenuated absorption features in reflectance spectra of lunar soils as compared to finely comminuted rocks from the same Apollo sites. Space weathering effects are largely surface-correlated, concentrated in the fine size fractions, and occur as amorphous rims on individual soil grains. Rims on lunar soil grains are highly complex and span the range between erosional surfaces modified by solar wind irradiation to depositional surfaces modified by the condensation of sputtered ions and impact-generated vapors. The optical effects of space weathering effects are directly linked to the production of nanophase Fe metal in lunar materials]. The size of distribution of nanophase inclusions in the rims directly affect optical properties given that large Fe(sup o) grains (approx 10 nm and larger) darken the sample (lower albedo) while the tiny Fe(sup o) grains (<5nm) are the primary agent in spectral "reddening". More recent work has focused on the nature and abundance of OH/H2O in the lunar regolith using orbital data and samples analyses. Advances in sample preparation techniques have made possible detailed analyses of patina-coated rock surfaces. Major advances are occurring in quantifying the rates and efficiency of space weathering processes through laboratory experimentation.

Keller, L. P.

2013-01-01

26

Controls on the Development of Rock Weathering Pits  

NSDL National Science Digital Library

Weathering pits are well known from granite terrains and they also form in metaquartzite along the Blue Ridge Parkway in North Carolina. We will drive to Flat Rock Trail, along the Blue Ridge Parkway near Linville, NC. After a short hike up the trail we will observe the weathering pits exposed on the bedrock surface overlooking the Linville Valley. Each group of students will write down 3 hypotheses for how and why they form. Consider what factors control the size and shape of the pits. Collect data that can be used to test the hypotheses including orientation, size, and shape. Plot the data collected in the field. Present data on graphs and charts. Do trends in the data support one hypothesis over another? Designed for a geomorphology course

Cowan, Ellen

27

Weathering of expansive sedimentary rock due to cycles of wetting and drying  

Microsoft Academic Search

There are several different mechanisms by which sedimentary rock can weather, such as: (1) Rebound: for cut areas, where the overburden has been removed by erosion or during mass-grading operations, the sedimentary rock will rebound due to the release in overburden pressure, the rebound can cause the opening or widening of cracks and joints; (2) Physical Weathering: sedimentary rock can

Day

1994-01-01

28

Investigating sedimentary rock deposition and weathering in Mawikwe Bay Sea Caves  

NSDL National Science Digital Library

A field investigation to the Mawikwe Bay Sea Caves of northern Wisconsin along Lake Superior in the winter. Students will investigate deposition of sedimentary rocks and weathering of the rocks to produce sea caves.

29

Rock weathering processes and landform development in the Sør Rondane Mountains, Antarctica  

NASA Astrophysics Data System (ADS)

Field observations of weathering processes and the related landforms, combined with laboratory analyses of weathering products, permit a synthetic evaluation of Late Cenozoic weathering environments in the Sør Rondane Mountains, Antarctica, an arid upland characterized by low temperatures and strong winds. Rates and character of weathering depend mainly on moisture availability and the bedrock geology. Under the humid weathering regime that occurs only locally around the margin of the present sheet, frequent diurnal freeze-thaw cycles in summer cause relatively rapid rock fragmentation. Most of the mountains are situated in the arid weathering regime, under which rock breakdown is very slow unless the rock contains plenty of salts. Salt weathering becomes more intensive and extensive with exposure age, as a result of salt accumulation in rock, eventually producing soils as small as fine-silt size. Lack of clay mineralization even in weathered rocks having been exposed above the ice sheet prior to 4 Ma ago indicates that hydrolysis or carbonation of rock minerals has been insignificant during the past 4 Ma. The final products of weathering are due mainly to salt action and reflect the parent lithology. Resistant fine-grained granite forms strongly oxidized tors carved with tafoni, or fields of mushroom-like boulders overlying the fractured bedrock. Less resistant rocks, like biotite gneiss and amphibolite, produce stone pavements underlain by saline, silty soils up to 30-40 cm thick, the thickness of which corresponds to the maximum thaw depth.

Matsuoka, Norikazu

1995-07-01

30

Generalized soil thaumarchaeota community in weathering rock and saprolite.  

PubMed

Relatively little is known of the archaeal communities associated with endolithic environments, compared to other microbial groups such as bacteria and fungi. Analyzing the pyrosequenced archaeal 16S ribosomal RNA (rRNA) gene V1-V3 region, we investigated the archaeal community associated with aboveground-exfoliated weathering layers of a granite gneiss, and of the saprolite derived from this rock at 1 m depth below the soil surface, in a forested hilly area south of Seoul, South Korea. In both these sites, an archaeal community dominated by the phylum Thaumarchaeota was identified. The archaeal community in all cases closely resembled that of the surface layer of acidic soils in temperate climates of Korea. It appears that there is no clear distinction in archaeal community composition between a soil and a rock and a saprolite despite a tremendous difference in the concentration of total nitrogen and organic carbon. Of the chemical properties we measured, pH was the best predictor of the archaeal community composition and relative abundance of thaumarchaeal subphyla. These findings reinforce the view that soil archaea are mostly generalists, whose ecology is not closely dependent on nitrogen concentration or soil organic matter status, the presence of living roots, or the abundant presence of any other biota. PMID:25370886

Dong, Ke; Kim, Woo-Sung; Tripathi, Binu Mani; Adams, Jonathan

2015-02-01

31

Chemical weathering of granitic rock: experiments and Pb-Li isotopes tracing Romain Millot  

E-print Network

Chemical weathering of granitic rock: experiments and Pb-Li isotopes tracing Romain Millot Philippe shown that most of the lead in the groundwaters is of geogenic origin. Combining a weathering model and field observations, we were able to define a two-step weathering process that includes a control

Paris-Sud XI, Université de

32

Antarctic glaciers and rock weathering: Exploring chemical and mineralogy processes within the blue ice fields  

E-print Network

Antarctic glaciers and rock weathering: Exploring chemical and mineralogy processes within the blue, and precipitation of weathering products (e.g. magnesium carbonates and iron oxyhydroxides, or `rust'), is highly into a virtue by using weathering products to unlock the information that contain regarding the mechanisms

Guo, Zaoyang

33

Field Guide to Rock Weathering. Earth Science Curriculum Project Pamphlet Series PS-1.  

ERIC Educational Resources Information Center

Highlighted are the effects of weathering through field investigations of the environment, both natural rocks, and the urban environment's pavements, buildings, and cemeteries. Both physical weathering and chemical weathering are discussed. Questions are presented for post-field trip discussion. References and a glossary are provided. (Author/RE)

Boyer, Robert E.

34

Chitinophaga qingshengii sp. nov., isolated from weathered rock surface.  

PubMed

A novel type of mineral-weathering bacterium was isolated from weathered rock (potassic trachyte) surfaces collected from Nanjing (Jiangsu, China). Cells of strain JN246T were Gram-stain-negative, rod-shaped, and non-motile. Strain JN246T was aerobic, catalase- and oxidase-positive, and grew optimally at 28 °C and pH 7.0. On the basis of 16S rRNA gene sequence analysis, strain JN246T belonged to the genus Chitinophaga and the closest phylogenetic relatives were Chitinophaga eiseniae YC6729T (98.5 %), Chitinophaga terrae KP01T (96.8 %), and Chitinophaga jiangningensis JN53T (96.3 %). The major respiratory quinine was MK-7 and the major polyamine was homospermidine. The major fatty acids were iso-C15:0, C16:1?5c, C16:0, iso-C17:0 3-OH, iso-C15:0 3-OH, C14:O, C16:0 3-OH, C16:1?7c and/or C16:1?6c (summed feature 3), and C13:1. The polar lipid profile of strain JN246T consisted of phosphatidylethanolamine, unknown aminolipids and unknown lipids. The genomic DNA G + C content of strain JN246T was 48.8 mol%. Based on the low level of DNA-DNA relatedness (ranging from 22.6 % to 42.4 %) to these type strains of species of the genus Chitinophaga and unique phenotypic characteristics, strain JN246T represents a novel species of the genus Chitinophaga, for which the name Chitinophaga qingshengii sp. nov. is proposed. The type strain is JN246T (= CCTCC AB 2014201 T= JCM 30026 T). PMID:25342110

Cheng, Cheng; Wang, Qi; He, Lin-Yan; Huang, Zhi; Sheng, Xia-Fang

2014-10-23

35

Development of unusual rock weathering features in the Cordillera Blanca, Peru  

NASA Astrophysics Data System (ADS)

Mylonite textures in granodiorite boulders are responsible for higher rates of surface denudation of host rocks and the progressive development of unusual rock weathering features, termed weathering posts. These textures are characterized by smaller grain sizes, higher biotite content, and a higher biotite axial ratio in host rocks relative to weathering posts. Elemental concentrations do not show a significant difference between weathering posts and the host rocks in which they are found, and this reflects the absence of a weathering residue on the rock surfaces. Chemical weathering loosens the bonds between mineral grains through the expansion of biotite, and the loosened grains fall off or are blown off the boulder surface and continue their chemical alteration in the surrounding soil. The height of weathering posts on late Quaternary moraines increases at a linear rate of ~ 1.45 ± 0.45 cm (1000 yr)- 1 until post heights reach the diameter of host rocks. Such a rate of boulder denudation, if unrecognized, would generate significant errors (> 20%) in cosmogenic exposure ages for Pleistocene moraines. Given the paucity of boulders with diameters that significantly exceed 1.5 m, the maximum age of utility of weathering posts as a numeric age indicator is ~ 100 ka.

Rodbell, Donald T.; Frey, Holli M.; Manon, Matthew R. F.; Smith, Jacqueline A.; McTurk, Nicholas A.

2012-01-01

36

The Hole as a Whole: Geological and Microbiological Features of Rock Weathering in Arid and Hyper-Arid Environments  

E-print Network

The Hole as a Whole: Geological and Microbiological Features of Rock Weathering in Arid and Hyper, Kibbutz Qetura, Hevel Eilot 88840, Israel A variety of rock weathering patterns and morphologies were and honeycomb weathering). Many studies attempted to explain the weathering morphology and mechanism. Yet

Simon, Emmanuel

37

Weathering grade of rock masses as a predisposing factor to slope instabilities: Reconnaissance and control procedures  

NASA Astrophysics Data System (ADS)

Weathering of rock masses often assumes importance as a predisposing factor to slope instability and it is possible to map it at various scales depending on the different purposes. The effects of weathering processes are particularly intense on crystalline rocks (plutonic and metamorphic). These rocks are present in large areas of the globe and widespread in Calabria. The relationships between rock mass weathering grades and slope instabilities are analysed, with reference to sectors (1:50,000 scale) and areas (1:10,000 scale) where crystalline rocks are strongly affected by weathering. To this aim a reconnaissance procedure has been proposed to delimitate the zones with different weathering condition, three macro-classes at average scale (1:50,000) and six classes at detail scale (1:10,000). In this procedure first analysis of aerial photos and then field observations of representative situations have been used. The reconnaissance procedure has been verified in a selected study area (Acri), whose geological features are provided, by the comparison with weathering maps obtained by means of a control procedure. This last procedure consists of observations and index tests carried out in check points located in representative check sites (discolouration, sound when struck by geological hammer, effect of the point of geological pick, breaking with the hands, rebound of Schmidt Hammer, grain-size analysis). The results obtained confirm through quantitative data that the weathering of a rock mass can be assumed as a predisposing factor to slope instability. At average scale (1:50,000) the reconnaissance procedure is able to give weathering maps representative for this type of evaluation (the ratio between the landslides area in each weathering macro-class and the whole landslide area goes from 67% to 14% for the macro-class A and from 24% to 9% for the macro-class B); at detail scale (1:10,000) it is necessary to use a control procedure to obtain weathering maps indicative of predisposition to slope instabilities.

Borrelli, L.; Greco, R.; Gullà, G.

2007-06-01

38

An Examination of the Space Weathering Patina of Lunar Rock 76015  

NASA Technical Reports Server (NTRS)

Space weathering discussions have generally centered around soils but exposed rocks will also incur the effects of weathering. Rocks have much longer surface lifetimes than an individual soil grain and thus record a longer history of exposure. By studying the weathering products which have built up on a rock surface, we can gain a deeper perspective on the weathering process and better assess the relative importance of various weathering components. The weathered coating, or patina, of the lunar rock 76015 has been previously studied under SEM and also by TEM using ultramicrotome sample preparation methods. However, to really understand the products involved in creating these coatings, it is helpful to examine the patina in cross section, something which is now possible though the use of Focused Ion Beam (FIB) sample prep techniques, which allows us to preserve intact the delicate stratigraphy of the patina coating and provides a unique cross-sectional view of the space weathering process. Several samples have been prepared from the rock and the coatings are found to be quite variable in thickness and composition from one sample to the next.

Noble, S.; Chrisoffersen, R.; Rahman, Z.

2011-01-01

39

Storage and release of fossil organic carbon related to weathering of sedimentary rocks  

E-print Network

Storage and release of fossil organic carbon related to weathering of sedimentary rocks Yoann of various mineral and organic carbon forms. Among these carbon forms, fossil organic carbon (FOC) (i basins; weathering; fossil organic carbon flux; fossil organic carbon storage #12;1. Introduction Fossil

Paris-Sud XI, Université de

40

The effect of rock composition on cyanobacterial weathering of crystalline basalt and rhyolite.  

PubMed

The weathering of volcanic rocks contributes significantly to the global silicate weathering budget, effecting carbon dioxide drawdown and long-term climate control. The rate of chemical weathering is influenced by the composition of the rock. Rock-dwelling micro-organisms are known to play a role in changing the rate of weathering reactions; however, the influence of rock composition on bio-weathering is unknown. Cyanobacteria are known to be a ubiquitous surface taxon in volcanic rocks. In this study, we used a selection of fast and slow growing cyanobacterial species to compare microbial-mediated weathering of bulk crystalline rocks of basaltic and rhyolitic composition, under batch conditions. Cyanobacterial growth caused an increase in the pH of the medium and an acceleration of rock dissolution compared to the abiotic controls. For example, Anabaena cylindrica increased the linear release rate (R(i)(l)) of Ca, Mg, Si and K from the basalt by more than fivefold (5.21-12.48) and increased the pH of the medium by 1.9 units. Although A. cylindrica enhanced rhyolite weathering, the increase in R(i)(l) was less than threefold (2.04-2.97) and the pH increase was only 0.83 units. The R(i)(l) values obtained with A. cylindrica were at least ninefold greater with the basalt than the rhyolite, whereas in the abiotic controls, the difference was less than fivefold. Factors accounting for the slower rate of rhyolite weathering and lower biomass achieved are likely to include the higher content of quartz, which has a low rate of weathering and lower concentrations of bio-essential elements, such as, Ca, Fe and Mg, which are known to be important in controlling cyanobacterial growth. We show that at conditions where weathering is favoured, biota can enhance the difference between low and high Si-rock weathering. Our data show that cyanobacteria can play a significant role in enhancing rock weathering and likely have done since they evolved on the early Earth. PMID:22694082

Olsson-Francis, K; Simpson, A E; Wolff-Boenisch, D; Cockell, C S

2012-09-01

41

Microbial populations and activities in the rhizoplane of rock-weathering desert plants. I. Root colonization and weathering of igneous rocks.  

PubMed

Dense layers of bacteria and fungi in the rhizoplane of three species of cactus (Pachycereus pringlei, Stenocereus thurberi, Opuntia cholla) and a wild fig tree (Ficus palmeri) growing in rocks devoid of soil were revealed by bright-field and fluorescence microscopy and field emission scanning electron microscopy. These desert plants are responsible for rock weathering in an ancient lava flow at La Purisima-San Isidro and in sedimentary rock in the Sierra de La Paz, both in Baja California Sur, Mexico. The dominant bacterial groups colonizing the rhizoplane were fluorescent pseudomonads and bacilli. Seven of these bacterial species were identified by the 16S rRNA molecular method. Unidentified fungal and actimomycete species were also present. Some of the root-colonizing microorganisms fixed in vitro N(2), produced volatile and non-volatile organic acids that subsequently reduced the pH of the rock medium in which the bacteria grew, and significantly dissolved insoluble phosphates, extrusive igneous rock, marble, and limestone. The bacteria were able to release significant amounts of useful minerals, such as P, K, Mg, Mn, Fe, Cu, and Zn from the rocks and were thermo-tolerant, halo-tolerant, and drought-tolerant. The microbial community survived in the rhizoplane of cacti during the annual 10-month dry season. This study indicates that rhizoplane bacteria on cacti roots in rock may be involved in chemical weathering in hot, subtropical deserts. PMID:15375735

Puente, M E; Bashan, Y; Li, C Y; Lebsky, V K

2004-09-01

42

Probing the Depths of Space Weathering: A Cross-sectional View of Lunar Rock 76015  

NASA Technical Reports Server (NTRS)

The term "space weathering" refers to the cumulative effects of several processes operating at the surface of any solar system body not protected by a thick atmosphere. These processes include cosmic and solar ray irradiation, solar wind implantation and sputtering, as well as melting and vaporization due to micrometeorite bombardment. Space weathering discussions have generally centered around soils but exposed rocks will also incur the effects of weathering. Rocks have much longer surface lifetimes than an individual soil grain and thus record a longer history of exposure. By studying the weathering products which have built up on a rock surface, we can gain a deeper perspective on the weathering process and better assess the relative importance of various weathering components. The weathered coating, or patina, of the lunar rock 76015 has been previously studied using SEM and TEM. It is a noritic breccia with both "glazed" (smooth glassy) and "classic" (microcratered and pancake-bearing) patina coatings. Previous TEM work on 76015 relied on ultramicrotomy to prepare cross sections of the patina coating, but these sections were limited by the "chatter" and loss of material in these brittle samples. Here we have used a focused ion beam (FIB) instrument to prepare cross sections in which the delicate stratigraphy of the patina coating is beautifully preserved.

Noble, Sarah K.; Keller, L. P.; Stroud, Rhonda

2007-01-01

43

Uranium thorium chronometry of weathering rinds: Rock alteration rate and paleo-isotopic record of weathering fluids  

NASA Astrophysics Data System (ADS)

The potential of 238U- 234U- 230Th chronometry for constraining the formation rate of weathering rinds developed on fresh rocks is assessed by analyzing a weathering rind on a basaltic clast from a 125 kyr old Costa Rican alluvial terrace. Eighteen subsamples were collected from one section of the clast by drilling cores (4 mm in diameter and 5 mm depth) along two transects straddling the core-rind boundary. Variations of major and trace element concentrations along the two transects point out (a) intense loss of alkaline and alkaline-earth elements, (b) conservative behaviour of elements such as Zr, Hf and Th, and (c) external input of U into the rind without any evidence of U loss during basalt weathering. In addition, variations in U concentrations along the transects show that the main U-Th fractionation process associated with the weathering of the basaltic clast is an external input of U (without addition nor loss of Th) in the basalt rind transition zone, and that, once deposited U is immobile in the weathering rind. In the frame of this interpretation scheme, a weathering rate of 0.5 ± 0.2 mm/kyr can be calculated for the studied clast, which is consistent with geological and isotopic evidence constraining the depositional ages of the terraces. In addition, the variations in the ( 234U/ 238U) ratio along the analysed transects as well as the increase in Sr isotopic ratios within the weathering rind are best explained by temporal variation of the U activity ratios and Sr isotope ratios of the soil solutions brought into the rind. This work highlights how well detailed U-Th chronological studies of weathering rinds can (1) constrain the formation rates of weathering systems, and (2) record the time variation of isotopic composition of weathering fluids.

Pelt, E.; Chabaux, F.; Innocent, C.; Navarre-Sitchler, A. K.; Sak, P. B.; Brantley, S. L.

2008-11-01

44

[Role of microscopic fungi in the process of weathering of pegmatite deposit rocks and minerals].  

PubMed

The object of this work was to study the effect of microscopic fungi isolated from the weathering zone of a pegmatite deposit on the transport of elements and the degradation of rocks and minerals. Regardless of the chemical composition of rocks and minerals, microscopic fungi accelerated the leaching of elements as compared to the purely chemical process. The extraction of Li, Si, Al and Fe under the action of microorganisms increased by factors of 1.4-1.7, 2.7-4.0, 5.0-8.7 and 4-18, respectively. In the case of chemical weathering, the extraction of elements occurred at a high rate only at the beginning; then the process either decelerated or stopped. The mechanism of action of microscopic fungi on rocks and minerals is discussed as well as the role of these microorganisms in the weathering of spodumene and the surrounding rocks, pegmatites an shales, which occurs in the zone of hypergenesis. PMID:7194415

Avakian, Z A; Karavaiko, G I; Mel'nikova, E O; Krutsko, V S; Ostroushko, Iu I

1981-01-01

45

Chitinophaga longshanensis sp. nov., a mineral-weathering bacterium isolated from weathered rock.  

PubMed

A Gram-stain-negative, aerobic, yellow-pigmented, non-motile, non-spore-forming, rod-shaped bacterial strain, Z29T, was isolated from the surface of weathered rock (potassic trachyte) from Nanjing, Jiangsu Province, PR China. Phylogenetic analysis based on 16S rRNA gene sequences suggested that strain Z29T belongs to the genus Chitinophaga in the family Chitinophagaceae. The similarities of the 16S rRNA gene sequence between strain Z29T and other type strains of established species in the genus Chitinophaga ranged from 92.7 to 98.2%. The main fatty acids of strain Z29T were iso-C15:0, C16:0, iso-C13:0 and iso-C17:0. It also contained menaquinone 7 (MK-7) as the major respiratory quinone and homospermidine as the main polyamine. The polar lipid profile contained phosphatidylethanolamine, unknown aminolipids, unknown phospholipids, and unknown glycolipids. The total DNA G+C content of strain Z29T was 51.3 mol%. Phenotypic properties and chemotaxonomic data supported the affiliation of strain Z29T with the genus Chitinophaga. The low level of DNA-DNA relatedness (ranging from 14.6% to 29.8%) to other species of the genus Chitinophaga and the many phenotypic properties demonstrated that strain Z29T should represent a novel species of the genus Chitinophaga, for which the name Chitinophaga longshanensis sp. nov. is proposed. The type strain is Z29T (= CCTCC AB 2014066 T= LMG 28237 T). PMID:25376849

Gao, Shan; Zhang, Wen-Bin; Sheng, Xia-Fang; He, Lin-Yan; Huang, Zhi

2014-11-01

46

Changes in the weathering of rock surfaces in different geomorphological environments: glacial, nival and coastal.  

NASA Astrophysics Data System (ADS)

The sclerometer or Schmidt Rock Test Hammer has been broadly applied in geomorphology to estimate the strength of different rock types and to measure the degree of rock weathering. It has been proved that for a rock type, the rebound values are lower in weathered than in fresh rock surfaces. This evidence suggests that if there is any factor that causes a gradual change in the weathering degree, it must be possible to identify a distinctive tendency with the sclerometer. There are two types of factors that can cause gradual changes in the weathering degree. First, those related with the time of exposure of a rock surface, which are the basis of works that attempt to use the sclerometer as a tool for relative chronology. Second, those related with the frequency or duration at which the weathering agents operate, which are the basis for the studies focused on the efficacy of weathering. In both cases it is essential to understand how the factors of weathering are spatially distributed in order to achieve a good sampling procedure. We applied the sclerometer in three different environments: rock coasts, glacially exposed surfaces and rock surfaces subjected to nival processes. The sclerometer was used in a receding glacier in Tierra de Fuego, Argentina, assuming that the rock surface must be more weathered as more time passed since the exposure. The hypothesis was confirmed by the negative correlation between rebound values and the distance to the glaciar front. In rocky coasts, it was proved by field and laboratory data that one of the main factors responsible for variations in rock strength is the degree of weathering by tidally-induced wetting and drying. We found negative correlations between rebound values and tidal elevation in very different coastal environments in the NW of Spain and in the Beagle Channel. We also found that the absence of this relationship may be caused by processes of mechanical erosion, but they also can respond to disequilibrium of the intertidal surfaces with tidal range. The research on nival processes was conducted in an ancient glacial cirque in the western mountains of Galicia (NW Spain). The hypothesis here was that weathering degree of rock surface is related with the abrasion produced when a late-lying snow cover slides in the spring. The frequency and extent to which abrasion and other erosional processes take place depends mainly on the thickness of the snow accumulated in a rock wall. Therefore, the rock surfaces are more weathered as frequency and intensity of abrasion decreases with the distance to the rock wall. The experience in three different types of environment suggests that when the sclerometer is used to measure the weathering degree, the sampling method arises as one of the most important factors. The distribution of the sampling points must respond to the characteristics of each area, which needs a previous understanding of the processes and factors responsible of the variations in the degree of weathering. Aknowledgements This work was supported by the research projects GL2004-3380/BOS (Ministerio de Educación y Ciencia) and PGIDIT06PXIB239226PR and PGDIT05PXIC21001PN (Xunta de Galicia). A. Feal Pérez is supported by the grant AP2006-03854

Feal-Pérez, A.; Blanco-Chao, R.; Pérez-Alberti, A.; López-Bedoya, J.; Valcárcel-Díaz, M.

2009-04-01

47

Geoelectric investigations into sandstone moisture regimes: Implications for rock weathering and the deterioration of San Rock Art in the Golden Gate Reserve, South Africa  

NASA Astrophysics Data System (ADS)

The Clarens sandstone in the Golden Gate Reserve, South Africa, is the canvas for a collection of San (Bushmen) Rock Art, dating from Neolithic times until as recently as 150 years ago. This Rock Art is under threat from human interference but also, to a greater degree, from weathering processes on the rock surface. The dominant weathering processes occurring in the rock shelters which host the Rock Art are flaking and honeycombing. Two rock shelter sites in the Reserve have been investigated using electric resistivity tomography (ERT) and supportive methods for measuring surface moisture (Protimeter) and surface hardness (Equotip). These non-destructive techniques can be used in situ to assess the extent of weathering within a rock outcrop and are especially suited for investigations in sensitive areas such as Rock Art sites. Moisture movement has been mapped and related to the weathering processes observed on the surface. The aim of the study is to aid Rock Art conservation in the Golden Gate Reserve through a better understanding of the driving processes of surface weathering. The evidence shows that the extensive flaking and honeycombing found in the rock shelters is most likely caused by water pockets in the near-surface zone, which are replenished through internal moisture transport, driving the superficial weathering processes. These weathering processes pose a significant problem: Rock Art in the Golden Gate Reserve shows severe deterioration due to flaking. Conservation strategies should therefore take internal processes into account as much as their superficial expression.

Mol, L.; Viles, H. A.

2010-06-01

48

Porosity and surface area evolution during weathering of two igneous rocks  

SciTech Connect

During weathering, rocks release nutrients and storewater vital for growth ofmicrobial and plant life. Thus, the growth of porosity as weathering advances into bedrock is a life-sustaining process for terrestrial ecosystems. Here, we use small-angle and ultra small-angle neutron scattering to show how porosity develops during initial weathering under tropical conditions of two igneous rock compositions, basaltic andesite and quartz diorite. The quartz diorite weathers spheroidally while the basaltic andesite does not. The weathering advance rates of the two systems also differ, perhaps due to this difference in mechanism, from 0.24 to 100 mm kyr1, respectively. The scattering data document how surfaces inside the feldspar-dominated rocks change as weathering advances into the protolith. In the unaltered rocks, neutrons scatter fromtwo types of featureswhose dimensions vary from6 nmto 40 lm: pores and bumps on pore grain surfaces. These features result in scattering data for both unaltered rocks that document multi-fractal behavior: scattering is best described by amass fractal dimension (Dm) and a surface fractal dimension (Ds) for features of length scales greater than and less than 1 lm, respectively. In the basaltic andesite, Dm is approximately 2.9 and Ds is approximately 2.7. The mechanism of solute transport during weathering of this rock is diffusion. Porosity and surface area increase from 1.5%to 8.5%and 3 to 23 m2 g1 respectively in a relatively consistent trend across themm-thick plagioclase reaction front. Across this front, both fractal dimensions decrease, consistentwith development of amoremonodisperse pore networkwith smoother pore surfaces. Both changes are consistent largely with increasing connectivity of pores without significant surface roughening, as expected for transport-limited weathering. In contrast, porosity and surface area increase from 1.3% to 9.5% and 1.5 to 13 m2 g1 respectively across a many cm-thick reaction front in the spheroidally weathering quartz diorite. In that rock, Dm is approximately 2.8 andDs is approximately 2.5 prior to weathering. These two fractals transform during weathering to multiple surface fractals as micro-cracking reduces the size of diffusion-limited subzones of thematrix.Across the reaction front of plagioclase in the quartz diorite, the specific surface area and porosity change very little until the pointwhere the rock disaggregates into saprolite. The different patterns in porosity development of the two rocks are attributed to advective infiltration plus diffusion in the rock that spheroidally fractures versus diffusion-only in the rock that does not. Fracturing apparently diminishes the size of the diffusion-limited parts of the spheroidally weathering rock system to promote infiltration of meteoric fluids, thereforeexplaining the faster weathering advance rate into that rock.

Navarre-Sitchler, Alexis [Colorado School of Mines, Golden; Cole, David [Ohio State University; Rother, Gernot [ORNL; Jin, Lixin [University of Texas, El Paso; Buss, Heather [University of Bristol, UK; Brantley, S. L. [Pennsylvania State University, University Park, PA

2013-01-01

49

[Enrichment and release of uranium during weathering of sedimentary rocks in Wujiang catchments].  

PubMed

Thirteen weathering profiles of typical rocks such as limestone, dolomitic limestone, dolomite, sillcalite, black shale and purple sandrock from Wujiang catchments were selected for discussing enrichment and release behavior of uranium (U) during rock weathering, and studying its impact on riverine U distribution in the catchments during weathering of these rocks with methods of correlation analysis and mass balance calculation. The purpose of this study is to improve our understanding on biogechemical cycling of U and set a basis for catchment protection against U pollution. The results show that the enrichment extent of U in soils from the Wujiang catchments is usually higher than that of upper continental crust (UCC), China soil (CS) and world soil (WS). The ability of enrichment and release of U is partly controlled by content of U in bedrocks, contents and adsorption ability of clay minerals and Fe-oxides/hydroxides in weathering profiles. Our study also reveals that release of U mainly from weathering of limestone and partly from weathering of dolomite and clastic rocks exerts an important control on riverine U distribution. PMID:17326439

Song, Zhao-Liang; Liu, Cong-Qiang; Han, Gui-Lin; Wang, Zhong-Liang; Yang, Cheng; Liu, Zhan-Min

2006-11-01

50

Nitrogen production from geochemical weathering of rocks in southwest Montana, USA  

NASA Astrophysics Data System (ADS)

30 day time course laboratory weathering experiment was conducted using rock samples collected from the West Fork of the Gallatin River watershed (WFW) in southwestern Montana, USA. The goal of these experiments was to quantify the amount of labile nitrogen in rock samples collected from the watershed and determine if chemical weathering is a source of dissolved nitrogen in stream water. Several rock samples investigated produced nitrate in significantly higher concentrations than the silica bead control (p < 0.05), and the data were consistent with elevated NO3- concentrations measured in associated WFW streams. Isotopic analyses of 15N-NO3 in 22 stream water samples from the WFW and four rock:water extracts from the laboratory experiments indicated that the isotopic composition of NO3 was comparable with rocks and stream water samples in the same watershed and differed strongly from waters downstream of development. We suggest that the NO3- measured in WFW streams includes nitrogen derived from mineral dissolution products from soils and rock. The results presented herein further indicate that rock weathering is a source of stream water N in the West Fork watershed and inform water quality assessment, total maximum daily load development, and the relative influences of natural and anthropocentrically derived N sources across this developing mountain watershed.

Montross, Galena G.; McGlynn, Brian L.; Montross, Scott N.; Gardner, Kristin K.

2013-07-01

51

WATER WEATHERING IN ROCKS DISCONTINUITIES Sandra Dochez*1,2  

E-print Network

discontinuities and relative sliding blocks or benches [ASR05]. Runoff, which will produce mechanical erosion in the tensile strength of rock bridges fatigue [FRA05] [DRU11]. The study presented in this paper concerns and in the evolution of the cliffs. Our research aim to take into account the geomorphological features related

Paris-Sud XI, Université de

52

Effect of groundwater and sea weathering cycles on the strength of chalk rock from unstable coastal cliffs of NW France.  

E-print Network

1 Effect of groundwater and sea weathering cycles on the strength of chalk rock from unstable of ground water and sea weathering on the strength of the chalk rocks exposed on the coastline representative chalk units (Lewes Chalk, Seaford Chalk and Newhaven Chalk) exposed at various locations

Boyer, Edmond

53

Rock cities, periglacial mass-wasting, and honeycomb weathering in Warren County, northwestern Pennsylvania  

SciTech Connect

Imposing hilltop rock-cities developed from widely jointed outcrops of Olean conglomerate (Lower Pennsylvanian) create picturesque scenery on the Allegheny High Plateau in Warren Co., Pa. At least six such rock cities 2 to 5 acres in extent are associated with the Late Wisconsinan glacial border in the northern half of the county. Farther to the south, jumbled Olean and Knapp (Lower Mississippian) joint blocks occur on steep slopes below valley-wall cliffs. The rock cities and accumulations of displaced joint blocks are largely relics of Late Wisconsinan periglacial mass-wasting. Frost splitting initiated opening of bedrock joints to form buildings. Gravity, soil wedging, and possibly gelifluction then widened the fissures into streets. Gelifluction moved blocks downslope and oriented their long axes parallel with slope (Warren Rocks). Forward toppling of high, unstable blocks contributed to mass-movement on some steep slopes (Rimrock). Today, rock cities and downslope blocks are stable in areas of gentle (less than 10 percent) slopes, but toppling, solifluction, creep, and debris flows cause continued slow movement of large blocks on moderately steep to steep (greater than 30 percent) slopes. Blocks of Olean and Knapp conglomerate have both stratabound pitting and intricate honeycomb weathering. Deep pitting is controlled largely by variations in silica cementation. Honeycomb weathering is most evident in sandy layers and results from patterns of iron-oxide impregnation. Both are Holocene surface-weathering processes.

Inners, J.D.; Sevon, W.D.; Moore, M.E. (Pennsylvania Geological Survey, Harrisburg, PA (United States)); Berg, T.M. (Ohio Division of Geological Survey, Columbus, OH (United States))

1993-03-01

54

Effects of Space Weathering on Lunar Rocks: Scanning Electron Microscope Petrography  

NASA Technical Reports Server (NTRS)

Lunar rocks that have undergone direct exposure to the space weathering environment at the surface of the Moon commonly have patinas on their surfaces. Patinas are characterized by visible darkening and other changes in spectral properties of rocks. They form as a result of bombardment by micrometeorites, solar wind, and solar flares. Processes of space weathering and patina production have clearly been significant in the formation and history of the lunar regolith. It is very likely that other planetary bodies without atmospheres have undergone similar alteration processes; therefore, it is critical to determine the relationship between patinas and their host rocks in view of future robotic and remote-sensing missions to the Moon and other planetary bodies.

Wentworth, Susan J.; Keller, Lindsay P.; McKay, David S.

1998-01-01

55

In-Situ and Experimental Evidence for Acidic Weathering of Rocks and Soils on Mars  

NASA Technical Reports Server (NTRS)

Experimental data for alteration of synthetic Martian basalts at pH=0-1 indicate that chemical fractionations at low pH are vastly different from those observed during terrestrial weathering. Rock analyses from Gusev crater are well described by the relationships apparent from low pH experimental alteration data. A model for rock surface alteration is developed which indicates that a leached alteration zone is present on rock surfaces at Gusev. This zone is not chemically fractionated to a large degree from the underlying rock interior, indicating that the rock surface alteration process has occurred at low fluid-to-rock ratio. The geochemistry of natural rock surfaces analyzed by APXS is consistent with a mixture between adhering soil/dust and the leached alteration zone. The chemistry of rock surfaces analyzed after brushing with the RAT is largely representative of the leached alteration zone. The chemistry of rock surfaces analyzed after grinding with the RAT is largely representative of the interior of the rock, relatively unaffected by the alteration process occurring at the rock surface. Elemental measurements from the Spirit, Opportunity, Pathfinder and Viking 1 landing sites indicate that soil chemistry from widely separated locations is consistent with the low-pH, low fluid to rock ratio alteration relationships developed for Gusev rocks. Soils are affected principally by mobility of FeO and MgO, consistent with alteration of olivine-bearing basalt and subsequent precipitation of FeO and MgO bearing secondary minerals as the primary control on soil geochemistry.

Hurowitz, J. A.; McLennan, S. M.; Tosca, N. J.; Arvidson, R. E.; Michalski, J. R.; Ming, D.; Schroeder, C.; Squyres, S. W.

2006-01-01

56

Microstructural weathering of sedimentary rocks by freeze–thaw cycles: Experimental study of state and transfer parameters  

Microsoft Academic Search

The frost sensitivity of a rock is resulting from the combined action of processes linked to porous network characteristics (state parameters) and to the way water flows into this porous network (transfer parameters), our study was thus about the influence of these parameters on frost weathering of rocks. Sedimentary rocks often found on buildings (limestone and sandstone) and consequently submitted

Alice Saad; Sylvine Guédon; François Martineau

2010-01-01

57

Water Rock Interaction [WRI 14] Impact of rock weathering on the chemical composition of  

E-print Network

weathering and quantifying the inputs from each of several end-members (i.e silicate, carbonate, evaporite which, carbonate inputs dominate, evaporites often plays the second role, and silicate inputs may with evaporites domes. Groundwater recharge may occur to the east at the edge of the Massif Central, to the south

Paris-Sud XI, Université de

58

Behaviour of chemical elements during weathering of pyroclastic rocks, Hong Kong.  

PubMed

The behaviour of whole-rock major, trace and rare earth elements (REE) during weathering under subtropical conditions is examined along a profile developed over crystal--vitric tuffs with eutaxitic texture. The intensity of weathering within the profile varies erratically, indicating weathering processes operate over different scales. Quartz, K-feldspar, plagioclase and biotite are the main primary minerals, whereas clays, sesquioxides, sericite and chlorite are the alteration products. Kaolinite, halloysite and illite-mica are the dominant clay minerals present in significantly varying proportions. Two competing processes, namely leaching and fixation, are the main regulators of variations in mostly major and some trace element concentrations along the profile. In general, as the intensity of weathering increases, Ca, Na, K, Sr +/- Si decrease, while Fe, Ti, Al and loss of ignition (LOI) increase. Likewise, the intensity of negative Eu-anomaly decreases while the intensity of negative Ce-anomaly and the La/Lu and Sm/Nd ratios increases. In detail, however, the behaviour of chemical elements cannot be solely explained in terms of the degree of weathering. This study makes it clearly evident that the type and abundance of sesquioxides and clay minerals can significantly modify the geochemical signatures of weathering processes. PMID:11392752

Malpas, J; Duzgoren-Aydin, N S; Aydin, A

2001-05-01

59

The role of disseminated calcite in the chemical weathering of granitoid rocks  

USGS Publications Warehouse

Accessory calcite, present at concentrations between 300 and 3000 mg kg-1, occurs in fresh granitoid rocks sampled from the Merced watershed in Yosemite National Park, CA, USA; Loch Vale in Rocky Mountain National Park CO USA; the Panola watershed, GA USA; and the Rio Icacos, Puerto Rico. Calcite occurs as fillings in microfractures, as disseminated grains within the silicate matrix, and as replacement of calcic cores in plagioclase. Flow-through column experiments, using de-ionized water saturated with 0.05 atm. CO2, produced effluents from the fresh granitoid rocks that were dominated by Ca and bicarbonate and thermodynamically saturated with calcite. During reactions up to 1.7 yr, calcite dissolution progressively decreased and was superceded by steady state dissolution of silicates, principally biotite. Mass balance calculations indicate that most calcite had been removed during this time and accounted for 57-98% of the total Ca released from these rocks. Experimental effluents from surfically weathered granitoids from the same watersheds were consistently dominated by silicate dissolution. The lack of excess Ca and alkalinity indicated that calcite had been previously removed by natural weathering. The extent of Ca enrichment in watershed discharge fluxes corresponds to the amounts of calcite exposed in granitoid rocks. High Ca/Na ratios relative to plagioclase stoichiometries indicate excess Ca in the Yosemite, Loch Vale, and other alpine watersheds in the Sierra Nevada and Rocky Mountains of the western United States. This Ca enrichment correlates with strong preferential weathering of calcite relative to plagioclase in exfoliated granitoids in glaciated terrains. In contrast, Ca/Na flux ratios are comparable to or less than the Ca/Na ratios for plagioclase in the subtropical Panola and tropical Rio Icacos watersheds, in which deeply weathered regoliths exhibit concurrent losses of calcite and much larger masses of plagioclase during transport-limited weathering. These results indicate that the weathering of accessory calcite may strongly influence Ca and alkalinity fluxes from silicate rocks during and following periods of glaciation and tectonism but is much less important for older stable geomorphic surfaces.

White, A.F.; Bullen, T.D.; Vivit, D.V.; Schulz, M.S.; Clow, D.W.

1999-01-01

60

Weathering products of basic rocks as sorptive materials of natural radionuclides  

SciTech Connect

The principal requirements for employing natural minerals as buffer and backfill material in high-level waste (HLW) repositories are high sorptive properties, low water permeability, relatively high thermal conductivity, and thermostability. The major task of the buffer is to prevent the penetration of radionuclides into groundwater. The authors of this report examined weathered basic rocks from three regions of Russia in consideration as a suitable radioactive waste barrier.

Omelianenko, B.I.; Niconov, B.S.; Ryzhov, B.I.; Shikina, N.D. [AN SSSR, Moscow (Russian Federation). Inst. Geologii Rudnykh Mestorozhdenij, Petrografii, Mineralogii i Geokhimii

1994-06-01

61

Characterization of weathering profile in granites and volcanosedimentary rocks in West Africa under humid tropical climate conditions. Case of the Dimbokro Catchment (Ivory Coast)  

NASA Astrophysics Data System (ADS)

In granitic rocks, various models of weathering profile have been proposed, but never for the hard rocks of West Africa. Besides, in the literature there is no description of the weathering profile in volcanosedimentrary rocks. Therefore, we propose three models describing the weathering profiles in granites, metasediments, and volcanic rocks for hard rock formations located in West Africa. For each of these models proposed for granitic and volcanosedimentary rocks of the Dimbokro catchment, vertical layered weathering profiles are described, according to the various weathering and erosion cycles (specific to West Africa) that the geological formations of the Dimbokro catchment experienced from the Eocene to the recent Quaternary period. The characterization of weathering profiles is based on: i) bedrocks and weathering profile observations at outcrop, and ii) interpretation and synthesis of geophysical data and lithologs from different boreholes. For each of the geological formations (granites, metasediments, and volcanic rocks), their related weathering profile model depicted from top to bottom comprises four separate layers: alloterite, isalterite, fissured layer, and fractured fresh basement. These weathering profiles are systematically covered by a soil layer. Though granites, metasediments and volcanic rocks of the Dimbokro catchment experience the same weathering and erosion cycles during the palaeoclimatic fluctuations from Eocene to recent Quaternary period, they exhibit differences in thickness. In granites, the weathering profile is relatively thin due to the absence of iron crust which protects weathering products against dismantling. In metasediments and volcanic rocks iron crusts develop better than in granites; in these rocks the alterite are more resistant to dismantling.

