GL102 Final: Geology Exam Notes
Document Summary
Recognized the immensity of earth"s history in the late 1700"s. Demonstrated earth had many mountain building episodes. Arranged pub"n of darwin and wallace"s work. Relative dating: rocks are placed in their proper sequence of formation. Doesn"t give us the age of rocks, only order. In an undeformed sequence of sedimentary rocks, each bed is older than the one above it, and younger than the one below it. All surface-deposited materials: lava flows, ash bends and sediments thus sedimentary rocks. Rock layers that are flat have not been disturbed. Younger features (dykes, faults) cut across older features (pre-existing rocks) Fragments of one rock unit that have been enclosed within another. The rock containing the inclusions is younger than the inclusion itself. Break/gap in the record caused by erosion and/or non-deposition of rock units (if no breaks, rocks are considered confortable) Unconformities represent significant geological events in earth"s history.
