Geologic Time Flashcards
processes observed today were the same in the past
Uniformitarianism
Sedimentary rocks laid out in horizontal pattern and gravity causes it to even out; does not accumulate on a slop ; tilted rocks mustve been deformed
Principle of original horizontality
Rocks in an undeformed horizontal sequence
oldest on the bottom and youngest on top
principle of superstition
Younger features cut across older features
Principle of cross cutting relationship
rock fragment within another; xenoliths older rock (foreign rock)
principle of inclusions
3 unconformities
angular, disconformity, and nonconformity
at an angle, gap between the angle and horizontal shows huge gap of time
Angular unconformity
igneous/metamorphic rock capped by sedimentary rocks
rocks forming inside mountains
nonconformity
Parallel that are bounded by either side
stops depositing sediment changes in sea level caused
disconformity
used bible to figure how old earth was
Archbishop james usher
Scottish physician and farmer that used principle of uniformitarianism
James Hutton