Koita, M.; Jourde, H.; Koffi, K. J. P.; da Silveira, K. S.; Biaou, A.

2013-06-01

62

International Symposium on Hydrogeology and the Environment, Wuhan, China, Oct. 17 20, 2000 A confined groundwater zone in weathered igneous rocks and its impact  

E-print Network

A confined groundwater zone in weathered igneous rocks and its impact on slope stability Jiu Jimmy Jiao in igneous rock saprolites are a serious natural hazard in Hong Kong and have been extensively studied groundwater zone may exist in the weathered igneous rock profile due to a highly fractured zone. In Hong Kong

Jiao, Jiu Jimmy

63

Mechanical Weathering  

NSDL National Science Digital Library

This activity was designed to give students an opportunity to realize that all rocks weather mechanically and each specific rock type has its own particular rate of weathering. Students discover that mechanical weathering is the process of breaking down bedrock into smaller fragments by physical as opposed to chemical means and that rock weathering, although it seems to occur slowly in human terms, is an extremely significant part of the rock cycle. They will learn that weathered rock materials are called sediments and are the structural basis for soils and can also be compacted into sedimentary rock. Students will realize that rock weathering rates vary widely depending on mineral content, texture, rock type, and climate and that differential weathering (varying weathering rates for two or more rock types in physical contact with each other) has given rise to some of the world's most breathtaking scenery.

64

The role of forest trees and their mycorrhizal fungi in carbonate rock weathering and its significance for global carbon cycling.  

PubMed

On million-year timescales, carbonate rock weathering exerts no net effect on atmospheric CO2 concentration. However, on timescales of decades-to-centuries, it can contribute to sequestration of anthropogenic CO2 and increase land-ocean alkalinity flux, counteracting ocean acidification. Historical evidence indicates this flux is sensitive to land use change, and recent experimental evidence suggests that trees and their associated soil microbial communities are major drivers of continental mineral weathering. Here, we review key physical and chemical mechanisms by which the symbiotic mycorrhizal fungi of forest tree roots potentially enhance carbonate rock weathering. Evidence from our ongoing field study at the UK's national pinetum confirms increased weathering of carbonate rocks by a wide range of gymnosperm and angiosperm tree species that form arbuscular (AM) or ectomycorrhizal (EM) fungal partnerships. We demonstrate that calcite-containing rock grains under EM tree species weather significantly faster than those under AM trees, an effect linked to greater soil acidification by EM trees. Weathering and corresponding alkalinity export are likely to increase with rising atmospheric CO2 and associated climate change. Our analyses suggest that strategic planting of fast-growing EM angiosperm taxa on calcite- and dolomite-rich terrain might accelerate the transient sink for atmospheric CO2 and slow rates of ocean acidification. PMID:25211602

Thorley, Rachel M S; Taylor, Lyla L; Banwart, Steve A; Leake, Jonathan R; Beerling, David J

2014-09-11

65

Weather  

NSDL National Science Digital Library

What are the different types of weather? In this project you will compare different types of weather by drawing pictures and making it into a flip book. First you will begin by learning about the different types of weather. Read about each topic. Then get together with your partner and draw a picture of each type of weather. 1. Thunder storm Thunder storm Thunder storm Kids 2. Lightning Lightning Lightning picture 3. Tornado Tornadoes Tornado Kids 4. ...

Jennie, Miss

2009-10-22

66

Chemical weathering on Mars - Thermodynamic stabilities of primary minerals /and their alteration products/ from mafic igneous rocks  

NASA Technical Reports Server (NTRS)

Chemical weathering on Mars is examined theoretically from the standpoint of thermodynamic equilibrium between primary rock-forming minerals and the atmospheric gases O2, H2O, and CO2. The primary minerals considered are those common to mafic igneous rocks and include olivine, pyroxene, plagioclase, magnetite, troilite, pyrrhotite, and apatite. The importance of kinetics and reaction mechanisms in controlling possible weathering processes on Mars is discussed within the limits of currently available data, and the possible influence of liquid water on Martian weathering processes is evaluated where appropriate. For gas-solid weathering of mafic igneous rocks at the Martian surface, it is concluded that upon attainment of thermodynamic equilibrium: (1) oxides and carbonates should dominate the mineral assemblage of weathering products; (2) hematite rather than goethite should be the stable mineral form of Fe (III); (3) FeSO4 or FeSO4.H2O could be the stable weathering product of iron sulfides in the absence of liquid water; and (4) kaolinite is apparently the only clay mineral that should be thermodynamically stable over all ranges of temperature and water-vapor abundance at the Martian surface.

Gooding, J. L.

1978-01-01

67

Controls on Weathering of Pyrrhotite in a Low-Sulfide, Granitic Mine-Waste Rock in the Canadian Arctic  

NASA Astrophysics Data System (ADS)

Increased environmental risk is incurred with expansion of mineral extraction in the Arctic. A greater understanding of geochemical processes associated with hard-rock mining in this cold climate is needed to evaluate and mitigate these risks. A laboratory and in-situ experiment was conducted to examine mineral weathering and the generation of acid rock drainage in a low-sulfide, run-of-mine waste rock in an Arctic climate. Rock with different concentrations of sulfides (primarily pyrrhotite [Fe7S8] containing small amounts of Co and Ni) and carbonates were weathered in the laboratory and in-situ, large-scale test piles to examine leachate composition and mineral weathering. The relatively larger sulfide-containing rock produced sufficient acid to overcome carbonate buffering and produced a declining pH environment with concomitant release of SO4, Fe, Co, and Ni. Following carbonate consumption, aluminosilicate buffering stabilized the pH above 4 until a reduction in acid generation. Results from the laboratory experiment assisted in determining that after consumption of 1.6 percent of the total sulfide, the larger sulfide-concentration test pile likely is at an internal steady-state or maximal weathering rate after seven years of precipitation input and weathering that is controlled by an annual freeze-thaw cycle. Further weathering of the test pile should be driven by external factors of temperature and precipitation in this Arctic, semi-arid region instead of internal factors of wetting and non-equilibrium buffering. It is predicted that maximal weathering will continue until at least 20 percent of the total sulfide is consumed. Using the identified evolution of sulfide consumption in this Arctic climate, a variable rate factor can now be assessed for the possible early evolution and maximal weathering of larger scale waste-rock piles and seasonal differences because of changes in the volume of a waste-rock pile undergoing active weathering due to the freeze-thaw cycle. Such rate factors are necessary to predict acid rock drainage and implement best management practices to minimize environmental impacts. To better understand the early geochemical evolution of the waste rock, sulfide minerals from different periods in the experiments were analyzed for discrete mineral characteristics indicative of a weathered state. Element transfer from the mineral to aqueous phase is transport limited because of the formation of Fe-(oxy)hydroxide weathered rims that can be an inhibitor of dissolution. Application of various x-ray spectroscopy techniques indicated that pyrrhotite transforms to marcasite [FeS2] prior to formation of Fe(II)-(oxy)hydroxides and further to Fe(III)-hydroxide/oxides. Iron appears to migrate through the weathered rims leaving the S-rich layer behind, and oxygen likely is retarded from migrating inward with formation of Fe(III) species. As these Fe-mineral transformations occur, they influence the retention of the secondary metals such as Co and Ni that preferentially remain in the +2 oxidation state and may leave the system as hydroxides, oxides, and sulfates. Understanding mineral evolution in this climate assists in adjusting appropriate rate factors for temporal changes in element release from the weathering of the pyrrhotite.

Langman, J. B.; Holland, S.; Sinclair, S.; Blowes, D.

2013-12-01

68

Weathering of chrysotile asbestos by the serpentine rock-inhabiting fungus Verticillium leptobactrum.  

PubMed

Verticillium leptobactrum, a rare fungal species, has repeatedly been isolated from serpentinic rocks in the Western Alps, thus suggesting that it adapts easily to this selective mineral substrate. The rRNA internal transcribed spacer region of several isolates has been sequenced to confirm their identity and taxonomic position within Verticillium, a recently revised polyphyletic entity. Isolates of V. leptobactrum have also been investigated to establish their ability to weather asbestos chrysotile, the most common mineral in the isolation sites. The results of solubilization assays on magnesium and silicon, as well as measurement of the Mg/Si ratio in the asbestos fibres after exposure to fungal mycelia, indicate a high bioweathering activity of V. leptobactrum towards chrysotile. Comparison with data on Fusarium oxysporum shows differences among species, with V. leptobactrum being more active than F. oxysporum in removing structural ions from chrysotile. Asbestos weathering by fungi could be envisaged as a bioremediation strategy for hazardous asbestos-rich soils (e.g. abandoned mines). Fungi that have adapted to live in serpentine sites could be good candidates for this purpose. PMID:19453742

Daghino, Stefania; Turci, Francesco; Tomatis, Maura; Girlanda, Mariangela; Fubini, Bice; Perotto, Silvia

2009-07-01

69

Excavatability Assessment of Weathered Sedimentary Rock Mass Using Seismic Velocity Method  

SciTech Connect

Seismic refraction method is one of the most popular methods in assessing surface excavation. The main objective of the seismic data acquisition is to delineate the subsurface into velocity profiles as different velocity can be correlated to identify different materials. The physical principal used for the determination of excavatability is that seismic waves travel faster through denser material as compared to less consolidated material. In general, a lower velocity indicates material that is soft and a higher velocity indicates more difficult to be excavated. However, a few researchers have noted that seismic velocity method alone does not correlate well with the excavatability of the material. In this study, a seismic velocity method was used in Nusajaya, Johor to assess the accuracy of this seismic velocity method with excavatability of the weathered sedimentary rock mass. A direct ripping run by monitoring the actual production of ripping has been employed at later stage and compared to the ripper manufacturer's recommendation. This paper presents the findings of the seismic velocity tests in weathered sedimentary area. The reliability of using this method with the actual rippability trials is also presented.

Bin Mohamad, Edy Tonnizam; Noor, Muhazian Md; Isa, Mohamed Fauzi Bin Md.; Mazlan, Ain Naadia [Department of Geotechnics and Transportation, Faculty of Civil Engineering, Universiti Teknologi Malaysia, 81310 UTM Skudai. Johor (Malaysia); Saad, Rosli [Universiti Sains Malaysia, Penang (Malaysia)

2010-12-23

70

Subduction of Serpentinized and Weathered Ultramafic Rocks in the Puerto Rico Trench: Preliminary Results  

NASA Astrophysics Data System (ADS)

Exposure of mantle peridotite and its interactions with seawater to form serpentinite are integral parts of seafloor spreading, and play a key role in affecting the rheology, chemistry, and microbial habitability of the oceanic lithosphere at slow- and ultra-slow spreading ridges. Away from the spreading centers, within subduction zones, the formation and dehydration of serpentinized peridotite impacts seismicity, element cycling, and melt generation. Here we present preliminary results of a petrographic and spectroscopic study of altered rocks recovered from the from the north wall of the trench Puerto Rico Trench (PRT). In fact, the PRT represents one of two subduction zones worldwide where slow spreading oceanic lithosphere is presently subducted, and where serpentinized peridotite has been directly evidenced by seafloor sampling {Bowin, 1966}. Thin section petrography, XRF analysis, scanning electron microscopy, and confocal Raman spectroscopy reveal that the peridotite, which in all likelihood originated at the Mid-Atlantic Ridge during the early Cretaceous, was virtually completely serpentinized under static conditions (as it is evidenced by the preserved mesh texture after olivine and bastite after orthopyroxene), and underwent subsequent seafloor weathering. While it is questionable where exactly serpentinization and subsequent seafloor weathering took place, our preliminary results strongly suggest that the material presently subducted in the PRT is not simply composed of serpentine, magnetite, and brucite; it is rather a complex disequilibrium assemblage of minerals including serpentine, brucite, chlorite, talc, magnetite, hematite, goethite, sulfur-rich sulfides and various clay minerals. Furthermore, our results imply that serpentinite and its weathering products influence the loci of dehydration and mineral replacement reactions, as well as the water input and element recycling in subduction zones.

Horning, G.; Klein, F.

2012-12-01

71

Geochemistry of Neogene sedimentary rocks from Borneo Basin, Malaysia: implications on paleo-weathering, provenance and tectonic setting  

NASA Astrophysics Data System (ADS)

Multi-element geochemistry and mineralogy are used to characterize the chemical composition, degree of paleo-weathering, provenance and tectonic settingsof the Neogene sedimentary rocks of Borneo Basin from east Malaysia. The sedimentary rocks are classified as extremely weathered sandstones (i.e. wacke, arkose, litharenite, Fe-sandstone and quartz arenite). Higher values of both weathering indices of alteration (i.e. CIA>83 and PIA>89) suggest that the sandstones have undergone extreme chemical weathering. Absence of any feldspar in the mineralogical analysis indicates its degradation during the weathering. Except for the quartz arenite, all other sandstones are characterized by post-depositional K-metasomatism and zircon enrichment through sediment recycling. The geochemical characteristics suggest a mixed-nature provenance for the sandstones with contribution coming from both felsic and mafic igneous rocks. Enriched Cr in quartz arenite and Fe-sandstone are related to contribution from ophiolite or fractionation of Cr-bearing minerals. The inferred tectonic settings are variable and suggest a complex nature of tectonic environment in the basin.

Ramasmay, N.; Roy, P.; MP, J.; Rufino, L.; Franz, L. K.; Viswanathan, P. M.

2013-05-01

72

Air temperature-driven CO2 consumption by rock weathering at short timescales: Evidence from a Holocene lake sediment record  

NASA Astrophysics Data System (ADS)

The role that air temperature plays in the interaction between atmospheric CO2 levels and continental rock weathering at relatively short time scales is still a matter of debate. Laboratory studies reveal a strong dependence of mineral dissolution on temperature, but field comparisons among watersheds under different climate conditions often indicate correlations with other environmental factors. Using a paleolimnological approach, here we show that there has been an extremely good coupling between rock weathering, water alkalinity (CO2 consumption), and air temperature during the last 10,000 years at sub-millennial time scales in a small watershed of silicate bedrock and scarce vegetation. The calculation of apparent activation energy for the weathering reaction (as a means to describe the temperature dependence of the process) provides a value (Ea = 67 ± 7 kJ mol-1) that is comparable to those found for silicate rocks similar to those in the watershed in laboratory experiments and some field studies. Our results provide evidence that regulatory constraints between air temperature, atmospheric CO2 and silicate rock weathering can be fine-tuned at geological timescales and may not be negligible in the current context of global change.

Catalan, Jordi; Pla-Rabés, Sergi; García, Joan; Camarero, Lluís

2014-07-01

73

Chemical weathering on Mars thermodynamic stabilities of primary minerals (and their alteration products) from mafic igneous rocks  

Microsoft Academic Search

Chemical weathering on Mars is examined theoretically from the standpoint of heterogeneous equilibrium between solid mineral phases and gaseous 02, H20, and CO2 in the Martian atmo- sphere. Thermochemical calculations are performed in order to identify important gas-solid decomposition reactions involving the major mineral constituents of mafic igneous rocks. Where unavailable in the thermochemical literature, Gibbs free energy and enthalpy

JAMES L. GOODING

1978-01-01

74

Microbial populations and activities in the rhizoplane of rock-weathering desert plants. II. Growth promotion of cactus seedlings.  

PubMed

Four bacterial species isolated from the rhizoplane of cacti growing in bare lava rocks were assessed for growth promotion of giant cardon cactus seedlings (Pachycereus pringlei). These bacteria fixed N(2), dissolved P, weathered extrusive igneous rock, marble, and limestone, and significantly mobilized useful minerals, such as P, K, Mg, Mn, Fe, Cu, and Zn in rock minerals. Cardon cactus seeds inoculated with these bacteria were able to sprout and grow normally without added nutrients for at least 12 months in pulverized extrusive igneous rock (ancient lava flows) mixed with perlite. Cacti that were not inoculated grew less vigorously and some died. The amount of useful minerals (P, K, Fe, Mg) for plant growth extracted from the pulverized lava, measured after cultivation of inoculated plants, was significant. This study shows that rhizoplane bacteria isolated from rock-growing cacti promote growth of a cactus species, and can help supply essential minerals for a prolonged period of time. PMID:15375736

Puente, M E; Li, C Y; Bashan, Y

2004-09-01

75

Weathering  

NSDL National Science Digital Library

This interactive Flash resource provides information regarding physical and chemical weathering at an introductory physical geology or Earth science level. It includes animations, diagrams, and supplementary information and is suitable for high school or undergraduate students.

Smoothstone; Mifflin, Houghton

76

Integrating topography, hydrology and rock structure in weathering rate models of spring watersheds  

NASA Astrophysics Data System (ADS)

SummaryWeathering rate models designed for watersheds combine chemical data of discharging waters with morphologic and hydrologic parameters of the catchments. At the spring watershed scale, evaluation of morphologic parameters is subjective due to difficulties in conceiving the catchment geometry. Besides, when springs emerge from crystalline massifs, rock structure must be accounted in formulas describing the area of minerals exposed to the percolating fluids, for a realistic evaluation of the rates. These particular features are not included in the available approaches and for that reason a new model was developed, coined THROW model. This is a lumped approach that integrates (T)opography, (H)ydrology, (RO)ck structure and (W)eathering in a single algorithm. The study area comprises several stream watersheds and spring sites of the Vouga River basin (northern Portugal), shaped on granites. Firstly, the THROW model couples a terrain modeling analysis with hydrologic models based on discharge rates, to determine hydraulic conductivities (K), effective porosities (ne) and annual recharges (Vr) at the stream watershed scale. Subsequently, these parameters are used in a water balance model to estimate concomitant groundwater travel times (t). The mean K [(4.7 ± 3.2) × 10-7 m s-1] and ne [(2.0 ± 1.3) × 10-2] values are adopted as proxies for the spring watersheds and a firm regression equation is defined between time and stream watershed area (A). Secondly, two more runs of terrain modeling analysis are executed to extrapolate morphologic parameters for the spring watersheds. The first run hinges on scaling properties of the drainage networks, known as Horton laws, and is used to scale watershed areas across stream orders (i). The scaling function is described by another regression equation. The second run evaluates the order of a spring watershed, defined as equivalent order (ieq) and equated to the mean order of the surrounding stream watersheds. Having calculated the ieq, spring watershed areas and travel times were downscaled using the regression equations (A < 10 km2 and t = 1.4-2.8 year). Standing on the physical and hydrologic parameters of the spring watersheds, the THROW model finally calculates plagioclase weathering rates in the vicinity of the spring sites. The SiB model (Pacheco and Van der Weijden, 1996) was used before to estimate the contribution of plagioclase dissolution to the chemical composition of these springs (Van der Weijden and Pacheco, 2006). The chemical data were now coupled with K, ne and t in a rate equation to estimate chemical weathering rates of plagioclase in the basin. In the THROW model, the rate equation describes the exposed surface area as a function of fracture spacings, openings and porosities (Pacheco and Alencoão, 2006). The calculated rates (WPl = (2.5 ± 1.2) × 10-14 mol m-2 s-1) are consistent with previous reports and with results of experimental kinetic models. The SiB results predict formation of halloysite and gibbsite along the flow path, which were indeed close to equilibrium with the dissolved Al and Si activities.

Pacheco, Fernando A. L.; Van der Weijden, Cornelis H.

2012-03-01

77

Studies of Fe/sup 2 +/. -->. Fe/sup 3 +/ transitions during the process of rock weathering by nuclear gamma-resonance spectroscopy  

SciTech Connect

This paper presents a method for the mineral and weathering assessment of rocks and carbonaceous matter based in gamma spectroscopy and transitions between iron ions. The method is applied to rocks collected near the Teberda preserve. Four latitudinal bands of rocks parallel to the Greater Caucasus Ridge are identified in this territory. Isomer shift and hyperfine parameters of the Moessbauer spectra are given.

Vasil'ev, S.P.; Babanin, V.F.; Solov'ev, A.A.

1986-11-01

78

Worldwide distribution of continental rock lithology: Implications for the atmospheric\\/soil CO2 uptake by continental weathering and alkalinity river transport to the oceans  

Microsoft Academic Search

The silicate rock weathering followed by the formation of carbonate rocks in the ocean, transfers CO2 from the atmosphere to the lithosphere. This CO2 uptake plays a major role in the regulation of atmospheric CO2 concentrations at the geologic timescale and is mainly controlled by the chemical properties of rocks. This leads us to develop the first world lithological map

Philippe Amiotte Suchet; Jean-Luc Probst; Wolfgang Ludwig

2003-01-01

79

Characterizing the process and quantifying the rate of subaerial rock weathering on desert surfaces using roughness analysis  

NASA Astrophysics Data System (ADS)

Subaerial weathering of rocks is a common process observed on desert surfaces on Earth and other planetary terrestrial surfaces such as on Mars. On Earth, this weathering process has been previously identified as one of the key erosion agent driving geomorphic surface evolution and the development of desert pavements. And yet, fundamental aspects of the process, such as the relative contribution of the different weathering modes that drive it (e.g., mechanical breakdown of rocks, chemical weathering, aeolian abrasion and exfoliation) as well as the rate by which this weathering process occurs have not been systematically examined. Here, we present a new approach for quantitatively addressing these fundamental aspects of process geomorphology on desert surfaces. We focus here on co-genetic desert alluvial surfaces of different ages, i.e. alluvial chronosequences, which provide excellent recorders for the evolution of boulder-strewn surfaces into smooth desert pavements through in-situ subaerial weathering of rocks. Our approach combines independent measures of two different surface attributes: High resolution (mm-scale) 3D ground-based laser scanning (LiDAR) of surface micro-topography, and numerical dating of surface age. Roughness analysis of the LiDAR data in power spectral density (PSD) space allows us to characterize the geometric manifestation of rock weathering on the surface and to distinguish between the different weathering modes. Numerical age constraints provide independent estimates for the time elapsed since the process began. Accordingly, we are able to constrain surface roughness evolution on alluvial fan desert chronosequences through time, and present PSD analysis of surface roughness as a new quantitative tool to examine the process of subaerial rock weathering in desert environments. In this study we present results from two late Quaternary alluvial chronosequences along the Dead Sea Transform in the hyper-arid Negev desert of southern Israel. LiDAR scanning was applied on representative areas (~30-50 m2) of 10 separate surfaces ranging from rough Holocene surfaces to fairly smooth surfaces with well-developed pavements displaying an OSL age of 87 kyr. We find typical and recurring time-dependent changes in the offset as well as shape of the PSD curves in both chronosequences: PSD offset is continuously reduced over time reflecting the overall reduction in the amplitude of roughness at all wavelengths. The PSD curves display progressive moderation of slopes at the longer wavelengths with the moderation point itself systematically shifted to shorter wavelengths. This characteristic evolution of PSD offset and slope moderation at longer wavelengths reflects the typical break up of boulder-sized clasts through time as the surfaces mature into well-developed desert pavements and points towards mechanical breakdown as the dominant weathering mode. In addition, we are able to determine the rate by which the larger clasts are removed from the system. We build on these new insights into process and rate of rock weathering to propose PSD analysis of surface roughness as a complementary method for constraining the age of desert alluvial surfaces in places where 'conventional' dating cannot be applied.

Mushkin, Amit; Sagy, Amir; Trabelci, Eran

2013-04-01

80

External Resource: Mechanical Weathering  

NSDL National Science Digital Library

A student activity with teacher's sheet, to give the students an opportunity to realize that all rocks weather mechanically and each specific rock type has its own particular rate of weathering. Mechanical weathering is the process of breaking down bedroc

1900-01-01

81

Mismatched Physical and Chemical Weathering of Rocks on Mars: Clues to Past Climate  

NASA Astrophysics Data System (ADS)

Here we quantify the degree of weathering experienced by the Adirondack-class basalts at the MER Spirit site by performing comparative analyses on the strength and chemistry of a series of progressively weathered Columbia River Basalt samples.

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

2014-07-01

82

Weathering Animation  

NSDL National Science Digital Library

Weathering is the term that describes all the processes that break down rocks in the environment near the Earth's surface. This module will help you to understand two weathering processes: mechanical and chemical.

2002-01-01

83

Weather  

NSDL National Science Digital Library

In the project you will learn about thunderstorms and tornadoes and play a weather matching game. What exactly are thunderstorms and tornadoes? Use your T- chart to explain some facts about a thunderstorm and a tornado as we review each. T-Chart Begin by reviewing what a thunderstorm is and how they form. Thunderstorm information What is a thunderstorm? What are thunderstorms most likely to occur? What causes thunder? Next review what a tornado ...

Caitlin, Ms.

2009-10-21

84

Rocks  

NSDL National Science Digital Library

This year we are going to learn about rocks. Do you like to collect rocks? Rocks are the most common material on earth. We will learn about the parts that make up the rocks and sort rocks based upon color, hardness, texture, layering, and particle size. So you want to learn about rocks? Go to Intro to Rocks for some fascinating facts about rocks! Now lets learn about some of the different kinds of rocks. Igneous Rocks Metamorphic Rocks Sedimentary Rocks Click here to see the differences between the types of rocks that you have learned about What Type Of Rock Do I Have?. After doing all the activities above, ...

Woodruff, Mrs.

2010-06-21

85

Groundwater flows in weathered crystalline rocks: Impact of piezometric variations and depth-dependent fracture connectivity  

NASA Astrophysics Data System (ADS)

Groundwater in shallow weathered and fractured crystalline rock aquifers is often the only perennial water resource, especially in semi-arid region such as Southern India. Understanding groundwater flows in such a context is of prime importance for sustainable aquifer management. Here, we describe a detailed study of fracture properties and relate the hydraulic connectivity of fractures to groundwater flows at local and watershed scales. Investigations were carried out at a dedicated Experimental Hydrogeological Park in Andhra Pradesh (Southern India) where a large network of observation boreholes has been set up. Twenty-height boreholes have been drilled in a small area of about 18,000 m2 in which borehole loggings and hydraulic tests were carried out to locate the main flowing fractured zones and investigate fractures connectivity. Several hydraulic tests (nineteen slug tests and three pumping tests) performed under two water level conditions revealed contrasting behavior. Under high water level conditions, the interface including the bottom of the saprolite and the first flowing fractured zone in the upper part of the granite controls groundwater flows at the watershed-scale. Under low water level conditions, the aquifer is characterized by lateral compartmentalization due to a decrease in the number of flowing fractures with depth. Depending on the water level conditions, the aquifer shifts from a watershed flow system to independent local flow systems. A conceptual groundwater flow model, which includes depth-dependent fracture connectivity, is proposed to illustrate this contrasting hydrological behavior. Implications for watershed hydrology, groundwater chemistry and aquifer vulnerability are also discussed.

Guihéneuf, N.; Boisson, A.; Bour, O.; Dewandel, B.; Perrin, J.; Dausse, A.; Viossanges, M.; Chandra, S.; Ahmed, S.; Maréchal, J. C.

2014-04-01

86

Nutrient Release from Weathering of Purplish Rocks in the Sichuan Basin, China 1 1 Project supported by the National Basic Research Program of China (No. 2003CB415202) and the National Natural Science Foundation of China (Nos. 40571093 and 49601009)  

Microsoft Academic Search

Purplish soils having high fertility with mineral nutrients inherited from the parent rock are widely distributed in the hills along the Yangtze River, especially in the Sichuan Basin. Pot and field weathering experiments were conducted to mimic rock weathering and nutrient release processes in order to better understand soil fertility and nutrient compensation. Three types of purplish rock formations formed

Bo ZHU; Tao WANG; Xiang YOU; Mei-Rong GAO

2008-01-01

87

Release of uranium and thorium from granitic rocks during in situ weathering and initial erosion  

E-print Network

of release is dependent on the specific phases involved. PLILER and ADAMS (1962), in a Pennsylvanian soil profile de- veloped on granodiorite, found that the first stages of weathering removed 25% of the Th and 60% of the U, re- sulting in initial...- cluded that U is present in resistates while Th is asso- ciated with clays and secondary minerals such as Th(OH) 4. The granodiorite was noticeably weathered to a depth of 24 meters. U and Th distribution in soil profiles developed on Precambrian...

Ledger, Ernest Broughton

1978-01-01

88

The ubiquitous nature of accessory calcite in granitoid rocks: Implications for weathering, solute evolution, and petrogenesis  

USGS Publications Warehouse

Calcite is frequently cited as a source of excess Ca, Sr and alkalinity in solutes discharging from silicate terrains yet, no previous effort has been made to assess systematically the overall abundance, composition and petrogenesis of accessory calcite in granitoid rocks. This study addresses this issue by analyzing a worldwide distribution of more than 100 granitoid rocks. Calcite is found to be universally present in a concentration range between 0.028 to 18.8 g kg-1 (mean = 2.52 g kg-1). Calcite occurrences include small to large isolated anhedral grains, fracture and cavity infillings, and sericitized cores of plagioclase. No correlation exists between the amount of calcite present and major rock oxide compositions, including CaO. Ion microprobe analyses of in situ calcite grains indicate relatively low Sr (120 to 660 ppm), negligible Rb and 87Sr/86Sr ratios equal to or higher than those of coexisting plagioclase. Solutes, including Ca and alkalinity produced by batch leaching of the granitoid rocks (5% CO2 in DI water for 75 d at 25??C), are dominated by the dissolution of calcite relative to silicate minerals. The correlation of these parameters with higher calcite concentrations decreases as leachates approach thermodynamic saturation. In longer term column experiments (1.5 yr), reactive calcite becomes exhausted, solute Ca and Sr become controlled by feldspar dissolution and 87Sr/ 86Sr by biotite oxidation. Some accessory calcite in granitoid rocks is related to intrusion into carbonate wall rock or produced by later hydrothermal alteration. However, the ubiquitous occurrence of calcite also suggests formation during late stage (subsolidus) magmatic processes. This conclusion is supported by petrographic observations and 87Sr/86Sr analyses. A review of thermodynamic data indicates that at moderate pressures and reasonable CO2 fugacities, calcite is a stable phase at temperatures of 400 to 700??C. Copyright ?? 2005 Elsevier Ltd.

White, A.F.; Schulz, M.S.; Lowenstern, J. B.; Vivit, D.V.; Bullen, T.D.

2005-01-01

89

Venus - Chemical weathering of igneous rocks and buffering of atmospheric composition  

NASA Technical Reports Server (NTRS)

Data from the Pioneer Venus radar mapper, combined with measurements of wind velocity and atmospheric composition, suggest that surface erosion on Venus varies with altitude. Calcium- and magnesium-rich weathering products are produced at high altitudes by gas-solid reactions with igneous minerals, then removed into the hotter lowlands by surface winds. These fine-grained weathering products may then rereact with the lower atmosphere and buffer the composition of the observed gases carbon dioxide, water vapor, sulfur dioxide, and hydrogen fluoride in some regions of the surface. This process is a plausible mechanism for the establishment in the lowlands of a calcium-rich mineral assemblage, which had previously been found necessary for the buffering of these species.

Nozette, S.; Lewis, J. S.

1982-01-01

90

Rock Solid  

NSDL National Science Digital Library

Rocks cover the earth's surface, including what is below or near human-made structures. With rocks everywhere, breaking rocks can be hazardous and potentially disastrous to people. Students are introduced to three types of material stress related to rocks: compressional, torsional and shear. They learn about rock types (sedimentary, igneous and metamorphic), and about the occurrence of stresses and weathering in nature, including physical, chemical and biological weathering.

Integrated Teaching And Learning Program

91

Upscaling Fracture Network Models to Continua: An Example Using Weathered Granitic Rock  

NASA Astrophysics Data System (ADS)

In the early 1990's, a proposed landfill site on the Campo Indian Reservation in San Diego County, California, was the object of a characterization program involving over ninety exploration and monitoring wells, geophysical investigations, flow meter logging, tracer testing, and fracture characterization. This intensively studied site rests on deeply weathered tonalite. The weathered zone extends several tens to about 100 feet below the surface; however, the deeply weathered material follows hydraulically active fractures to even greater depths. The flow meter logging was especially valuable both for locating conductive fractures but also, in un- pumped mode, for defining regions of upward and downward vertical flow. The deep weathering on the conductive fractures gives each pathway a large effective porosity that translates to lower flow velocities compared with unweathered fractures with similar transmissivities. The simulation of the groundwater flow at this site used a local-scale fracture network model which was upscaled to a continuum code at regional scales. At the largest scale we generated a small number of major fractures to match the topographic lineaments. At an intermediate scale we had geophysical lineaments that were deterministic under the site footprint, and stochastic elsewhere using generation parameters based on the lengths, orientations and intensities of the deterministic features. The fractures of the most detailed scale were background fractures that were stochastically generated from borehole data. The site-scale fracture network model was incorporated into a regional-scale MODFLOW model, by overlaying the MODFLOW grid on the fracture network model and calculating equivalent porous medium properties for each MODFLOW grid cell using the Oda tensor method. This fast algorithm calculates a permeability tensor for each MODFLOW grid cell by summing the oriented area-weighted permeabilities of each fracture. The resulting MODFLOW model was then calibrated to hydraulic head data collected from the site. The calibration process showed that the level of the groundwater heads could be maintained in the site only if there were a strong decrease in permeability with depth.

Clark, A.; Doe, T.; Jones, J. W.

2006-12-01

92

The role of disseminated calcite in the chemical weathering of granitoid rocks  

Microsoft Academic Search

Accessory calcite, present at concentrations between 300 and 3000 mg kg?1, occurs in fresh granitoid rocks sampled from the Merced watershed in Yosemite National Park, CA, USA; Loch Vale in Rocky Mountain National Park CO USA; the Panola watershed, GA USA; and the Rio Icacos, Puerto Rico. Calcite occurs as fillings in microfractures, as disseminated grains within the silicate matrix,

Art F White; T HOMAS D. BULLEN; DAVISON V. VIVIT; MARJORIE S. SCHULZ; DAVID W. CLOW

1999-01-01

93

Rocks.  

ERIC Educational Resources Information Center

This science unit is designed for limited- and non-English speaking students in a Chinese bilingual education program. The unit covers rock material, classification, characteristics of types of rocks, and rock cycles. It is written in Chinese and simple English. At the end of the unit there is a list of main terms in both English and Chinese, and…

Lee, Alice

94

Experimental Acid Weathering of Fe-Bearing Mars Analog Minerals and Rocks: Implications for Aqueous Origin of Hematite-Bearing Sediments in Meridiani Planum, Mars  

NASA Technical Reports Server (NTRS)

A working hypothesis for Meridiani evaporite formation involves the evaporation of fluids derived from acid weathering of Martian basalts and subsequent diagenesis [1, 2]. However, there are no reported experimental studies for the formation of jarosite and gray hematite (spherules), which are characteristic of Meridiani rocks from Mars analog precursor minerals. A terrestrial analog for hematite spherule formation from basaltic rocks under acidic hydrothermal conditions has been reported [3], and we have previously shown that the hematite spherules and jarosite can be synthetically produced in the laboratory using Fe3+ -bearing sulfate brines under hydrothermal conditions [4]. Here we expand and extend these studies by reacting Mars analog minerals with sulfuric acid to form Meridiani-like rock-mineral compositions. The objective of this study is to provide environmental constraints on past aqueous weathering of basaltic materials on Mars.

Golden, D. C.; Koster, A. M.; Ming, D. W.; Morris, R. V.; Mertzman, S. A.

2011-01-01

95

Rocks  

NSDL National Science Digital Library

This lesson plan is part of the DiscoverySchool.com lesson plan library for grades 6-8. This lesson focuses on sedimentary rocks and how they are formed. Students review the rock cycle and three rock types: igneous, metamorphic and sedimentary. They then write children's books about sedimentary rocks to explain the process to a younger audience. Included are objectives, materials, procedures, discussion questions, evaluation ideas, performing extensions, suggested readings, and vocabulary. Also available are videos which complement this lesson, audio vocabulary, and links to teaching tools for making custom quizzes, worksheets, puzzles and lesson plans.

2007-12-12

96

Rocking Changes  

NSDL National Science Digital Library

In this earth science activity, learners conduct a series of short experiments to explore how rocks change. Learners will examine the components of the rock cycle as well as how rocks can change over time due to weathering, erosion, pressure and heat. In particular, learners will model igneous, sedimentary, and metamorphic rocks.

Workshop, Mission S.

2013-01-01

97

Weathering of Igneous, Metamorphic, and Sedimentary Rocks in a Semi-arid Climate - An Engineering Application of Petrology  

NASA Astrophysics Data System (ADS)

Over the last 10 years, analytical methods have been introduced to students in CSM's undergraduate geological engineering program through a multi-year and multi-course approach. Beginning with principles and simple applications of XRD and SEM in sophomore Mineralogy and building on these skills in subsequent junior and senior year courses, geological engineers acquire proficiency in analytical methods. Essential workplace skills are thus acquired without adding an extra course in the undergraduate program. The following exercise is completed by juniors in an integrated Ig.-Met.-Sed. petrology course. The identification of clay mineral assemblages in soils provides a unique opportunity to demonstrate how basic principles of petrology and geochemistry are applied to engineering design criteria in construction site preparation. Specifically, the problem investigates the conditions leading to the formation of smectite in soils and the resulting construction risk due to soil expansion. Students examine soils developed on igneous, metamorphic, and sedimentary rocks near Denver, Colorado. The field locations are areas of suburban growth and several have expansive soil problems. The 2-week exercise includes sample collection, description, and preparation, determining clay mineralogy by XRD, and measurement of Atterberg Plasticity Indices. Teaching materials may be found at: http://serc.carleton.edu/NAGTWorkshops/petrology03/. This exercise accomplishes three objectives: First, skills in XRD analysis are developed by introducing students to concepts of particle size separation, particle orientation, and sequential analysis steps which are standard practices in clay characterization. Second, lecture material on the geochemistry of weathering of different rock types is reinforced. Students interpret the origin of clay mineral assemblages developed in soils derived from Precambrian gneisses, lower Paleozoic feldspathic sandstones, upper Paleozoic marine shales, and Tertiary basalts and volcaniclastics. Third, the role of petrologic characterization in site engineering is demonstrated. Students use Atterberg Limits measurements in conjunction with soil mineralogy to assess swelling potential and to design soil treatment needs for each building site.

Harrison, W. J.; Wendlandt, R. F.

2003-12-01

98

The Crayon Rock Cycle  

NSDL National Science Digital Library

In this activity, learners use crayons to draw conclusions about rocks and the rock cycle. Learners form crayons ((which can be "weathered"âheated, compressed and cooledâlike rocks) into models of sedimentary, metamorphic, and igneous rocks.

Muller, Eric

2004-01-01

99

Characterization and petrophysical properties of hydrothemally altered lacustrine volcanistic rock in Geyser Valley (Kamchatka) and its transformation by weathering  

NASA Astrophysics Data System (ADS)

Work is devoted to the study of volcano sedimentary hydrothermally altered rocks in Geyser Valley (Kamchatka peninsula, Russia). The Geyser Valley is one of the most unique nature objects in Russia. There are quite large geyser fields. The valley of the river is part of the Uson-Geysernaya depression, where hydrothermal activity is very high. Besides geysers here are hot springs, mud pots and fumarols. In the late Pleistocene (about 45-35 thousand years ago) the lake was located in the site of the modern valley of the Geysernaya river, where sediments accumulated intensively. Sedimentary material came from several sources in the form of pyroclastic flows, ash falls, was supplied by permanent and temporary water streams. The total deposit thickness reached several hundred meters. In the late Pleistocene there was breakthrough of reservoir and further conditions for the lacustrine deposits formation did not arose. Later the rocks were intensively processed by thermal water. In 2007 large landslide was formed in lower part of the Geysernaya River on their left slope. Deposits of Geysernaya (Q34grn) series and Pemsovaya (Q34pmz) series were involved in landslide displacement. The headscarp was formed up to 100 m and a length of 800 m, exposing the volcano-sedimentary section of hydrothermally altered rocks - a unique opportunity for sampling and subsequent laboratory study. Thickness of lake sediments is interbedding of coarse-grain, medium-grain, fine-grain tuffites predominantly acidic composition. The study of thin sections revealed that all samples are lithoclastic and vitroclastic hydrothermally altered tuffits. Currently, the primary minerals and volcanic glass is largely replaced by clay minerals of the smectite group. Pores and cracks are made zeolites (heulandite and clinoptilolite). All this points to the low-temperature (<200 ° C) hydrothermal conditions with a pH near neutral. Tyere are acid plagioclase and quartz in most samples The high content of smectite causes high hygroscopy of deposits. Rocks are highly porous - of 37-65%, primarily low density - 0,9-1,65 g/cm3 wave velocities - from 0.74 km/s for porous to 3.42 km/sec for dense varieties. All samples are characterized by low strength characteristics: uniaxial compressive strength - 1.2 - 21.7 MPa, uniaxial tension - 0,6-4,7 MPa. By water saturation strength decreases rapidly. Soft coefficient ranges from 0.22 to 0.57. Proving to be on the land surface as a result of slope deformation, volcanic-sedimentary hydrothermally altered rocks are destroyed quickly by precipitation and temperature fluctuations Rock turned to sand, silt and clay depending on the original composition. It was found that often weathered to clayey state tuffites inherit structural and textural features of the primary species. The composition also varies: increased content of clay minerals (to 90%), decreasing the content of zeolites (not to exceed 10%). Quartz and plagioclase form sans fraction. Physical and mechanical properties vary widely: the density of the soil increases slightly up to 1,57-1,59 g/cm3 for sands, 1,2-1,79 g/cm3 for clays, porosity of 51-52% and 49-78% respectively, moisture 22-23% and 43-98/ Clays are in a state of semi-solid to fluid. The high content of smectite determines high plastic properties. Plasticity Index varies widely from 11 to 57. Cohesion and the internal friction angle obtained from shear tests also change widely. For clayey sand grip reaches 137 kPa, internal friction angle - 17 degrees. In clay grip ranges from 13 kPa to 120 kPa, and the internal friction angle - from 11 degrees to 31 degrees. Large variation of properties of the investigated soils is explained by the inhomogeneity of volcano-sedimentary formations both vertically and laterally, varying degrees of hydrothermal alteration and of weathering, fracturing and cracks filling The obtained datas can adequately characterize the volcanic-lacustrine sediments in the valley of the Geysernaya river and use them in calculations of slope stability and for and geological mapping.

