The River Loop Trail at Black Hawk State Historic Site in Rock Island, Illinois, has exposures revealing nearly 130 million years of geologic history. At the base of the hill is Devonian-aged limestone containing brachiopods and bryozoans. Above the limestone is Pennsylvanian-aged shale, with an unconformity between the two. The black shale is rich with fossils of ferns and marsh grasses. Directly on top of the shale is Pennsylvanian-aged sandstone. Using the geologic materials described, determine the environment of deposition for each unit. How has the overall environment changed from the Devonian to the end of the Pennsylvanian?
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Geography, 23.06.2019 11:00, anasfis35ovmbff
This diagram show the most important texts of.
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Geography, 23.06.2019 17:30, hhugfatqtyc
Good scientists always report their observations and results truthfully. this is especially important when a scientist's results go against previous ideas or predictions. coming up with inventive ways to solve problems or produce new things
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The River Loop Trail at Black Hawk State Historic Site in Rock Island, Illinois, has exposures revea...
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