One of the principal objectives of geologists studying sedimentary rocks is the reconstruction of the environment in which the rocks were deposited. Correct reconstruction may result in the discovery of oilfields, deposits of salts, or base metals, and provide insight to our earth's past. As evidence to ancient environments the geologist has the structures, textures, and composition of the grains that make up the sediments, and the fossils preserved in them. Organisms are far more …showed first 75 words of 1083 total…

…showed last 75 words of 1083 total…fossil species are extinct, and their tolerances are not directly known. Comparing the morphology of the fossils to those of modern organisms can often lead to conclusions concerning their adaptation to a specific climate. For example, the plants of tropical rainforests have large leaves with tips shaped for dripping moisture, and large breathing pores; these features in extinct fossil plants, such as those of the coal forests, are interpreted as indicative of warm, moist climates.