Gvozdeva, Irina; Zerkal, Oleg; Samarin, Evgeny

2013-04-01

100

Distribution of Sc, Ta, Hf, Zr, Co, and Fe in the crust of weathering of metalliferous gabbro-norites in volodarsk-volyn rock body  

SciTech Connect

Nuclear physics methods are used to determine the Sc, Ta, Hf, Zr, Co, and Fe contents in gabbro-norites and the component minerals of these rocks, as well as in the various zones of the crusts of weathering developed on gabbro-norites. It has been established that Sc, Ta, Hf, and Zr accumulate in the kaolinite zone, but Co is partly washed out of it.

Borisenko, L.F.; Chudinov, V.I.

1986-09-01

101

Sedimentary RocksSedimentary Rocks Geology 200  

E-print Network

Sedimentary RocksSedimentary Rocks Geology 200 Geology for Environmental ScientistsGeology for Environmental Scientists #12;Major Concepts · Sedimentary rocks form by the processes of weathering, erosion · Sedimentary structures are critical to interpreting sedimentary rocks. #12;The Rock CycleThe Rock Cycle #12

Kammer, Thomas

102

Permafrost and snow monitoring at Rothera Point (Adelaide Island, Maritime Antarctica): Implications for rock weathering in cryotic conditions  

NASA Astrophysics Data System (ADS)

In February 2009 a new permafrost borehole was installed close to the British Antarctic Survey Station at Rothera Point, Adelaide Island (67.57195°S 68.12068°W). The borehole is situated at 31 m asl on a granodiorite knob with scattered lichen cover. The spatial variability of snow cover and of ground surface temperature (GST) is characterised through the monitoring of snow depth on 5 stakes positioned around the borehole and with thermistors placed at three different rock surfaces (A, B and C). The borehole temperature is measured by 18 thermistors placed at different depths between 0.3 and 30 m. Snow persistence is very variable both spatially and temporally with snow free days per year ranging from 13 and more than 300, and maximum snow depths varying between 0.03 and 1.42 m. This variability is the main cause of high variability in GST, that ranged between - 3.7 and - 1.5 °C. The net effect of the snow cover is a cooling of the surface. Mean annual GST, mean summer GST, and the degree days of thawing and the n-factor of thawing were always much lower at sensor A where snow persistence and depth were greater than in the other sensor locations. At sensor A the potential freeze-thaw events were negligible (0-3) and the thermal stress was at least 40% less than in the other sensor locations. The zero curtain effect at the rock surface occurred only at surface A, favouring chemical weathering over mechanical action. The active layer thickness (ALT) ranged between 0.76 and 1.40 m. ALT was directly proportional to the mean air temperature in summer, and inversely proportional to the maximum snow depth in autumn. ALT temporal variability was greater than reported at other sites at similar latitude in the Northern Hemisphere, or with the similar mean annual air temperature in Maritime Antarctica, because vegetation and a soil organic horizon are absent at the study site. Zero annual amplitude in temperature was observed at about 16 m depth, where the mean annual temperature is - 3 °C. Permafrost thickness was calculated to range between 112 and 157 m, depending on the heat flow values adopted. The presence of sub-sea permafrost cannot be excluded considering the depth of the shelf around Rothera Point and its glacial history.

Guglielmin, Mauro; Worland, M. Roger; Baio, Fabio; Convey, Peter

2014-11-01

103

Sedimentary Rocks  

NSDL National Science Digital Library

This interactive lesson about sedimentary rocks begins with weathering and sediments and shows a sediment size chart. Next, it covers the three processes by which sediments are changed to rock: compaction, cementation, and recrystallization. Stream deposits along with the difference between clastic and non-clastic rocks are discussed and the formation of coal, shale, sandstone, limestone, conglomerate, and breccia is explained.

104

Gravestone Weathering  

NSDL National Science Digital Library

In this activity (located on pages 9-14 of PDF), learners visit a cemetery to examine the distinguishing characteristics of rock weathering. After researching stone weathering and acid rain, learners apply their knowledge to collect data related to chemical decomposition and physical disintegration at a cemetery site. This detailed lesson guide includes tips for educators, pre/post activity suggestions, hands-outs, and background information.

Wiberg, Leanne; History, National M.

2000-01-01

105

Rocks, Rocks, Rocks!  

NSDL National Science Digital Library

What are the three types of rocks in the earth? Miss Rogers will hand out this chart. Compare and contrast the three rock types as you read. Three-circle Venn Diagram Record what you learn for each type of rock (IGNEOUS, SEDIMENTARY, METAMORPHIC). 3 Types of Rocks Watch this video. Rock Video Read about the rock cycle. Think about what objects in our classroom could represent the rock cycle. The Rock Cycle Read over the activity we ...

Rogers, Miss

2011-10-26

106

Rates of Chemical Weathering  

NSDL National Science Digital Library

In this activity, students will investigate the weathering of rocks by chemical processes. They will use effervescent cleansing tablets as a model for rock, and vary surface area, temperature, and acidity to see how rapidly the "rock" dissolves. This investigation will help them understand three of the factors that affect the rate of chemical weathering and develop better understanding of how to design controlled experiments by exploring only one experimental variable at a time.

Passow, Michael

107

Fracture-controlled fluid circulation and dissolutional weathering in sinkhole-prone carbonate rocks from central Italy  

NASA Astrophysics Data System (ADS)

Fractures, karstic cavities, and calcite precipitates are analysed on Mesozoic, carbonate strata from the Cornicolani Mountains, central Italy, to quantify the relationships between fractures and related karstic cavities and to infer the fracture-controlled fluid pathways. The study area is characterized by active sinkholes and other karstic caves, which are among the deepest ones in the world. Results show a clear control of fractures on the process of dissolutional weathering and, therefore, on the fluid circulation. A model is proposed, in which two different modes of dissolutional weathering coexist: (i) a mode of diffuse weathering consisting in the dissolutional enlargement of closely spaced joints and bedding surfaces. This process affects the strata situated at depths of up to 5 m; (ii) a mode of more concentrated weathering active along highly permeable fault damage zones at depths of at least 70 m. These processes are mostly connected with the shallow circulation of calcite-dissolving meteoric waters, and are controlled by the disparity of permeability between the fault damage zones and the surrounding jointed strata. Some calcite precipitates along the studied fault damage zones may be connected with a dissolutional process operated by waters that interacted with the adjacent quiescent volcanic district. Such calcite-dissolving waters and the presence of high-permeable fault damage zones, along which the waters may ascent, are probably the cause for the development of some of the deep sinkholes along faults in the study area.

Billi, Andrea; Valle, Andrea; Brilli, Mauro; Faccenna, Claudio; Funiciello, Renato

2007-03-01

108

Climate and rock weathering: a study of terrestrial age dated ordinary chondritic meteorites from hot desert regions  

Microsoft Academic Search

Ordinary chondrites (OC) recovered from the desert areas of Roosevelt County, New Mexico, the Nullarbor Region of Western Australia, and the Algerian and Libyan Sahara, for which 14C terrestrial ages have been determined, were examined by 57Fe Mössbauer spectroscopy. OC were chosen as a standard sample to investigate weathering processes as their well constrained trace and bulk element chemistry, normative

P. A. Bland; A. S. Sexton; A. J. T. Jull; A. W. R. Bevan; F. J. Berry; D. M. Thornley; T. R. Astin; D. T. Britt; C. T. Pillinger

1998-01-01

109

Silica- and sulfate-bearing rock coatings in smelter areas: Products of chemical weathering and atmospheric pollution I. Formation and mineralogical composition  

NASA Astrophysics Data System (ADS)

Black rock-coatings occur in proximity to smelters and roast yards of the Greater Sudbury area, Ontario, Canada and contain information about the past interactions between surface minerals, and gaseous and particulate atmospheric components, many of which were pollutants. Rock-coatings were collected from various locations within the Sudbury area and are characterized with scanning electron microscopy, transmission electron microscopy, X-ray diffraction, electron microprobe analysis, infrared spectroscopy and X-ray photoelectron spectroscopy. Acidic fumigations and rain, the result of vast quantities of SO2 released from smelting, increased the chemical weathering rate of exposed rocks in the Sudbury area. Non-stoichiometric dissolution of the silicate minerals under acidic conditions resulted in the accumulation of silicic acid and the subsequent formation of a silica-gel type coating. The silica gel transformed overtime into amorphous silica, opal (opal C and opal-CT) and cristobalite. Dissolution of the underlying rock and also of metal-bearing particles by sulfuric acid resulted in the in situ formation of metal-sulfate-rich layers on the interfaces between the atmosphere and the silica-rich coating (atmosphere-coating interface, ACI) and between the silica-rich coating and the underlying rock (rock-coating interface, RCI). These metal-sulfate-rich layers contain nanometer aggregates of Fe-Cu-sulfate-hydroxide, goldichite, mereiterite, guildite, butlerite and antlerite. The silica-rich matrix also contains a mix of detrital grains from adjacent rocks and soils (feldspar, quartz, hematite, chlorite, montmorillonite) and non-dissolved smelter-derived nano- to micro-size particulates (metal-silicates, metal-oxides, C-spheres). The apparent disequilibrium between the embedded particles and the Fe-Cu-sulfates suggests that trapped nanoparticles were encapsulated into pores which prevented their equilibration with acidic metal-sulfate-bearing fluids. An XPS depth profile indicates a gradual transition from lower to higher concentrations of metals from the coating surface towards the metal-sulfate-rich layer on the ACI, which suggests that the outer surface of the coatings is currently leached on an angstrom scale by surface waters.

Mantha, Nathalie M.; Schindler, Michael; Murayama, Mitsuhiro; Hochella, Michael F.

2012-05-01

110

Space Weathering of Apollo 16 Sample 62255: Lunar Rocks as Witness Plates for Deciphering Regolith Formation Processes  

NASA Technical Reports Server (NTRS)

Space weathering, or alteration that occurs at the surfaces of materials exposed directly to space, has been one of the primary areas of focus of lunar studies for the past several years. It is caused by processes such as micrometeorite impacts and solar wind bombardment, and effects can include microcraters, spall zones, and vapor deposits. Much of the recent work on space weathering has been concentrated on nanoscale features, especially the amorphous rims commonly found on individual lunar soil grains. The rims typically contain nanophase Fe metal globules, which, along with Fe metal globules in agglutinates, have a profound effect on optical properties of lunar soils. The nanophase metallic iron globules cause the characteristic optical changes (reddening and darkening) found in mature lunar soils.

Wentworth, S. J.; McKay, D. S.; Keller, L. P.

2004-01-01

111

Effects of direct and indirect heating on the validity of rock weathering simulation studies and durability tests  

Microsoft Academic Search

Rock surface and subsurface temperature responses in samples exposed to direct heating (insolation) under natural hot desert conditions reveal considerable variability between lithologies related to differences in thermal properties, especially albedo and thermal conductivity. However, when the same samples are heated indirectly by air in an oven-based environmental cabinet, lithological differences in temperature response disappear and all samples attain temperatures

P. A. Warke; B. J. Smith

1998-01-01

112

Geochemistry of lower Vindhyan clastic sedimentary rocks of Northwestern Indian shield: Implications for composition and weathering history of Proterozoic continental crust  

NASA Astrophysics Data System (ADS)

The western margin of the ˜1600 Ma Vindhyan basin of the Indian shield is marked by the presence of lower Vindhyan Group (LVG) comprising shales and sandstone with minor limestone, conglomerate and mafic volcanic flows at the base. Major and trace element compositions of sandstones and shales of the LVG have been investigated to infer the nature of provenance, weathering processes, and tectonic setting. Provenance analysis using trace elements and petrography suggests that the Archaean Banded Gneissic Complex (BGC) of Rajasthan is most likely the source of these clastic rocks. The shale and sandstone comprising lower part of LVG namely Khardeola Formation are distinctive in having high LILE such as Th, Rb, and K 2O, high ferromagnesian trace elements and also higher values of K 2O/Na 2O, Rb/Sr and (La/Yb) n ratios in comparison to succeeding sedimentary units comprising upper formations of the LVG. The significantly different geochemical characteristics of Khardeola Formation suggest change in provenance with sediments in the lower formation being derived from proximal source and those of upper formations from distal source. Based on REE patterns and Eu/Eu ? values, the clastic sediments of Khardeola formation can be modeled by a mixture of 60% Berarch Granite and 40% mafic volcanic rocks of Hindoli belt. On the other hand, the upper formations are best modeled with a mixture of 60% BGC granitic gneisses, 20% BGC mafic enclaves and 20% Berach Granite. CIA (chemical index of alteration) values and A-CN-K plot suggest that the source area experienced moderate to high degree of chemical weathering under warm and humid conditions. The shift of sediment source from local in the beginning to distal during later period suggests sedimentation in a tectonically active basin.

Raza, Mahshar; Dayal, A. M.; Khan, Abdullah; Bhardwaj, V. R.; Rais, Sarwar

2010-07-01

113

Do Rocks Last Forever?  

NSDL National Science Digital Library

In this activity, students learn about chemical and mechanical weathering in rocks. From the background material, they will learn that the change that takes place in rocks is called weathering and that this term refers to the destructive processes that change the character of rock at or near the Earth's surface. Processes of mechanical weathering (or physical disintegration) break rock into smaller pieces but do not change its chemical composition; processes of chemical weathering (or rock decomposition) transform rocks and minerals exposed to water and atmospheric gases into new chemical compounds (different rocks and minerals), some of which can be dissolved away. Four experiments that illustrate the effects of mechanical and chemical weathering are provided.

114

Weathering Experiment  

NSDL National Science Digital Library

After discussing weathering and erosion in class, students are asked to do a small amount of research on different types of chemical weathering, physical weathering, and erosion processes (mostly out of their textbook). Outside of class students then dirty at least four similar dishes with the same type, thickness and aerial extent of food, preferably baked on to ensure maximum stick. One dish is set aside as a control (no weathering or erosion will occur for that dish). For each of the remaining three dishes, students devise an experiment that mimics some sort of chemical weathering, physical weathering, or erosion process (freeze/thaw, sand abrasion, oxidation, etc.). Prior to the experiments, the thickness of food is measured. Experiments are timed, and at the end of the experiment each plate is turned over to determine how much which method removed the greatest aerial extent of food. Experimental results are compared to the control plate to determine the actual effectiveness. Erosion/weathering rates are determined by dividing the thickness of food removed by the experimental time. Students then calculate how long it would take to remove a pile of food the size of the Geology building (assume a 50 m radius sphere), and to remove an amount of food equivalent to the depth of the Grand Canyon. Students then compare these results to rock erosion and weathering rates, performing similar calculations using these "real" rates (see the full project description for details). Photos of each step and the scientists are encouraged in their 2-3 page writeup.

Stelling, Pete

115

Rocks, Rocks, Rocks  

NSDL National Science Digital Library

Continuing the Asteroid Impact challenge, student teams test rocks to identify their physical properties (such as luster, hardness, color, etc.) and classify them as igneous, metamorphic or sedimentary. They complete a worksheet table to record all of the rock properties, and then answer worksheet questions to deepen their understanding of rock properties and relate them to the cavern design problem.

Adventure Engineering

116

Rocks, Rocks, Rocks  

NSDL National Science Digital Library

Students test rocks to identify their physical properties (such as luster, hardness, color, etc.) and classify them as igneous, metamorphic or sedimentary. They complete a worksheet table to record all of the rock properties, and then answer worksheet questions to deepen their understanding of rock properties and relate them to the cavern design problem.

Adventure Engineering

117

Characteristics of chemical weathering and water-rock interaction in Lake Nyos dam (Cameroon): Implications for vulnerability to failure and re-enforcement  

NASA Astrophysics Data System (ADS)

For the first time, comprehensive study of hydrogeochemistry of water seeps, role of chemical weathering on dam failure, estimation of minimum width of dam to resist failure and simulation of changes in dissolved ions and secondary mineral was conducted on the Lake Nyos dam. The salient results and conclusions were; the dam spring water represented a mixture of 60-70% rainwater and 30-40% Lake water (from 0 to -40 m). The chemistry of the observed waters was Ca-HCO3 for rainwater, Ca-Mg-HCO3 in boreholes, and Mg-Ca-HCO3- for spring water. The relative rate at which ions dissolved in water was HCO3- > Mg2+ > Ca2+ > Na+ > SiO2 > K+ > NO3- > SO42- > Cl-. Weathering of rocks resulted in the formation of clay minerals such as kaolinite and smectite. Relative mobility of elements compared to Alumina (Al2O3) indicated that in monzonites there was a loss of CaO, Na2O, K2O, P2O5 and gain of SiO2, Fe2O3, TiO2, MnO and MgO, while in basalts there was a loss of SiO2, Fe2O3, Ca2O, NaO, MgO and gain of TiO2, K2O and P2O5. Values of chemical alteration index that ranged from 49 to 82 suggest a weak to intermediate categories of chemical weathering that occurred at a rate of 5.7 mm/year. Paired to that rate, which suggests that the dam is not vulnerable to failure at the previously thought time scale, some other processes (physical weathering, secondary mineral formation and lake overflow) can cause instant failure. Hydrostatic pressure of 1.6 GN generated by Lake water can be supported only when the width of the dam is greater than 19 m. PHREEQC-based simulation for 10 years indicates decoupling of Ca and Mg, and Na and Mg. Multidisciplinary monitoring of the dam is advocated.

Fantong, Wilson Y.; Kamtchueng, Brice T.; Yamaguchi, Kohei; Ueda, Akira; Issa; Ntchantcho, Romaric; Wirmvem, Mengnjo J.; Kusakabe, Minoru; Ohba, Takeshi; Zhang, Jing; Aka, Festus T.; Tanyileke, Gregory; Hell, Joseph V.

2015-01-01

118

Testing the limits of micro-scale analyses of Si stable isotopes by femtosecond laser ablation multicollector inductively coupled plasma mass spectrometry with application to rock weathering  

NASA Astrophysics Data System (ADS)

An analytical protocol for accurate in-situ Si stable isotope analysis has been established on a new second-generation custom-built femtosecond laser ablation system. The laser was coupled to a multicollector inductively coupled plasma mass spectrometer (fsLA-MC-ICP-MS). We investigated the influence of laser parameters such as spot size, laser focussing, energy density and repetition rate, and ICP-MS operating conditions such as ICP mass load, spectral and non-spectral matrix effects, signal intensities, and data processing on precision and accuracy of Si isotope ratios. We found that stable and reproducible ICP conditions were obtained by using He as aerosol carrier gas mixed with Ar/H2O before entering the plasma. Precise ?29Si and ?30Si values (better than ± 0.23‰, 2SD) can be obtained if the area ablated is at least 50 × 50 ?m; or, alternatively, for the analysis of geometric features down to the width of the laser spot (about 20 ?m) if an equivalent area is covered. Larger areas can be analysed by rastering the laser beam, whereas small single spot analyses reduce the attainable precision of ?30Si to ca. ± 0.6‰, 2SD, for < 30 ?m diameter spots. It was found that focussing the laser beam beneath the sample surface with energy densities between 1 and 3.8 J/cm2 yields optimal analytical conditions for all materials investigated here. Using pure quartz (NIST 8546 aka. NBS-28) as measurement standard for calibration (standard-sample-bracketing) did result in accurate and precise data of international reference materials and samples covering a wide range in chemical compositions (Si single crystal IRMM-017, basaltic glasses KL2-G, BHVO-2G and BHVO-2, andesitic glass ML3B-G, rhyolitic glass ATHO-G, diopside glass JER, soda-lime glasses NIST SRM 612 and 610, San Carlos olivine). No composition-dependent matrix effect was discernible within uncertainties of the method. The method was applied to investigate the Si isotope signature of rock weathering at the micro-scale in a corestone sampled from a highly weathered roadcut profile in the tropical Highlands of Sri Lanka. The results show that secondary weathering products accumulated in cracks and grain boundaries are isotopically lighter than their unweathered plagioclase host, consistent with isotopically heavy dissolved Si found in rivers.

Schuessler, Jan A.; von Blanckenburg, Friedhelm

2014-08-01

119

Vertical anisotropy of hydraulic conductivity in fissured layer of hard-rock aquifers due to the geological structure of weathering profiles  

E-print Network

to the geological structure of weathering profiles Jean-Christophe Maréchala,* , Robert Wynsb , Patrick Lachassagnec, the fissured layer of the weathered granite profile showing the existence of many sub-horizontal fissures. It confirms that, within the fissured layer, the permeability of sub-horizontal fissures due to the weathering

Paris-Sud XI, Université de

120

Quantification of physical weathering rates using thermodynamics  

Microsoft Academic Search

Physical weathering plays an important role in the global rock cycle in that it breaks up primary rock, thereby increasing the surface area for chemical weathering and providing the substrate for soil formation. We use a simple, thermodynamics based approach to quantify magnitudes of weathering, their spatial variation across climatic regions and their sensitivity to climatic change. Our approach is

F. Gans; S. Arens; S. J. Schymanski; A. Kleidon

2010-01-01

121

Rock Cycle Animation  

NSDL National Science Digital Library

The rock cycle is an ongoing process in which rock, driven by tectonic processes such as volcanoes and earthquakes, the surface processes of weathering and erosion, and compaction, is created, destroyed, and recycled. This interactive feature introduces viewers to the processes which come into play as rock proceeds through the various portions of the cycle.

2005-11-01

122

Rock Cycle Animation  

NSDL National Science Digital Library

The rock cycle is an ongoing process in which rock, driven by tectonic processes such as volcanoes and earthquakes, the surface processes of weathering and erosion, and compaction, is created, destroyed, and recycled. This interactive feature introduces viewers to the processes which come into play as rock proceeds through the various portions of the cycle.

2011-06-22

123

Rock Cycle Animation  

NSDL National Science Digital Library

The rock cycle is an ongoing process in which rock, driven by tectonic processes such as volcanoes and earthquakes, the surface processes of weathering and erosion, and compaction, is created, destroyed, and recycled. This interactive feature introduces viewers to the processes which come into play as rock proceeds through the various portions of the cycle.

124

Vertical anisotropy of hydraulic conductivity in the fissured layer of hard-rock aquifers due to the geological structure of weathering profiles  

E-print Network

1 Vertical anisotropy of hydraulic conductivity in the fissured layer of hard-rock aquifers due the transmissive function in the aquifer and is pumped by most of the wells drilled in hard-rock areas; - Fresh

Paris-Sud XI, Université de

125

Rock weathering and Carbon cycle  

Microsoft Academic Search

In the history of the Earth system, we can find indicators of hot or glacial periods, as well as brutal climatic change... How can we explain those climate variations on a geological timescale ? One of the causative agents is probably the fluctuation of atmospheric CO2 amounts, (gas responsible for the greenhouse effect). A concrete study of some CO2 fluxes

Patrick Strozza

2010-01-01

126

Rock Cycle  

NSDL National Science Digital Library

Through five lessons, students are introduced to all facets of the rock cycle. Topics include rock and mineral types, material stresses and weathering, geologic time and fossil formation, the Earth's crust and tectonic plates, and soil formation and composition. Lessons are presented in the context of the related impact on humans in the form of roadway and tunnel design and construction, natural disasters, environmental site assessment for building structures, and measurement instrumentation and tools. Hands-on activities include experiencing tensional, compressional and shear material stress by using only hand force to break bars of soap; preparing Jeopardy-type trivia questions/answers for a class game that reinforces students' understanding of rocks and the rock cycle; creating "fossils" using melted chocolate; working within design constraints to design and build a model tunnel through a clay mountain; and soil sampling by creating tools, obtaining soil cores, documenting a soil profile log, and analyzing the findings to make engineering predictions.

Integrated Teaching And Learning Program

127

Honeycomb Weathering of Limestone Formations  

USGS Multimedia Gallery

Honeycomb weathering of sandstone located on the shores of Puget Sound occurs when expanding salt crystals break fragments of rock, creating a small hole that becomes larger as the process repeats itself over time....

128

Fracture characteristics in weathered granites  

NASA Astrophysics Data System (ADS)

The variability of weathered materials is an important factor in the geotechnical characterization of rock for engineering purposes. Most engineering rock mass classifications include weathering schemes that separate the weathering profile into zones or grades that depend upon the engineering and geological properties of the rock. Many geotechnical characteristics, including weathering, are controlled by the density and arrangement of fractures within the rock, but the relationships between fracture patterns and weathering grades are typically not addressed. Fracture characteristics were investigated in 13 exposures in five study areas in weathered granite in eastern Asia. All weathering grades were present, but never in the same exposure. Two approaches were used to evaluate the field data: (1) joint spacings were tabulated and examined within each weathering grade (tabulated classification); and (2) each exposure was classified according to the dominant weathering grade (visual classification). Mean and median joint spacings and joint spacing frequency distributions were analyzed and compared statistically for each approach. The box fractal dimensions for joint spacing were calculated for exposures classified visually in each weathering grade. Three-dimensional models of fresh and weathered granite were also generated and sampled for comparison to the field data. Mean joint spacing is usually 25% or more closer in weathered granite than it is in fresh granite, and the difference between the mean spacings for weathered granite and fresh granite tend to be statistically significant. There are no significant differences between any distribution medians. The joint spacing distributions for weathered granite and fresh granite are also not statistically significantly different, and there are no significant differences among the joint spacing frequency distributions for the different grades of weathered granite. Fractal analysis of joint spacings, however, suggests spacing characteristics of fresh and slightly weathered (SW) granite are very different from those in moderately, highly, and completely weathered granite, and sampling of three-dimensional models for weathered and fresh granite supports this. In an engineering context, this suggests that joint spacing relationships in the various grades of weathered granite can be treated as the same regardless of weathering grade and that joint patterns in fresh granite must be evaluated separately. This knowledge could result in significant time and cost savings in the geotechnical characterization of these materials.

Ehlen, Judy

1999-12-01

129

Weather Watch  

ERIC Educational Resources Information Center

Suggests a number of ways in which Federal Aviation Agency weather report printouts can be used in teaching the weather section of meteorology. These weather sequence reports can be obtained free of charge at most major airports. (JR)

Bratt, Herschell Marvin

1973-01-01

130

Weathering and weathering rates of natural stone  

NASA Astrophysics Data System (ADS)

Physical and chemical weathering were studied as separate processes in the past. Recent research, however, shows that most processes are physicochemical in nature. The rates at which calcite and silica weather by dissolution are dependent on the regional and local climatic environment. The weathering of silicate rocks leaves discolored margins and rinds, a function of the rocks' permeability and of the climatic parameters. Salt action, the greatest disruptive factor, is complex and not yet fully understood in all its phases, but some of the causes of disruption are crystallization pressure, hydration pressure, and hygroscopic attraction of excess moisture. The decay of marble is complex, an interaction between disolution, crack-corrosion, and expansion-contraction cycies triggered by the release of residual stresses. Thin spalls of granites commonly found near the street level of buildings are generally caused by a combination of stress relief and salt action. To study and determine weathering rates of a variety of commercial stones, the National Bureau of Standards erected a Stone Exposure Test Wall in 1948. Of the many types of stone represented, only a few fossiliferous limestones permit a valid measurement of surface reduction in a polluted urban environment.

Winkler, Erhard M.

1987-06-01

131

Weather Forecasting  

NSDL National Science Digital Library

Students consider how weather forecasting plays an important part in their daily lives. They learn about the history of weather forecasting — from old weather proverbs to modern forecasting equipment — and how improvements in weather technology have saved lives by providing advance warning of natural hazards.

Integrated Teaching and Learning Program,

132

UM Weather  

NSDL National Science Digital Library

Sponsored by The Weather Underground at the University of Michigan at Ann Arbor, UM Weather bills itself as the "Internet's premier source of weather information." The site offers several general audience tools such as the Fast Forecast for any city in the US, ski weather, and weather cams. But, it also provides access to over two dozen weather software packages, a new computer model forecasts page, and most impressively a list of close to 400 other weather related Web sites. Professionals and researchers will appreciate the non-technical feel of the site and the valuable information they can procure from it.

133

Winter Weather  

NSDL National Science Digital Library

This project explores factors that help create severe winter weather. An interactive simulation provides hands-on experience, followed by guiding questions and resource exploration. Weather affects our everyday lives. Some days it's sunny and some days its not. The years weather is split up into seasons. 1. What are the four seasons? 2. What kind of weather do you see in the summer? 3. What kind of weather is unique to winter? 4. ...

Mrs. Bellows

2009-09-28

134

Soil Genesis and Development, Lesson 1 - Rocks and Minerals  

Technology Transfer Automated Retrieval System (TEKTRAN)

All soil ultimately forms from rocks or their weathering products. Geologists classify rocks according to their origins. General rock types can weather to give soils with distinctive properties. The objectives of this lesson are: 1. To be able to classify rocks based on visual characteristics accord...

135

Winter Weather  

MedlinePLUS

... About CDC.gov . Natural Disasters and Severe Weather Earthquakes Being Prepared Emergency Supplies Home Hazards Indoor Safety ... What's New A - Z Index Disasters & Severe Weather Earthquakes Extreme Heat Floods Hurricanes Landslides Tornadoes Tsunamis Volcanoes ...

136

Weather Odds  

NSDL National Science Digital Library

The Weather Odds site helps users learn about the odds of various weather happening at monthly and daily levels. The site relies on past climate data from thousands of locations and it's a fine resource. In the Quick Weather Data area, visitors can check out popular United States locations or use the search engine to breeze along to their preferred habitat. This version of Weather Odds is compatible with all operating systems.

2014-05-08

137

The Rock Cycle Experiments  

NSDL National Science Digital Library

Maintained by the BBC Education Web site, The Rock Cycle Experiments page contains ten activities related to the rock cycle, beginning with weathering and ending with the uplift of rocks. Each activity pops up after clicking the link within the very well done interactive diagram of the rock cycle. The activities are simple but effective; for example, the transportation lesson has students run water through sand to see its effects. The hands-on experience of the activities helps reinforce the learning and of course makes it fun.

King, Chris.

138

World Weather  

NSDL National Science Digital Library

What's going on in the world of weather? Are there storms around Sri Lanka? What about the snows of Kilimanjaro? These can be pressing questions, indeed, and the World Weather app is a great way to stay in touch with weather patterns around the globe. Users will find that they can just type in a city name to see the current weather and also zoom around the globe as they see fit. It's a remarkable addition to the world of existing weather tracking apps and is compatible with all operating systems.

Elias, Jaume S.

2014-02-20

139

Predicting Weather  

NSDL National Science Digital Library

By performing the activities presented in this website, fourth grade students can learn about weather instruments and data collection. This website, produced by the Government of Saskatchewan, also explores how the weather can impact local communities. Each activity presented here includes both objectives and assessment techniques for the lesson. Sixteen different activity suggestions provide students and teachers with ample opportunities to explore weather in the classroom.

2008-03-28

140

Weather Watch  

NSDL National Science Digital Library

The weather watch activity is designed to provide instruction on how to collect weather data from on-line databases. Following completion of this activity the user will be able to look up weather conditions for any city in North America, know what radar maps are used for and how to access them, and know how to access satellite images and make estimated guesses on cloud conditions for their area from them.

Hopson, R.

141

Weather Instruments  

NSDL National Science Digital Library

This Topic in Depth discusses the variety of instruments used to collect climate and weather data. The first two websites provide simple introductions to the many weather instruments. Bethune Academy's Weather Center (1) discusses the functions of psychrometers, anemometers, weather balloons, thermometers, and barometers. The Illinois State Water Survey (2) furnishes many images of various instruments that collect data daily for legal issues, farmers, educators, students, and researchers. The third website (3), created by the Center for Improving Engineering and Science Education (CIESE), provides a classroom activity to educate users on how to build and use weather instruments. By the end of the group project, students should know all about wind vanes, rain gauges, anemometers, and thermometers. Next, the Miami Museum of Science provides a variety of activities to help students learn about the many weather instruments including wind scales and wind chimes (4). Students can learn about the wind, air pressure, moisture, and temperature. At the fifth website, the Tyson Research Center at Washington University describes the devices it uses in its research (5). At the various links, users can find out the center's many projects that utilize meteorological data such as acid rain monitoring. The sixth website, a pdf document created by Dr. John Guyton at the Mississippi State University Extension Service, provides guidance to teachers about the education of weather patterns and instruments (6). Users can find helpful information on pressure systems, humidity, cloud patterns, and much more. Next, the University of Richmond discusses the tools meteorologists use to learn about the weather (7). While providing materials about the basic tools discussed in the other websites, this site also offers information about weather satellites, radar, and computer models. After discovering the many weather instruments, users can learn about weather data output and analysis at the Next Generation Weather Lab website (8). This expansive website provides an abundance of surface data and upper air data as well as satellite and radar images for the United States.

142

Weather Experiments  

NSDL National Science Digital Library

Looking for fun ways to learn about weather? Weather Wiz Kids has 39 fun weather related experiments for you to try. These experiments can be done in the classroom with your friends or even at home! Some of the experiments on the site include: tornado in a bottle, make lightning, make it rain, cloud in a bottle, what's in the wind, the Doppler Effect, and baking soda volcano.

2010-01-01

143

Natural Weathering Rates of Silicate Minerals  

NASA Astrophysics Data System (ADS)

Silicates constitute more than 90% of the rocks exposed at Earth's land surface (Garrels and Mackenzie, 1971). Most primary minerals comprising these rocks are thermodynamically unstable at surface pressure/temperature conditions and are therefore susceptible to chemical weathering. Such weathering has long been of interest in the natural sciences. Hartt (1853) correctly attributed chemical weathering to "the efficacy of water containing carbonic acid in promoting the decomposition of igneous rocks." Antecedent to the recent interest in the role of vegetation on chemical weathering, Belt (1874) observed that the most intense weathering of rocks in tropical Nicaragua was confined to forested regions. He attributed this effect to "the percolation through rocks of rain water charged with a little acid from decomposing vegetation." Chamberlin (1899) proposed that the enhanced rates of chemical weathering associated with major mountain building episodes in Earth's history resulted in a drawdown of atmospheric CO2 that led to periods of global cooling. Many of the major characteristics of chemical weathering had been described when Merrill (1906) published the groundbreaking volume Rocks, Rock Weathering, and Soils.The major advances since that time, particularly during the last several decades, have centered on understanding the fundamental chemical, hydrologic, and biologic processes that control weathering and in establishing quantitative weathering rates. This research has been driven by the importance of chemical weathering to a number environmentally and economically important issues. Undoubtedly, the most significant aspect of chemical weathering is the breakdown of rocks to form soils, a process that makes life possible on the surface of the Earth. The availability of many soil macronutrients such as magnesium, calcium, potassium, and PO4 is directly related to the rate at which primary minerals weather. Often such nutrient balances are upset by anthropogenic activities. For example, Huntington et al. (2000) show that extensive timber harvesting in the southeastern forests of the United States, which are underlain by intensely weathered saprolites, produces net calcium exports that exceed inputs from weathering, thus creating a long-term regional problem in forest management.The role of chemical weathering has long been recognized in economic geology. Tropical bauxites, which account for most of world's aluminum ores, are typical examples of residual concentration of silicate rocks by chemical weathering over long time periods (Samma, 1986). Weathering of ultramafic silicates such as peridotites forms residual lateritic deposits that contain significant deposits of nickel and cobalt. Ores generated by chemical mobilization include uranium deposits that are produced by weathering of granitic rocks under oxic conditions and subsequent concentration by sorption and precipitation ( Misra, 2000).Over the last several decades, estimating rates of silicate weathering has become important in addressing new environmental issues. Acidification of soils, rivers, and lakes has become a major concern in many parts of North America and Europe. Areas at particular risk are uplands where silicate bedrock, resistant to chemical weathering, is overlain by thin organic-rich soils (Driscoll et al., 1989). Although atmospheric deposition is the most important factor in watershed acidification, land use practices, such as conifer reforestation, also create acidification problems ( Farley and Werritty, 1989). In such environments, silicate hydrolysis reactions are the principal buffer against acidification. As pointed out by Drever and Clow (1995), a reasonable environmental objective is to decrease the inputs of acidity such that they are equal to or less than the rate of neutralization by weathering in sensitive watersheds.The intensive interest in past and present global climate change has renewed efforts to understand quantitatively feedback mechanisms between climate and chemical weathering. On timescales longer than

White, A. F.

2003-12-01

144

Three classes of Martian rocks  

NASA Technical Reports Server (NTRS)

In this portion of the 360-degree color gallery pan, looking to the northeast, the colors have been exaggerated to highlight the differences between rocks and soils. Visible are the downwind sides of rocks, not exposed to wind scouring like Barnacle Bill (which faces upwind). There is a close correspondence between the shapes and colors of the rocks. Three general classes of rocks are recognized: large rounded rocks with weathered coatings, small gray angular rocks lacking weathered coatings, and flat white rocks. The large rounded rocks in the distance, marked by the red arrows, are comparable to Yogi. Spectral properties show that these rocks have a highly weathered coating in addition to a distinctive shape. A second population of smaller, angular rocks (blue arrows) in the foreground have unweathered surfaces even on the downwind side, except where covered on their tops by drift. These are comparable to Barnacle Bill. They may have been emplaced at the site relatively recently, perhaps as ejecta from an impact crater, so they have not had time to weather as extensively as the larger older rocks. The third kind of rock (white arrows) is white and flat, and includes Scooby Doo in the foreground and a large deposit in the background called Baker's Bank. The age of the white rock relative to the other two classes is still being debated. One representative rock of each class (Yogi, Barnacle Bill, and Scooby Doo) has been measured by the rover.

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator. JPL is an operating division of the California Institute of Technology (Caltech).

1997-01-01

145

Sedimentary Rocks: Carbonate Rocks  

NSDL National Science Digital Library

Sedimentary Rocks: Carbonate Rocks is a course handout meant to accompany the discussion of chemical and biochemical sedimentary rocks. Rock composition is broken into the main categories of limestone and dolostone. Depositional conditions are discussed, including the topics of coral reefs, plankton, and carbonate compensation depth (CCD). There are a few photographs, which display calcareous algae. Links are provided to the online Physical Geology resources at Georgia Perimeter College.

Gore, Pamela

146

Role of Microorganisms in Wear Down of Rocks and Minerals  

Microsoft Academic Search

Rock weathering is an awkward term. Near and below the Earth’s surface, physical and chemical processes operate under direct or indirect control of living matter. Weathering, however, strongly relates to physical and chemical changes produced by the weather and its long-term average, the climate. Meteorological connotation of the term ignores the importance of biological interactions in the process of rock

Anna A. Gorbushina; W. E. Krumbein

147

Wacky Weather  

ERIC Educational Resources Information Center

What do a leaf blower, water hose, fan, and ice cubes have in common? Ask the students who participated in an integrative science, technology, engineering, and mathematics (I-STEM) education unit, "Wacky Weather," and they will tell say "fun and severe weather"--words one might not have expected! The purpose of the unit…

Sabarre, Amy; Gulino, Jacqueline

2013-01-01

148

Weather Forecasting  

NSDL National Science Digital Library

This activity (on page 2 of the PDF) is a full inquiry investigation into meteorology and forecasting. Learners will research weather folklore, specifically looking for old-fashioned ways of predicting the weather. Then, they'll record observations of these predictors along with readings from their own homemade barometer, graphing the correct predictions for analysis. Relates to linked video, DragonflyTV: Forecasting.

2012-06-26

149

Rock Cycle: Environments of Formation  

NSDL National Science Digital Library

This Science Object is the second of four Science Objects in the Rocks SciPack. It provides an in-depth exploration of the conditions and environment required during the formation of igneous, sedimentary, and metamorphic rocks. Igneous rock forms from the cooling and crystallization of magma. Sometimes the magma reaches Earth's surface and cools quickly; sometimes it does not reach the surface and thus cools slowly. Rocks at Earth's surface are subjected to processes of weathering and erosion, producing sediments as they are broken down. Sedimentary rock is formed when sediments are buried and solidified through various processes. Sedimentary rock buried deep enough may be transformed into metamorphic rock or melted down to magma. Rock formed deep within the crust (either igneous or metamorphic) may be forced up again to become land surface and even mountains by the forces that drive the motion of Earth's plates. Subsequently, this new rock too will erode. Learning Outcomes:� Realize that different rocks have specific origins, and that they are the product of any number of processes.� Identify the processes through which igneous, sedimentary, and metamorphic rock form.� Explain the role of intermediary materials such as sediment and magma in the formation of different kinds of rock.� Provide an overarching description of the steps in the rock cycle, the formation of sedimentary rock, the re-forming of rock by heat and pressure, and the process by which re-formed rock can return to the surface.

National Science Teachers Association (NSTA)

2006-11-01

150

4, 555588, 2007 Weathering rates and  

E-print Network

deposits and thus decreasing soil/water contact resulting in lower weathering rates. Furthermore in sub arctic boreal climates is controlled by the residence time for soil water rock interactions significantly decreases alkalinity export20 to the sea because lower weathering rates gives less carbon dioxide

Paris-Sud XI, Université de

151

Weather Forecasting  

NSDL National Science Digital Library

Weather Forecasting is a set of computer-based learning modules that teach students about meteorology from the point of view of learning how to forecast the weather. The modules were designed as the primary teaching resource for a seminar course on weather forecasting at the introductory college level (originally METR 151, later ATMO 151) and can also be used in the laboratory component of an introductory atmospheric science course. The modules assume no prior meteorological knowledge. In addition to text and graphics, the modules include interactive questions and answers designed to reinforce student learning. The module topics are: 1. How to Access Weather Data, 2. How to Read Hourly Weather Observations, 3. The National Collegiate Weather Forecasting Contest, 4. Radiation and the Diurnal Heating Cycle, 5. Factors Affecting Temperature: Clouds and Moisture, 6. Factors Affecting Temperature: Wind and Mixing, 7. Air Masses and Fronts, 8. Forces in the Atmosphere, 9. Air Pressure, Temperature, and Height, 10. Winds and Pressure, 11. The Forecasting Process, 12. Sounding Diagrams, 13. Upper Air Maps, 14. Satellite Imagery, 15. Radar Imagery, 16. Numerical Weather Prediction, 17. NWS Forecast Models, 18. Sources of Model Error, 19. Sea Breezes, Land Breezes, and Coastal Fronts, 20. Soundings, Clouds, and Convection, 21. Snow Forecasting.

Nielsen-Gammon, John

1996-09-01

152

Weatherizing America  

ScienceCinema

As Recovery Act money arrives to expand home weatherization programs across the country, Zachary Stewart of Phoenix, Ariz., and others have found an exciting opportunity not only to start working again, but also to find a calling.

Stewart, Zachary; Bergeron, T.J.; Barth, Dale; Qualis, Xavier; Sewall, Travis; Fransen, Richard; Gill, Tony;

2013-05-29

153

Weatherizing America  

SciTech Connect

As Recovery Act money arrives to expand home weatherization programs across the country, Zachary Stewart of Phoenix, Ariz., and others have found an exciting opportunity not only to start working again, but also to find a calling.

Stewart, Zachary; Bergeron, T.J.; Barth, Dale; Qualis, Xavier; Sewall, Travis; Fransen, Richard; Gill, Tony

2009-01-01

154

Weather Creator  

NSDL National Science Digital Library

This project explores factors that help create severe winter weather. An interactive simulation provides hands-on experience, followed by guiding questions and resource exploration. Form groups of three. Explore the following simulation: Weather Maker Simulator Use the simulation to answer the following questions on paper. 1. In general, when are winds formed? 2. When winds are blowing, how can you get them to stop? 3. What can you do to make it rain or even snow? 4. Does it always snow when ...

