BIOL 1001 Chapter : 31a828feab6845f86d0ca58b0f048681
Document Summary
Present is the key to the past. Look at rock records and determine geologic history. Gaps in time in the rock record. Period of erosion: angular unconformity, non-conformity. Deposited rocks on top of intrusive igneous or metamorphic rocks. If rock layers aren t horizontal, they must be deformed. Layers that are on the bottom are older than those on top. Sedimentary rocks and extrusive igneous rocks (volcanic) If one geologic feature cuts another, the one being cut is older. Rock that has been baked is older than the intrusion. Rock that contains an inclusion must be younger than the inclusion. Determine the relative age of successive geologic events. Deposition of sedimentary rocks or volcanic rocks. Layers are parallel: principle of fossil successions, definition. Once an organism is extinct, its fossil will not appear in a younger rock. Find paleogeography => what the landscape looked like at different times.
