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deposit
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crevasse deposit
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Bedding
Bedding The term bedding (also called stratification) ordinarily describes the layering that occurs in sedimentary rocks and sometimes the layering found in metamorphic rock . Bedding may occur when one distinctly different layer of sediment is deposited on an older layer, such as sand and... Read more |
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period
period unit of time on the geologic timescale . Periods are shorter than an era and longer than an epoch. Periods are of variable length, generally lasting tens of millions of years, with characteristic fossils found preserved in the sediments deposited during the period. It is also used to... Read more |
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brownstone
brownstone red to brown variety of sandstone . Its unusual color is caused in some instances by the presence of red iron oxide which acts as a cement, binding the sand grains together. Vast thicknesses (up to 20,000 ft/6,096 m) of brownstone were deposited in the present-day Connecticut River... Read more |
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pentlandite
pentlandite , yellowish-bronze, opaque mineral, a sulfide of iron and nickel, (Fe,Ni) 9 S 8 . It is found in masses nearly always associated with the iron sulfide pyrrhotite. The largest deposit of this important ore of nickel is at Sudbury, Ont. Important deposits are mined in Manitoba, Russia, and... Read more |
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Old Red Sandstone
Old Red Sandstone series of red and brown sandstones, conglomerates, and shales deposited in Wales and Scotland and in England near the Welsh and Scottish borders in the Devonian period of geologic time. The Old Red Sandstone, in contrast to the typical formations of the Devonian, is largely a... Read more |
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fossil fuel
fossil fuel All deposits of organic material capable of being burnt for fuel; chiefly coal, oil, and gas. These are formed under pressure by alteration or decomposition of plant or animal remains.... Read more |
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varve
varve in geology, pair of thin sedimentary layers formed annually by seasonal climatic changes. Usually found in glacial lake deposits, varves consist of a coarse-grained, light-colored summer deposit and a finer-grained, dark-colored winter deposit formed when fine sediment settles out from the... Read more |
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fossil
fossil remains or imprints of plants or animals preserved from prehistoric times by the operation of natural conditions. Fossils are found in sedimentary rock, asphalt deposits, and coal and sometimes in amber and certain other materials. The scientific study of fossils is paleontology . Not... Read more |
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The world's oldest early human skeleton is unearthed in Ethiopia
...proves the creature walked upright...1974. The new find seems...species, were found last month...geological deposit, Mille, 37...where Lucy was found. Yohannes...Selassie, the Ethiopian palaeo-anthropologist who ... |