Kshumway

2009-09-28

155

Exploring Weather  

NSDL National Science Digital Library

Second Grade Standard 3: Students will develop an understanding of their environment. Objective 2: Observe and describe weather. Indicator a: Observe and describe patterns of change in weather. Monday, February 1st: Look at the five-day forecast for Salt Lake City, Utah at Five day forecasts. The high temperature for the day will be in red and the low temperature will be in blue. Make sure you look at the temperature listed in degrees Farenheit (F) not degrees Celcius (C). Make ...

Miss Emily

2010-01-29

156

Some topics on geochemistry of weathering: a review.  

PubMed

Weathering is a complex process comprising physical disaggregation, chemical and biological decomposition of rocks and minerals transforming complex structure minerals in simpler ones. Hydrolysis of silicates is perhaps the most important process but associated certainly to biological weathering. It is discussed the role ofwaters: activities/concentrations of chemical species, pH, Eh, importance of complexes. Weathering is not only a destructive process. It can concentrate chemical species and form mineral deposits (kaolin, bauxite, Fe, Mn, P, Nb, Au). Weathering studies are important in pedology, engineering geology, hydrogeology, paleoclimatology and ecology. The use of stonemeal is based upon the study of rock weathering. PMID:17143414

Formoso, Milton L L

2006-12-01

157

Rock Climbing  

NSDL National Science Digital Library

Join Jesse and Gordon on their rock climbing adventures. In this video you will learn about metamorphic, sedimentary, and igneous rocks. Learn what types of rocks are best for climbing and how to determine each rock type.

2006-01-01

158

Rad Rocks  

NSDL National Science Digital Library

Why do we have rocks? How are rocks formed? Why do we have rock cycles? There are all differnt kinds of rocks. What parts make up rocks? Can you sort rocks based on color, hardness, texture, layering, and particle size? How do the things rocks are made of determine how people use them? Organize rocks by color, weight, shape, and sizes. Click here to find out the basics about ...

2010-04-26

159

Long-term Stability of Global Erosion Rates and1 Weathering during late Cenozoic Cooling2  

E-print Network

1 of 18 Long-term Stability of Global Erosion Rates and1 Weathering during late Cenozoic Cooling2 3 and is7 removed from the atmosphere by silicate rock weathering and organic carbon8 burial. This balance of continental11 rock weathering and erosion1,2 are superimposed on fluctuations in organic12 carbon burial3

Willenbring, Jeb F.

160

Space Weather  

NSDL National Science Digital Library

With three levels to choose from on each page - beginner, intermediate or advanced - this site provides information on Space Weather and the terms scientists use to describe the everchanging conditions in space. Explosions on the Sun create storms of radiation, fluctuating magnetic fields, and swarms of energetic particles. These phenomena travel outward through the Solar System with the solar wind. Upon arrival at Earth, they interact in complex ways with Earth's magnetic field, creating Earth's radiation belts and the Aurora. Some space weather storms can damage satellites, disable electric power grids, and disrupt cell phone communications systems. This site provides images, activities, and interesting facts about all of these events.

2004-02-06

161

Wild Weather  

NSDL National Science Digital Library

In this online, interactive module, students learn about severe weather (thunderstorms, hurricanes, tornadoes, and blizzards) and the key features for each type of "wild weather" using satellite images. The module is part of an online course for grades 7-12 in satellite meteorology, which includes 10 interactive modules. The site also includes lesson plans developed by teachers and links to related resources. Each module is designed to serve as a stand-alone lesson, however, a sequential approach is recommended. Designed to challenge students through the end of 12th grade, middle school teachers and students may choose to skim or skip a few sections.

162

Weather Forecasting  

NSDL National Science Digital Library

Weather Forecasting is one of several online guides produced by the Weather World 2010 project at the University of Illinois. These guides use multimedia technology and the dynamic capabilities of the web to incorporate text, colorful diagrams, animations, computer simulations, audio, and video to introduce topics and concepts in the atmospheric sciences. This module introduces forecast methods and the numerous factors one must consider when attempting to make an accurate forecast. Sections include forecasting methods for different scenarios, surface features affecting forecasting, forecasting temperatures for day and night, and factors for forecasting precipitation.

2010-01-01

163

Correlations Between Index Properties and Unconfined Compressive Strength of Weathered Ocala Limestone  

Microsoft Academic Search

Weathering has a negative effect on both physical and engineering properties of rock specimens and rock masses. When rock masses are weathered it is often difficult to obtain core segments that are the correct size for unconfined compressive strength testing. Thus engineers must use index testing to estimate the strength of specimens for design purposes. This thesis relates the unconfined

Raoaa Farah

2011-01-01

164

Putting Weather into Weather Derivatives  

NASA Astrophysics Data System (ADS)

Just as weather forecasting has a colorful and often farsighted history within geophysics, financial mathematics has a long and turbulent history within mathematics. Thus it is no surprise that the intersection of real physics and real financial mathematics provides a rich source of problems and insight in both fields. This presentation targets open questions in one such intersection: quantifying ``weather risk.'' There is no accepted (operational) method for including deterministic information from simulation models (numerical weather forecasts, either best guess or by ensemble forecasting methods), into the stochastic framework most common within financial mathematics. Nor is there a stochastic method for constructing weather surrogates which has been proven successful in application. Inasmuch as the duration of employable observations is short, methods of melding short term, medium-range and long term forecasts are needed. On these time scales, model error is a substantial problem, while many methods of traditional statistical practice are simply inappropriate given our physical understanding of the system. A number of specific open questions, along with a smaller number of potential solutions, will be presented. >http://www.maths.ox.ac.uk/~lenny/WeatherRisk

Smith, L. A.; Smith, L. A.

2001-12-01

165

Tithonium Chasma's Sedimentary Rocks  

NASA Technical Reports Server (NTRS)

MGS MOC Release No. MOC2-565, 5 December 2003

Exposures of light-toned, layered, sedimentary rocks are common in the deep troughs of the Valles Marineris system. This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows an example from western Tithonium Chasma. The banding seen here is an eroded expression of layered rock. Sedimentary rocks can be composed of (1) the detritus of older, eroded and weathered rocks, (2) grains produced by explosive volcanism (tephra, also known as volcanic ash), or (3) minerals that were chemically precipitated out of a body of liquid such as water. These outcrops are located near 4.8oS, 89.7oW. The image covers an area 3 km (1.9 mi) wide and is illuminated from the lower left.

2003-01-01

166

Wacky Weather  

NSDL National Science Digital Library

This 5-lesson unit gives students practice in using calculating, graphing and modeling skills to analyze varoius aspects of weather. Students calculate fractions of a set of rainfall data, graph damage costs of selected hurricanes, and make Venn diagrams to compare droughts and hurricanes. Visuals and student handouts are provided.

Barbara Chichetti

2002-01-01

167

Today's Weather  

NSDL National Science Digital Library

This activity is part of Planet Diary and contains an online exploration of weather maps. Students use current maps to learn about and locate different features such as low-pressure areas and fronts. They then explore how these are related to severe storms.

168

Wonderful Weather  

NSDL National Science Digital Library

In this activity, learners conduct three experiments to examine temperature, the different stages of the water cycle, and how convection creates wind. These activities can be used individually or as a group for a lesson on weather. Note: boiling water is required for this activity; adult supervision required.

Mission Science Workshop

2013-01-01

169

Weather Stations  

NSDL National Science Digital Library

This is a series of seven brief activities about Jupiter's atmosphere and weather. Learners will look at Jupiter's distinct banded appearance, violent storms, and clouds of many different colors. The activities are part of Explore! Jupiter's Family Secrets, a series designed to engage children in space and planetary science in libraries and informal learning environments.

170

Tacoma Power Weatherization  

E-print Network

Tacoma Power Weatherization Specifications August 2009 KnowYourPower.com | #12;TACOMA POWER WEATHERIZATION SPECIFICATIONS 2009 edition Page 2 #12;TACOMA POWER WEATHERIZATION SPECIFICATIONS 2009 edition

171

Riverbank rock identification  

NSDL National Science Digital Library

This exercise is part of a field trip lab in which we see map different till deposits. At a small, meandering sand-bed river in Minnesota, students are directed to wander along the riverbank and pick up gravel-sized rocks. When they each have a handful, I lay a table-sized, laminated map of Minnesota bedrock geology on the ground. I ask the students to identify their rocks, then find the corresponding bedrock units on the map and throw their rocks down in those regions. Soon we have a pile of rocks in northwestern Minnesota into Canada (weathered shales, weathered limestones), northern and northeastern Minnesota (granites, gneisses, basalts and rhyolites if we are lucky) and central Minnesota (dolomite, sandstones, granites). This visually demonstrates that glaciers transported stones from many distant locations and brought them here to southern Minnesota. In addition, we talk about how the river is down-cutting through consecutive layers of till and mixing those particles together in the stream deposits. The exercise gives students practice in identifying rocks, reading maps, and synthesizing different fields of geology to answer a geomorphic question about glacial transport. Designed for a geomorphology course Has minimal/no quantitative component

Laura Triplett

172

Weathering: methods and techniques to measure  

NASA Astrophysics Data System (ADS)

Surface recession takes place when weathered material is removed from the rocks. In order to know how fast does weathering and erosion occur, a review of several methods, analyses and destructive and non-destructive techniques to measure weathering of rocks caused by physico-chemical changes that occur in bedrocks due to salt crystallization, freezing-thaw, thermal shock, influence of water, wind, temperature or any type of environmental agent leading to weathering processes and development of soils, in-situ in the field or through experimental works in the laboratory are addressed. From micro-scale to macro-scale, from the surface down to more in depth, several case studies on in-situ monitoring of quantification of decay on soils and rocks from natural landscapes (mountains, cliffs, caves, etc) or from urban environment (foundations or facades of buildings, retaining walls, etc) or laboratory experimental works, such as artificial accelerated ageing tests (a.a.e.e.) or durability tests -in which one or more than one weathering agents are selected to assess the material behaviour in time and in a cyclic way- performed on specimens of these materials are summarised. Discoloration, structural alteration, precipitation of weathering products (mass transfer), and surface recession (mass loss) are all products of weathering processes. Destructive (SEM-EDX, optical microscopy, mercury intrusion porosimetry, drilling resistance measurement, flexural and compression strength) and Non-destructive (spectrophotocolorimetry, 3D optical surface roughness, Schmidt hammer rebound tester, ultrasound velocity propagation, Nuclear Magnetic Resonance NMR, X ray computed micro-tomography or CT-scan, geo-radar differential global positioning systems) techniques and characterization analyses (e.g. water absorption, permeability, open porosity or porosity accessible to water) to assess their morphological, physico-chemical, mechanical and hydric weathering; consolidation products or methods to stop or to slow down their weathering or durability and stability of soils and rocks are also topics where the methods and techniques deal with the quantification of weathering. Cultural stone weathering studies contribute substantially to the knowledge of weathering rates revealing the importance of specific weathering agents and weathering factors.

Lopez-Arce, P.; Zornoza-Indart, A.; Alvarez de Buergo, M.; Fort, R.

2012-04-01

173

Z .Chemical Geology 158 1999 189202 Bacterial effects on the mobilization of cations from a weathered  

E-print Network

a weathered Pb-contaminated andesite Jeremy B. Fein a,) , Patrick V. Brady b , Jinesh C. Jain a , Ronald I from a weathered andesite was examined by conducting water­rock leaching experiments to measure release

Dorn, Ron

174

Rock Cycle  

NSDL National Science Digital Library

This interactive Flash animation about the rock cycle is suitable for a review or overview in an introductory level Physical Geology class. It includes animations, photos, and descriptions involving rock types and processes in the rock cycle.

Smoothstone; Company, Houghton M.

175

Talking Rocks.  

ERIC Educational Resources Information Center

Discusses some of the ways that rocks can be used to enhance children's creativity and their interest in science. Suggests the creation of a dramatic production involving rocks. Includes basic information on sedimentary, igneous, and metamorphic rocks. (TW)

Rice, Dale; Corley, Brenda

1987-01-01

176

Rock Cycle  

NSDL National Science Digital Library

This site, from Moorland School in England, describes the rock cycle. Topics briefly discussed include rock formation, erosion, transportation, and deposition, plus various types of rocks. The page is directed towards a middle-school audience.

Moorland School

177

Weather Cycles  

NSDL National Science Digital Library

We are professionals in the teaching profession. We designed this project for children ranging from 4th grade to 6th grade. This project explores factors that help create severe winter weather. An interactive simulation provides hands-on experience, followed by guiding questions and resource exploration. YOU WILL NEED: Paper with copied questions, Overhead projector and Students broken up into groups of 3. Form groups of three. Have each group explore the following simulation: Weather Maker Simulator Have students use the simulation to answer the following questions on paper. They should be discussing the questions in their groups. 1. In general, when are winds formed? 2. When winds are blowing, how can you get them to stop? 3. What ...

Mitchell, Mrs.

2010-09-23

178

Weather Watchers  

NSDL National Science Digital Library

Students are introduced to some essential meteorology concepts so they more fully understand the impact of meteorological activity on air pollution control and prevention. First, they develop an understanding of the magnitude and importance of air pressure. Next, they build a simple aneroid barometer to understand how air pressure information is related to weather prediction. Then, students explore the concept of relative humidity and its connection to weather prediction. Finally, students learn about air convection currents and temperature inversions. In an associated literacy activity, students learn how scientific terms are formed using Latin and Greek roots, prefixes and suffixes, and are introduced to the role played by metaphor in language development. Note: Some of these activities can be conducted simultaneously with the air quality activity (What Color Is Your Air Today?) of Air Pollution unit, Lesson 1.

Integrated Teaching And Learning Program

179

Rock, Paper, Scissors Probability!  

NSDL National Science Digital Library

Students learn about probability through a LEGO® MINDSTORMS® NTX-based activity that simulates a game of "rock-paper-scissors." The LEGO robot mimics the outcome of random game scenarios in order to help students gain a better understanding of events that follow real-life random phenomenon, such as bridge failures, weather forecasts and automobile accidents. Students learn to connect keywords such as certainty, probable, unlikely and impossibility to real-world engineering applications.

2014-09-18

180

Weather Observations  

NSDL National Science Digital Library

We will be observing the weather in our enviornment. Post your observations. Take a hike! Tell us what you see! Make sure and note the date/time/season. Take a walk in your neighboorhood- what signs show you the current season? Vacation? Make observations about the place you visited. Make obseravtions every week! Keep a journal about the changes you observe! Winter Storm ImageSeasonal ChangesAround the WorldSeasonsSeasons of the Year ...

sarahnp

2011-07-18

181

Rock Hounds  

NSDL National Science Digital Library

At this site students will learn about rocks and rock collecting. They will learn about sedimentary, metamorphic, and igneous rocks and be provided with examples, information, and pictures for each of the three kinds of rocks. Students can take a quiz to see if they can remember which rock is sedimentary, metamorphic, or igneous. Site includes a Web-based lesson plan and rock activities. Students will learn about erosion, the elements of soil, how a sedimentary rock becomes a metamorphic rock, gemstones, minerals, and geology. They will be able to make a volcano and a rock collection, and participate in a rock swap. Site also includes information about rock safety and additional links.

Wiredschool, Franklin I.; West, Loogootee E.; Payton, Tammy

2007-12-12

182

Observe the effects of mechanical weathering  

NSDL National Science Digital Library

In this interactive Earth science resource, students are first presented with six photographs, each featuring a different mechanical weathering event in which rock is broken down. Examples of the events include road damage due to ice heaving and the expansion of cracks in rocks due to tree growth. Students are instructed to click on each labeled image to see an enlarged version of it. In the enlarged view, brief text, often accompanied by visual cues such as arrows, explains the physical weathering process shown. Copyright 2005 Eisenhower National Clearinghouse

Education, Terc. C.; Littell, Mcdougal

2003-01-01

183

Igneous Rocks  

NSDL National Science Digital Library

This interactive lesson on igneous rocks begins with a comparison of intrusive and extrusive igneous rocks with diagrams to show their origin. This leads to a discussion of intrusive rock formations including dikes, sills, laccoliths and batholiths and a block diagram to show their location. Basaltic rocks are described to include basalt, pumice, and gabbro and are contrasted with granitic rhyolite and obsidian.

184

Rock Solid  

NSDL National Science Digital Library

A teacher describes how developing a structured, focused, and fun curriculum on rocks and minerals for learning-disabled students transformed her initial reluctance about Earth science into enthusiasm. Students observed, described, and sorted rocks and explored rock formation. A sample worksheet is included, as is a list of children's trade books about rocks.

Sorel, Katherine

2003-02-01

185

Mountain Weather  

NSDL National Science Digital Library

Mountains can be awe-inspiring both for the vistas they provide and for the weather events and long-term climate systems they support. This interactive feature illustrates how a moisture-laden air mass interacts with a mountain slope to produce characteristic patterns of precipitation over the mountain and surrounding areas. Viewers can see how clouds and precipitation form as the air mass ascends the windward side of the peak, and observe the rain shadow created on the leeward side by the descending, warmed, and moisture-depleted air. A background essay and list of discussion questions supplement the interactive feature.

186

Rock Cycle  

NSDL National Science Digital Library

The Rock Cycle SciPack explores different kinds and categories of rocks, the major processes through which they form and the cyclical nature of the formation and transformation of rock materials. The focus is on topics supporting Standards and Benchmarks related to the rock cycle as part of the transfer and transformation of matter and energy in Earth's system as well as a sense of the time scales involved and how rocks provide information about their own development and the history of Earth.In addition to comprehensive inquiry-based learning materials tied to Science Education Standards and Benchmarks, the SciPack includes the following additional components:? Pedagogical Implications section addressing common misconceptions, teaching resources and strand maps linking grade band appropriate content to standards. ? Access to one-on-one support via e-mail to content "Wizards".? Final Assessment which can be used to certify mastery of the concepts.Learning Outcomes:Rock Cycle: Categories by Process? List the three different types of rock. ? Make appropriate observations about rocks (e.g. describe rock composition and texture).? Make appropriate observations about the general environments in which the rocks formed.Rock Cycle: Environments of Formation? Realize that different rocks have specific origins, and that they are the product of any number of processes.? Identify the processes through which igneous, sedimentary, and metamorphic rock form.? Explain the role of intermediary materials such as sediment and magma in the formation of different kinds of rock.? Provide an overarching description of the steps in the rock cycle, the formation of sedimentary rock, the re-forming of rock by heat and pressure, and the process by which re-formed rock can return to the surface.Rock Cycle: Cycling? Recognize the formation and transformation processes as part of a continuing cycle.? Identify that while the form and location of different rocks change over time, the amount of material and the distribution among the elements remains constant.? Explain the different processes or paths that each type of rock may take in the rock cycle.Rock Cycle: Earth's Autobiography? State the amount of time over which the rock cycle has been in operation (4 billion years rather than 40 million or 400 million).? Recognize that the processes at work in the present are the same as those at work in the distant past.? Describe how rock formations and characteristics can be used to determine how different rock formed, making appropriate interpretations about the source of the rock, history and processes, and the environment of formation.? Describe how rocks provide a history of the changing surface of Earth and its lifeforms.

National Science Teachers Association (NSTA)

2007-03-21

187

Igneous Rocks  

NSDL National Science Digital Library

This site explores igneous rocks in-depth through descriptions and pictures. The formation and distribution of this rock type are covered, as well as magma types associated with them (mafic to felsic). Classification of igneous rocks covers their texture and composition, including the difference between intrusive and extrusive. An alphabetical listing of rocks connects the user with a description, picture, tectonic association, and mineral composition of the rock. Bowens Reaction Series is covered as well, with associated rock types. A self-test allows the user to identify rocks by picture alone. Links are provided to sites with further information.

2007-12-12

188

Investigaing Rocks  

NSDL National Science Digital Library

Your mission is to look at different types of rocks and be able to sort them based on color, feel, hardness, texture, layering they may have, and particle size they are made of. Identify how the properties of rocks determine how people use them. Click below to find out more about different kinds of rocks there are: Types of Rocks Now, Start Your Rock Collection! It's a race against time! Can you do it? Identify Rock Types How are rocks made? Check out: The Rock Cycle Now take the quiz: Diagram the rock cycle quiz Next, click the link to view the Virtual Quarry website. Here, you will be able to look at different rock ...

Lindsey, Tiffany A.

2010-06-21

189

Metamorphic Rocks  

NSDL National Science Digital Library

This interactive lesson on metamorphic rocks starts with a review of the rock cycle and goes on to describe the relationship between metamorphic rocks and their parent rock. The lesson then describes the agents of metamorphism (temperature, pressure, and chemical change) and moves into a discussion on contact, regional, and dynamic metamorphism. The remainder of the lesson consists of descriptions of foliated rocks such as slate, schist, and gneiss, and the non-foliates exemplified by quartzite and white marble.

190

Weathering of Stone Monuments in Cities: A Student Exercise.  

ERIC Educational Resources Information Center

Describes a college-level geography project for students limited to urban areas. Students investigate the rock-weathering process through library resources, then observe, collect, and analyze data about stone monuments. An individually written report concludes the project. (KC)

Dragovich, D.

1980-01-01

191

Cave development by frost weathering  

NASA Astrophysics Data System (ADS)

This paper deals with the description and genesis of a special type of shelter cave. In German they are termed Auswitterungshöhlen which goes back to the 19th century and the genesis is supposed to be related to frost weathering, but to our knowledge, detailed studies are missing so far. This type of cave is very common in the area of investigation that comprises pre-Alpine and Alpine regions in the north-eastern part of the Eastern Alps: They make up 32% of the 5138 registered caves but surprisingly they entirely developed in carbonate rocks. Although most of them are smaller than a dozen metres, some have lengths of more than 50 m and entrances can be more than 100 m wide or similarly high. Besides general observations that lead to a list of characteristics for these caves, two of them in a pre-Alpine setting were studied in-depth. A detailed map, descriptions, and measurements concerning cave morphology, host rock geology, and climate are given. The thickness and composition of clastic sediments were investigated by small trenches and electric resistivity measurements. Sediment thicknesses reach up to 2 m inside the caves and below the entrances. For one year nets were installed to measure rockfall in both caves. In warm periods generally less than 5 g/month of debris could be collected, but a few 100 g/month for frost periods. This strong correlation and the significant amount of debris together with other observations suggest that frost weathering is an on-going and very important process for the formation of these caves. Grain-size distribution of the collected debris argues for the activity of both microgelivation and ice segregation. Therefore we suggest that the term frost weathering caves should be used for shelter caves whose genesis is related to frost weathering. As dissolution seems to be of marginal importance for the genesis they are a paradox as they develop in karstic rock but have pseudokarst features.

Oberender, Pauline; Plan, Lukas

2015-01-01

192

The Weather Dude  

NSDL National Science Digital Library

The Weather Dude is a weather education Web site offered by meteorologist Nick Walker of The Weather Channel. For kids, the site offers a great online textbook entitled Weather Basics, which explains everything from precipitation to the seasons, using simple text and fun graphics. Other fun things for kids include weather songs, questions and quizzes, weather proverbs, and more. Teachers are also provided with helpful resources such as weather activity sheets and printable blank maps, as well as many other links to weather forecasts and information that will help make teaching about weather fun.

Walker, Nick.

2002-01-01

193

Release of biodegradable dissolved organic matter from ancient sedimentary rocks  

Microsoft Academic Search

Sedimentary rocks contain the largest mass of organic carbon on Earth, yet these reservoirs are not well integrated into modern carbon budgets. Here we describe the release of dissolved organic matter (DOM) from OM-rich sedimentary rocks under simulated weathering conditions. Results from column experiments demonstrate slow, sustained release of DOM from ancient sedimentary rocks under simulated weathering conditions. 1H-NMR analysis

Sarah Schillawski; Steven Petsch

2008-01-01

194

This Rock is Your Rock, This Rock is My Rock  

NSDL National Science Digital Library

In this activity students discover that the types and relative proportion of minerals that occur together in a rock tell scientists the story of how that rock was formed. They also learn that rocks are named based on how they formed and by the types, amounts, and sizes of minerals in the rocks. Students will realize that one of the most important skills a geologist needs when studying a rock is the ability to observe and describe what he or she sees. As a result of this activity students will improve their observational skills and learn that rocks are made up of one or more minerals.

195

Correlation of Rock Spectra with Quantitative Morphologic Indices: Evidence for a Single Rock Type at the Mars Pathfinder Landing Site  

NASA Technical Reports Server (NTRS)

The Mars Pathfinder (MPF) landing site was predicted to contain a broad sampling of rock types varying in mineralogical, physical, mechanical and geochemical characteristics. Although rocks have been divided into several spectral categories based on Imager for Mars Pathfinder (IMP) visible/near-infrared data, efforts in isolating and classifying spectral units among MPF rocks and soils have met with varying degrees of success, as many factors influencing spectral signatures cannot be quantified to a sufficient level to be removed. It has not been fully determined which spectral categories stem from intrinsic mineralogical differences between rocks or rock surfaces, and which result from factors such as physical or chemical weathering. This has made isolation of unique rock mineralogies difficult. Morphology, like composition, is a characteristic tied to the intrinsic properties and geologic and weathering history of rocks. Rock morphologies can be assessed quantitatively and compared with spectral data, to identify and classify rock types at the MPF landing site. They can also isolate actual rock spectra from spectral types that are surficial in origin, as compositions associated with mantling dust or chemical coatings would presumably not influence rock morphology during weathering events. We previously reported on an initial classification of rocks using the quantitative morphologic indices of size, roundness, sphericity and elongation. Here, we compare this database of rock characteristics with associated rock surface spectra to improve our ability to discriminate between spectra associated with rock types and those from other sources.

Yingst, R. A.; Biedermann, K. L.; Pierre, N. M.; Haldemann, A. F. C.; Johnson, J. R.

2005-01-01

196

Effects of climate on chemical_ weathering in watersheds  

Microsoft Academic Search

Climatic effects on chemical weathering are evaluated by correlating variations On solute concentrations and fluxes with temperature, precipitation, runoff, and evapotranspiration (ET) for a worldwide distribution of sixty-eight watersheds underlain by granitoid rock types. Stream solute concentrations are strongly correlated with proportional ET loss, and evaporative concentration makes stream solute concentrations an inappropriate surrogate for chemical weathering. Chemical fluxes are

Art F. White; Alex E. Blum

1995-01-01

197

Rock Pore Structure as Main Reason of Rock Deterioration  

NASA Astrophysics Data System (ADS)

Crashed or dimensional rocks have been used as natural construction material, decoration stone or as material for artistic sculptures. Especially old historical towns not only in Slovakia have had experiences with use of stones for construction purposes for centuries. The whole buildings were made from dimensional stone, like sandstone, limestone or rhyolite. Pavements were made especially from basalt, andesite, rhyolite or granite. Also the most common modern construction material - concrete includes large amounts of crashed rock, especially limestone, dolostone and andesite. However, rock as any other material if exposed to exogenous processes starts to deteriorate. Especially mechanical weathering can be very intensive if rock with unsuitable rock properties is used. For long it had been believed that repeated freezing and thawing in relation to high absorption is the main reason of the rock deterioration. In Slovakia for many years the high water absorption was set as exclusion criterion for use of rocks and stones in building industry. Only after 1989 the absorption was accepted as merely informational rock property and not exclusion. The reason of the change was not the understanding of the relationship between the porosity and rock deterioration, but more or less good experiences with some high porous rocks used in constructions exposed to severe weather conditions and proving a lack of relationship between rock freeze-thaw resistivity and water absorption. Results of the recent worldwide research suggest that understanding a resistivity of rocks against deterioration is hidden not in the absorption but in the structure of rock pores in relation to thermodynamic properties of pore water and tensile strength of rocks and rock minerals. Also this article presents some results of research on rock deterioration and pore structure performed on 88 rock samples. The results divide the rocks tested into two groups - group N in which the pore water does not freeze even when the temperature decreases to -20 ºC, and the second group F in which the pore water freezes. It has been found that the rocks from group N contain critical portion of adsorbed water in pores which prevents freezing of the pore water. The presence of adsorbed water enables thermodynamic processes related to osmosis which are dominantly responsible for deterioration of rocks from group N. A high correlation (R = 0.81) between content of adsorbed water and freeze-thaw loss was proved and can be used as durability estimator of rocks from group N. The rock deterioration of group F is caused not only by osmosis, but also by some other processes and influences, such as hydraulic pressure, permeability, grain size, rock and mineral tensile strength, degree of saturation, etc., and the deterioration cannot be predicted yet without the freeze-thaw test. Since the contents of absorbed water and ratio between adsorbed and bulk water (of which the absorbed water consists) is controlled by the porosity and pore structure, it can be concluded that the deterioration of some rocks is strongly related to rock pore structure.

Ondrášik, Martin; Kopecký, Miloslav

2014-03-01

198

Rock Cycle  

NSDL National Science Digital Library

The purpose of this activity is to demonstrate the principle of conservation of mass through the rock cycle. When students create the model, the various parts and processes in the rock cycle are reinforced for them.

School, Maryland V.

199

Sedimentary Rocks  

NSDL National Science Digital Library

This interactive Flash animation provides an overview of sedimentary rocks for introductory level high school or undergraduate Earth science or physical geology courses. It includes pictures and supplementary information about sedimentary rock formation and erosion.

Smoothstone; Company, Houghton M.

200

Rock Art  

ERIC Educational Resources Information Center

There are many interpretations for the symbols that are seen in rock art, but no decoding key has ever been discovered. This article describes one classroom's experiences with a lesson on rock art--making their rock art and developing their own personal symbols. This lesson allowed for creativity, while giving an opportunity for integration…

Henn, Cynthia A.

2004-01-01

201

Rock Finding  

ERIC Educational Resources Information Center

In this article, the authors discuss a literature-based activity that helps students discover the importance of making detailed observations. In an inspiring children's classic book, "Everybody Needs a Rock" by Byrd Baylor (1974), the author invites readers to go "rock finding," laying out 10 rules for finding a "perfect" rock. In this way, the…

Rommel-Esham, Katie; Constable, Susan D.

2006-01-01

202

Collecting Rocks.  

ERIC Educational Resources Information Center

One of a series of general interest publications on science topics, the booklet provides those interested in rock collecting with a nontechnical introduction to the subject. Following a section examining the nature and formation of igneous, sedimentary, and metamorphic rocks, the booklet gives suggestions for starting a rock collection and using…

Barker, Rachel M.

203

Sedimentary Rocks  

NSDL National Science Digital Library

Create a poster about sedimentary rocks! Directions: Make a poster about sedimentary rocks. (20 points) Include at least (1) large picture (15 points) on your poster complete with labels of every part (10 points). (15 points) Include at least three (3) facts about sedimentary rocks. (5 points each) (15 points) Write at least a three sentence summary of your poster ...

Walls, Mrs.

2011-01-30

204

Metamorphic Rocks  

NSDL National Science Digital Library

Here is an in-depth description of metamorphic rocks, from their classification to formation and identification. It covers types of metamorphism (including Barrovian, or regional rock changes), classification by foliation, and metamorphic processes (facies and zones). An alphabetical list of rocks with picture, composition, description, tectonic association, and type of metamorphism is given. Common metamorphic minerals are covered as well.

2007-12-12

205

Igneous Rocks  

NSDL National Science Digital Library

Create a poster about Igneous Rocks! Directions: Make a poster about Igneous Rocks. (20 points) Include at least (1) large picture (15 points) on your poster complete with labels of every part (10 points). (15 points) Include at least three (3) facts about igneous rocks. (5 points each) (15 points) Write at least a three sentence summary ...

Walls, Mrs.

2011-01-30

206

Controlling The Global Weather.  

NASA Astrophysics Data System (ADS)

the weather controller is extremely complex, the existence of the required technology is plausible in the time range of several decades.While the concept of controlling the weather has often appeared in science fiction literature, this statement of the problem provides a scientific basis and a system architecture to actually implement global weather control. Large-scale weather control raises important legal and ethical questions. The nation that controls its own weather will perforce control the weather of other nations. Weather "wars" are conceivable. An international treaty may be required, limiting the use of weather control technology.

Hoffman, Ross N.

2002-02-01

207

Weathering of granodioritic crust, long-term storage of elements in weathering profiles, and petrogenesis of siliciclastic sediments  

Microsoft Academic Search

The bulk composition and mineralogy of the Toorongo Granodiorite, Australia, are similar to average upper continental crust (AUCC). Weathering characteristics of the Toorongo profile consequently provide insight into large-scale chemical weathering of the upper crust. In situ weathered materials of the profile do not reflect parent granodiorite composition in quartz-plagioclase-K-feldspar (Q-P-K) or in quartz-feldspar-rock fragment (Q-F-L) compositional space. Intensive in

H. Wayne Nesbitt; G. Markovics

1997-01-01

208

Deep weathering, vegetation and fireburn Significant obstacles for geoscience remote sensing in Australia  

Microsoft Academic Search

Large areas of the land surface of Australia retain effects of prior weathering events, to tens or hundreds of metres depth, which altered previously-exposed rocks to clays and reconcentrated various minerals such as iron oxides, carbonates and silica. In such areas data about surface mineralogy obtained by remote sensing may not relate to rocks at depth beneath the weathered zone.

C. J. SIMPSON

1990-01-01

209

Salt-weathering simulations under hot desert conditions: agents of enlightenment or perpetuators of preconceptions?  

Microsoft Academic Search

Because of access difficulties and inhospitable environmental conditions, our understanding of rock weathering in hot deserts has been strongly influenced by laboratory simulations. However, a risk exists that results may come to owe more to experimental design than to actual environmental conditions experienced at the atmosphere\\/rock surface interface. This was especially true in early salt-weathering simulations that seemingly sought to

B. J. Smith; P. A. Warke; J. P. McGreevy; H. L. Kane

2005-01-01

210

Rock and the Rock Cycle  

NSDL National Science Digital Library

This interactive rock cycle shows students how all rock types are recycled into other types, and how the cycle progresses. Materials include the definitions of each rock type (igneous, sedimentary, metamorphic), how they change over time, and how tectonic movements help to drive the process.

211

Evolution of Oxidative Continental Weathering  

NASA Astrophysics Data System (ADS)

The Great Oxidation Event (GOE) is currently viewed as a protracted process during which atmospheric oxygen levels increased above 10-5 times the present atmospheric level. This value is based on the loss of sulphur isotope mass independent fractionation (S-MIF) from the rock record, beginning at 2.45 Ga and disappearing by 2.32 Ga. However, a number of recent papers have pushed back the timing for oxidative continental weathering, and by extension, the onset of atmospheric oxygenation several hundreds of million years earlier despite the presence of S-MIF (e.g., Crowe et al., 2013). This apparent discrepancy can, in part, be resolved by the suggestion that recycling of older sedimentary sulphur bearing S-MIF might have led to this signal's persistence in the rock record for some time after atmospheric oxygenation (Reinhard et al., 2013). Here we suggest another possibility, that the earliest oxidative weathering reactions occurred in environments at profound redox disequilibrium with the atmosphere, such as biological soil crusts, riverbed and estuarine sediments, and lacustrine microbial mats. We calculate that the rate of O2 production via oxygenic photosynthesis in these terrestrial microbial ecosystems provides largely sufficient oxidizing potential to mobilise sulphate and a number of redox-sensitive trace metals from land to the oceans while the atmosphere itself remained anoxic with its attendant S-MIF signature. These findings reconcile geochemical signatures in the rock record for the earliest oxidative continental weathering with the history of atmospheric sulphur chemistry, and demonstrate the plausible antiquity of a terrestrial biosphere populated by cyanobacteria. Crowe, S.A., Dossing, L.N., Beukes, N.J., Bau, M., Kruger, S.J., Frei, R. & Canfield, D.E. Atmospheric oxygenation three billion years ago. Nature 501, 535-539 (2013). Reinhard, C.T., Planavsky, N.J. & Lyons, T.W. Long-term sedimentary recycling of rare sulphur isotope anomalies. Nature 497, 100-104 (2013).

Konhauser, Kurt; Lalonde, Stefan

2014-05-01

212

Annual fossil organic carbon delivery due to mechanical and chemical weathering of marly badlands areas  

E-print Network

1 Annual fossil organic carbon delivery due to mechanical and chemical weathering of marly badlands Carbon (FOC) release by weathering of outcropping sedimentary rocks on continental surfaces is still weathering of marls in two experimental watersheds showing a typical badlands geomorphology (Draix watersheds

Paris-Sud XI, Université de

213

Sharp decrease in long-term chemical weathering rates along an altitudinal transect  

E-print Network

Sharp decrease in long-term chemical weathering rates along an altitudinal transect§ Cli¡ord S long-term rates of chemical weathering and physical erosion across a steep climatic gradient analyses indicate that, relative to the parent rock, soils are less intensively weathered with increasing

Kirchner, James W.

214

Estimation of the annual yield of organic carbon released from carbonates and shales by chemical weathering  

E-print Network

weathering Christian Di-Giovannia, Jean Robert Disnarb and Jean Jacques Macairea a Lab. de Géologie des matter yield induced by chemical weathering of carbonates and shales, considering their global surface carbonate rocks and shales weathering in major world watersheds, published by numerous authors. The results

Paris-Sud XI, Université de

215

Yaquina Bay Weather & Tides  

E-print Network

Yaquina Bay Weather & Tides Clay Creech Phil Barbour #12;HMSC Weather Station #12;Temp-Humidity Sensor at Library #12;http://weather.hmsc.oregonstate.edu #12;#12;#12;#12;#12;#12;Archived Data is Available every 15 mins. #12;#12;A pyranometer measures solar radiation #12;#12;National Weather Service

Wright, Dawn Jeannine

216

Future Weather Station  

NSDL National Science Digital Library

In this activity students build dioramas of futuristic weather stations to demonstrate their knowledge of weather forecasting. They will work in groups to research modern forecasting equipment and techniques, and then build a weather station that will do something we cannot do at present (such as stopping tornadoes). They will present their dioramas and then discuss the pros and cons of controlling the weather.

217

Relationship between mineral weathering and groundwater composition  

NSDL National Science Digital Library

In this pair of activities, students start by using published data to predict what will happen to groundwater composition as a consequence of chemical weathering. The data are provided in a spreadsheet (Hinman_weathering). Students are given the histograms only; both are normalized to 100 %, while one includes silica and the other does not. Students must use resources to predict how groundwater composition will change as a consequence of the observed weathering, and support those predictions using balanced chemical-weathering equations. Afterwards, they conduct a laboratory experiment in which they subject crushed rock to four types of solutions (acid solution, organic-rich solution, rainwater, and alkaline solution). The pH of each solution is measured, and subsequently adjusted after 24 and 48 hours. Solutions are sampled after 14 days. They are analyzed by ICP, and the compositions reported to students for comparison with their predictions.

Hinman, Nancy

218

Australian Severe Weather  

NSDL National Science Digital Library

The Australian Severe Weather Web site is maintained by self proclaimed severe weather enthusiasts Michael Bath and Jimmy Deguara. Other weatherphobes will fully appreciate what the authors have assembled. Everything from weather images, storm news, tropical cyclone data, bush fire and wild fire information, weather observation techniques, and even video clips and Web cam links. Although these other items make the site well rounded, the extensive amount of categorized weather pictures (which are quite extraordinary) are reason enough to visit.

219

Science Rocks!  

ERIC Educational Resources Information Center

It all began one Monday morning. Raymond could not wait to come to large group. In his hand, he held a chunk of white granite he had found. "Look at my beautiful rock!" he cried. The rock was passed around and examined by each student. "I wonder how rocks are made?" wondered one student. "Where do they come from?" asked another. At this moment, a…

Prestwich, Dorothy; Sumrall, Joseph; Chessin, Debby A.

2010-01-01

220

Earth Rocks!  

NSDL National Science Digital Library

The purpose of this lesson is to introduce students to the basic elements of our Earth's crust: rocks, soils and minerals. They learn how we categorize rocks, soils and minerals and how they are literally the foundation for our civilization. Students also explore how engineers use rocks, soils and minerals to create the buildings, roads, vehicles, electronics, chemicals, and other objects we use to enhance our lives.

Integrated Teaching And Learning Program

221

Fan morphodynamics and slope instability in the Mucone River basin (Sila Massif, southern Italy): Significance of weathering and role of land use changes  

Microsoft Academic Search

In the present paper, the preliminary results of a study concerning the fan dynamics in the valley of the Mucone River (Sila Massif, southern Italy) are presented. In the study area highly weathered Palaeozoic crystalline rocks crop out, ranging from residual soils to moderately weathered rocks. Because of the rugged topography and the abundance of weathered deposits, mass movements affect

G. Garfí; D. E. Bruno; D. Calcaterra; M. Parise

2007-01-01

222

Reaping Rocks  

NSDL National Science Digital Library

This is an activity about collecting, describing and classifying terrestrial and lunar rocks. Learners will collect and describe rocks of varying texture, color and shapes. Descriptors will include color, presence or absence of grains and grain size, textures, banding and other patterns. From the descriptions, learners will classify their collected rocks and extend their knowledge to classify lunar rocks. This activity is in Unit 1 of the Exploring the Moon teacher's guide and is designed for use especially, but not exclusively, with the Lunar Sample Disk program.

2012-08-03

223

Sedimentary Rocks  

NSDL National Science Digital Library

This in-depth description of sedimentary rocks covers their classification as clastic, carbonate, or chemical/biochemical as well as their depositional environments, known as long and short clastic systems and carbonate depositional environments. It also presents a discussion of sedimentary rock evolution with an evolutionary diagram and a section on tectonics and sedimentary rocks. An alphabetical list of rocks with photograph, quartz-feldspar-lithic (QFL) composition, description, tectonic association, and formation and environments is given. Identification keys, both basic and QFL are also provided.

Fichter, Lynn

224

Sampling Rocks  

NSDL National Science Digital Library

In this lesson, students will learn about sampling through an investigation of rocks found in the schoolyard. This will provide a start to understanding everyday statistics. They will first collect and analyze a sample of rocks from the schoolyard and array the collected rocks by characteristics such as size, weight, and color, to see if any generalizations can be made about the types of rocks that can be found in the schoolyard. Students will then be introduced to the notion of a sample and how the size and method of collection of a sample can bias findings.

225

Weather Camp 2012 "Weather and Climate All Around Us"  

E-print Network

Weather Camp 2012 "Weather and Climate All Around Us" Are you interested in the weather? Come to Weather Camp at UNL What is Weather Camp? For more information Weather camp is a week long day camp for students who will be 11-14 years old at the time of the camp Most of the activities at Weather Camp 2012

Farritor, Shane

226

Sedimentary Rocks  

NSDL National Science Digital Library

This overview of sedimentary rocks is part of an online historical geology class taught by Dr. Pamela J.W. Gore at Georgia Perimeter College. The outline format includes basic information about the different types and classifications of sedimentary rocks and their defining characteristics, sedimentary structures, and sedimentary environments. Photographs help illustrate the concepts by providing real-world examples.

