EARTH 7 Lecture Notes - Lecture 3: Siccar Point, James Hutton, Relative Dating
Document Summary
Note taker: deanna coughlin (714) 235-7896; deannajasmine@yahoo. com lecture 3: Deep time: no vestige of a beginning, no prospect of an end. Time is so immense, we cannot even fathom. Uniformitarianism: the present is the key to the past: uniformitarianism. Physical processes observed today operated in the geological past. Show processes acting over immense time have helped shape earth"s surface. Modern processes help us unravel ancient events: cross-cutting relationships. A rock unit is older than any feature that cuts or disrupts it. Dyke= disruptor, always younger: erosional contact (unconformity): siccar point. One layer of rock tilted in some way, others on top of it. Passage of millions of years: faunal succession (5th relative dating principle) Discovered it was always the same species of rock. Each group of organisms lived during a discrete time interval. This order is preserved in the rock record. What you really need to know about rocks. Igneous rocks form when melts cool down and become solids.
