GENERAL GEOLOGY

Detailed explanation-1: -Reason for sedimentary rocks to be the only rock type to contain fossils: The dead plants and animals, where they are buried by more sediment results in the accumulation of minerals from water in bones which leads to formation of fossils. This makes sedimentary rocks the only rock type to contain fossils.

Detailed explanation-2: -Fossils are typically found in sedimentary rocks and occasionally some fine-grained, low-grade metamorphic rocks. Sometimes the fossils have been removed, leaving moulds in the surrounding rock, or the moulds may have later been filled by other materials, forming casts of the original fossils.

Detailed explanation-3: -Fossils are formed when a plant or animal dies. Their soft tissues decomposes quickly, leaving the hard bones or shells behind. Over time, sediment builds over the top and hardens into rock. Therefore, one may find fossils in sedimentary rocks.

Detailed explanation-4: -Fossils are commonly found in sedimentary rocks. Sedimentary rocks are the most common type of rock since they are formed by the earth’s natural forces like wind and water. Q. Sometimes igneous and sedimentary rocks are changed into metamorphic rocks.

Detailed explanation-5: -Fossils are most common in limestones. That is because most limestones consist partly or mostly of the shells of organisms. Sometimes, however, the shells are worn so much that they look like sediment grains rather than “real” fossils. Fossils are also common in shales, which form from muds.