Gore, Pamela J.; College, Georgia P.

227

Pilot weather advisor  

NASA Technical Reports Server (NTRS)

The results of the work performed by ViGYAN, Inc., to demonstrate the Pilot Weather Advisor cockpit weather data system using a broadcast satellite communication system are presented. The Pilot Weather Advisor demonstrated that the technical problems involved with transmitting significant amount of weather data to an aircraft in-flight or on-the-ground via satellite are solvable with today's technology. The Pilot Weather Advisor appears to be a viable solution for providing accurate and timely weather information for general aviation aircraft.

Kilgore, W. A.; Seth, S.; Crabill, N. L.; Shipley, S. T.; Graffman, I.; Oneill, J.

1992-01-01

228

The Weather Man  

NSDL National Science Digital Library

This project is designed to let you be "The Weather Man" and control the weather through simulation, and hands on experience, followed by guided questioning and resource exploration. Form groups of three. Explore the following simulation: Weather Maker Simulator Use the simulation to answer the following questions on paper. 1. How does humility play a role in weather? How does more or less change weather? 2. What is water vapor? Where does it come from? 3. What happens when the weather drops below zero degrees? ...

Grasser, Mrs. E.

2012-09-27

229

'Tetl' Rock  

NASA Technical Reports Server (NTRS)

This image, taken by the panoramic camera on NASA's Mars Exploration Rover Spirit during the rover's trek through the 'Columbia Hills' at 'Gusev Crater,' shows the horizontally layered rock dubbed 'Tetl.' Scientists hope to investigate this rock in more detail, aiming to determine whether the rock's layering is volcanic or sedimentary in origin. If for some reason this particular rock is not favorably positioned for grinding and examination by the toolbox of instruments on the rover's robotic arm, Spirit will be within short reach of another similar rock, dubbed 'Coba.' Spirit took this image on its 264th martian day, or sol (Sept. 29, 2004). This is a false-color composite image generated from the panoramic camera's 750-, 530-, and 430-nanometer filters.

2004-01-01

230

Development of Rock Engineering  

NSDL National Science Digital Library

This chapter describes the development of rock engineering and provides introductory descriptions of the following concepts: rockbursts and elastic theory, discontinuous rock masses, engineering rock mechanics, geological data collection, laboratory testing of rock, rock mass classification, rock mass strength, in situ stress measurements, groundwater problems, rock reinforcement, excavation methods in rock, and analytical tools used in rock engineering.

2008-08-21

231

Rocks and Minerals  

NSDL National Science Digital Library

Rock Cycle Mineralogy 4 Kids Mineralogy 4 kids : rockin Internet site : the best place to learn about rocks and minerals Rock Cycle Map Rocks and Minerals Rocks and Minerals Pictures Rocks and Minerals Slide Show Rocks and Minerals Slide Show Earth Science Earth Science Uses for Minerals Metamorphic Rock Forming Sedimentary Rocks Observation ...

Richrigby

2010-02-23

232

Rock Mech. Rock Engng. (1999) 32 (2), 8199 Rock Mechanics  

E-print Network

Rock Mech. Rock Engng. (1999) 32 (2), 81±99 Rock Mechanics and Rock Engineering : Springer The microstructure of rock is known to in¯uence its strength and deformation characteristics. This paper presents thresholds of stress- induced brittle fracturing in crystalline rocks with similar mineralogical composi

233

Weather Camp 2012: Weather and Climate All Around Us Are you interested in the weather?  

E-print Network

Weather Camp 2012: Weather and Climate All Around Us Are you interested in the weather? Come to Weather Camp at UNL! What is Weather Camp? For more information Weather camp is a week-long day camp for students who will be 11-14 years old at the time of the camp. Most of the activities at Weather Camp 2012

Farritor, Shane

234

Weathering Grade Classification of Granite Stone Monument Using Reflectance Spectroscopy  

NASA Astrophysics Data System (ADS)

Stone monument has been placed in field and exposed to rain and wind. This outdoor environment and air pollution induced weathering of stone monument. Weathering grade classification is necessary to manage and conserve stone monuments. Visual interpretation by geologist and laboratory experiments using specimens fallen off from the monument to avoid damage on the monument have been applied to classify weathering grade conventionally. Rocks and minerals absorb some particular wavelength ranges of electromagnetic energy by electronic process and vibrational process of composing elements and these phenomena produce intrinsic diagnostic spectral reflectance curve. Non-destructive technique for weathering degree assessment measures those diagnostic absorption features of weathering products and converts the depths of features related to abundance of the materials to relative weathering degree. We selected granite outcrop to apply conventional six folded weathering grade classification method using Schmidt hammer rebound teste. The correlations between Schmidt hammer rebound values and absorption depths of iron oxides such as ferric oxide in the vicinity of 0.9 micrometer wavelength and clay minerals such as illite and kaolinite in the vicinity of 2.2 micrometer wavelength, representative weathering products of granite, were analyzed. The Schmidt hammer rebound value decreased according to increase of absorption depths induced from those weathering products. Weathering grade classification on the granite stone monument was conducted by using absorption depths of weathering products This research is supported from National Research Institute of Cultural Heritage and we appreciate for this.

Hyun, C.; Roh, T.; Choi, M.; Park, H.

2009-05-01

235

11. COULTERVILLE ROAD AT ROCK SLIDE AREA WITH HWY 140 ...  

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

11. COULTERVILLE ROAD AT ROCK SLIDE AREA WITH HWY 140 AT REAR. LOOKING NNE. GIS: N-37 43 04.7 / W-119 43 00.3 - Coulterville Road, Between Foresta & All-Weather Highway, Yosemite Village, Mariposa County, CA

236

Owlie Skywarn's Weather Book  

NSDL National Science Digital Library

This is an online activity book from the National Weather Service that teaches about hazardous weather. The site also includes links to kids sites for the Federal Emergency Management Agency (FEMA) and the National Oceanic and Atmospheric Agency (NOAA).

Cris Garcia

2001-06-22

237

Favorite Demonstration: Differential Weathering  

NSDL National Science Digital Library

In this inquiry-based demonstration, the consumption of a Baby Ruth candy bar is used to nurture students' interest in chemical and physical weathering. In addition, two other concepts can be illustrated: the difference between weathering and erosion and

Francek, Mark

2002-10-01

238

Weather and Road Management  

NSDL National Science Digital Library

Anticipating and dealing with weather and the hazards it creates is a real challenge for those in departments of transportation. This module gives road and highway managers a basic understanding of meteorology and weather hazards so that they can better interpret weather forecast information used to make road management decisions. The module also highlights web-based forecast products available from the National Weather Service that can help in the decision-making process.

Comet

2008-07-21

239

Weathering and Erosion  

NSDL National Science Digital Library

This unit provides an introduction for younger students to the concepts of weathering and erosion. Topics include types of weathering (physical versus chemical), rates of weathering, and weathering products (soil). The section on erosion explains the importance of water and gravity in the process, and discusses some of the more important erosional agents such as wind, water and ice, streams and glaciers. A vocabulary list and downloadable, printable student worksheets are provided.

Medina, Philip

2010-09-07

240

Stormfax Weather Services  

NSDL National Science Digital Library

This site offers links to a variety of weather information, including national, international and local weather maps and forecasts, satellite and radar imagery, and severe weather warnings. There are also links to diverse resources such as fire maps, glacier inventories, snow depths, storm surges and tropical storms. There are reports and advisories about El Nino and La Nina. The site also has a glossary of weather terms and conversion charts for temperature, wind speed and atmospheric pressure.

2002-06-10

241

Web Weather for Kids  

NSDL National Science Digital Library

This set of resources for younger students includes activities and information on thunderstorms, tornadoes, hurricanes, blizzards and clouds: how they form, and how they impact our lives. There are games about clouds, stories about extreme weather events, and a set of activities in which students create simulations of various weather phenomena such as fog, clouds, tornadoes, and others. The 'Recipe for Weather' segment provides an overview of four atmospheric properties (temperature, pressure, volume, and density) which drive most weather phenomena.

242

Terby's Rocks  

NASA Technical Reports Server (NTRS)

27 January 2006 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows some of the light-toned, layered, sedimentary rock outcrops in northern Terby Crater. Terby is located along the north edge of Hellas Planitia. The sedimentary rocks might have been deposited in a greater, Hellas-filling sea -- or not. Today, the rocks are partly covered by dark-toned sediment and debris.

Location near: 27.2oS, 285.3oW Image width: 3 km (1.9 mi) Illumination from: upper left Season: Southern Summer

2006-01-01

243

Winter Weather Introduction  

E-print Network

Winter Weather Management #12;Introduction · Campus Facilities Staff · Other Campus Organizations #12;Purpose · Organize and coordinate the campus response to winter weather events to maintain campus for use by 7 AM. · Response will be modified depending upon forecast and current weather conditions. #12

Taylor, Jerry

244

Aviation weather services  

NASA Technical Reports Server (NTRS)

The primary responsibilities of the National Weather Service (NWS) are to: provide warnings of severe weather and flooding for the protection of life and property; provide public forecasts for land and adjacent ocean areas for planning and operation; and provide weather support for: production of food and fiber; management of water resources; production, distribution and use of energy; and efficient and safe air operations.

Sprinkle, C. H.

1983-01-01

245

Weather Fundamentals: Meteorology. [Videotape].  

ERIC Educational Resources Information Center

The videos in this educational series, for grades 4-7, help students understand the science behind weather phenomena through dramatic live-action footage, vivid animated graphics, detailed weather maps, and hands-on experiments. This episode (23 minutes) looks at how meteorologists gather and interpret current weather data collected from sources…

1998

246

Severe Weather Perceptions.  

ERIC Educational Resources Information Center

Severe weather is an element of nature that cannot be controlled. Therefore, it is important that the general public be aware of severe weather and know how to react quickly and appropriately in a weather emergency. This study, done in the community surrounding the Southern Illinois University at Carbondale, was conducted to compile and analyze…

Abrams, Karol

247

Climate and Weather  

NSDL National Science Digital Library

This video discusses the differences between climate and weather by defining and presenting examples of each. When presenting examples of weather, the video focuses on severe events and how meteorologists predict and study the weather using measurement, satellites, and radar. The climate focus is primarily on an overview of climate zones.

Geographic, National

248

Hot Weather Tips  

MedlinePLUS

... Form - A A + A You are here Home HOT Weather Tips Printer-friendly version We all suffer in hot weather. However, for elderly and disabled people and ... stress and following these tips for dealing with hot weather. Wear cool clothing: See that the person ...

249

Weather Maps in Motion  

NSDL National Science Digital Library

In this activity, students learn to interpret current weather maps. They will observe weather map loop animations on the internet, learn the concept of Zulu time (Universal Time Coordinated, UTC) and visualize the movement of fronts and air masses. They will then analyze a specific weather station model, generate a meteogram from their observations, and answer a set of questions about their observations.

Charles Burrows

250

External Resource: Rock and the Rock Cycle  

NSDL National Science Digital Library

This Windows to the Universe interactive site investigates the rock cycle and illustrates that over millions of years, rocks are recycled into other rocks. Topics: rock cycle, igneous, metamorphic, sedimentary, plate tectonics, and geologic time.

1900-01-01

251

Rock Shots  

NSDL National Science Digital Library

Recently debuted on Adam Curry's METAVERSE site is Rock Shots, the first exclusive gallery of Rock 'n Roll photography on the Web by photographer Niels Van Iperen. Niels has been shooting musicians, fans and festivals for over 12 years in Europe and the U.S. His clients include the magazines Rolling Stone, Musician, Metal Hammer, OOR and Guitar World . Rock Shots brings you face to face with Aerosmith live in Brazil, Pearl Jam in their dressing room, the Red Hot Chili Peppers in a swimming pool and more ... on stage, backstage and audience rage. Portraits are viewed in Rock Shots through a custom-made search engine and is updated weekly with new artists.

Iperen, Niels V.

1995-01-01

252

Igneous Rocks  

NSDL National Science Digital Library

This interactive Flash page provides information about the formation and crystallization of igneous rocks. It includes pictures and animations with supplementary information and is suitable for high school or introductory level undergraduate physical geology courses.

Smoothstone; Company, Houghton M.

253

External Resource: Weathering and Erosion  

NSDL National Science Digital Library

This activity includes background information about weathering, as well as simple demonstrations/activities to model how weather conditions contribute to weathering and erosion. Topics include: chemical weathering, dunes, erosion, floods, glaciers, physi

1900-01-01

254

Monitoring moisture dynamics in weathered, fractured bedrock  

NASA Astrophysics Data System (ADS)

Variably weathered, fractured bedrock underlying hillslopes influences runoff pathways, moisture availability, and slope stability yet direct measurement of moisture dynamics within this zone remains challenging. Established methods for monitoring moisture content in soils are not easily transferrable to fractured rock environments due to inaccessibility and the difficulties associated with the installation and calibration of sensors. At a steep, intensively instrumented hillslope in coastal northern California we explore 7 methods of varying spatial scale and temporal frequency to document moisture dynamics in weathered, fractured argillite bedrock. The forested 4000 m2 catchment is mantled by approximately 50 cm of soil and underlain by a thick weathered bedrock zone which extends to 25 m at the ridge top and thins downslope to a depth of 4 m. The Mediterranean climate at the site is characterized by cool, wet winters and warm, dry summers receiving most of the annual precipitation (1900 mm on average) between October and May. The following measurement methods are employed at the site: 1) downhole neutron moisture logging (CPN 503DR Hydroprobe) in 12 wells, 6-35 m deep 2) time domain reflectometer probes (TDR100, Campbell Scientific) installed in trenches and augured holes of varying backfill material 3) capacitance sensors (SM200, Dynamax, Inc) installed near the surface 4) electrical resistance sensor array systems (ERSAS) installed in augured and backfilled holes, 5) time lapse, non-invasive electrical resistivity tomography, 6) pressure transducers installed in deep wells and 7) laboratory gravimetric measurements of samples collected in augured holes and wells. Our observations highlight how each measurement method individually or collectively contributes to the understanding of moisture dynamics and runoff processes in fractured, weathered bedrock. We found that though backfill material and well casing significantly influence the magnitude of the measured response, using the timing of the response and manufacturer or site specific calibration, allowed us to effectively quantify moisture storage and transport rates in the weathered bedrock. We found that in response to rainfall, all water passes through the soil and weathered bedrock at the site and perches above the fresh bedrock before it travels laterally downslope. The rapid water table response to the first storm events of the season often occurs before the wetting front progresses through the first few meters of the weathered profile. Though shallower weathered bedrock wets and dries annually, deeper portions of the weathered bedrock zone do not show significant seasonal changes in moisture content. As investigations of the critical zone extend deeper, robust techniques for monitoring moisture in weathered bedrock are needed to quantify the significance of rock moisture in hydrologic and geomorphic processes.

Rempe, D. M.; Salve, R.; Oshun, J.; Dietrich, W. E.

2013-12-01

255

Match Rock  

NSDL National Science Digital Library

In this activity, learners try to figure out who has their matching rock type by reading a description of their rock (no talking!). This activity can be used in a variety of ways: to introduce students to each other (icebreaker), to improve communication and writing skills, to introduce classification schemes and taxonomy, and to show how scientists use observations and descriptions to draw links between others' data and interpretations.

Muller, Eric

2003-01-01

256

[Weathering seasonal variations in karst valley in southwest China].  

PubMed

Jialing River is a 1st grade tributary of upstream Yangzi River. In two years, Samples were collected monthly in Wentang Gorge section of Jialing River and analyzed multi-parameters including hydrochemistry and isotopes. Thus, a general result was concluded that the hydrochemical characteristic of Jialing River in Wentang gorge is controlled by weathering of stratum and the hydrochemical type is HCO3(-) -Ca. Most irons were influenced by dilution, which had higher concentrations in dry season than that in rainy season, but nitrate. Nitrate, which was controlled by human activities, has higher concentrations in rainy season. However, some other analyst revealed weathering impacts. The contrast ratio of (Ca(2+) + Mg2+) and HCO3- were between 0.5-1, the same as (Ca(2+) + Mg2+) and (HCO3(-) + SO4(2-)), Which implied that the weathering impacts in this basin was mainly carbonated and sulfate weathering of carbonated, and sulphate rocks weathering was not so significant. The values of delta13C(HCO3- in Jialing River were -8.74 per thousand(-) - 7.36 per thousand, and delta34S(SO)(4)2 - was 14.43 per thousand in dry season and 12.21 per thousand in rainy season. The data of isotopes inferred that, in rainy season sulfate weathering of carbonated and sulphate rocks weathering both had more impacts and sulphate rocks weathering played a more important role than sulfate weathering of carbonated, but, in dry season, carbonated weathering of carbonated was more meaningful. PMID:22720555

Xiao, Qiong; Shen, Li-Cheng; Yang, Lei; Wu, Kun-Yu; Chen, Zhan-Tu

2012-04-01

257

Weather affects us  

NSDL National Science Digital Library

2nd grade weather unit. The students will learn how weather affects us in our daily lives Read and view the video on meteorologists Kid Meteorologist Learn about clouds - watch S'cool Clouds All About Clouds Do scholastic: weather watch and game Weather Read winter storms Interactive Weather Web Pages Read a reason for the season A Reason for the Season Read about precipitation Precipitation Read and view video on flooding Flood: Farming and Erosion Read about air pressure It's a Breeze: How Air Pressure Affects You Read about Hurricanes Hurricanes Do the activities and read ...

Kimmy

2009-11-09

258

Clay Mineral Formation and Transformation in Rocks and Soils  

Microsoft Academic Search

Three mechanisms for clay mineral formation (inheritance, neoformation, and transformation) operating in three geological environments (weathering, sedimentary, and diagenetic-hydrothermal) yield nine possibilities for the origin of clay minerals in nature. Several of these possibilities are discussed in terms of the rock cycle. The mineralogy of clays neoformed in the weathering environment is a function of solution chemistry, with the most

D. D. Eberl; V. C. Farmer; R. M. Barrer

1984-01-01

259

Fossil microorganisms and formation of Early Precambrian weathering crusts  

NASA Astrophysics Data System (ADS)

Weathering crusts are the only reliable evidences of continental conditions existence, and often are the only source of information about exogenous processes and subsequently about conditions under which the development of biosphere occurred. Complex of diverse fossil microorganisms was discovered in result of electronic-microscope investigations. Chemical composition of discovered fossils is identical to that of the host rocks and is represented by Si, Al, Fe, Ca and Mg. Probably, microorganisms fixed in rocks played role of catalyst. Decomposition of minerals, comprising rocks, and their transformation into clayey (argillaceous) minerals, occurred most likely under influence of microorganisms. And may be unique weathering crusts of Early Precambrian were formed due to interaction between specific composition of microorganism assemblage and conditions of hypergene transformations. So it is possible to speak about colonization of land by microbes already at that time and about existence of single raw from weathering crusts (Primitive soils) to real soils.

Astafieva, M. M.; Rozanov, A. Yu.; Vrevsky, A. B.; Alfimova, N. A.; Matrenichev, V. A.; Hoover, R. B.

2009-08-01

260

Beyond the Weather Chart: Weathering New Experiences.  

ERIC Educational Resources Information Center

Describes an early childhood educator's approach to teaching children about rain, rainbows, clouds, precipitation, the sun, air, and wind. Recommends ways to organize study topics and describes experiments that can help children better understand the different elements of weather. (MOK)

Huffman, Amy Bruno

1996-01-01

261

Severe Weather 101: Winter Weather Basics  

MedlinePLUS

... Educators For Students For Everyone Severe Weather 101 Thunderstorms Basics Types Detection Forecasting FAQ Tornadoes Basics Types ... moisture. What we do: NSSL researchers studied winter thunderstorms and found that there is some evidence that ...

262

National Weather Service- Severe Weather Awareness  

NSDL National Science Digital Library

This website provides access to information designed to protect and prepare individuals from severe weather. Materials presented here include forecasts for aviation and marine interests and the general public, maps, statistical data, educational materials, publications, and links to related sites.

263

Geochemistry of Mesoproterozoic sedimentary rocks of upper Vindhyan Group, southeastern Rajasthan and implications for weathering history, composition and tectonic setting of continental crust in the northern part of Indian shield  

NASA Astrophysics Data System (ADS)

The upper Vindhyan succession of southeastern Rajasthan is divisible into Kaimur, Rewa and Bhander Groups. The major and trace element (including rare earth elements) data of the upper Vindhyan shales and sandstones are investigated to determine the weathering history, composition, and tectonic setting of Mesoproterozoic continental crust. CIA (chemical index of alteration) values, A-CN-K plot (A = Al2O3, CN = CaO* + Na2O, K = K2O) and depletion in U, Na2O, CaO, Sr and Ba suggest that the source area experienced moderate to high degree of chemical weathering under warm and humid conditions. Provenance modeling indicates that the Kaimur sandstones are best modeled with a mixture having 40% granitic gneiss, 20% Tonalite-Trondhjemite-Granodiorite (TTG), 20% mafic enclaves and 20% Berach Granite of the Banded Gneissic Complex (BGC). A mixture of 60% granitic gneiss, 20% mafic enclaves and 20% Berach Granite of the BGC can model the Rewa and Bhander Groups. It is suggested that the upper Vindhyan sedimentation commenced at the time of Delhi-Sausar orogeny at about 1100-1000 Ma. The orogenic movements uplifted the parts of old continental crust in the BGC terrain creating positive areas, which exposed older crustal blocks containing TTG as important component. The debris of Kaimur sandstone probably derived from these uplifted blocks. As indicated by Palaeocurrent data, the Rewa and Bhander formations were derived from Bundelkhand Granitic Gneiss Complex (BGGC) occurring to the north of the basin and/or the Chotanagpur Granitic Gneiss Complex (CGGC) of eastern Indian shield. The derivation of Lower and upper groups of Vindhyan succession from different source terrains of identical composition suggests that at the time of Vindhyan sedimentation, the BGC of Rajasthan, the BGGC of Central India and the CGGC of eastern India had similar lithological composition. This implies that well before the origin of the Vindhyan basin these discrete terrains evolved as a single unit that existed as a Mesoarchaean nucleus in the northern part of the Indian shield.

Raza, Mahshar; Khan, Abdullah; Bhardwaj, V. R.; Rais, Sarwar

2012-04-01

264

Seafloor weathering buffering climate: numerical experiments  

NASA Astrophysics Data System (ADS)

Continental silicate weathering is widely held to consume atmospheric CO2 at a rate controlled in part by temperature, resulting in a climate-weathering feedback [Walker et al., 1981]. It has been suggested that weathering of oceanic crust of warm mid-ocean ridge flanks also has a CO2 uptake rate that is controlled by climate [Sleep and Zahnle, 2001; Brady and Gislason, 1997]. Although this effect might not be significant on present-day Earth [Caldeira, 1995], seafloor weathering may be more pronounced during snowball states [Le Hir et al., 2008], during the Archean when seafloor spreading rates were faster [Sleep and Zahnle, 2001], and on waterworld planets [Abbot et al., 2012]. Previous studies of seafloor weathering have made significant contributions using qualitative, generally one-box, models, and the logical next step is to extend this work using a spatially resolved model. For example, experiments demonstrate that seafloor weathering reactions are temperature dependent, but it is not clear whether the deep ocean temperature affects the temperature at which the reactions occur, or if instead this temperature is set only by geothermal processes. Our goal is to develop a 2-D numerical model that can simulate hydrothermal circulation and resulting alteration of oceanic basalts, and can therefore address such questions. A model of diffusive and convective heat transfer in fluid-saturated porous media simulates hydrothermal circulation through porous oceanic basalt. Unsteady natural convection is solved for using a Darcy model of porous media flow that has been extensively benchmarked. Background hydrothermal circulation is coupled to mineral reaction kinetics of basaltic alteration and hydrothermal mineral precipitation. In order to quantify seafloor weathering as a climate-weathering feedback process, this model focuses on hydrothermal reactions that influence carbon uptake as well as ocean alkalinity: silicate rock dissolution, calcium and magnesium leaching reactions, carbonate precipitation, and clay formation.

Farahat, N. X.; Archer, D. E.; Abbot, D. S.

2013-12-01

265

A framework for predicting global silicate weathering and CO2 drawdown rates over geologic time-scales  

E-print Network

A framework for predicting global silicate weathering and CO2 drawdown rates over geologic time (received for review February 15, 2008) Global silicate weathering drives long-time-scale fluctuations in atmospheric CO2. While tectonics, climate, and rock-type influence silicate weathering, it is unclear how

Hilley, George

266

A visual analytical approach to rock art panel condition assessment  

NASA Astrophysics Data System (ADS)

Rock art is a term for pecked, scratched, or painted symbols found on rock surfaces, most typically joint faces called rock art panels. Because rock art exists on rock at the atmosphere interface, it is highly susceptible to the destructive processes of weathering. Thus, rock weathering scientists, including those that study both natural and cultural surfaces, play a key role towards understanding rock art longevity. The mapping of weathering forms on rock art panels serves as a basis from which to assess overall panel instability. This work examines fissures, case hardened surfaces, crumbly disintegration, and lichen. Knowledge of instability, as measured through these and other weathering forms, provides integral information to land managers and archaeological conservators required to prioritize panels for remedial action. The work is divided into five chapters, three of which are going to be submitted as a peer-reviewed journal manuscript. The second chapter, written as a manuscript for International Newsletter on Rock Art, describes a specific set of criteria that lead to the development of a mapping tool for weathering forms, called 'mapping weathering forms in three dimensions' (MapWeF). The third chapter, written as a manuscript for Remote Sensing of Environment, presents the methodology used to develop MapWeF. The chapter incorporates terrestrial laser scanning, a geographic information system (GIS), geovisualization, image analysis, and exploratory spatial data analysis (ESDA) to identify, map, and quantify weathering features known to cause instability on rock art panels. The methodology implemented in the third chapter satisfies the criteria described in Chapter Two. In the fourth chapter, prepared as a manuscript for Geomorphology, MapWeF is applied to a site management case study, focusing on a region---southeastern Colorado---with notoriously weak and endangered sandstone rock art panels. The final conclusions chapter describes contributions of the work to GIScience and rock weathering, and discusses how MapWeF, as a diagnostic tool, fits into a larger national vision by linking existing rock art stability characterizations to cultural resource management-related conservation action.

Vogt, Brandon J.

267

Identifying varnished rocks on Mars using thermal infrared spectroscopy  

Microsoft Academic Search

Thermal infrared (TIR) spectroscopy is widely implemented in attempts to determine the composition of the Mars's surface. Discoveries include basaltic rocks, possible andesites, and hematite-rich terrains associated with areas of probable hydrothermal alteration [Bandfield et al., 2000; Christensen et al., 2001; Glotch et al., 2004]. Some of the basaltic rocks appear to be covered by either a weathering rind or

C. A. Hibbitts; A. Gillespie; G. B. Hansen

2004-01-01

268

Rock Pioneers  

NSDL National Science Digital Library

In this outdoor activity/field trip, learners investigate organisms that live along the ocean's rocky coast. Learners add bare rocks to an intertidal zone, and over the course of 6-8 weeks observe what plant and animals colonize (come to live) on the new rocks. The intertidal zone, covered by water during high tides and uncovered at low tides, is usually densely covered with marine organisms such as seaweeds, mussels, barnacles, snails, limpets, anemones and sea stars. Learners may not only discover pioneer organisms (first colonizers) of their new rocks, but other organisms that replace the first arrivals in the process of succession. This activity calls for multiple, weekly return visits to the intertidal zone.

Science, Lawrence H.

1981-01-01

269

Chemical kinetics of water-rock interactions  

Microsoft Academic Search

The recent literature on the kinetics of water-rock interactions is reviewed. The data are then extended to provide a quantitative framework for the description of weathering and alteration. The available experimental data on dissolution of silicates verifies quantitatively the usual mineral stability series in sedimentary petrology. The rate of hydration of carbonic acid is shown to be a possible limiting

Antonio C. Lasaga

1984-01-01

270

Geochemical discrimination of clastic sedimentary rock sources  

Microsoft Academic Search

Factors controlling the geochemistry of a clastic sedimentary rock can include: (1) composition of source terrain, (2) chemical weathering, (3) hydraulic sorting, (4) diagenesis, (5) metamorphism, and (6) hydrothermal alteration. A linear solution inferring source terrain composition from geochemistry of the sediment is impossible in this multivariate system as several unknowns will commonly be present. The use of graphical analysis

P. W. Fralick; B. I. Kronberg

1997-01-01

271

E-Rock: A Virtual Field Trip  

NSDL National Science Digital Library

This virtual field trip shows students the geologic features of Enchanted Rock, a dome of Precambrian granite located in central Texas. They can see small faults, fault gouge, close-up photos showing the texture of the granite, and a variety of features produced by weathering.

Reed, Robert

272

Evidence of frost-cracking inferred from acoustic emissions in a high-alpine rock-wall  

E-print Network

Evidence of frost-cracking inferred from acoustic emissions in a high-alpine rock-wall D. Amitranoa within rock is known to be an important driver of near-surface frost weathering as well as of rock damage at the depth of several meters, which may play a crucial role for the slow preconditioning of rock fall

Paris-Sud XI, Université de

273

Biogenic rock varnishes of the negev desert (Israel) an ecological study of iron and manganese transformation by cyanobacteria and fungi  

Microsoft Academic Search

The ecology of the microflora, which produces rock varnishes in the Negev is described. It is shown that biogenic rock varnishes may form within relatively short periods (1967–1981) on places where pre-existing varnishes were eliminated. Rock varnishes are thin coatings, mainly composed of Fe and Mn hydroxides and clay material. Biogenic rock varnishes form at places where “microbial weathering fronts”,

W. E. Krumbein; K. Jens

1981-01-01

274

Tales of future weather  

NASA Astrophysics Data System (ADS)

Society is vulnerable to extreme weather events and, by extension, to human impacts on future events. As climate changes weather patterns will change. The search is on for more effective methodologies to aid decision-makers both in mitigation to avoid climate change and in adaptation to changes. The traditional approach uses ensembles of climate model simulations, statistical bias correction, downscaling to the spatial and temporal scales relevant to decision-makers, and then translation into quantities of interest. The veracity of this approach cannot be tested, and it faces in-principle challenges. Alternatively, numerical weather prediction models in a hypothetical climate setting can provide tailored narratives for high-resolution simulations of high-impact weather in a future climate. This 'tales of future weather' approach will aid in the interpretation of lower-resolution simulations. Arguably, it potentially provides complementary, more realistic and more physically consistent pictures of what future weather might look like.

Hazeleger, W.; van den Hurk, B. J. J. M.; Min, E.; van Oldenborgh, G. J.; Petersen, A. C.; Stainforth, D. A.; Vasileiadou, E.; Smith, L. A.

2015-02-01

275

NOAA Daily Weather Maps  

NSDL National Science Digital Library

The charts on this website are the principal charts of the former Weather Bureau publication, "Daily Weather Map." They are the Surface Weather Map, the 500-Millibar Height Contours chart, the Highest and Lowest Temperatures chart, and the Precipitation Areas and Amounts chart. For each day, simple charts are arranged on a single page. These charts are the surface analysis of pressure and fronts, color shading, in ten degree intervals,of maximum and minimum temperature, 500-Millibar height contours, and color shaded 24-hour total precipitation. These charts act as links to their respective Daily Weather Map charts. All charts are derived from the operational weather maps prepared at the National Centers for Environmental Prediction, Hydrometeorological Prediction Center, National Weather Service.

Hydrometeorological Prediction Center

2011-01-01

276

Start a Rock Collection  

NSDL National Science Digital Library

Learners follow a three-step process to start their own rock collection. Learners will collect rocks, record information about each rock on a Rock Chart, observe and sort their rocks, and create a rock display. This activity also includes a book list with resources for rock classification.

History, American M.

2012-06-26

277

Backyard Weather Stations  

NSDL National Science Digital Library

Learn how to build your own backyard weather station with complete directions provided by FamilyEducation.com's Web site, Backyard Weather Stations. The site shows exactly what you'll need and how to build the necessary components (e.g., rain gauge and barometer), as well as how to keep records of the data collected. Parents and teachers will enjoy watching the kids "learn the basics of scientific observation and record-keeping while satisfying their natural curiosity about weather."

Randall, Dennis.

278

Winter weather activity  

NSDL National Science Digital Library

This project explores factors that help create severe winter weather. An interactive simulation provides hands-on experience, followed by guiding questions and resource exploration. Weather Maker Simulator Use the weather simulation above to answer the following questions in complete sentences on paper. 1. In general, when are winds formed? 2. When winds are blowing, how can you get them to stop? 3. What usually happens when there is a large difference between the temperatures? 4. What happens when there is high ...

Frankovic, Whitney

2009-09-28

279

RBSP Space Weather data  

NASA Astrophysics Data System (ADS)

On August 23, 2012, NASA will launch two identical probes into the radiation belts to provide unprecedented insight into the physical processes and dynamics of near-Earth space. The RBSP mission in addition to the scientific data return, provides a 1Kbps real-time space weather broadcast data in support of real time space weather modeling, forecast and prediction efforts. Networks of ground stations have been identified to downlink the space weather data. The RBSP instrument suites have selected space weather data to be broadcast from their collected space data on board the spacecraft, a subset from measurements based on information normally available to the instrument. The data subset includes particle fluxes at a variety of energies, and magnetic and electric field data. This selected space weather data is broadcast at all times through the primary spacecraft science downlink antennas when an observatory is not in a primary mission-related ground contact. The collected data will resolve important scientific issues and help researchers develop and improve various models for the radiation belts that can be used by forecasters to predict space weather phenomena and alert astronauts and spacecraft operators to potential hazards. The near real-time data from RBSP will be available to monitor and analyze current environmental conditions, forecast natural environmental changes and support anomaly resolution. The space weather data will be available on the RBSP Science Gateway at http://athena.jhuapl.edu/ and will provide access to the space weather data received from the RBSP real-time space weather broadcast. The near real-time data will be calibrated and displayed on the web as soon as possible. The CCMC will ingest the RBSP space weather data into real-time models. The raw space weather data will be permanently archived at APL. This presentation will provide a first look at RBSP space weather data products.

Weiss, M.; Fox, N. J.; Mauk, B. H.; Barnes, R. J.; Potter, M.; Romeo, G.; Smith, D.

2012-12-01

280

Weather Radar Fundamentals  

NSDL National Science Digital Library

This 2-hour module presents the fundamental principles of Doppler weather radar operation and how to interpret common weather phenomena using radar imagery. This is accomplished via conceptual animations and many interactive radar examples in which the user can practice interpreting both radar reflectivity and radar velocity imagery. Although intended as an accelerated introduction to understanding and using basic Doppler weather radar products, the module can also serve as an excellent refresher for more experienced users.

COMET

2012-03-21

281

Everything Weather- Archived Data  

NSDL National Science Digital Library

Users can obtain current weather forecasts for their own areas by entering a ZIP code, or they can access a large archive of historic data on severe weather (tornadoes, hail, high winds, hurricanes). Materials presented in the archive include dates, times, and intensities of storms, a photo gallery, maps, radar and other satellite data, storm chaser reports, and links to other weather sites. Raw data can be found in several forms for teachers wishing to have unprocessed data to work with.

2001-01-01

282

National Weather Service  

NSDL National Science Digital Library

Sick and tired of the heat? Feel like it will never end? Then check out the National Weather Service's (NWS) Heat Wave, a site devoted to the extreme weather that is crippling the south. The NWS provides information on the heat index, heat's affect on the body, and how to beat the heat. For those who want an up-to-the-minute look at the weather, the site links to current conditions, forecasts, and watches and warnings.

283

Weathering of limestone beds at the great sphinx  

Microsoft Academic Search

The weathering characteristics of the sphinx limestones are evaluated in the context of their pore system. The latter consists of “ink-bottle” pores. This pore system varies from one stratum to another. In the lower micritic rocks the large cavities of the ink-bottle pores are interconnected through the fine capillary network of the narrow throats. In the upper skeletal-rich rocks the

Ahad N. Chowdhury; Adinarayana R. Punuru; K. L. Gauri

1990-01-01

284

Weathering of limestone beds at the great sphinx  

Microsoft Academic Search

The weathering characteristics of the sphinx limestones are evaluated in the context of their pore system. The latter consists of ``ink-bottle'' pores. This pore system varies from one stratum to another. In the lower micritic rocks the large cavities of the ink-bottle pores are interconnected through the fine capillary network of the narrow throats. In the upper skeletal-rich rocks the

Ahad N. Chowdhury; Adinarayana R. Punuru; K. L. Gauri

1990-01-01

285

Iron isotopic fractionation during continental weathering  

SciTech Connect

The biological activity on continents and the oxygen content of the atmosphere determine the chemical pathways through which Fe is processed at the Earth's surface. Experiments have shown that the relevant chemical pathways fractionate Fe isotopes. Measurements of soils, streams, and deep-sea clay indicate that the {sup 56}Fe/{sup 54}Fe ratio ({delta}{sup 56}Fe relative to igneous rocks) varies from +1{per_thousand} for weathering residues like soils and clays, to -3{per_thousand} for dissolved Fe in streams. These measurements confirm that weathering processes produce substantial fractionation of Fe isotopes in the modern oxidizing Earth surface environment. The results imply that biologically-mediated processes, which preferentially mobilize light Fe isotopes, are critical to Fe chemistry in weathering environments, and that the {delta}{sup 56}Fe of marine dissolved Fe should be variable and negative. Diagenetic reduction of Fe in marine sediments may also be a significant component of the global Fe isotope cycle. Iron isotopes provide a tracer for the influence of biological activity and oxygen in weathering processes through Earth history. Iron isotopic fractionation during weathering may have been smaller or absent in an oxygen-poor environment such as that of the early Precambrian Earth.

Fantle, Matthew S.; DePaolo, Donald J.

2003-10-01

286

Cockpit weather information needs  

NASA Technical Reports Server (NTRS)

The primary objective is to develop an advanced pilot weather interface for the flight deck and to measure its utilization and effectiveness in pilot reroute decision processes, weather situation awareness, and weather monitoring. Identical graphical weather displays for the dispatcher, air traffic control (ATC), and pilot crew should also enhance the dialogue capabilities for reroute decisions. By utilizing a broadcast data link for surface observations, forecasts, radar summaries, lightning strikes, and weather alerts, onboard weather computing facilities construct graphical displays, historical weather displays, color textual displays, and other tools to assist the pilot crew. Since the weather data is continually being received and stored by the airborne system, the pilot crew has instantaneous access to the latest information. This information is color coded to distinguish degrees of category for surface observations, ceiling and visibilities, and ground radar summaries. Automatic weather monitoring and pilot crew alerting is accomplished by the airborne computing facilities. When a new weather information is received, the displays are instantaneously changed to reflect the new information. Also, when a new surface or special observation for the intended destination is received, the pilot crew is informed so that information can be studied at the pilot's discretion. The pilot crew is also immediately alerted when a severe weather notice, AIRMET or SIGMET, is received. The cockpit weather display shares a multicolor eight inch cathode ray tube and overlaid touch panel with a pilot crew data link interface. Touch sensitive buttons and areas are used for pilot selection of graphical and data link displays. Time critical ATC messages are presented in a small window that overlays other displays so that immediate pilot alerting and action can be taken. Predeparture and reroute clearances are displayed on the graphical weather system so pilot review of weather along the route can be accomplished prior to pilot acceptance of the clearance. An ongoing multiphase test series is planned for testing and modifying the graphical weather system. Preliminary data shows that the nine test subjects considered the graphical presentation to be much better than their current weather information source for situation awareness, flight safety, and reroute decision making.

Scanlon, Charles H.

1992-01-01

287

Winter Storm (weather)  

NSDL National Science Digital Library

This project explores factors that help create severe winter weather. An interactive simulation provides hands-on experience, followed by guiding questions and resource exploration. First think about these questions: 1. What is your favorite aspect of winter weather? 2. How does the weather effect your everyday life? Form groups of THREE. Explore the following simulation: Weather Maker Simulator Use the simulation to answer the following questions on paper... 1. In general, when are winds formed? 2. When winds are blowing, how can you ...

Miller, Aubree

2009-09-28

288

Pilot Weather Advisor System  

NASA Technical Reports Server (NTRS)

The Pilot Weather Advisor (PWA) system is an automated satellite radio-broadcasting system that provides nearly real-time weather data to pilots of aircraft in flight anywhere in the continental United States. The system was designed to enhance safety in two distinct ways: First, the automated receipt of information would relieve the pilot of the time-consuming and distracting task of obtaining weather information via voice communication with ground stations. Second, the presentation of the information would be centered around a map format, thereby making the spatial and temporal relationships in the surrounding weather situation much easier to understand

Lindamood, Glenn; Martzaklis, Konstantinos Gus; Hoffler, Keith; Hill, Damon; Mehrotra, Sudhir C.; White, E. Richard; Fisher, Bruce D.; Crabill, Norman L.; Tucholski, Allen D.

2006-01-01

289

Weathering of sulfides on Mars  

NASA Technical Reports Server (NTRS)

Pyrrhotite-pentlandite assemblages in mafic and ultramafic igneous rocks may have contributed significantly to the chemical weathering reactions that produce degradation products in the Martian regolith. By analogy and terrestrial processes, a model is proposed whereby supergene alteration of these primary Fe-Ni sulfides on Mars has generated secondary sulfides (e.g., pyrite) below the water table and produced acidic groundwater containing high concentrations of dissolved Fe, Ni, and sulfate ions. The low pH solutions also initiated weathering reactions of igneous feldspars and ferromagnesian silicates to form clay silicate and ferric oxyhydroxide phases. Near-surface oxidation and hydrolysis of ferric sulfato-and hydroxo-complex ions and sols formed gossan above the water table consisting of poorly crystalline hydrated ferric sulfates (e.g., jarosite), oxides (ferrihydrite, goethite), and silica (opal). Underlying groundwater, now permafrost contains hydroxo sulfato complexes of Fe, Al, Mg, Ni, which may be stabilized in frozen acidic solutions beneath the surface of Mars. Sublimation of permafrost may replenish colloidal ferric oxides, sulfates, and phyllosilicates during dust storms on Mars.

Burns, Roger G.; Fisher, Duncan S.

1987-01-01

290

Rock Groups  

NSDL National Science Digital Library

In this one-page article Steven Strogatz explains how representing numbers with concrete objects can make calculations less confusing. By using images of rocks, he demystifies concepts such as square numbers, parity, primes, and sums of consecutive numbers. This is the second in Steven's series of 15 articles on the Elements of Math (home page cataloged separately).

