Wards1-100
Wards1-100(contued)
Wards101-130 Wards131-160
Wards131-160(continued)
Wards161-190 Wards191-200
Wards
Collection
131-160
(Continued)
Wards1-100
Wards1-100(contued)
Wards101-130 Wards131-160
Wards131-160(continued)
Wards161-190 Wards191-200
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Siltstone Location: Collinsville, IL Description: "a sedimentary rock composed of substantial, but variable, amounts of silt-size grains. The name is applied to rocks of varying structure, including laminated, fissile, nonlaminated, and nonfissile rocks."
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Chalcedony Location: Tampa Bay, FL Description: "Chalcedony is the name given to compact varieties of silica which comprise minute quartz crystals with sub-microscopic pores. There are two main varieties: chalcedony, which is uniformly colored, and agate which is characterized by curved bands or zones of differing color."
http://www.hf.uio.no/iakk/roger/lithic/chal.html |
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Diffusion Dolomite Location: Fremont County, CO Description: Acording to Loren Raymond, "diffusion refers to the migration of chemical species through magma in respounce to differences (gradients) in pressure, temperature, or chemical state."
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Welded Tuff Location: Inyo County, CA Description: "a banded or streaky pyroclastic rock, indurated by the combined action of the heat retained by the particles, the weight of overlying material, and hot gases."
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Marble breccia Location: Madoc, Ontario, Canada Description: breccia refers to a coarse clastic rock composed of angular fragments of older rocks that are cemented together in a fine matrix; formed in a number of ways from a variety of materials. In this sample those broken-up materials consist of marble fragments which are metamorphosed limestone.
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Flint Location: Dover, England Description: N/A
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Travertine Location: Trivoli, Italy Description: composed almost exclusively of calcium carbonate. |
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Volcanic Ash Location: Mt. St. Helen's, Washington Description: "volcanic ash in the air is composed of fine pulverised rock and accompanied by a number of gases which are then converted into droplets of sulphuric acid and hydrochloric acid."
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Novaculite Location: Hot Springs, AR Description: "a light-colored, dense, hard, fine-grained, even-textured siliceous sedimentary rock characterized by the dominance of microcrystalline quartz over chalcedony."
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Chalk Location: Dover, England Description: a soft, earthy, friable, porous, light-colored limestone. |