What information can be gained from a study of sedimentary rocks?
1. Sedimentary rocks are classified as fragmental, chemical, or organic, depending upon how they were formed. Most sedimentary rocks are formed originally in horizontal layers. 2. Fragmental sedimentary rocks are classified on the basis of grain size. 3. Organic and chemically formed sedimentary rocks are primarily identified through composition and texture. 4. Fossils in sedimentary rocks provide good evidence of the environment in which they formed. D. What can we learn by investigating metamorphic rocks? 1. It is possible to infer the parent rock from the mineral composition and structure of most metamorphic rocks. (ex. Shale-slate, limestone-marble, sandstone-quartzite) 2. Contact metamorphism occurs when molten rock comes in contact with surrounding rocks. Transition zones can be identified from unaltered to altered to unaltered rock. 3. Regional metamorphism occurs over large areas, and is generally associated with mountain building. 4. Metamorphic rocks are classified according