Steven Strogatz

2010-02-07

291

Sedimentary Rocks  

NSDL National Science Digital Library

This is a course handout that accompanies the discussion of the origin of sedimentary rocks. Topics include depositional tectonic settings, texture as an indicator of energy levels in the depositional environment, interpretation of various sandstones, and the influences of paleoclimate and source area lithology. Photos depict grain size and texture. Links are provided to the online Physical Geology resources at Georgia Perimeter College.

Gore, Pamela

1995-09-24

292

Classic Rock  

ERIC Educational Resources Information Center

While "early college" programs designed for high-school-age students are beginning to proliferate nationwide, a small New England school has been successfully educating teens for nearly four decades. In this article, the author features Simon's Rock, a small liberal arts college located in the Great Barrington, Massachusetts, that has been…

Beem, Edgar Allen

2004-01-01

293

Stillwater Rocks  

USGS Multimedia Gallery

Rocks from the Stillwater Mine are brought to the USGS in Denver, Colorado, where they are ground before entering the plasma melter at Zybek Advanced Products. __________ The USGS has created man-made moon dirt, or regolith, to help NASA prepare for upcoming moon explorations. Four tons of the sim...

2009-05-26

294

Rock Grinding  

USGS Multimedia Gallery

Rocks from the Stillwater Mine are brought to the USGS in Denver, Colorado, where they are sledged and ground before entering the plasma melter at Zybek Advanced Products. __________ The USGS has created man-made moon dirt, or regolith, to help NASA prepare for upcoming moon explorations. Four ton...

2009-05-26

295

Geochemistry of large river suspended sediments: Silicate weathering or recycling tracer?  

SciTech Connect

This study focuses on the major and trace element composition of suspended sediments transported by the world's largest rivers. Its main purpose is to answer the following question: is the degree of weathering of modern river-borne particles consistent with the estimated river dissolved loads derived from silicate weathering? In agreement with the well known mobility of elements during weathering of continental rocks, the authors confirm that river sediments are systematically depleted in Na, K, Ba with respect to the Upper Continental Crust. For each of these mobile elements, a systematics of weathering indexes of river-borne solids is attempted. A global consistency is found between all these indexes. Important variations in weathering intensities exist. A clear dependence of weathering intensities with climate is observed for the rivers draining mostly lowlands. However, no global correlation exists between weathering intensities and climatic or relief parameters because the trend observed for lowlands is obscured by rivers draining orogenic zones. An inverse correlation between weathering intensities and suspended sediment concentrations is observed showing that the regions having the highest rates of physical denudation produce the least weathered sediments. Finally, chemical and physical weathering are compared through the use of a simple steady state model. The authors show that the weathering intensities of large river suspended sediments can only be reconciled with the (silicate-derived) dissolved load or rivers, by admitting that most of the continental rocks submitted to weathering in large river basins have already suffered previous weathering cycles. A simple graphical method is proposed for calculating the proportion of sedimentary recycling in large river basins. Finally, even if orogenic zones produce weakly weathered sediments, the authors emphasize the fact that silicate chemical weathering rates (and hence CO{sub 2} consumption rates by silicate weathering) are greatly enhanced in mountains simply because the sediment yields in orogenic drainage basins are higher. Hence, the parameters that control chemical weathering rates would be those that control physical denudation rates.

Gaillardet, J.; Dupre, B.; Allegre, C.J.

1999-12-01

296

Weather and emotional state  

NASA Astrophysics Data System (ADS)

Introduction Given the proven effects of weather on the human organism, an attempt to examine its effects on a psychic and emotional level has been made. Emotions affect the bio-tonus, working ability and concentration, hence their significance in various domains of economic life, such as health care, education, transportation, tourism, etc. Data and methods The research has been made in Sofia City within a period of 8 months, using 5 psychological methods (Eysenck Personality Questionnaire (EPQ), State-Trait Anxiety Inventory (STAI), Test for Self-assessment of the emotional state (developed by Wessman and Ricks), Test for evaluation of moods and Test "Self-confidence - Activity - Mood" (developed by the specialists from the Military Academy in Saint Petersburg). The Fiodorov-Chubukov's complex-climatic method was used to characterize meteorological conditions because of the purpose to include in the analysis a maximal number of meteorological elements. 16 weather types are defined in dependence of the meteorological elements values according to this method. Abrupt weather changes from one day to another, defined by the same method, were considered as well. Results and discussions The results obtained by t-test show that the different categories of weather lead to changes in the emotional status, which indicates a character either positive or negative for the organism. The abrupt weather changes, according to expectations, have negative effect on human emotions but only when a transition to the cloudy weather or weather type, classified as "unfavourable" has been realized. The relationship between weather and human emotions is rather complicated since it depends on individual characteristics of people. One of these individual psychological characteristics, marked by the dimension "neuroticism", has a strong effect on emotional reactions in different weather conditions. Emotionally stable individuals are more "protected" to the weather influence on their emotions, while those who are emotionally unstable have a stronger dependence to the impacts of the weather.

Spasova, Z.

2010-09-01

297

From Rocks to Cement. What We Make. Science and Technology Education in Philippine Society.  

ERIC Educational Resources Information Center

This module deals with the materials used in making concrete hollow blocks. Topics discussed include: (1) igneous, metamorphic, and sedimentary rocks; (2) weathering (the process of breaking down rocks) and its effects on rocks; (3) cement; (4) stages in the manufacturing of Portland cement; and (5) the transformation of cement into concrete…

Philippines Univ., Quezon City. Science Education Center.

298

A micromechanics-based elastoplastic damage model for quasi-brittle rocks  

E-print Network

is applied to simulate triaxial compression tests on two sets of diabase samples, the first cored from a fresh diabase rock mass and the second from a slightly weathered one. Comparisons between numerical in the area of Danjiangkou Water Reservoir, such as diabase rock, sandstone, schist rock, etc. Among them

Paris-Sud XI, Université de

299

What Is Space Weather?  

NSDL National Science Digital Library

This resource provides a brief overview of the phenomenon known as space weather, which happens when energetic particles emitted by the Sun impact the Earth's magnetosphere. Users can view images, video clips, and animations of auroras and other types of space weather. A set of links to related websites is also provided.

300

People and Weather.  

ERIC Educational Resources Information Center

Provides: (1) background information on ways weather influences human lives; (2) activities related to this topic; and (3) a ready-to-copy page with weather trivia. Each activity includes an objective, list of materials needed, recommended age level(s), subject area(s), and instructional strategies. (JN)

NatureScope, 1985

1985-01-01

301

Mild and Wild Weather.  

ERIC Educational Resources Information Center

Presents background information and six activities that focus on clouds, precipitation, and stormy weather. Each activity includes an objective, recommended age level(s), subject area(s), and instructional strategies. Also provided are two ready-to-copy pages (a coloring page on lightning and a list of weather riddles to solve). (JN)

NatureScope, 1985

1985-01-01

302

Home Weatherization Visit  

ScienceCinema

Secretary Steven Chu visits a home that is in the process of being weatherized in Columbus, OH, along with Ohio Governor Ted Strickland and Columbus Mayor Michael Coleman. They discuss the benefits of weatherization and how funding from the recovery act is having a direct impact in communities across America.

Chu, Steven

2013-05-29

303

Designing a Weather Station  

ERIC Educational Resources Information Center

The collection and analysis of weather data is crucial to the location of alternate energy systems like solar and wind. This article presents a design challenge that gives students a chance to design a weather station to collect data in advance of a large wind turbine installation. Data analysis is a crucial part of any science or engineering…

Roman, Harry T.

2012-01-01

304

Weather Fundamentals: Wind. [Videotape].  

ERIC Educational Resources Information Center

The videos in this educational series, for grades 4-7, help students understand the science behind weather phenomena through dramatic live-action footage, vivid animated graphics, detailed weather maps, and hands-on experiments. This episode (23 minutes) describes the roles of the sun, temperature, and air pressure in creating the incredible power…

1998

305

Weather Fundamentals: Clouds. [Videotape].  

ERIC Educational Resources Information Center

The videos in this educational series, for grades 4-7, help students understand the science behind weather phenomena through dramatic live-action footage, vivid animated graphics, detailed weather maps, and hands-on experiments. This episode (23 minutes) discusses how clouds form, the different types of clouds, and the important role they play in…

1998

306

Uncertain weather, uncertain climate  

E-print Network

of the Speckled Band" "Good-morning, madam," said Holmes cheerily. "My name is Sherlock Holmes. #12;222b Baker sit on the left-hand side of the driver." #12;Holmes' calculation D. Nychka Uncertain weather Maximize over vehicle #12;D. Nychka Uncertain weather, uncertain climate 8 Holmes' conclusion ­ the highest

Nychka, Douglas

307

Redistribution of uranium and thorium series isotopes during isovolumetric weathering of granite  

NASA Astrophysics Data System (ADS)

Previous studies of the distribution of U and Th in parent versus weathered granites have shown both depletion and enrichment of these elements during weathering. In this study, the distribution of U and Th decay series isotopes was determined in a weathering profile of a granitic saprolite, which showed textural preservation indicating isovolumetric weathering. Two types of dissolution methods were used: a whole-rock dissolution and a sodium-citrate dithionite leach to preferentially attack noncrystalline phases of weathering products. Using volume-based activities, 45-70 percent of the total 232Th was gradually removed during weathering. Although the whole-rock 228Th /232Th activity ratios were in equilibrium, there were large excesses of 228Th in the leachable fraction of both parent rock ( 228Th /232Th = 2.06 ) and partially weathered saprolite ( 228Th /232Th = 3-6.5 ), due to alpha recoil and release of daughter 228Th to the weathering rind of the mineral grain. For the most weathered sample, 81 percent of the thorium was in the teachable fraction and 228Th /232Th = 1 , indicating that even the more resistant minerals were attacked. The total U activities showed as much variation in the six parent rock samples as in the weathered profile, and 234U /238U were in equilibrium in both the whole-rock and leachable fractions. 230Th was deficient relative to 234U and 226Ra in both fractions, suggesting recent addition of U and Ra to the entire profile. The large variation in U was not from absorption onto the intermediate weathering products, because only 11-23 percent of the U was in the leachable fraction.

Michel, Jacqueline

1984-06-01

308

Q00906010024 rock check dam  

E-print Network

00906010024 rock check dam Q00906010025 rock check dam Q00906010021 rock check dam Q00906010022 rock check dam Q00906010027 rock check dam Q00906010026 rock check dam Q00906010018 rock check dam Q00906010023 rock check dam Q00906010011 rock check dam Q00906010008 rock check dam Q00906010007 rock check dam Q

309

External Resource: Rock and Roll  

NSDL National Science Digital Library

This page contains information on exactly what a rock is, as well as a diagram of the rock cycle. Topics include: characteristics of rocks, types of rocks, igneous rocks, metamorphic rocks, and sedimentary rocks.

1900-01-01

310

Rock Cycle Animation  

NSDL National Science Digital Library

Use this interactive rock cycle animation to help you with your schoolwork! This cutaway view of Earth shows where some common rock-forming processes occur. Embedded animations will illustrate the path of a rock moving through the rock cycle.

2010-01-01

311

Predicting the Weather  

NSDL National Science Digital Library

This Topic in Depth explores the science behind predicting the weather. First, the United States Search and Rescue Task Force describe the basic tools and knowledge used to create weather forecasts (1). Students can find concise, clear explanations of weather, fronts and air masses, high and low pressure, precipitation, and water vapor and humidity as well. By performing the activities presented in the second website, fourth grade students can learn about weather instruments and data collection (2). This website, produced by the Government of Saskatchewan, also explores how the weather can impact local communities. Third, Edheads offers a Macromedia Flash Player enhanced interactive module allowing students to predict the weather by examining weather maps (3 ). Through this website, users can become familiar with the concepts of warm and cold fronts, wind direction and speed, air pressure, and humidity. The fourth website, supplied by Annenberg / CPB, discusses weather satellites, Doppler radar, and additional tools forecasters use to predict the weather (4). Students can find a wind chill calculator along with a brief discussion of the history of forecasting and weather lore. Next, NOAA provides graphics for five forecast models: the ETA, the Global Forecast System (GFS), the Wave Watch III (WW3), the Nested Grid model (NGM), and the Rapid Update Cycle (RUC) (5). Outputs are available for North America, North Pacific, Western North Atlantic, and the Polar Ice Drift. Users can find links to detailed descriptions of the inputs and history of each model. Sixth, the British government's Met Office describes numerical modeling and its components (6). Students and educators can learn about the future in forecasting as well as educational opportunities with the Cooperative Program for Meteorology, Education, and Training (COMET).

312

Terby's Rocks  

NASA Technical Reports Server (NTRS)

25 August 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows light-toned, layered, sedimentary rock outcrops in the crater, Terby. The crater is located on the north rim of Hellas Basin. If one could visit the rocks in Terby, one might learn from them whether they formed in a body of water. It is possible, for example, that Terby was a bay in a larger, Hellas-wide sea.

Location near: 27.9oS, 285.7oW Image width: width: 3 km (1.9 mi) Illumination from: upper left Season: Southern Winter

2005-01-01

313

Meridiani Rocks  

NASA Technical Reports Server (NTRS)

16 September 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows the complex surfaces of some of the light- and intermediate-toned sedimentary rock exposed by erosion in eastern Sinus Meridiani. Similar rocks occur at the Mars Exploration Rover, Opportunity, site, but they are largely covered by windblown sand and granules. The dark feature with a rayed pattern is the product of a meteor impact.

Location near: 0.8oN, 355.2oW Image width: width: 3 km (1.9 mi) Illumination from: lower left Season: Northern Autumn

2005-01-01

314

Poohbear Rock  

NASA Technical Reports Server (NTRS)

This image, taken by Sojourner's front right camera, was taken when the rover was next to Poohbear (rock at left) and Piglet (not seen) as it looked out toward Mermaid Dune. The textures differ from the foreground soil containing a sorted mix of small rocks, fines and clods, from the area a bit ahead of the rover where the surface is covered with a bright drift material. Soil experiments where the rover wheels dug in the soil revealed that the cloudy material exists underneath the drift.

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech).

1997-01-01

315

Geochemistry and origin of ferruginous nodules in weathered granodioritic gneisses, Mysore Plateau, Southern India  

Microsoft Academic Search

Fe-nodules occur within saprolites formed from weathering of granodioritic gneisses in the rain-shadow region of the Mysore Plateau adjacent to the Sahyadri Mountains in Southern India. These nodules and their host saprolites were studied for their geochemistry, including chemical speciation, to understand nodule formation and chemical redistribution processes during rock weathering. From their mode of occurrence, and mineralogical and geochemical

Jayant K. Tripathi; V. Rajamani

2007-01-01

316

Environmental Education Tips: Weather Activities.  

ERIC Educational Resources Information Center

Provides weather activities including questions, on weather, heating the earth's surface, air, tools of the meteorologist, clouds, humidity, wind, and evaporation. Shows an example of a weather chart activity. (RT)

Brainard, Audrey H.

1989-01-01

317

Weathering of the Rio Blanco quartz diorite, Luquillo Mountains, Puerto Rico: Coupling oxidation, dissolution, and fracturing  

Microsoft Academic Search

In the mountainous Rio Icacos watershed in northeastern Puerto Rico, quartz diorite bedrock weathers spheroidally, producing a 0.2–2m thick zone of partially weathered rock layers (?2.5cm thickness each) called rindlets, which form concentric layers around corestones. Spheroidal fracturing has been modeled to occur when a weathering reaction with a positive ?V of reaction builds up elastic strain energy. The rates

Heather L. Buss; Peter B. Sak; Samuel M. Webb; Susan L. Brantley

2008-01-01

318

Basalt weathering in Central Siberia under permafrost conditions  

Microsoft Academic Search

Chemical weathering of basalts in the Putorana Plateau, Central Siberia, has been studied by combining chemical and mineralogical analysis of solids (rocks, soils, river sediments, and suspended matter) and fluid solution chemistry. Altogether, 70 large and small rivers, 30 soil pore waters and groundwaters and over 30 solids were sampled during July to August 2001. Analysis of multiannual data on

O. S. Pokrovsky; J. Schott; D. I. Kudryavtzev; B. Dupré

2005-01-01

319

A model of weathering intensity for the Australian continent  

NASA Astrophysics Data System (ADS)

Regolith encompasses all weathered materials in the zone between the Earth's surface and fresh bedrock at depth. This weathered zone includes the soil, which may constitute the whole of the regolith profile or represent only its upper part. Important hydrological and biogeochemical processes operate within the regolith, including the infiltration and storage of near-surface water and nutrients, which sustain agricultural productivity. The degree to which the regolith is weathered (or its weathering intensity) is intrinsically linked to the factors involved in soil formation including parent material, climate, topography, biota and time. The degree to which the bedrock or sediments are weathered has a significant effect on the nature and distribution of regolith materials. There is commonly a strong correlation between weathering intensity and the degree of soil development as well as the depth of the weathering front. Changes in weathering intensity correspond to changes in the geochemical and physical properties of bedrock, ranging from essentially unweathered parent materials through to intensely weathered and leached regolith where all traits of the original protolith (original unweathered rock) are overprinted or lost altogether. With increasing weathering intensity we see mineral and geochemical convergence to more resistant secondary weathered materials including clay, silica, and various oxides. A weathering intensity index (WII) over the Australian continent has been developed at a 100 m resolution using two regression models based on airborne gamma-ray spectrometry imagery and the Shuttle Radar Topography Mission (SRTM) elevation data. Airborne gamma-ray spectrometry measures the concentration of three radioelements -- potassium (K), thorium (Th) and uranium (U) at the Earth's surface. The total gamma-ray flux (dose) is also calculated based on the weighted additions of the three radioelements. In general K is leached with increasing weathering whereas Th and U typically show increases due to their association in clays and oxides in the profile. These geochemical relationships underpin the first model prediction. In the case where no gamma-ray data is available or where the bedrock is very low in radioelements (e.g. basalt, quartz-rich sandstone) surface relief is used as surrogate in the second prediction model. The two models are combined to generate a weathering intensity index of the Australian continent. The weathering intensity index has been developed for erosional landscapes but also provides useful information on deposition processes and materials. The weathering intensity prediction is evaluated with surface geochemistry (compared with geochemical indices) and previous regolith-landform mapping. The use of the weathering intensity index in natural resource management and mineral exploration is discussed.

Wilford, J.

2013-12-01

320

Confined groundwater near the rockhead in igneous rocks in the Mid-Levels area, Hong Kong, China  

Microsoft Academic Search

It is customary in Hong Kong to assume that the hydraulic conductivity of weathered igneous rocks decreases with depth or as the rock mass becomes less weathered. Such a hydraulic conductivity pattern can only lead to an unconfined aquifer. This paper presents a case study in the regions in and around the Mid-Levels area in Hong Kong regarding a possible

Jiu J. Jiao; Guoping Ding; Chi-Man Leung

2006-01-01

321

Effects of pure silica coatings on thermal emission spectra of basaltic rocks: Considerations for Martian surface mineralogy  

Microsoft Academic Search

(1) On Mars, silica derived from chemical weathering could precipitate to coat rocks and particles. We suggest that rock coatings of secondary amorphous silica may account for a widespread Martian surface spectral unit previously modeled as andesite or weathered basalt. In a laboratory study, we investigated the effects of synthetic silica coatings on thermal infrared (TIR) spectroscopic measurements. Secondary amorphous

Michael D. Kraft; Joseph R. Michalski; Thomas G. Sharp

2003-01-01

322

Sliding Rocks on Racetrack Playa, Death Valley National Park: First Observation of Rocks in Motion  

PubMed Central

The engraved trails of rocks on the nearly flat, dry mud surface of Racetrack Playa, Death Valley National Park, have excited speculation about the movement mechanism since the 1940s. Rock movement has been variously attributed to high winds, liquid water, ice, or ice flotation, but has not been previously observed in action. We recorded the first direct scientific observation of rock movements using GPS-instrumented rocks and photography, in conjunction with a weather station and time-lapse cameras. The largest observed rock movement involved >60 rocks on December 20, 2013 and some instrumented rocks moved up to 224 m between December 2013 and January 2014 in multiple move events. In contrast with previous hypotheses of powerful winds or thick ice floating rocks off the playa surface, the process of rock movement that we have observed occurs when the thin, 3 to 6 mm, “windowpane” ice sheet covering the playa pool begins to melt in late morning sun and breaks up under light winds of ?4–5 m/s. Floating ice panels 10 s of meters in size push multiple rocks at low speeds of 2–5 m/min. along trajectories determined by the direction and velocity of the wind as well as that of the water flowing under the ice. PMID:25162535

Lorenz, Ralph D.; Ray, Jib; Jackson, Brian

2014-01-01

323

Sliding rocks on Racetrack Playa, Death Valley National Park: first observation of rocks in motion.  

PubMed

The engraved trails of rocks on the nearly flat, dry mud surface of Racetrack Playa, Death Valley National Park, have excited speculation about the movement mechanism since the 1940s. Rock movement has been variously attributed to high winds, liquid water, ice, or ice flotation, but has not been previously observed in action. We recorded the first direct scientific observation of rock movements using GPS-instrumented rocks and photography, in conjunction with a weather station and time-lapse cameras. The largest observed rock movement involved > 60 rocks on December 20, 2013 and some instrumented rocks moved up to 224 m between December 2013 and January 2014 in multiple move events. In contrast with previous hypotheses of powerful winds or thick ice floating rocks off the playa surface, the process of rock movement that we have observed occurs when the thin, 3 to 6 mm, "windowpane" ice sheet covering the playa pool begins to melt in late morning sun and breaks up under light winds of -4-5 m/s. Floating ice panels 10 s of meters in size push multiple rocks at low speeds of 2-5 m/min. along trajectories determined by the direction and velocity of the wind as well as that of the water flowing under the ice. PMID:25162535

Norris, Richard D; Norris, James M; Lorenz, Ralph D; Ray, Jib; Jackson, Brian

2014-01-01

324

Microclimatic factors controlling tafoni weathering in Tafraoute, Morocco  

NASA Astrophysics Data System (ADS)

Cavernous tafoni-type weathering is observed in many arid and semiarid regions of the world and the underlying processes, as well as the respective weathering rates, are still not fully understood. Although the conditions of Tafoni formation has been under consideration for approx. 100 years, there is still no unifom view about their formation process. Their distribution pattern is thought to be controlled by distance to shore, duration of the arid season, local fault systems or by the age of the respective exposure. Three possible ways of tafoni genesis are under discussion: (1) mechanical weathering by temperature and volume fluctuations in short periods which are reinforced by micro-circulation of air in the cavities; (2) mechanical weathering by hydration of salts; (3) chemical weathering including case hardening on the surface and "core weathering" of the interior. To understand the tafoni weathering process it boils down to three significant influential factors: temperature fluctuations, rock moisture and salt distribution. Our study focuses on tafoni weathering in Tafraoute, Morocco, located in the granites of the Kerdouse Massif. We attempt to clarify the formation process using a combination of various micro-climatic and geophysical methods. The most important technique is small-scale 2D-resistivity profiling which allows to look some decimetres inside the rock and to visualise rock moisture and salt concentration patterns. First morphometric analysis and mappings have been conducted in summer 2013, and micro-climatic investigations are carried out in February 2014. Mapping results show that tafoni distribution is influenced by topography and aspect. However, no relation between exposure and depth of the hollows was found; e.g. no significant differences in morphometric parameters were observed between northern and western rock faces. Temperature sensors were installed at different expositions and depths to measure daily temperature changes. These are supplemented by infrared images used to detect subtle spatio-temporal changes in surface temperature. The spatial distribution of rock moisture is derived from the aforementioned 2D-geoelectric profiles which have not been aplied in this context before. The geophysical measurements are complemented by capacitive handheld sensor surveys and borehole humidity measurements. Salt content is determined in a narrow grid using paper pulp poultices; the samples are analyzed in the laboratory for salt types and concentration. The investigations will contribute to understanding the importance of local- and microclimatic conditions, rock parameters and salt concentrations on the occurrence and shape of tafoni.

Fruhmann, Stefanie; Schnepfleitner, Harald; Sass, Oliver

2014-05-01

325

Space Weather Now  

NSDL National Science Digital Library

The NOAA Space Weather Now website provides non-technical information and an assortment of images detailing current space weather. Visitors can find summaries describing auroras, plots of current auroral ovals on the poles, and viewing information for the Northern and Southern Hemispheres. The Real-Time Solar Wind Pages furnish dynamic plots of data, geomagnetic activity test product information, and resources about the four instruments used to collect data on geomagnetic storms. The website features Space Weather Scales to help the public understand the severity of environmental disturbances due to geomagnetic storms, solar radiation storms, and radio blackouts. Visitors can find the latest news, alerts, advisory bulletins, and much more.

326

Weather Observing Fundamentals  

NSDL National Science Digital Library

"Weather Observing Fundamentals" provides guidance for U.S. Navy Aerographer's Mates, Quartermasters, and civilian observers tasked with taking and reporting routine, special, and synoptic observations. Although the focus of this lesson is on shipboard observations, much of the content applies to land-based observing and reporting as well. The lesson details standard procedures for taking accurate weather observations and for encoding those observations on COMNAVMETOCCOM Report 3141/3. Exercises throughout the lesson and four weather identification drills at the end provide learners with opportunities to practice and build their skills. The lesson covers a large amount of content. You may wish to work through the material in multiple sessions.

2014-09-14

327

World Weather Information Service  

NSDL National Science Digital Library

The World Meteorological Organization Web site offers the World Weather Information Service page. Here, visitors will find official weather forecasts and climatological information for selected cities worldwide. Users choose a particular continent and country, and are then presented with a list of various cities they can get information on. This includes the date and time of the current forecast, minimum and maximum temperatures for that day, a general cloud description, and a monthly review of various data for that city. If for nothing else, the site does a good job of providing a very straightforward and easy way to find weather information from hundreds of cities around the globe.

328

Weather Map Assignment  

NSDL National Science Digital Library

I gave this assignment so that students could relate real-time weather changes to mid-latitude cyclones and air mass movement. Basically, by the time I assigned the project, we have discussed all the necessary weather phenomena and this project gives the students a way to apply what we have discussed to "reality" by explaining why the weather occurred the way it did over a short time period. It also provides me with a way to assess how well they are able to tie all the major concepts together, which is one of the goals of the course.

Brueseke, Matt

329

Weather and Climate  

NSDL National Science Digital Library

This unit introduces younger students to the concepts of weather and climate. Topics include the structure of the atmosphere, the definitions of weather and climate, and temperature and how it is measured. There are also discussions of heat transfers (radiation, conduction, convection), air pressure, wind, and the Coriolis effect. Other topics include types of storms, larger-scale weather systems such as pressure systems and fronts, and factors (insolation, land-sea breezes, orographic effect) that influence the climate in a given region. A vocabulary list and downloadable, printable student worksheets are provided.

Medina, Philip

330

Extreme Weather Sourcebook 2001  

NSDL National Science Digital Library

Originally reviewed in the February 26, 1999 Scout Report, the latest version of the National Center for Atmospheric Research (NCAR) Extreme Weather Sourcebook offers easy access to updated data on the economic damage from hurricanes, floods, and tornadoes in the United States and its territories. Time spans for each type of extreme weather vary, with hurricane data covering 1900-99, tornadoes 1950-99, floods 1955-1999, and lightning 1959-1994; however, all damage data are reported in constant 1999 dollars to simplify comparisons. The data are offered by weather event and state by rank or alphabetically.

2001-01-01

331

WeatherTracker  

NSDL National Science Digital Library

WeatherTracker is the ideal desktop application for anyone who always wants to know what the weather outside is like. The temperature, barometric pressure, humidity, winds, and current conditions can be displayed in three different formats, updated hourly for North American Cities. The local forecasts, climate data and near shore marine forecasts can be displayed in other windows and are available for select North American cities. Other cities are limited to temperature and current conditions. WeatherTracker is shareware with a fee of $20.00.

332

Radiogenic Isotopes in Weathering and Hydrology  

NASA Astrophysics Data System (ADS)

There are a small group of elements that display variations in their isotopic composition, resulting from radioactive decay within minerals over geological timescales. These isotopic variations provide natural fingerprints of rock-water interactions and have been widely utilized in studies of weathering and hydrology. The isotopic systems that have been applied in such studies are dictated by the limited number of radioactive parent-daughter nuclide pairs with half-lives and isotopic abundances that result in measurable differences in daughter isotope ratios among common rocks and minerals. Prior to their application to studies of weathering and hydrology, each of these isotopic systems was utilized in geochronology and petrology. As in the case of their original introduction into geochronology and petrology, isotopic systems with the highest concentrations of daughter isotopes in common rocks and minerals and systems with the largest observed isotopic variations were introduced first and have made the largest impact on our understanding of weathering and hydrologic processes. Although radiogenic isotopes have helped elucidate many important aspects of weathering and hydrology, it is important to note that in almost every case that will be discussed in this chapter, our fundamental understanding of these topics came from studies of variations in the concentrations of major cations and anions. This chapter is a "tools chapter" and thus it will highlight applications of radiogenic isotopes that have added additional insight into a wide spectrum of research areas that are summarized in almost all of the other chapters of this volume.The first applications of radiogenic isotopes to weathering processes were based on studies that sought to understand the effects of chemical weathering on the geochronology of whole-rock samples and geochronologically important minerals (Goldich and Gast, 1966; Dasch, 1969; Blaxland, 1974; Clauer, 1979, 1981; Clauer et al., 1982); as well as on the observation that radiogenic isotopes are sometimes preferentially released compared to nonradiogenic isotopes of the same element during acid leaching of rocks ( Hart and Tilton, 1966; Silver et al., 1984; Erel et al., 1991). A major finding of these investigations was that weathering often results in anomalously young Rb-Sr isochron ages, and discordant Pb-Pb ages. Rubidium is generally retained relative to strontium in whole-rock samples, and in some cases radiogenic strontium and lead are lost preferentially to common strontium and lead from weathered minerals.The most widely utilized of these isotopic systems is Rb-Sr, followed by U-Pb. The K-Ar system is not directly applicable to most studies of rock-water interaction, because argon is a noble gas, and upon release during mineral weathering mixes with atmospheric argon, limiting its usefulness as a tracer in most weathering applications. Argon and other noble gas isotopes have, however, found important applications in hydrology (see Chapter 5.15). Three other isotopic systems commonly used in geochronology and petrology include Sm-Nd, Lu-Hf, and Re-Os. These parent and daughter elements are in very low abundance and concentrated in trace mineral phases. Sm-Nd, Lu-Hf, and Re-Os have been used in a few weathering studies but have not been utilized extensively in investigations of weathering and hydrology.The decay of 87Rb to 87Sr has a half-life of 48.8 Gyr, and this radioactive decay results in natural variability in the 87Sr/86Sr ratio in rubidium-bearing minerals (e.g., Blum, 1995). The trace elements rubidium and strontium are geochemically similar to the major elements potassium and calcium, respectively. Therefore, minerals with high K/Ca ratios develop high 87Sr/86Sr ratios over geologic timescales. Once released into the hydrosphere, strontium retains its isotopic composition without significant fractionation by geochemical or biological processes, and is therefore a good tracer for sources and cycling of calcium. The decay of 235U to 207Pb, 238U to 206Pb, and 232Th to 208Pb hav

Blum, J. D.; Erel, Y.

2003-12-01

333

All About Rocks  

NSDL National Science Digital Library

We will be learning about different types of rocks today.This project will teach you how to sort rocks based upon color, hardness, texture, layering, and particle size. We will even see a video of new rocks being formed! Visit this link to read an intro about rocks. Intro to Rocks Then visit these three links 1) Metamorphic Rocks 2) Igneous Rocks 3) Sedimentary Rocks Now answer these questions: 1) What types of rocks do you think you would find in your backyard? 2)Compare and contrast 2 of the 3 different types of rocks. 3)What is your favorite ...

Heffernan, Laura

2010-06-21

334

Edible Rocks  

NSDL National Science Digital Library

This lesson has been designed as a comfortable introduction to describing meteorites. It helps students become better observers by making a connection between the familiar (candy bars) and the unfamiliar (meteorites). Edible "rocks" are used in a scientific context, showing students the importance of observation, teamwork and communication skills. In everyday terms, students draw and describe the food. They pair their observations with short descriptions that are in geologic "Field Note" style. As the teacher and class review, appropriate geologic terminology may be substituted by the teacher and subsequently embraced by even very young students.

Lindstrom, Marilyn

335

Sedimentary Rocks  

NASA Technical Reports Server (NTRS)

6 November 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows outcrops of sedimentary rocks in a crater located just north of the Sinus Meridiani region. Perhaps the crater was once the site of a martian lake.

Location near: 2.9oN, 359.0oW Image width: width: 3 km (1.9 mi) Illumination from: lower left Season: Northern Autumn

2005-01-01

336

Microbial Weathering of Peridotites by a Tropical Cyanobacterial Mat  

NASA Astrophysics Data System (ADS)

Nickeliferous tropical laterites represent more than 60 percent of the worlds Ni reserves and are believed to be the product of millions of years of weathering on ultramafic peridotite rocks in tropical regions. While both Cyanobacterial mats and microbial weathering processes are well characterized in general, these structures have never been implicated in ultramafic rock weathering. We used Au/Hg amalgam voltammetric microelectrodes to measure several important dissolved redox-active species (Fe (II), Mn (II), oxygen, peroxide, and organo-Fe/Mn complexes) in situ. Dissolved Fe II/III, phosphate, nitrite, nitrate and electrical conductivity, pH, & Eh were measured on site by spectrophotometry and combination electrodes, respectively. Mat, rock and water samples were compared using a suite of analytical techniques (XRD, SIMS, XPS, ICP-MS). Microbial community structure was determined using ESEM and 16S rDNA cloning. In order to further investigate the relative importance of peroxide and organic ligands (e.g. DFAM) on weathering, laboratory incubations, monitored by voltammetry, were also conducted. In situ voltammetric profiles revealed significant redox zonation and the presence of both organo-Mn (III/IV) and organo-Fe(III) complexes within the mat. Importantly, 50 ?M peroxide was detected within 15 mm of the atmosphere/mat interface. The mat was highly enriched in Ni and Mn compared to the substrate. XPS and dynamic SIMS characterization of the rock surface showed trace metal zonation within a weathering rind. Laboratory experiments demonstrated maximal dissolution of Ni and Mn from the substrate in the presence of both peroxide and DFAM. The high peroxide concentrations in the mat are likely produced via a photochemical reaction involving DOC. Microbial successions resulting in the accumulation of organic material allow the development of redox zonation. We propose a mechanism for enhanced weathering of serpentenized peridotites under microaerophilic conditions, by means of a combination of peroxide and bacterially produced organic ligands. This process may be important for the development of nickeliferous laterite deposits.

Fowle, D.; Crowe, S.; O'Neill, A.; Weisener, C.

2006-12-01

337

Salt Weathering, a Neglected Geological Erosive Agent in Coastal and Arid Environments  

Microsoft Academic Search

THE fragmentation of rocks by the crystallization of salts, for convenience termed `salt weathering', is important in a restricted range of environments and produces distinctive topographic forms. Relatively hard rocks can be completely broken down into their component particles by soaking them in a salt solution and allowing the salt to crystallize in the interstices1. The chemical free energy of

H. W. Wellman; A. T. Wilson

1965-01-01

338

The formation of residual pedogenic clays by limestone weathering  

SciTech Connect

The weathering of carbonate rocks and formation of residual soils differs markedly from processes associated with formation of soils on other rock types. Soils derived from non-carbonate rocks, for example, will invariably produce a weathered product whose volume significantly exceeds that of the original parent rock (because of the formation of less dense, hydrated silicates and oxyhydroxides); the weathering of carbonate rocks, however, produces an infinitely smaller volume of residual weathering products because the soil must originate from the small amount of insoluble residue present in the parent limestone. Further, because limestones are often deposited in a quiet (low energy) shelf environment, or adjacent to land areas where a minimal supply of clastic debris is available, the minerals that are involved in the formation of residual soils are largely authigenic in origin. The Yucatan Peninsula of Mexico is an ideal site to observe these processes and all stages of soil development on limestones are present. Emergence of the region began in the Middle Tertiary and, because surface streams are wholly lacking in the northern peninsula, the soils that are now present do not include any detrital, clastic components. Examination of the insoluble residues of limestones shows that the source materials for the soils consisted of authigenic talc, chlorite, palygorskite, smectite, and mixed layer clays. Subaerial weathering of these limestones initially results in release of the trace amount of clays and formation of poorly crystalline, 10 angstrom halloysite (plus amorphous oxyhydroxides of iron and aluminum); as the profiles thicken and mature, halloysite is slowly transformed to well crystallized kaolinite and goethite, lepidocrocite, and boehmite may also appear. The stage of development of the soils was noted to be closely related with the geomorphic maturity of the region, and the thickest profiles were associated with areas of mature cone karst.

Carr, M.B.; Isphording, W.C.; O'Hearn, S.M.; Kusion, J.E. (Univ. of South Alabama, Mobile, AL (United States). Dept. of Geology-Geography)

1992-01-01

339

Building a Weather-Ready Nation Winter Weather Safety  

E-print Network

-Ready Nation Flooding Winter Weather Safety www.weather.gov · Flooding is possible due to snowmelt, ice jams and coastal storms such as Nor'easters. · Ice jams are common during the winter. · As ice moves downstream www.weather.gov · Snow/Ice · Blizzards · Flooding · Cold Temperatures #12;Building a Weather

340

Weathering of limestone beds at the great sphinx  

NASA Astrophysics Data System (ADS)

The weathering characteristics of the sphinx limestones are evaluated in the context of their pore system. The latter consists of “ink-bottle” pores. This pore system varies from one stratum to another. In the lower micritic rocks the large cavities of the ink-bottle pores are interconnected through the fine capillary network of the narrow throats. In the upper skeletal-rich rocks the interconnections are provided by large as well as small throats. The pore systems in these limestones reflect the depositional regime as well as the diagenetic alterations. The development of microspar from the micritic mud resulted in the formation of microporosity, and the extended circulation of freshwater enlarged some micropores preferentially, forming large cavities. The relationship of micro- and macropores has strongly influenced the weathering of the sphinx rocks.

Chowdhury, Ahad N.; Punuru, Adinarayana R.; Gauri, K. L.

1990-05-01

341

Weathering of Martian Evaporites  

NASA Technical Reports Server (NTRS)

Evaporites in martian meteorites contain weathering or alteration features that may provide clues about the martian near-surface environment over time. Additional information is contained in the original extended abstract.

Wentworth, S. J.; Velbel, M. A.; Thomas-Keprta, K. L.; Longazo, T. G.; McKay, D. S.

2001-01-01

342

Weathering in a Cup.  

ERIC Educational Resources Information Center

Two easy student activities that demonstrate physical weathering by expansion are described. The first demonstrates ice wedging and the second root wedging. A list of the needed materials, procedure, and observations are included. (KR)

Stadum, Carol J.

1991-01-01

343

Waste glass weathering  

SciTech Connect

The weathering of glass is reviewed by examining processes that affect the reaction of commercial, historical, natural, and nuclear waste glass under conditions of contact with humid air and slowly dripping water, which may lead to immersion in nearly static solution. Radionuclide release data from weathered glass under conditions that may exist in an unsaturated environment are presented and compared to release under standard leaching conditions. While the comparison between the release under weathering and leaching conditions is not exact, due to variability of reaction in humid air, evidence is presented of radionuclide release under a variety of conditions. These results suggest that both the amount and form of radionuclide release can be affected by the weathering of glass.

Bates, J.K.; Buck, E.C.

1993-12-31

344

TypoWeather  

NSDL National Science Digital Library

The TypoWeather application is a great way to stay on top of the latest weather conditions. This handy device presents users with a five day outlook and an hourly breakdown that is updated based on data from the National Meteorological Service. Visitors can customize their layout to include alerts about certain meteorological conditions, such as wind patterns, humidity, and more. This version is compatible with all operating systems.

2014-03-13

345

Wonderful World of Weather  

NSDL National Science Digital Library

This standards-based unit has been created for use by students in the elementary grades to investigate weather phenomena both locally as well as in other places around the world. By using hands-on activities and real-time data investigations, students develop a basic understanding of how weather can be described in measurable quantities. The lesson plans have been designed to allow teachers to select the ones which fit into their curriculum, and to allow for flexibility in implementation.

2011-01-01

346

Weathering and Erosion  

NSDL National Science Digital Library

In this multi-station lab, learners conduct a series of experiments to explore the processes and effects of weathering and erosion. Using the results from these explorations, learners design and conduct an experiment comparing the rate of erosion in different biomes. Use this activity to teach weathering and erosion, and also to illustrate how scientists often use the results of one experiment to inspire another. This activity is intended to be conducted over multiple meetings.

Whitfield, Lise

2010-01-01

347

Extreme Weather Sourcebook: Tornadoes  

NSDL National Science Digital Library

The Extreme Weather Sourcebook is a database maintained by the Societal Impacts Program (SIP) at NCAR of statistics on extreme weather events. The Sourcebook is intended as a resource for researchers, policy makers, the media, and the general public, among other users. This page from the Sourcebook showcases data on tornado damages as total losses for the years 1950-2009 in the United States.

University Consortium for Atmospheric Research (UCAR)

348

Rock Driller  

NASA Technical Reports Server (NTRS)

The next series of planetary exploration missions require a method of extracting rock and soil core samples. Therefore a prototype ultrasonic core driller (UTCD) was developed to meet the constraints of Small Bodies Exploration and Mars Sample Return Missions. The constraints in the design are size, weight, power, and axial loading. The ultrasonic transducer requires a relatively low axial load, which is one of the reasons this technology was chosen. The ultrasonic generator breadboard section can be contained within the 5x5x3 limits and weighs less than two pounds. Based on results attained the objectives for the first phase were achieved. A number of transducer probes were made and tested. One version only drills, and the other will actually provide a small core from a rock. Because of a more efficient transducer/probe, it will run at very low power (less than 5 Watts) and still drill/core. The prototype generator was built to allow for variation of all the performance-effecting elements of the transducer/probe/end effector, i.e., pulse, duty cycle, frequency, etc. The heart of the circuitry is what will be converted to a surface mounted board for the next phase, after all the parameters have been optimized and the microprocessor feedback can be installed.

Peterson, Thomas M.

2001-01-01

349

Cockpit weather information system  

NASA Technical Reports Server (NTRS)

Weather information, periodically collected from throughout a global region, is periodically assimilated and compiled at a central source and sent via a high speed data link to a satellite communication service, such as COMSAT. That communication service converts the compiled weather information to GSDB format, and transmits the GSDB encoded information to an orbiting broadcast satellite, INMARSAT, transmitting the information at a data rate of no less than 10.5 kilobits per second. The INMARSAT satellite receives that data over its P-channel and rebroadcasts the GDSB encoded weather information, in the microwave L-band, throughout the global region at a rate of no less than 10.5 KB/S. The transmission is received aboard an aircraft by means of an onboard SATCOM receiver and the output is furnished to a weather information processor. A touch sensitive liquid crystal panel display allows the pilot to select the weather function by touching a predefined icon overlain on the display's surface and in response a color graphic display of the weather is displayed for the pilot.

