Download Unit 7 Study Guide

UNIT 7 STUDY GUIDE
Studying
Earth’s
History.
GEOLOGIC CHANGE OVER TIME
 Due to continental drift, tectonic plates move causes Earth’s
surface to change. Some ef fects of this change:
 Mountains are created and eroded, The sea floor spreads as
new rock pushes up to create ocean ridges. Layers of rock are
disturbed causing them to be tilted, folded, eroded to form
uncomformities, broken to form faults, and intrusions where
magma pushes upwards and cuts through layers of rock.
 Evidence of these changes are provided when Fossils are
found in areas they can no longer live. The composition or
texture of sedimentary rock also provides clues to where the
sediment originated.
DATING ROCKS & FOSSILS
 Relative ages of rock simply tell us whether an object is older
or younger but DOES NOT provide an actual age. This is done
by applying the law of superposition.
 Absolute Dating using mostly Igneous rocks to determine the
actual age of an object or event in numbers.