Tu, Jeffrey Chen-Yu (Inventor)

2000-01-01

350

2012 Severe Weather Awareness Guide  

E-print Network

Florida's 2012 Severe Weather Awareness Guide 2012 Severe Weather Awareness Guide F L O R I D A D I of Emergency Management #12;Florida's Severe Weather Awareness Guide 2 Florida is affected by many natural. That is why I am proud to present the 2012 Severe Weather Awareness Guide. By reading this guide you can learn

Meyers, Steven D.

351

The Influence of Weathering on the Engineering Properties of Dunites  

NASA Astrophysics Data System (ADS)

Weathering processes cause important changes in the engineering properties of rocks. In this study, dunites in the Bursa region in western Turkey were investigated and the changes in engineering properties due to weathering were evaluated. The studies were initiated with field observations including measurement of the characteristics of discontinuities such as spacing, aperture, fill material, roughness, and Schmidt hammer rebound value. Subsequently, laboratory studies were conducted in two stages. The first stage comprised mineralogical, petrographic, and chemical analyses. The second stage included physicomechanical tests to determine specific gravity, unit weights, water absorption, effective porosity, uniaxial compressive strength, P-wave velocity, and slake-durability index. According to these evaluations, the changes in engineering properties were determined to be mostly related to serpentinization at every stage of weathering. The most suitable parameters for characterizing the degree of weathering of the studied dunites are loss-on-ignition values, specific gravity, unit weight, water absorption, and effective porosity.

Ündül, Ömer; Tu?rul, Atiye

2012-03-01

352

External Resource: Rock Cycle Animation  

NSDL National Science Digital Library

This cutaway view of Earth shows where some common rock-forming processes occur. Embedded animations will illustrate the path of a rock moving through the rock cycle. Topics include: rock cycle, magma chamber, magma, igneous rock, sedimentary rock, erosio

1900-01-01

353

Rocks and Minerals  

NSDL National Science Digital Library

This web page offers a simple illustrated guide to the three rock types- igneous, sedimentary, and metamorphic; and the most common rock-forming mineral groups: quartz, plagioclase feldspars, potassium feldspars, micas, amphiboles, olivine, and calcite. The rock types include extrusive and intrusive igneous rocks, clastic, biologic, and chemical sedimentary rocks, and both foliated and non-foliated metamorphic rocks. A section is included on naming igneous rocks. The igneous rocks tuff and basalt are also discussed, as is sediment. Users are directed to related resources and may print out a simplified rock classification chart.

354

Rocks and Minerals  

NSDL National Science Digital Library

This guide provides introductory information about rocks and minerals. Topics include some of the common rock-forming minerals, what rocks are made of, and where they come from (the three basic rock types). There are descriptions and photos of igneous, sedimentary, and metamorphic rocks, a glossary, and a simple identification chart that has links to websites with additional information.

2010-11-08

355

Sojourner Rover View of Souffle Rock  

NASA Technical Reports Server (NTRS)

Sojourner's observations in the Ares region on Mars raise and answer questions about the origins of the rocks and other deposits found there. This image shows the vesicular and pitted textures of Souffle Rock (32 cm wide) which could be a result of volcanic, sedimentary, or weathering processes.

NOTE: original caption as published in Science Magazine

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech).

1997-01-01

356

Oceans, Climate and Weather  

NSDL National Science Digital Library

What is the difference between weather and climate? What do the oceans have to do with them? Weather is the day-to-day state of the atmosphere and its short-term (minutes to weeks) variation. Climate is typically described by the regional patterns of seasonal temperature and precipitation over 30 years. The averages of annual temperature, rainfall, cloud cover, and depth of frost penetration are all typical climate-related statistics. The oceans influence the worlds climate by storing solar energy and distributing it around the planet through currents and atmospheric winds.This publication is all about developing your students understandings of earths oceans and the major effect they have on climate. Understanding and interpreting local weather data and understanding the relationship between weather and climate are important first steps to understanding larger-scale global climate changes. Activities that ask students to collect and analyze local weather data as well as analyze global data can be found in the Lessons and Activities section. Analyzing and interpreting data is a major focus of this publication. Numerous data sets can be found in the Sources for Real Data section. The Background Information section and the article Tomorrows Forecast will help reinforce your own content knowledge.

Lightle, Kimberly

2006-01-01

357

Major Rock Groups  

NSDL National Science Digital Library

This resource from the University of Saskatchewan contains general information on the major rock groups: igneous, metamorphic and sedimentary. Describes the rock cycle and the properties and formation of each major rock group.

358

Large-Scale Weather  

NSDL National Science Digital Library

In the previous chapter, we dealt with how the properties of air and water affected small-scale weather such as the formation of clouds, the formation of fog, and how comfortable you feel at different times of the year. In this chapter, we're going to go global, talking about major interactions between the Sun and Earth, the resulting effects on large air masses, and how these major interactions help us figure out what the weather's going to be tomorrow. As discussed earlier in the book, when science concepts are applied to the real world, things don't always work out exactly as expected. However, it is possible to get an overall picture of what's happening in large-scale weather.

Robertson, William C.

2005-01-01

359

Delicious Differential Weathering  

NSDL National Science Digital Library

Students are asked to place a Baby Ruth candy bar in their mouths but are asked not to bite it. Once they have sucked off all the chocolate and caramel the students are given permission to bite the peanuts. After lecturing on the differences between chemical and physical weathering students are asked to list the order of ingredients they tasted. Each group is given a sample of granite. Students are asked to list three visible minerals in the granite. Relate the minerals of the granite (hornblende, feldspar, and quartz) to the ingredients of the candy bar. Explain Bowen's reaction series and how different minerals will weather first and how climate will affect weathering rates.

Gorte, Mary

360

Texas Rock Cycle  

NSDL National Science Digital Library

The Texas Rock Cycle is an exercise demonstrating rock transformation. Materials needed for this activity are the Texas Rock Kit and a page-size Geologic Map of Texas, each available from the publications department of the Bureau of Economic Geology. Each rock kit contains samples of calcite, quartz, feldspar, granite, basalt, sandstone, gneiss, limestone, chert, and schist. This site contains a rock cycle puzzle to print out and instructions on how to conduct a rock cycle investigation.

361

Rock albedo and thermal monitoring 801 Copyright 2005 John Wiley & Sons, Ltd. Earth Surf. Process. Landforms 30, 801811 (2005)  

E-print Network

Rock albedo and thermal monitoring 801 Copyright © 2005 John Wiley & Sons, Ltd. Earth Surf. Process.1002/esp.1189 Rock albedo and monitoring of thermal conditions in respect of weathering: some expected within geomorphic circles, a general acceptance that rocks with low albedos will warm both faster

Lindgren, Staffan

362

Chemical weathering of granite under acid rainfall environment, Korea  

NASA Astrophysics Data System (ADS)

Chemical weathering was investigated by collecting samples from five selected weathering profiles in a high elevation granitic environment located in Seoul, Korea. The overall changes of chemistry and mineralogical textures were examined reflecting weathering degrees of the samples, using polarization microscopy, X-ray diffraction (XRD), electron probe micro analysis (EPMA), X-ray fluorescence spectroscopy (XRF), and inductively coupled plasma-mass spectroscopy (ICP-MS). The chemical distribution in the weathering profiles shows that few trace elements are slightly immobile, whereas most major (particularly Ca and Na) and trace elements are mobile from the beginning of the granite weathering. On the other hand, there were mineralogical changes initiated from a plagioclase breakdown, which shows a characteristic circular dissolved pattern caused by a preferential leaching of Ca cation along grain boundaries and zoning. The biotite in that region is also supposed to be sensitive to exterior environmental condition and may be easily dissolved by acidic percolated water. As a result, it seems that some rock-forming minerals in the granitic rock located in Seoul are significantly unstable due to the environmental condition of acidic rainfall and steep slopes, where they are susceptible to be dissolved incongruently leading some elements to be highly depleted.

Lee, Seung Yeop; Kim, Soo Jin; Baik, Min Hoon

2008-08-01

363

Weather Station Model  

NSDL National Science Digital Library

This lesson instructs students on how to read station models, the symbols used on weather maps to show data (temperature, wind speed and direction, barometeric pressure, etc.) for a given reporting station. It includes a diagram of a station model, an explanation of the data conveyed by the numbers and symbols, and a table of definitions for the graphic symbols used with models. There is also a set of interactive station models students can use for practice at interpretation, and an interactive exercise in which students use real-time weather data to interpret models.

364

Reading Weather Maps  

NSDL National Science Digital Library

From the University of Illinois at Urbana-Champaign's Department of Atmospheric Sciences comes the Reading Weather Maps Web site. Visitors learn how to convert their local time to the standard used by all meteorologists; to tell the difference between Kelvin, Celsius, and Fahrenheit temperatures; and how to read maps with weather data collected on and above the Earth's surface. For example, wind bards, which are flag-like symbols that indicate wind direction and wind speed, always point in the direction the wind is blowing "from." Other interesting facts, descriptions, and illustrations are available on the site.

1969-12-31

365

Weather and Climate  

NSDL National Science Digital Library

This background chapter reviews the basic principles of meteorology that educators need to guide inquiry activities in the classroom. Topics include structure of the atmosphere, Coriolis effect, water cycle, greenhouse effect, cyclones, anticyclones, and jet streams. This is chapter 2 of Meteorology: An Educator's Resource for Inquiry-Based Learning for Grades 5-9. The guide includes a discussion of learning science, the use of inquiry in the classroom, instructions for making simple weather instruments, and more than 20 weather investigations ranging from teacher-centered to guided and open inquiry investigations.

366

Weather and Health  

NSDL National Science Digital Library

This course will help meteorologists and others broaden their understanding of the impacts of weather and climate on public health, including the impacts of heat waves and cold temperatures, winter storms and thunderstorms, flooding, drought, poor air quality, tornadoes, hurricanes, wildfire, UV radiation, and others. This course is directed to broadcast meteorologists, in particular, who play a critical role in the community by helping the public to protect against weather-related health threats and by promoting good health. The course also describes the public health communication system, providing information about reliable public health services, tools, and resources.

Comet

2008-11-25

367

Wonderful World of Weather  

NSDL National Science Digital Library

This standards-based module uses hands-on activities and real-time data investigations to allow students in the elementary grades to investigate weather phenomena both locally as well as in other places around the world. By using hands-on activities and real-time data investigations, the students will develop a basic understanding of how weather can be described in measurable quantities, such as temperature, wind and precipitation. The lesson plans which make up this module have been designed to allow teachers to select the ones which fit into their curriculum to allow for flexibility in implementation

2003-01-01

368

Rock Cycle Roundabout  

NSDL National Science Digital Library

In this activity, learners will learn how igneous rock, metamorphic rock, and sedimentary rock are formed as part of the rock cycle and that the same forces that produce/change rocks also produce/change landforms. They will learn this by playing a game where one player must describe a type of rock (that is chosen by random card selection) to another player who then must guess what type of rock that is. Then, there may be a discussion of geologic time and learners can create a timeline model based on the sequence of rock types that were chosen in the game.

Sciences, California A.

2010-01-01

369

Rocks are fun  

NSDL National Science Digital Library

Rocks are the most common material on earth. We will learn about the parts that make up the rocks and sort rocks based upon color, hardness, texture, layering, and particle size. Click on each of the links below to learn about the main types of rocks and then answer the questions that follow. *Igneous Rocks 1. In your own words, explain the TWO ways in which an igneous rock can be formed. 2. Please illustrate ONE of the ways an igneous rock is formed. *Metamorphic Rocks 1. Why ...

Peterson, Lori

2009-12-14

370

Estimating rock mass properties using Monte Carlo simulation: Ankara andesites  

NASA Astrophysics Data System (ADS)

In the paper, a previously introduced method ( Sari, 2009) is applied to the problem of estimating the rock mass properties of Ankara andesites. For this purpose, appropriate closed form (parametric) distributions are described for intact rock and discontinuity parameters of the Ankara andesites at three distinct weathering grades. Then, these distributions are included as inputs in the Rock Mass Rating ( RMR) classification system prepared in a spreadsheet model. A stochastic analysis is carried out to evaluate the influence of correlations between relevant distributions on the simulated RMR values. The model is also used in Monte Carlo simulations to estimate the possible ranges of the Hoek-Brown strength parameters of the rock under investigation. The proposed approach provides a straightforward and effective assessment of the variability of the rock mass properties. Hence, a wide array of mechanical characteristics can be adequately represented in any preliminary design consideration for a given rock mass.

Sari, Mehmet; Karpuz, Celal; Ayday, Can

2010-07-01

371

Interactive Rock Cycle Animation  

NSDL National Science Digital Library

This highly simplified Flash animation displays some of the most common rock-forming processes. Embedded animations include crystallization of magma to form igneous rock, rock erosion to create sediment, transportation of sediment, deposition of sediment to create sedimentary rock, and creation of a metamorphic rock in a subduction zone. The neat feature of this animation is that each step in the sequence above is linked to other animations in the Exploring Earth collection, providing a fairly in depth exposure to the processes involved in the rock cycle. Caution students against the oversimplified linear pattern of igneous, sedimentary, and metamorphic rock formation. In reality, there are many interconnections in the cycle with, for example, sedimentary rocks being eroded and becoming transformed to a different sedimentary rock type without being metamorphosed or, as another example, igneous rocks never being reduced to sediment, and instead directly evolving to metamorphic rocks. The animation can be paused and rewound to stress important points.

Armstrong, Lenni; Earth, Exploring

372

All About Rocks  

NSDL National Science Digital Library

What does igneous mean? What is a sedimentary rock? You have been given the challenge to learn all you can about rocks and minerals. Use the following sites to collect information. You will be compiling the information you learn into a book for the other classes. These two sites will give you information about how rocks are formed. Make sure you find out the 3 types of rocks! Discover How Rocks Are Formed Rocks for Kids What is the difference between a rock and a mineral? See if you can figure it out on these two sites. This planet really rocks! : all about rocks and minerals Rocks for Kids Test your knowledge about rocks with a ...

Quinn, Miss

2005-06-16

373

A Photographic Atlas of Rock Breakdown Features in Geomorphic Environments  

NSDL National Science Digital Library

This downloadable (15 mb) atlas features photos of rocks, rock formations, and landscapes that have been shaped by aeolian (wind), fluvial (river), and other weathering processes. The photos are accompanied by descriptions of the features and discussion of the processes involved in creating them. There is also a discussion of the applicability of these same processes to explain similar features seen on Mars and Venus, and the use of high-resolution imagery from Mars to identify these features. A bibliography is included.

374

Fungal attack on rock: solubilization and altered infrared spectra.  

PubMed

Penicillium simplicissimum, isolated from weathering basalt, produced citric acid when grown in a glucose-mineral salts medium with basalt, granite, granodiorite, rhyolite, andesite, peridotite, dunite, or quartzite. After 7 days' growth as much as 31 percent of the silicon, 11 percent of the aluminum, 64 percent of the iron, and 59 percent of the magnesium in some of the rocks were solubilized, and a number of rocks showed altered infrared absorption in the silicon-oxygen vibration region. PMID:17838175

Silverman, M P; Munoz, E F

1970-09-01

375

Weatherization Works: An interim report of the National Weatherization Evaluation  

SciTech Connect

The National Weatherization Evaluation is the first comprehensive evaluation of the Weatherization Assistance Program since 1984. The evaluation was designed to accomplish the following goals: Estimate energy savings and cost effectiveness; Assess nonenergy impacts; Describe the weatherization network; Characterize the eligible population and resources; and Identify factors influencing outcomes and opportunities for the future. As a national program, weatherization incorporates considerable diversity due to regional differences. Therefore, evaluation results are presented both in aggregate and for three climate regions: cold, moderate and hot.

Brown, M.A.; Berry, L.G. [Oak Ridge National Lab., TN (United States); Kinney, L.F. [Synertech Systems Corp., Syracuse, NY (United States)

1993-11-01

376

Weathering of Mars - Antarctic analog studies  

NASA Technical Reports Server (NTRS)

Subaerial extrusion of lavas above permafrost is proposed as a possible weathering regime leading to the presence of Martian surface fines, and the characteristics of this process are examined through a study of the analogous altered terrestrial basalts from Antarctica. On the basis of mineralogical and petrological analyses of samples obtained from core cuttings recovered by the Dry Valley Drilling Program from rocks predominantly of an aklalic basalt-phonolite suite, it is found that in the absence of liquid water, weathering is geologically slow, and that zeolites predominate over clays as secondary mineral. Of the possible weathering processes proposed for Mars, it is concluded that both subaerial extrusion and subpermafrost intrusion of lavas involving liquid water would be less important volumetrically than the hydrothermal alteration of impact melt sheets if water were present during an intense phase of early bombardment, or than subsequent solid-gas alteration reactions. It is thus predicted that the present Martian fines should contain a major contribution from the ancient crust as typified by the southern cratered highlands, and a lesser contribution from the younger basaltic lavas.

Berkley, J. L.; Drake, M. J.

1981-01-01

377

Rainy Weather Science.  

ERIC Educational Resources Information Center

Presents ideas on the use of rainy weather for activities in the earth, life, and physical sciences. Topics include formation and collision of raindrops, amount and distribution of rain, shedding of water by plants, mapping puddles and potholes, rainbow formation, stalking storms online, lightning, and comparing particles in the air before and…

Reynolds, Karen

1996-01-01

378

Weathering and mass wasting  

NSDL National Science Digital Library

This class exercise is an opportunity for students to apply textbook information about weathering and mass wasting to local and nationally-recognized surface features, such as Stone Mountain (GA), Half Dome (CA), and others. It also serves as an introduction to the use of Google Earth as an analytical tool for calculating distances, slopes, and evaluating landforms. Designed for a geomorphology course

Clayton, Jordan

379

Microbial Weathering of Olivine  

NASA Technical Reports Server (NTRS)

Controlled microbial weathering of olivine experiments displays a unique style of nanoetching caused by biofilm attachment to mineral surfaces. We are investigating whether the morphology of biotic nanoetching can be used as a biosignature. Additional information is contained in the original extended abstract.

McKay, D. S.; Longazo, T. G.; Wentworth, S. J.; Southam, G.

2002-01-01

380

Weathering the Double Whammy.  

ERIC Educational Resources Information Center

Discusses how governing boards can help their institutions weather the "double-whammy" of doing more with less: identify the institution's short-term and long-term challenges; refocus the institution's mission, planning, and programming; assess and integrate the institution's tuition, aid, and outreach strategies; redouble the institution's…

Wellman, Jane V.

2002-01-01

381

Gulf of Maine: Weather  

NSDL National Science Digital Library

Lessons and activities from the Gulf of Maine Research Institute (formerly Gulf of Maine Aquarium), focused on hurricanes, El Nino, fog, and volcanic eruptions. Emphasis on important hurricanes of the past. Resources include lessons, guides for simple experiments, and a student weather network. Downloadable materials and additional webpages also provided.

2010-08-04

382

Weather and emotional state  

Microsoft Academic Search

Introduction Given the proven effects of weather on the human organism, an attempt to examine its effects on a psychic and emotional level has been made. Emotions affect the bio-tonus, working ability and concentration, hence their significance in various domains of economic life, such as health care, education, transportation, tourism, etc. Data and methods The research has been made in

Z. Spasova

2010-01-01

383

Weather Stations: Storms  

NSDL National Science Digital Library

In this activity, learners test how cornstarch and glitter in water move when disturbed. Learners compare their observations with videos of Jupiter's and Earth's storm movements. This activity is one station that can be combined with other stations for an hour and half lesson on weather patterns on Jupiter and Earth.

Institute, Lunar A.; Nasa

2011-01-01

384

Blogging About the Weather  

NSDL National Science Digital Library

Since the majority of the content standards related to weather focus on forecasting, elementary students often spend a lot of time studying cloud types, fronts, storms, and using a barometer to read air pressure. Although this allows students to "do" scie

Kyle Evans

2010-04-01

385

Weather and the Sky  

NSDL National Science Digital Library

This self-contained module on weather and objects in the sky includes a range of fun activities that students can perform in the classroom and at home with family members. They impart important concepts such as observation, identification, measurement, and differentiation.

Houghton Mifflin Science

386

Sunspots and Space Weather  

NSDL National Science Digital Library

This activity is part of Planet Diary and is an online investigation for students in how sunspots impact space weather between the Sun and Earth. Students research solar maximum and minimum as well as recent sunspot numbers to determine a connection between the numbers and solar activity. This page is accompanied by a page of websites for further resources.

387

METEOROLOGICAL Weather and Forecasting  

E-print Network

AMERICAN METEOROLOGICAL SOCIETY Weather and Forecasting EARLY ONLINE RELEASE This is a preliminary it is available. © 2010 American Meteorological Society #12;Generated using version 3.0 of the official AMS LATEX template Multidisciplinary Analysis of an Unusual Tornado: Meteorology,1 Climatology, and the Communication

388

Weather, Climate, and You.  

ERIC Educational Resources Information Center

Information from the American Institute of Medical Climatologists on human responses to weather and climatic conditions, including clouds, winds, humidity, barometric pressure, heat, cold, and other variables that may exert a pervasive impact on health, behavior, disposition, and the level of efficiency with which individuals function is reviewed.…

Blai, Boris, Jr.

389

Uncertain weather, uncertain climate  

E-print Network

Adventure of the Speckled Band" "Good-morning, madam," said Holmes cheerily. "My name is Sherlock Holmes, and then only when you sit on the left-hand side of the driver." #12;Holmes' calculation D. Nychka Uncertain of vehicle Maximize over vehicle #12;D. Nychka Uncertain weather, uncertain climate 8 Holmes' conclusion

Nychka, Douglas

390

Space Weather Action Center  

NSDL National Science Digital Library

The Space Weather Action Center is a computer-based activity that allows students to track, from their classroom, the development and progress of solar storms. The activity incorporates online NASA data and addresses national education standards in science, technology and math. Students rotate through four space weather learning stations and are challenged to answer the following questions: Do sunspot regions exist today that could be a source of solar storms?; Have radio signals been recorded today from a flare or coronal mass ejection that could affect Earth?; Has there been a measurable disturbance in the Earth's magnetic field?; and Have auroras been seen within the last 24 hours because of a solar storm? A setup guide is provided to show how to create a Space Weather Action Center in the classroom, including recommendations, diagrams, and the necessary list of materials. The instructional guide features background and evaluation materials, alignments to national standards, extension activities, and instructions on how to read, analyze and record space weather data.

391

Weather and Flight Testing  

NASA Technical Reports Server (NTRS)

This viewgraph document reviews some of the weather hazards involved with flight testing. Some of the hazards reviewed are: turbulence, icing, thunderstorms and winds and windshear. Maps, pictures, satellite pictures of the meteorological phenomena and graphs are included. Also included are pictures of damaged aircraft.

Wiley, Scott

2007-01-01

392

Beneath it all: bedrock geology of the Catskill Mountains and implications of its weathering.  

PubMed

The Devonian-age bedrock of the Catskill Mountains has been the focus of many studies. This paper reviews the character and composition of the rocks of the Catskills, and examines weathering (rock decay) processes and their implications in the Catskills. Rocks of the Catskills and closest foothills consist of siliciclastic rocks (sandstones, mudrocks, conglomerates) with minimal, locally dispersed carbonate rocks. The former are dominated by quartz, metamorphic and sedimentary rock fragments, and clay minerals. Other minor sediment components include cements, authigenic and heavy minerals, and fossil organic matter. Physical, chemical, and biological weathering of the Catskill bedrock since uplift of the Appalachian region, combined with glaciation, have dissected a plateau of nearly horizontally layered rocks into a series of ridges, valleys, and peaks. The varied weathering processes, in conjunction with many factors (natural and anthropogenic), fragment the rocks, forming sediment and releasing various elements and compounds. These may have positive, neutral, or negative implications for the region's soils, waters, ecology, and human usage. A new generation of studies and analyses of the Catskill bedrock is needed to help answer a broad set of questions and problems across various fields of interest. PMID:23895551

Ver Straeten, Charles A

2013-09-01

393

Can Low Water/Rock Hydrothermal Alteration of Impact Materials Explain the Rock Component of the Martian Soil?  

NASA Technical Reports Server (NTRS)

The martian regolith is a globally homogenized product of chemical and aeolian weathering processes. The soil is thought to consist of a rock component, with lesser amounts of mobile elements (Ca, Na, and K) than a presumed protolith, and a salt or mobile element component enriched in sulfur and chlorine. In this study we consider the contributions of hydrothermal processes to the origin of the rock component of the martian soil.

Nelson, M. J.; Newsom, H. E.

2003-01-01

394

Involving high school students in meteorological research: the SF-ROCKS experience  

E-print Network

meetings of the AGU in San Francisco in 2003 and 2004. The 2003 "weather group" conducted a comparison and the delivery of weather information by the "on-air talent". The research component of the SF-ROCKS summer-fall in August (2003 and 2004) at SFSU during which they worked closely with faculty and graduate students

395

When winter weather disrupts work.  

PubMed

Paul Beevers, of the BVA's legal helpline, explains the implications for employers of travel disruption resulting from bad weather and offers a few pointers on dealing with exceptional weather conditions. PMID:25556140

2015-01-01

396

External Resource: Erosion and Weathering  

NSDL National Science Digital Library

This is a Teachers' Domain photo essay with images that depict surface features on Earth that result from weathering and erosion, as well as measures designed to mitigate their unwanted effects. Topics: weathering, erosion, sediments, dunes, deltas, glaci

1900-01-01

397

Aeromagnetic mapping of deep-weathered fracture zones in the Oslo Region - a new tool for improved planning of tunnels  

Microsoft Academic Search

Deep weathering produces negative magnetic anomalies because ferromagnetic minerals such as magnetite are altered to less magnetic hematite and ironhydroxide minerals. In situ measurements at four different locations show that the magnetic susceptibility in the weathered zones is redu - ced by 35-93 % compared to fresh rocks. We have developed a filtering technique to enhance the magnetic signal from

Odleiv Olesen; John F. Dehls; Jörg Ebbing; Helge Henriksen; Ola Kihle; Erik Lundin

398

Rollerjaw Rock Crusher  

NASA Technical Reports Server (NTRS)

The rollerjaw rock crusher melds the concepts of jaw crushing and roll crushing long employed in the mining and rock-crushing industries. Rollerjaw rock crushers have been proposed for inclusion in geological exploration missions on Mars, where they would be used to pulverize rock samples into powders in the tens of micrometer particle size range required for analysis by scientific instruments.

Peters, Gregory; Brown, Kyle; Fuerstenau, Stephen

2009-01-01

399

Identifying and Classifying Rocks  

NSDL National Science Digital Library

How do we identify and classify rocks? In this lesson, we are going to learn about different ways that we classify and identify rocks! There are three types of rocks. Sedimentary Metamorphic Igneous As we are learning about the three types of rocks, print out this chart and use it to write down what you learn about each type of ...

Owen, Elisabeth

2010-11-03

400

Long-term rates of chemical weathering and physical erosion from cosmogenic nuclides and geochemical mass balance  

Microsoft Academic Search

Quantifying long-term rates of chemical weathering and physical erosion is important for understanding the long-term evolution of soils, landscapes, and Earth's climate. Here we describe how long-term chemical weathering rates can be measured for actively eroding landscapes using cosmogenic nuclides together with a geochemical mass balance of weathered soil and parent rock. We tested this approach in the Rio Icacos

Clifford S. Riebe; James W. Kirchner; Robert C. Finkel

2003-01-01

401

Space Weather Impacts on Aviation  

NSDL National Science Digital Library

Space Weather Impacts on Aviation examines the effects of solar flares, coronal mass ejections, and other solar phenomena on aviation operations. The module builds on background science knowledge taught in the course prerequisite, Space Weather Basics, 2nd Edition. The content gives aviation forecasters and others an overview of the information and products available from NOAA's Space Weather Prediction Center and provides practice interpreting and using those products for decision support during space weather events.

Comet

2012-06-12

402

Real-Time Weather Data  

NSDL National Science Digital Library

This website provides real-time and forecast weather maps and data for the United States. The Satellite section contains satellite weather images from the GOES 8 and GOES 10 satellites, the Radar section contains radar weather images from NEXRAD radars, the Surface Data section contains plots of various weather conditions (temperatures, winds, pressure, precipitation), and the Upper Air section plots winds and temperatures across the United States.

403

Become A Rock Expert!  

NSDL National Science Digital Library

Rocks are the most common material on earth. But how do we identify and classify rocks? Your mission is to become an amateur geologist by exploring the different types of rocks; sorting them by color, hardness, texture, layering, and particle size; and discussing with your classmates what you learned! Rockin Rocks, Ms. Andersen's site about the Big6. Rock Expert Webquest INTRODUCTION The Museum of Natural History is creating a new exhibit on rocks and minerals. They are looking for expert knowledge to share with museum visitors. They need your help, Rock Expert! MISSION You will work as an Amateur Geologist for the Museum of Natural ...

Ms. Andersen

2010-11-13

404

Road Weather and Transportation Systems  

E-print Network

Road Weather and Transportation Systems Rhonda Young, P.E., PhD Associate Professor Dept. of Civil & Arch. Engineering Portland State University April 18, 2014 #12;Engineering Perspective of Road Weather · How does weather impact transportation systems? · As engineers, is there anything we can do

Bertini, Robert L.

405

Spring Break-Weathering Homework  

NSDL National Science Digital Library

Students are asked to photograph something that shows either physical or chemical weathering. They must be in the photograph for purposes of scale. They must then write up their description of the weathering feature and explain the actual weathering processes. This assignment can also be expanded to include mass wasting and mass wasting prevention.

Farthing, Dori

406

Weather Forecasting for Radio Astronomy  

E-print Network

Weather Forecasting for Radio Astronomy Part I: The Mechanics and Physics Ronald J Maddalena August 1, 2008 #12;Outline Part I Background -- research inspirations and aspirations Vertical weather, .... Part II Results on refraction & air mass (with Jeff Paradis) Part III Results on opacity, weather

Groppi, Christopher

407

Science Sampler: Clever with weather  

NSDL National Science Digital Library

In eighth-grade Earth science at Louisville Middle School in Louisville, Colorado, students learn how large-scale weather patterns such as the jet stream and weather fronts interact to generate local weather conditions. The authors have developed a modeli

David Crowder

2011-02-01

408

Weather Fundamentals: Climate & Seasons. [Videotape].  

ERIC Educational Resources Information Center

The videos in this educational series for grades 4-7, help students understand the science behind weather phenomena through dramatic live-action footage, vivid animated graphics, detailed weather maps, and hands-on experiments. This episode (23 minutes), describes weather patterns and cycles around the globe. The various types of climates around…

1998

409

Differences Between Climate and Weather  

NSDL National Science Digital Library

In this activity, students collect weather data over several days or weeks, graph temperature data, and compare the temperature data collected with long-term climate averages from where they live. Understanding the difference between weather and climate and interpreting local weather data are important first steps to understanding larger-scale global climate changes.

Research, National C.

410

Seasonal Extreme Weather Forecasts  

NSDL National Science Digital Library

Forecasts for UK winter gales and severe gales, North Atlantic and US landfalling hurricanes, Northwest Pacific and Far East landfalling typhoons, Southwest Pacific and Australian landfalling cyclones, and US Cooling Degree Days are available at this site from the Benfield Greig Hazard Research Centre at University College, London. Forecast summaries, descriptions of forecasting methodology, and graphics of historical and predicted events through time are presented in .pdf format for each weather subcategory. This site also tells users when the next predictions are to be released and has links to press releases and other extreme weather Websites. This is a good site for those interested in methods of climatology or those who want to prepare for that next big typhoon.

411

Weather Stations: Winds  

NSDL National Science Digital Library

In this activity, learners use a toaster to generate wind and compare the appliance's heat source to Jupiter's own hot interior. Learners discover that convection drives wind on Jupiter and on Earth. This activity is one station that can be combined with other stations for an hour and half lesson on weather patterns on Jupiter and Earth. For safety reasons, this activity should be facilitated by an adult or used as a demonstration only.

Institute, Lunar A.; Nasa

2011-01-01

412

National Weather Service Glossary  

NSDL National Science Digital Library

This glossary contains information on more than 2000 terms, phrases and abbreviations used by the National Weather Service (NWS). Many of these terms and abbreviations are used by NWS forecasters to communicate between each other and have been in use for many years; the glossary will aid users in better understanding NWS products. The glossary is searchable by keyword or browsable by letter of the alphabet.

413

Characterization of Fungal Community Structure on a Weathered Pegmatitic Granite  

Microsoft Academic Search

This study exploited the contrasting major element chemistry of adjacent, physically separable crystals of framework and sheet\\u000a silicates in a pegmatitic granite to investigate the mineralogical influences of fungal community structure on mineral surfaces.\\u000a Large intact crystals of variably weathered muscovite, plagioclase, K-feldspar, and quartz were individually extracted, together\\u000a with whole-rock granite. Environmental scanning electron microscopy (ESEM) revealed a diversity

Deirdre B. Gleeson; Nicholas Clipson; Karrie Melville; Geoffrey M. Gadd; Frank P. McDermott

2005-01-01

414

Kazakhstan Space Weather Initiative  

NASA Astrophysics Data System (ADS)

Kazakhstan experimental complex is a center of experimental study of space weather. This complex is situated near Almaty, Kazakhstan and includes experimental setup for registration of cosmic ray intensity (neutron monitor) at altitude of 3340 m above sea level, geomagnetic observatory and setup for registration of solar flux density with frequency of 1 and 3 GHz with 1 second time resolution. Results of space environment monitoring in real time are accessible via Internet. This experimental information is used for space weather investigations and different cosmic ray effects. Almaty mountain cosmic ray station is one of the most suitable and sensitive stations for investigation and forecasting of the dangerous situations for satellites; for this reason Almaty cosmic ray station is included in the world-wide neutron monitor network for the real-time monitoring of the space weather conditions and European Database NMDB (www.nmdb.eu). All data are represented on the web-site of the Institute of Ionosphere (www.ionos.kz) in real time. Since July, 2006 the space environment prediction laboratory represents the forecast of geomagnetic activity every day on the same site (www.ionos.kz/?q=en/node/21).

Kryakunova, Olga

2012-07-01

415

Dilatometrical behaviour of porous calcareous rock samples subjected to freeze-thaw cycles  

Microsoft Academic Search

Dilatometry can be used in geomorphology as an evaluation method for the behaviour of rocks during weathering by frost shattering and also for the role of unfrozen water migration during this process. It has already been demonstrated in other publications that calcareous rock cylinders undergoing humidification\\/drying cycles (no freezing) vary in length. These length changes are most significant when water

A. Prick

1995-01-01

416

Sedimentary rocks at Meridiani Planum: Origin, diagenesis, and implications for life on Mars  

Microsoft Academic Search

The MER rover Opportunity has carried out the first outcrop-scale investigation of ancient sedimentary rocks on Mars. The rocks, exposed in craters and along fissures in Meridiani Planum, are sandstones formed via the erosion and re-deposition of fine grained siliciclastics and evaporites derived from the chemical weathering of olivine basalts by acidic waters. A stratigraphic section more than seven meters

Steven W. Squyres; Andrew H. Knoll

2005-01-01

417

Solid As A Rock: The Utilization of Polyvinyl Acetate to Stabilize and Consolidate Museum Sandstone Objects  

E-print Network

Solid As A Rock: The Utilization of Polyvinyl Acetate to Stabilize and Consolidate Museum Sandstone) commonly used sandstone in creating various objects. Sandstone slabs used in hearth construction these objects unstable. Sandstone is a porous rock. The heat treatment and weathering drives off water and makes

Rock, Chris

418

Rock fragment distributions and regolith evolution in the Ouachita Mountains, Arkansas, USA  

Microsoft Academic Search

Rock fragments in the regolith are a persistent property that reflects the combined influences of geologic controls, erosion, deposition, bioturbation, and weathering. The distribution of rock fragments in regoliths of the Ouachita Mountains, Arkansas, shows that sandstone fragments are common in all layers, even if sandstone is absent in parent material. Shale and sandstone fragments are produced at the bedrock

Jonathan D. Phillips; Ken Luckow; Daniel A. Marion; Kristin R. Adams

2005-01-01

419

Evolution of trees and mycorrhizal fungi intensifies silicate mineral weathering  

PubMed Central

Forested ecosystems diversified more than 350 Ma to become major engines of continental silicate weathering, regulating the Earth's atmospheric carbon dioxide concentration by driving calcium export into ocean carbonates. Our field experiments with mature trees demonstrate intensification of this weathering engine as tree lineages diversified in concert with their symbiotic mycorrhizal fungi. Preferential hyphal colonization of the calcium silicate-bearing rock, basalt, progressively increased with advancement from arbuscular mycorrhizal (AM) to later, independently evolved ectomycorrhizal (EM) fungi, and from gymnosperm to angiosperm hosts with both fungal groups. This led to ‘trenching’ of silicate mineral surfaces by AM and EM fungi, with EM gymnosperms and angiosperms releasing calcium from basalt at twice the rate of AM gymnosperms. Our findings indicate mycorrhiza-driven weathering may have originated hundreds of millions of years earlier than previously recognized and subsequently intensified with the evolution of trees and mycorrhizas to affect the Earth's long-term CO2 and climate history. PMID:22859556

Quirk, Joe; Beerling, David J.; Banwart, Steve A.; Kakonyi, Gabriella; Romero-Gonzalez, Maria E.; Leake, Jonathan R.

2012-01-01

420

Evolution of trees and mycorrhizal fungi intensifies silicate mineral weathering.  

PubMed

Forested ecosystems diversified more than 350 Ma to become major engines of continental silicate weathering, regulating the Earth's atmospheric carbon dioxide concentration by driving calcium export into ocean carbonates. Our field experiments with mature trees demonstrate intensification of this weathering engine as tree lineages diversified in concert with their symbiotic mycorrhizal fungi. Preferential hyphal colonization of the calcium silicate-bearing rock, basalt, progressively increased with advancement from arbuscular mycorrhizal (AM) to later, independently evolved ectomycorrhizal (EM) fungi, and from gymnosperm to angiosperm hosts with both fungal groups. This led to 'trenching' of silicate mineral surfaces by AM and EM fungi, with EM gymnosperms and angiosperms releasing calcium from basalt at twice the rate of AM gymnosperms. Our findings indicate mycorrhiza-driven weathering may have originated hundreds of millions of years earlier than previously recognized and subsequently intensified with the evolution of trees and mycorrhizas to affect the Earth's long-term CO(2) and climate history. PMID:22859556

Quirk, Joe; Beerling, David J; Banwart, Steve A; Kakonyi, Gabriella; Romero-Gonzalez, Maria E; Leake, Jonathan R

2012-12-23

421

Green Bank Weather Dana S. Balser  

E-print Network

Green Bank Weather Dana S. Balser #12;Weather Resources 1. Weather Stations 2. Weather Forecasts (NOAA/Maddalena) 3. Pyrgeometer 4. 86 GHz Tipping Radiometer 5. 12 GHz Interferometer #12;Weather Parameters 1 May 2004 to 1 March 2007 speedwindousInstantaneV :Hz)(12StationWeather e

Balser, Dana S.

422

Interactives: The Rock Cycle  

NSDL National Science Digital Library

How much do you know about rocks? Well, if you are a bit unsure about distinguishing an igneous rock from a sedimentary rock you'll certainly be on solid ground after taking a tour through this feature created by Annenberg Media. Visitors can make their way through graphically-enhanced sections that include "Types of Rocks", "How Rocks Change", and "The Rock Cycle Diagram". In the "Types of Rocks" area visitors will learn about the basic types of rocks and they can even check out a handy chart that will give them some of the finer points of rock identification. The "How Rocks Change" area provides a basic overview of the processes involved with rock creation and transformation through a heady blend of Flash animations and straight-forward prose. Finally, the "Rock Cycle Diagram" provides an illustration of rock transformation over time. This site will be quite useful to educators and anyone who has peered at a rock and wondered: "How did you come to be?"

2008-04-11

423

Interactives: The Rock Cycle  

NSDL National Science Digital Library

How much do you know about rocks? Well, if you are a bit unsure about distinguishing an igneous rock from a sedimentary rock you'll certainly be on solid ground after taking a tour through this feature created by Annenberg Media. Visitors can make their way through graphically-enhanced sections that include "Types of Rocks", "How Rocks Change", and "The Rock Cycle Diagram". In the "Types of Rocks" area visitors will learn about the basic types of rocks and they can even check out a handy chart that will give them some of the finer points of rock identification. The "How Rocks Change" area provides a basic overview of the processes involved with rock creation and transformation through a heady blend of Flash animations and straight-forward prose. Finally, the "Rock Cycle Diagram" provides an illustration of rock transformation over time. This site will be quite useful to educators and anyone who has peered at a rock and wondered: "How did you come to be?"

424

Fossil Microorganisms and Formation of Early Precambrian Weathering Profiles  

NASA Technical Reports Server (NTRS)

Weathering crusts are the only reliable evidences of the existence of continental conditions. Often they are the only source of information about exogenous processes and subsequently about conditions under which the development of the biosphere occurred. A complex of diverse fossil microorganisms was discovered as a result of Scanning Electron Microscope investigations. The chemical composition of the discovered fossils is identical to that of the host rocks and is represented by Si, Al, Fe, Ca and Mg. Probably, the microorganisms fixed in rocks played the role of catalyst. The decomposition of minerals comprising the rocks and their transformation into clayey (argillaceous) minerals, most likely occurred under the influence of microorganisms. And may be unique weathering crusts of Early Precambrian were formed due to interaction between specific composition of microorganism assemblage and conditions of hypergene transformations. So it is possible to speak about colonization of land by microbes already at that time and about existence of single raw from weathering crusts (Primitive soils) to real soils.

Rozanov, A. Yu; Astafieva, M. M.; Vrevsky, A. B.; Alfimova, N. A.; Matrenichev, V. A.; Hoover, R. B.

2009-01-01

425

Biotic enhancement of weathering, atmospheric oxygen and carbon dioxide in the Neoproterozoic  

NASA Astrophysics Data System (ADS)

It has been suggested that biological colonization of the land surface began in the Neoproterozoic 1000-544 million years ago (Ma). We hypothesize that this colonization involved selective weathering of P from rocks, as well as an amplification of overall weathering rates. We show that two recent models, despite differences in the feedback mechanisms represented, predict that an increase in the weathering flux of P to the ocean would have caused a rise in atmospheric O2 in the Neoproterozoic. This in turn may have provided a necessary condition for the evolution of animals with hard skeletons seen in the 'Cambrian explosion'. Increased weathering of silicate rocks would also have caused a decline in atmospheric CO2, which could have been a causal factor in the Neoproterozoic glaciations.

Lenton, Timothy M.; Watson, Andrew J.

2004-03-01

426

Fossils and tFossils and the Rock Cyclehe Rock Cycle The rock cycle explains how one type of rock  

E-print Network

1 Fossils and tFossils and the Rock Cyclehe Rock Cycle h ^ The rock cycle explains how one type of rock can be transformed into another in nature. The Geologic Cycle 3 key events: deposition, uplift geologic time Forms Strata: layers of rock The rock cycle explains how one type of rock can be transformed

Cochran-Stafira, D. Liane

427

Spectral reflectance and photometric properties of selected rocks  

USGS Publications Warehouse

Studies of the spectral reflectance and photometric properties of selected rocks at the USGS Mill Creek, Oklahoma, remote sensing test site demonstrate that discrimination of rock types is possible through reflection measurements, but that the discrimination is complicated by surface conditions, such as weathering and lichen growth. Comparisons between fresh-broken, weathered, and lichen-covered granite show that whereas both degree of weathering and amount of lichen cover change the reflectance quality of the granite, lichen cover also considerably changes the photometric properties of the granite. Measurements of the spectral reflectance normal to the surface of both limestone and dolomite show limestone to be more reflective than dolomite in the wavelength range from 380 to 1550 nanometers. The reflectance difference decreases at view angles greater than 40?? owing to the difference in the photometric properties of dolomite and limestone. ?? 1971.

Watson, R.D.

1971-01-01

428

Severe Weather Forecast Decision Aid  

NASA Technical Reports Server (NTRS)

This report presents a 15-year climatological study of severe weather events and related severe weather atmospheric parameters. Data sources included local forecast rules, archived sounding data, Cloud-to-Ground Lightning Surveillance System (CGLSS) data, surface and upper air maps, and two severe weather event databases covering east-central Florida. The local forecast rules were used to set threat assessment thresholds for stability parameters that were derived from the sounding data. The severe weather events databases were used to identify days with reported severe weather and the CGLSS data was used to differentiate between lightning and non-lightning days. These data sets provided the foundation for analyzing the stability parameters and synoptic patterns that were used to develop an objective tool to aid in forecasting severe weather events. The period of record for the analysis was May - September, 1989 - 2003. The results indicate that there are certain synoptic patterns more prevalent on days with severe weather and some of the stability parameters are better predictors of severe weather days based on locally tuned threat values. The results also revealed the stability parameters that did not display any skill related to severe weather days. An interactive web-based Severe Weather Decision Aid was developed to assist the duty forecaster by providing a level of objective guidance based on the analysis of the stability parameters, CGLSS data, and synoptic-scale dynamics. The tool will be tested and evaluated during the 2005 warm season.

Bauman, William H., III; Wheeler, Mark M.; Short, David A.

2005-01-01

429

Complex Molybdenum Isotope Behavior During Weathering and Erosional Transport  

NASA Astrophysics Data System (ADS)

The oceans play a major role in regulating global climate because they both react and drive changes in other geochemical reservoirs. Non-traditional stable isotope systems have become important proxies for changes in ocean chemistry making the quantification of these changes possible. Molybdenum isotopes have great potential as tracers of changes in the oxygenation of the oceans over geological time scales. Although significant progress has been made and the amount of data on the biogeochemical behaviour of Mo in the marine environment has been increasing rapidly over the last few years, some important aspects of Mo geochemistry remain poorly understood. These include diagenetic processes at continental margins and continental weathering. Mo isotope behaviour in these settings has a potentially large impact on the interpretation of the geological record. A recent study of Archer and Vance (2008) has shown that dissolved Mo in many of Earths major rivers has a heavy isotope composition relative to most magmatic rocks. A potential cause for this isotope composition in modern rivers is isotope fractionation during weathering and erosion processes. We investigated Mo isotope behaviour in weathering profiles from Hawaii and Puerto Rico. Results clearly show significant Mo isotope fractionation during chemical weathering. Mo retained in saprolithe samples from Hawaii has light isotope compositions of up to -0.5 permill. The extent of fractionation is dependent on redox-conditions in the investigated profiles. The particular setting of these profiles keeps other factors that might influence the Mo isotope composition to a minimum. The results also indicate the possible use of Mo isotope signals as paleoredox-proxy of weathering processes. However, a weathering profile with intermittent changes in redox, pH and porewater saturation show more variable Mo isotope signals with partly positive isotope values. Sequential extractions of saphrolite samples show a clear correlation of Mo with Fe in organic poor weathering profiles. However, in more organic rich profiles Mo and Fe seem to behave differently. We found a clear indication of the influence of weathering on the Mo isotope composition of groundwater. Deep groundwater shows a Mo isotope composition close to that of magmatic rocks, whereas shallow groundwater in contact with actively weathered horizons has light isotope compositions. These results point to complex behaviour of Mo in terrestrial environments and it is likely that there is not a single governing process causing the observed isotope composition of rivers. In addition, the isotope composition of Mo in rivers might have changed over geological time scales. A better understanding of the processes controlling the Mo isotope compositions of rivers is therefore essential for the use of Mo as paleo-proxy.

Siebert, C.; Pett-Ridge, J. C.; Burton, K.; Halliday, A. N.

2009-12-01

430

Rock Mech. Rock Engng. (2000) 33 (1), 113 Rock Mechanics  

E-print Network

was originally developed to compare the surface rebound hardness of concrete (Kolek, 1958), it has been widely was in a good agreement with rock drillability or cutting ability, to the knowledge of the authors there does

431

Nitrogen in rock: Occurrences and biogeochemical implications  

USGS Publications Warehouse

There is a growing interest in the role of bedrock in global nitrogen cycling and potential for increased ecosystem sensitivity to human impacts in terrains with elevated background nitrogen concentrations. Nitrogen-bearing rocks are globally distributed and comprise a potentially large pool of nitrogen in nutrient cycling that is frequently neglected because of a lack of routine analytical methods for quantification. Nitrogen in rock originates as organically bound nitrogen associated with sediment, or in thermal waters representing a mixture of sedimentary, mantle, and meteoric sources of nitrogen. Rock nitrogen concentrations range from trace levels (>200 mg N kg -1) in granites to ecologically significant concentrations exceeding 1000 mg N kg -1 in some sedimentary and metasedimentary rocks. Nitrate deposits accumulated in arid and semi-arid regions are also a large potential pool. Nitrogen in rock has a potentially significant impact on localized nitrogen cycles. Elevated nitrogen concentrations in water and soil have been attributed to weathering of bedrock nitrogen. In some environments, nitrogen released from bedrock may contribute to nitrogen saturation of terrestrial ecosystems (more nitrogen available than required by biota). Nitrogen saturation results in leaching of nitrate to surface and groundwaters, and, where soils are formed from ammonium-rich bedrock, the oxidation of ammonium to nitrate may result in soil acidification, inhibiting revegetation in certain ecosystems. Collectively, studies presented in this article reveal that geologic nitrogen may be a large and reactive pool with potential for amplification of human impacts on nitrogen cycling in terrestrial and aquatic ecosystems.

Holloway, J.M.; Dahlgren, R.A.

2002-01-01

432

Finding Space Weather Events  

NSDL National Science Digital Library

This is an activity about searching online data archives for solar wind events. Learners will find at least three episodes of increased solar wind activity impacting Earth using direct measurements of solar wind velocity and density. Then, they will characterize each events by its rise time, the time it takes for the solar wind speed to rise from normal levels to the peak speed of the event, and the percentage increase in solar wind velocity. This is Activity 11 of the Space Weather Forecast curriculum.

433

Weather Stations: Phase Change  

NSDL National Science Digital Library

In this activity, learners observe the water cycle in action! Water vapor in a tumbler condenses on chilled aluminum foil — producing the liquid form of water familiar to us as rain and dew. Learners discuss how Jupiter's lack of a surface simplifies its water cycle. Learners then consider the roles ammonia and ammonia compounds play in Jupiter's more complicated atmosphere. This activity is one station that can be combined with other stations for an hour and half lesson on weather patterns on Jupiter and Earth.

2014-07-11

434

Global Weather Patterns  

NSDL National Science Digital Library

This tutorial introduces students to global weather patterns and how they affect the kinds of trees and plants that grow in different latitudes of the Earth. The discussion covers the tropics and the lush rainforests that live there, temperate forests in the mid-latitudes, and boreal forests in the far north. There is also a description of how treeless areas occur in various climate zones (desert, tundra, savannah), and how plants adapt to low-water conditions in the desert. A quiz and glossary are included.

435

Weather Forecasting Aid  

NASA Technical Reports Server (NTRS)

Weather forecasters are usually very precise in reporting such conditions as temperature, wind velocity and humidity. They also provide exact information on barometric pressure at a given moment, and whether the barometer is "rising" or "falling"- but not how rapidly or how slowly it is rising or falling. Until now, there has not been available an instrument which measures precisely the current rate of change of barometric pressure. A meteorological instrument called a barograph traces the historical ups and downs of barometric pressure and plots a rising or falling curve, but, updated every three hours, it is only momentarily accurate at each updating.

1979-01-01

436

Theory of wing rock  

NASA Technical Reports Server (NTRS)

Wing rock is one type of lateral-directional instabilities at high angles of attack. To predict wing rock characteristics and to design airplanes to avoid wing rock, parameters affecting wing rock characteristics must be known. A new nonlinear aerodynamic model is developed to investigate the main aerodynamic nonlinearities causing wing rock. In the present theory, the Beecham-Titchener asymptotic method is used to derive expressions for the limit-cycle amplitude and frequency of wing rock from nonlinear flight dynamics equations. The resulting expressions are capable of explaining the existence of wing rock for all types of aircraft. Wing rock is developed by negative or weakly positive roll damping, and sustained by nonlinear aerodynamic roll damping. Good agreement between theoretical and experimental results is obtained.

Hsu, C.-H.; Lan, C. E.

1985-01-01

437

The Rock Cycle  

ERIC Educational Resources Information Center

Presents a rock cycle diagram suitable for use at the secondary or introductory college levels which separates rocks formed on and below the surface, includes organic materials, and separates products from processes. (SL)

Singh, Raman J.; Bushee, Jonathan

1977-01-01

438

Online Field Journal: Rocks  

NSDL National Science Digital Library

This online activity is part of the museum's Online Field Journal Web site, where young children can explore the wonders of nature with the help of an adult. The challenge here is to take a closer look at three rocks. On the opening page, there are side-by-side photos of the three rocks; students are asked to describe each rock Clicking a rock's photo takes students to a magnified view of the rock that also asks students two additional questions. When students click on the magnified rock photo, they get a fun fact. The site also includes links to a Tips for Adult Helpers page and to a printable Rocks Field Journal page that has instructions for using it on a "rock hunt."

439

Rock Cycle Animations  

NSDL National Science Digital Library

Many people might know about the life cycle of a rock, but it can be a process that is hard to understand without a handy visual aid. Just such a series of aids can be found right here, courtesy of Mark Francek of Central Michigan University. These rock cycle animations display some of the most common rock-forming processes, including the crystallization of magma to form igneous rock, rock erosion to create sediment, and several others. That's not all, as visitors can also examine a comprehensive Flash animation which contains three separate movies, each of which looks at the formation of igneous rocks in environments that include a deep magma chamber and rocks forming from a pyroclastic flow. The site is rounded out by an interactive igneous rocks classification chart, arranged by texture and chemical composition.

440

Rocks in Our Pockets  

ERIC Educational Resources Information Center

To introduce students to rocks and their characteristics, teacher can begin rock units with the activities described in this article. Students need the ability to make simple observations using their senses and simple tools.

Plummer, Donna; Kuhlman, Wilma

2005-01-01

441

Rock drilling, cooling liquids  

NSF Publications Database

Title : Rock drilling, cooling liquids Type : Antarctic EAM NSF Org: OD / OPP Date : October 23 ... impacts that could accrue from the use of cooling liquids during rock drilling. Our discussion of ...

442

Igneous Rock Animation  

NSDL National Science Digital Library

Through a simple Flash roll over, view hand specimens of different igneous rocks classified according by texture and chemical composition. There are also views of the more common rock forming minerals. Expect long loading times.

Wiley

443

The Rock Cycle  

NSDL National Science Digital Library

This site from Satellite Geodesy describes the rock cycle, and quantitative ways to estimate how long geological features took to form. Popcorn is used to demonstrate half-life and radio-active decay, which is used to date rocks.

Tauxe, Lisa; Geodesy, Satellite

444

The Rock Cycle  

NSDL National Science Digital Library

This site contains a basic explanation of the rock cycle along with information on the difference between a rock and a mineral and a description of the three types of rocks (igneous, metamorphic, and sedimentary). The site also describes the crust, mantle, outer core, and inner core, which are the four different layers of the Earth. In addition, it has a diagram of the rock cycle showing its relationship to the Theory of Plate Tectonics.

445

Feasibility and Implications of a Rock Coating Catena: Analysis of a Desert Hillslope  

NASA Astrophysics Data System (ADS)

This research analyzes rock coatings on a basaltic hill in the western Mojave Desert using a combination of aerial imagery, a new method of digital in-field ground-based image processing, and statistical analyses. In addition, this research resulted in the development of a new rock coating index (RCI) to generalize changes in rock coatings along a slope, applied here to 2,760 individual clasts. RCI values reveal variations of different types of rock coatings on different particle sizes, in this case rock varnish, iron films, and rocks eroding too fast to host any coating. Larger particles host more rock varnish, iron films do not prefer a particular particle size, and highly weathered no-coating rocks are relatively smaller.

Palmer, Ronald E.

2002-08-01

446

Rock control on microweathering of bedrock surfaces in a periglacial environment  

NASA Astrophysics Data System (ADS)

Microweathering of ice-smoothed bedrock surfaces was investigated in the Røldal area of Hardanger Plateau (60°), southern Norway. Postglacial rates of weathering were determined from surface lowering using quartz veins as reference surfaces. Weathering processes are inferred from assessment of weathering rind formation, surface hardness, and the preservation of small-scale glacial erosional features. Surface lowering rates for a range of metamorphic rocks vary from 0.05 to 2.20 mm ka - 1 and are broadly comparable with those obtained from crystalline rocks in other periglacial environments. The mean rate of surface lowering at 0.55 mm ka - 1 is low and demonstrates the relatively small impact of microweathering on postglacial landscape evolution. Variations in bedrock microweathering can be explained by lithological variation. Amphibolite and mica-rich bedrock surfaces experience greater denudation and weakening, least weathering rind formation, and abundant preservation of glacial striae, despite greater surface lowering. Conversely, quartz-rich bedrock surfaces are most resistant to denudation and weakening, but have greater weathering rind formation and fewer preserved striae. Postglacial microweathering is achieved primarily through granular disintegration involving detachment and removal of mineral grains and weakening from increased porosity. Granular decomposition is manifest in the formation of weathering rinds. Analysis of interactions between weathering indices indicates that rind accumulation is limited by microerosion. A conceptual model is proposed that illustrates the temporal interrelationships between in situ and erosional facets of microweathering in two contrasting mineral assemblages. The model proposes that cyclic processes of in situ disintegration, decomposition, and erosion are at work. The relative balance between these processes varies with lithology so that in more resistant quartz-rich rocks the net effect is minimal surface lowering and accumulation of weathering rind. In weaker, amphibolitic and micaceous rocks, the net effect is greater surface lowering and minimal accumulation of weathering rind. The results of the research demonstrate the important influence of rock properties, notably mineral composition, in postglacial microweathering of crystalline bedrock in a periglacial environment.

Nicholson, Dawn T.

2008-11-01

447

The Rock Cycle  

NSDL National Science Digital Library

Create a poster about the rock cycle! Directions: Make a poster about the rock cycle. (20 points) Include at least (1) large picture (15 points) on your poster complete with labels of every part (10 points). (15 points) Include at least three (3) facts about the rock cycle. (5 points each) (15 points) Write at least a three sentence summary of your poster ...

Walls, Mrs.

2011-01-30

448

Friction of rocks  

Microsoft Academic Search

Experimental results in the published literature show that at low normal stress the shear stress required to slide one rock over another varies widely between experiments. This is because at low stress rock friction is strongly dependent on surface roughness. At high normal stress that effect is diminished and the friction is nearly independent of rock type. If the sliding

J. Byerlee

1978-01-01

449

The fracture of rocks  

Microsoft Academic Search

This book contains an introduction and review of natural fractures in rock and their methods of study. It begins with the theoretical background of stress, strain and elasticity. The subject of rock fracture is presented from the perspective of structural geology. It provides a tool for structural studies in various fields of applied geology: mining research, hydrogeology of rock formations

J. L. Bles; B. Fuega

1986-01-01

450

PETER A. ROCK Thermochemistry  

E-print Network

NCGC PETER A. ROCK Thermochemistry LaboratoryENERGY U.S. DEPARTMENT OF Office of Science Center, and precipitation in deep subsurface rock formations, to achieve the e cient lling of pore space with injected and computational methods, to build a next-generation understanding of molecular­to­pore scale processes in uid-rock

451

Bottle Rock Power Corporation  

E-print Network

Bottle Rock Power Corporation 1275 4th Street, No. 105 Phone: 707.541.0976 Santa Rosa, CA 95404 Fax 1516 9th Street, MS-2000 Sacramento, CA 95814-5512 RE: Bottle Rock Power Plant (79-AFC-4C) Petition for Extending Environmental Monitoring Program Dear Ms. Tronaas: The Bottle Rock Power Corporation (BRPC

452

Robotic Rock Classification and  

E-print Network

Robotic Rock Classification and Autonomous Exploration Liam Pedersen #12;Acknowledgements for me to spend three summers at NASA's Ames Research Center working with him on rock classification to himself, a marvelous spectrometer with which to study rocks in Antarctica. Dr. Bill Cassidy's unstinting

Shamos, Michael I.

453

Ranking the Rocks  

NSDL National Science Digital Library

Student teams assign importance factors, called "desirability points," the rock properties found in the previous lesson/activity in order to mathematically determine the overall best rocks for building caverns within. They learn the real-world connections and relationships between the rock and the important engineering properties for designing and building caverns (or tunnels, mines, building foundations, etc.).

Adventure Engineering

454

Science Shorts: Science Rocks!  

NSDL National Science Digital Library

It all began one Monday morning. Raymond could not wait to come to large group. In his hand, he held a chunk of white granite he had found. "Look at my beautiful rock!" he cried. The rock was passed around and examined by each student. "I wonder how rocks

Chessin, Debby A.; Prestwich, Dorothy; Sumrall, Joseph

2010-03-01

455

Precambrian Rocks in Ireland  

Microsoft Academic Search

Irish Precambrian rocks occur in restricted outcrops as part of the foreland and as a basement to the Irish Caledonides. Caledonian deformation affected rocks of the Dalradian Supergroup of late Proterozoic to Cambrian age. Concealed pre-Caledonian basement is inferred to be largely granulite facies gneisses on the basis of geophysical and isotopic data. Basement rocks may be fundamentally different on

Cornelius Gillen

1980-01-01

456

Igneous Rocks Animation  

NSDL National Science Digital Library

In this section, see close-up pictures of the major rock types and learn about where different types of igneous rocks are formed, what style of magmatic activity is associated with each type of magma, and what rock types are melted to form each of these magma compositions.

2002-01-01

457

Megascopic Classification of Rocks.  

ERIC Educational Resources Information Center

A new classification of rocks that requires no tools other than a hand lens and that is both comprehensive and informative is described. Each of the three main rock groups is treated in two-dimensional, rectangular charts with additional appended boxes that provide optional mineralogical and textural terms that can be used in rock names. (PR)

Brown, Vernon Max; Harrell, James Anthony

1991-01-01

458

Rocks and Minerals  

NSDL National Science Digital Library

This description of rocks and minerals includes representatives of all three major groups: igneous, sedimentary, and metamorphic. Users can access introductory information about the three major rock types and the minerals that form them. A simple rock classification chart is included, with embedded links to a glossary and more detailed material for advanced learners.

459

Intense weathering of Archean basement associated with acid saline lakes in Western Australia  

NASA Astrophysics Data System (ADS)

Understanding the relationship between bedrock weathering and surface chemistry is challenging and it is rare to find an environment where the bedrock has been exposed over geologic time scales (e.g. millions of years), has not undergone significant mechanical weathering, and has not been deeply buried by subsequent deposition. However, the Yilgarn Craton in southern Western Australia provides just such an environment. The Yilgarn Craton hosts a combination of exposed and highly weathered Archean bedrock, a variety of discontinuous Cenozoic sedimentary rocks, and thousands of modern ephemeral saline lakes. Here, we use major oxide and trace element geochemistry to compare the weathering histories of rocks preserved in drill cores from two of these saline lakes - one acid (Prado Lake, pH ~3) and one neutral (Gastropod Lake, pH ~8). The extreme fluid chemistry of these lakes is reflected in the mineralogy and geochemistry of both drill cores, which preserve a combination of chemical sediments, early cements and long-term weathering products. The use of weathering indices (e.g. CIA, CIA-K, WIP) and trace element ratios (e.g. Ti/Al, Ti/Zr, Zr/Hf) through sediment and regolith cored below these lakes provides insight into the relationship between bedrock weathering and surface chemistry at Prado Lake and Gastropod Lake. The use of weathering indices and trace element data reveal that at both lakes, the Archean bedrock at depth is highly weathered (Chemical Index of Alteration (CIA) = 45-88, CIA-K = 49-93, Weathering Index of Parker (WIP) = 16-92). Trace element ratios from the cores suggest that the local basement material the primary lithologic source of the overlying sedimentary material (?-Zr/Hf = -0.15-0.41). Weathering patterns in the Prado Lake drill core reflect weathering of the original crystalline bedrock and as well as that of a younger sandstone and the variably weathered surface materials. Despite the length of time the bedrock is interpreted to have been exposed, correlations between the CIA and CIA-K indicate the presence/preservation of only one well-developed paleosol/highly weathered surface. The relationship between the bedrock weathering histories at both lakes and their surface pH appears to be dependent on the availability of reactive surfaces within the near-surface material. When compared to other global data, this work and previously published studies in the region confirm that not only is the Yilgarn Craton is one of the largest intact pieces of Archean crust, it is also host to some of the most highly weathered and preserved pieces of Archean crust in the world.

Bowen, B. B.; Story, S.; Benison, K. C.; Oboh-Ikuenobe, F. E.

2012-12-01

460

Chronology of rock falls and slides in a desert mountain range: Case study from the Sonoran Desert in south-central Arizona  

E-print Network

Chronology of rock falls and slides in a desert mountain range: Case study from the Sonoran Desert Keywords: Desert Medieval Warm Period Physical weathering Rock fall Rock slides In order to respond the slopes of desert mountain ranges, a case study in the Sonoran Desert reveals new insight into the desert

Dorn, Ron

461

Make Your Own Weather Station  

NSDL National Science Digital Library

In this OLogy activity, kids learn about climate and atmospheric conditions by making their own weather station. The activity begins with an overview that explains that weather happens in the atmosphere, where conditions are always changing. Students are given step-by-step, illustrated directions to make a wind vane, a rain gauge and a barometer. The activity includes a printable Weather Chart and wind vane cutouts.

462

Science Sampler: Weathering database technology  

NSDL National Science Digital Library

Collecting weather data is a traditional part of a meteorology unit at the middle level, but making connections between the data and weather conditions can be a challenge for students. One way to help students make these connections clearer is to enter the data into a database. This allows students to quickly compare different fields of data and recognize which readings are associated with certain types of weather.

Robert Snyder

2005-02-01

463

Boulder weathering in McMurdo Dry Valleys, Antarctica  

NASA Astrophysics Data System (ADS)

Earth's dynamic surface undergoes a continuous cycle of mountain building and denudation. One of the important links in this cycle is the break-up and comminution of the rocks that allows for effective transportation of debris by surface processes. The starting and end points in this transformation are well known: bedrock and boulders on one end and silt and clay on the other. However, the existing knowledge of the rates and processes responsible of the intermediate steps is currently limited. To fill this gap in knowledge we studied boulders and their weathering products in the McMurdo Dry Valleys, Antarctica, that have been weathering for hundreds of thousands of years sub-aerially exposed at the ground surface. Our study boulders of locally distinct lithology have trails of rock fragments leading downhill revealing the rate of weathering and subsequent transport rate of the fragments. The rock fragments emanate from the source boulder and decrease in size as the distance downslope increases. We measured the fragment sizes and distances for various lithologies on varying slope angles. We found that large fragments up to 0.4 m in diameter can be transported up to 60 m downslope by unknown processes. The total length of the fragment trail increases with the slope angle. The maximum transport distances of sandstone boulders are approximately 10 times longer than other lithologies, which may be explained by the larger observed fragment sizes of the sandstones. On the other hand measurements of the smaller, generally less than 0.04 m diameter fragments that are transported by wind, revealed much shorter transport distances (< 10 m). To gain insights of the boulder and resulting fragment weathering rates we constructed a boulder weathering-fragment transport computer model. The model is based on simple rules and probabilities that describe the weathering and transportation. The model is constrained by the observed fragment size distribution, fragment distribution in space, fragment size/distance relationship, and other observed properties of the fragments. This model allows us to determine the weathering rates of the source boulder and the resulting fragments on the ground, and the fragment size dependent transport rate that are consistent with the observations. Our modeling suggests that the boulders on average spall a fragment over 250 times more often than the resulting fragments re-break and that the currently observed fragment transport rate is consistent with our modeled long term average transport rate.

Putkonen, Jaakko; Morgan, Daniel; Balco, Greg

2014-08-01

464

Vodcasting Space Weather  

NASA Astrophysics Data System (ADS)

The topic of space weather is the subject of a series of vodcasts (video podcasts) produced by MIT Haystack Observatory (Westford, MA) and Loch Ness Productions (Groton, MA). This paper discusses the production and distribution of the series via Webcast, Youtube, and other avenues. It also presents preliminary evaluation of the effectiveness and outreach of the project through feedback from both formal and information education venues. The vodcast series is linked to the NASA Living With a Star Targeted Research and Technology project award "Multi-Instrument Investigation of Inner-Magnetospheric/Ionosphere Disturbances.” It is being carried out by Principal Investigator Dr. John Foster, under the auspices of NASA Grant # NNX06AB86G. The research involves using ionospheric total electron content (TEC) observations to study the location, extent, and duration of perturbations within stormtime ionospheric electric fields at mid- to low latitudes. It combines ground-based global positioning system (GPS) TEC data, incoherent scatter radar measurements of the mid-latitude ionospheric state, and DMSP satellite observations to characterize conditions which lead to severe low-latitude ionospheric perturbations. Each vodcast episode covers a certain aspect of space weather and the research program.

Collins Petersen, Carolyn; Erickson, P. J.; Needles, M.

2009-01-01

465

Rates of oxidative weathering on the surface of Mars  

NASA Technical Reports Server (NTRS)

Implicit in the mnemonic 'MSATT' (Mars surface and atmosphere through time) is that rates of surface processes on Mars through time should be investigated, including studies of the kinetics and mechanism of oxidative weathering reactions occurring in the Martian regolith. Such measurements are described. Two major elements analyzed in the Viking Lander XRF experiment that are most vulnerable to atmospheric oxidation are iron and sulfur. Originally, they occurred as Fe(2+)-bearing silicate and sulfide minerals in basaltic rocks on the surface of Mars. However, chemical weathering reactions through time have produced ferric- and sulfate-bearing assemblages now visible in the Martian regolith. Such observations raise several question about: (1) when the oxidative weathering reactions took place on Mars; (2) whether or not the oxidized regolith is a fossilized remnant of past weathering processes; (3) deducting chemical interactions of the ancient Martian atmosphere with its surface from surviving phases; (4) possible weathering reactions still occurring in the frozen regolith; and (5) the kinetics and mechanism of past and present-day oxidative reactions on Mars. These questions may be addressed experimentally by studying reaction rates of dissolution and oxidation of basaltic minerals, and by identifying reaction products forming on the mineral surfaces. Results for the oxidation of pyrrhotite and dissolved ferrous iron are reported.

Burns, Roger G.

1992-01-01

466

Space Weathering: An Ultraviolet Indicator  

NASA Technical Reports Server (NTRS)

We present evidence suggesting that the spectral slope of airless bodies in the UV-visible wavelength range can be used as an indicator of exposure to space weathering. While space weathering generally produces a reddening of spectra in the visible-NIR spectral regions, it tends to result in a bluing of the UV-visible portion of the spectrum, and may in some cases produce a spectral reversal. The bluing effect may be detectable with smaller amounts of weathering than are necessary to detect the longer-wavelength weathering effects.

Hendrix, A. R.; Vilas, F.

2004-01-01

467

Space Weathering: An Ultraviolet Indicator  

NASA Technical Reports Server (NTRS)

We present evidence suggesting that the spectral slope of airless bodies in the UV-visible wavelength range can be used as an indicator of exposure to space weathering. While space weathering generally produces a reddening of spectra in the visible-NIR spectral regions, it tends to result in a bluing of the UV-visible portion of the spectrum, and may in some cases produce a spectral reversal. The bluing effect may be detectable with smaller amounts of weathering than are necessary to detect the longer-wavelength weathering effects.

Hendrix, A. R.; Vilas, F.

2003-01-01

468

AWE: Aviation Weather Data Visualization  

NASA Technical Reports Server (NTRS)

The two official sources for aviation weather reports both require the pilot to mentally visualize the provided information. In contrast, our system, Aviation Weather Environment (AWE) presents aviation specific weather available to pilots in an easy to visualize form. We start with a computer-generated textual briefing for a specific area. We map this briefing onto a grid specific to the pilot's route that includes only information relevant to his flight route that includes only information relevant to his flight as defined by route, altitude, true airspeed, and proposed departure time. By modifying various parameters, the pilot can use AWE as a planning tool as well as a weather briefing tool.

Spirkovska, Lilly; Lodha, Suresh K.

2001-01-01

469

Physical weathering and modification of a rhyolitic hyaloclastite in Iceland  

NASA Astrophysics Data System (ADS)

Fragmental volcanic glass or `hyaloclastite' is a common glaciovolcanic eruption product that is formed in large abundance during basaltic, andesitic and rhyolitic subglacial eruptions. The physical weathering of rhyolitic hyaloclastites differs notably from basaltic hyaloclastites due to differences in cementation and edifice consolidation. As rhyolitic glasses are also much rarer, comparatively little is known about their physical weathering and fracturing characteristics. In the presented study, we provide a process-oriented analysis of the physical modification of subglacially erupted rhyolitic hyaloclastites from the Bláhnúkur edifice in Torfajökull (Iceland). Frost weathering experiments were performed to determine how vesicular glass particles fragment to finer particle sizes. The surficial porosity of the glass drives such frost weathering through the process of pore pressurisation and was quantified using high-pressure mercury intrusion. Uniaxial compression experiments were carried out to understand how the glass structure responds to the application of external stress. The observed fracturing in both experimental treatments was found to adhere to fractal statistics, which allowed the compression experiments to be used in conjunction with the frost weathering experiments for inferring the fracturing characteristics of rhyolitic volcanic glasses. Transport processes by wind and gravity were simulated by long-duration abrasion experiments in rock tumblers (through granular avalanching), but these low-energy particle interactions were not found to significantly abrade particles. A notable result from our fragmentation experiments was the production of <10 ?m particles. This size range is considered respirable and illustrates how physical weathering can continuously create potentially harmful ash textures; a process which is often overlooked in health hazard assessments after volcanic eruptions. Fragmentation by post-eruptive weathering can lead to overestimations of the fine ash fraction produced by syneruptive fragmentation and granulometric studies therefore need to be appreciative of the effects of such secondary fracturing processes.

de Vet, S. J.; Mittelmeijer-Hazeleger, M. C.; Braakhekke, J. J. M.; Cammeraat, L. H.

2014-06-01

470

Infrared spectroscopy of weathering products in a terrestrial glacial environment: Implications for cold weathering on planetary surfaces  

NASA Astrophysics Data System (ADS)

Geologic features on Mars show evidence of modification by water and water ice. Past obliquity variations are hypothesized to have allowed the formation and stability of ground ice near the equator, possibly promoting the accumulation of glaciers. Massive ice deposits, including probable glacial and periglacial features have also been observed in the east Hellas Basin and Deuteronilus Mensae regions, located at the midlatitudes of Mars. These features indicate present-day, near-surface ice has been in contact with geologic materials, creating an environment in which cold weathering processes could have been occurring, and might still be at work. Weathering processes in cold terrestrial environments are not well understood, and processes acting on subglacial and englacial sediments and rocks are not well characterized due to the remote location of many glaciers and the difficulty of collecting samples. The types of weathering products and energy sources produced in a glacial environment will drive the overall energy budget for any microbial communities present. The subglacial energy budget for microbes thus has implications in the search for life on other planets, making glacial and periglacial terrains excellent sites for future exploration. However, planetary ice deposits are difficult to study due to their sensitive nature and are thus limited to observation from orbit at present. It is therefore a key concern to better understand the types materials and alteration products that can be observed and constrained from orbital data. In this study, we characterize the types of weathering products present in a glacial system using ground-truthed remote sensing techniques. Robertson Glacier, Alberta, Canada (115°20'W, 50°44'N) provides an excellent testbed for this technique as it is accessible, and its recent and continuing retreat allows fresh subglacial and englacial sediments to be sampled. Samples of bedrock and glacially altered rock and sediments were collected from Robertson Glacier. Infrared laboratory spectra of these samples were collected and used to determine the composition and abundance of minerals in rock and sediment samples, with a primary focus on differentiating weathering products. These spectra were then correlated to multispectral images taken by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) satellite instrument. Initial results from both laboratory and ASTER data indicate the presence of weathering products. Laboratory spectra of field samples are promising in that major bedrock mineral assemblages and a variety of alteration products can be identified. However, more mineralogical work is required to refine the types of weathering products present in the system.

Rutledge, A. M.; Christensen, P. R.; Havig, J. R.

2011-12-01

471

V00306010057 rock check dam  

E-print Network

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472

Classification of rock bursts  

SciTech Connect

The authors provide classification criteria for rock bursts based primarily on three features: the location of the focal zone of a rock burst relative to the mine; the reciprocal interaction of a rock burst and the existing tectonic structure in the part of the bed experiencing the rock burst; and the distribution of rock bursts according to the energy released by the dynamic event, including the results of the event over the area and in the volume of the surrounding rocks. Their mathematical formulations for different classes of rock bursts take into account the effects of small earthquakes, the configuration of the stope and support pillars, and the stress and deformation behavior of the coal along with other considerations.

Shemyakin, E.I.; Kurlenya, M.V.; Kulakov, G.I.

1987-07-01

473

Weathering processes as predisposing factors of the landscape evolution along plutono-metamorphic profiles of the Sila Massif, Calabria, southern Italy  

NASA Astrophysics Data System (ADS)

This work is aimed to join interdisciplinary research topics of weathering profile stages on plutonic (granitoid) and metamorphic (gneissic) rocks related to tectonic and landscape evolution of the western Sila Grande Massif (southern Italy). The grain-size of the studied samples is related to the parent rocks in response to physical and chemical weathering processes. Weathering processes produce an unconsolidated rock characterized by sand-gravel grain-size fraction for the granitoid rocks and by sand-silt grain-size fraction for the gneissic rocks. Chemical and mineralogical analyses confirm the granulometric observations. The difference between granitoid and gneissic rocks are mainly related to a higher content of quartz and feldspars for the first one rock type, whereas the second rock type shows higher content of neoformed clay minerals as well expandable phases. The main mineralogical changes concern the partial transformation of biotite and the partial destruction of feldspars, associated with the neoformation of secondary minerals (clay minerals and Fe-oxides) during the most advanced weathering stage; these processes also produce a substitution of the original rock fabric. All these petrological, chemical and mineralogical observations associated to microfractures and morphological variations occur on both plutonic and metamorphic original rocks and, thereby, affect the surrounding landscape processes. Generally, the granitoid profiles are regular and simple, characterized by gradual variation in the degree of weathering from bottom to top; where granitoid rocks show strong morphologies characterized by high relief energy and steep slopes, earth and debris slides, soil slips and earth flow can occur especially when fresher granitoids is near the surface and is covered by organic debris, colluvium, or soil. The gneissic profiles are characterized by structural complexity may be related to several factors such as presence of faults, high state of fracturing and the compositional heterogeneity of the gneiss. These profile characteristics are strongly related to the tectonic setting of the studied area. In particular, many fractured zone associated to fault planes and completely degraded rocks associated to thrust planes have been observed along the cutslope studied, where physical and chemical weathering produce argillified levels. These profile features represents a predisposing factor to the development of mass movements such as deep landslide (e.g., rock slide) and DSGSD (Deep Seated Gravitational Slope Deformation) in the fresher rocks. The weathering puzzle resulting from this preliminary study, based on the reconstruction of the weathering profiles in the plutonic and metamorphic rocks will help to evaluate the landslides susceptibility and hazard assessment in homogeneous geological context.

Perri, Francesco; Borrelli, Luigi; Muto, Francesco; Gullà, Giovanni; Critelli, Salvatore; Conforti, Massimo; Filomena, Luciana; Rago, Valeria

2013-04-01

474

Conversion of bedrock to soil and feedback processes between the surface and the weathering front in a deeply weathered regolith, Central Sri Lankan Highlands  

NASA Astrophysics Data System (ADS)

In the Sri Lankan highlands denudation rates and chemical weathering rates represent the low-end-member in global weathering rates [1, 2]. Here we explore the causes for these low rates by a detailed soil-mineralogical study of a highly weathered deep saprolite profile developed from charnockite bedrock. Spheroidal weathering of the bedrock characterized the weathering front where rounded corestones are produced at the rock-saprolite interface. The first mineral attacked by weathering was found to be pyroxene but plagioclase is the first mineral depleted to near-completion at the corestone-saprolite-boundary. Weathering of pyroxene is initiated by in situ iron oxidation, leading to an increase of porosity due to micro-cracking [3]. The accrued micro cracks allow for fluid transport and the dissolution of biotite and plagioclase. The strong plagioclase weathering leads to formation of high secondary porosity over a small distance and the final disaggregation of bedrock to saprolite. Sequential extraction showed that the first secondary phases are amorphous oxides from which secondary minerals (gibbsite, kaolinite, goethite and minor amounts of smectites) precipitate. Modeling of the strain formation due to increasing volume during iron oxidation in pyroxene and biotite showed that spheroidal weathering can be explained with this process only if the formation of secondary porosity, due to a negative volume budget during primary mineral weathering to secondary phases, occurs. As oxidation is the first occurring reaction, O2 is a rate limiting factor for chemical weathering in this setting. Hence the supply of oxygen and the consumption at depth connects processes at the weathering front with those at the surface as a feedback mechanism. Advective and diffusive transport modeling shows that the feedback will be much more pronounced with dominating diffusive transport. Due to the low porosity of the bedrock the O2 transport in the pristine bedrock occurs via diffusion. The slow weathering rate is, beside tectonic quiescence, related to this feedback and to lithological factors such as low porosity and the amount of Fe-bearing primary minerals. 1. Hewawasam, T., et al., Slow advance of the weathering front during deep, supply-limited saprolite formation in the tropical Highlands of Sri Lanka. Geochimica et Cosmochimica Acta, 2013. 118: p. 202-230. 2. von Blanckenburg, F., T. Hewawasam, and P. Kubik, Cosmogenic nuclide evidence for low weathering and denudation in the wet tropical Highlands of Sri Lanka. J. Geoph. Res., 2004. 109: p. doi10.1029/2003JF000049. 3. Buss, H.L., et al., Weathering of the Rio Blanco quartz diorite, Luquillo Mountains, Puerto Rico: Coupling oxidation, dissolution, and fracturing. Geochimica et Cosmochimica Acta, 2008. 72(18): p. 4488-4507.

Behrens, Ricarda; Bouchez, Julien; Schuessler, Jan A.; Dultz, Stefan; Hewawasam, Tilak; von Blanckenburg, Friedhelm

2014-05-01

475

National Severe Storms Laboratory's Weather Room  

NSDL National Science Digital Library

This educational website from NOAA has: facts on tornadoes, hurricanes, lightning and thunderstorms; lessons on weather symbols, maps and systems; an extensive list of weather and climate resources for teachers; information on careers in weather; and a list of weather links including weather data. Additionally, the site includes all the latest meteorological research including tornado genesis and lightning.

2010-08-06

476

How Do Meteorologists Forecast the Weather?  

NSDL National Science Digital Library

This is a lesson that I developed where students learn how meteorologists predict the weather. Students will use surface weather maps, radar, satellite, and weather models from the National Weather Service to assess the current state of the weather and make a prediction.

David Faysash

2012-07-30

477

Space Weather Action Center  

NSDL National Science Digital Library

This is a revised "Tracking a Solar Storm-Student Observation Network" with a new format and Web site. The Space Weather Action Center (SWAC) allows students to use near real time data and track a solar storm. By following the basic steps in the Instructional Guide students can access, analyze and record NASA satellite and observatory data. There is a downloadable 'step-by-step' Educator's Setup Guide where you will find a variety of recommendations and diagrams detailing how to construct a fully functional SWAC while keeping potential limitations on space and technology in mind. Flip charts provide the step by step data use and there are also instructions for using green screen technology.

2009-01-01

478

Severe Weather: Hurricanes  

NSDL National Science Digital Library

Severe Weather: Hurricanes is part of an on-line series of modules entitled Exploring the Environment. Emphasizing an integrated approach to environmental Earth Science education through problem-based learning, this module asks student groups to track an actual (past) hurricane. Background information explains how hurricanes occur, how they are named, and the Saffir-Simpson Intensity Scale. Activities train groups on how to track hurricanes. Once they are given an actual hurricane to track, students must determine the speed of its movement and where it will come ashore. There are extension activities, a glossary of terms, teacher resources, a reference for the problem-based learning model, and links to additional resources.

479

Supporting Weather Data  

NASA Technical Reports Server (NTRS)

Since its founding in 1992, Global Science & Technology, Inc. (GST), of Greenbelt, Maryland, has been developing technologies and providing services in support of NASA scientific research. GST specialties include scientific analysis, science data and information systems, data visualization, communications, networking and Web technologies, computer science, and software system engineering. As a longtime contractor to Goddard Space Flight Center s Earth Science Directorate, GST scientific, engineering, and information technology staff have extensive qualifications with the synthesis of satellite, in situ, and Earth science data for weather- and climate-related projects. GST s experience in this arena is end-to-end, from building satellite ground receiving systems and science data systems, to product generation and research and analysis.

2004-01-01

480

The Weather Calculator  

NSDL National Science Digital Library

This collection of resources, provided by the National Weather Service Forecast Office for the El Paso area, allows users to be their own meteorologists. For example, armed with data such as current temperature, humidity, and windspeed, users may calculate the heat index or wind chill. Using the resources on this page, and providing basic meteorological data such as temperature, air pressure, and dew point, users can calculate such things as the vapor pressure, maxing ratio, or density altitude. This site also provides unit conversion calculators, allowing users to convert temperatures, air pressures, and wind speeds into various units. For some of the conversions, this site presumes its users to have an understanding of meteorological terms and to be able to read basic meteorological instruments.

1969-12-31