1. Studying Earth’s History. UNIT 7 STUDY GUIDE

2.  Due to continental drift, tectonic plates move causes Earth’s surface to change. Some effects 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. GEOLOGIC CHANGE OVER TIME

3.  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. DATING ROCKS & FOSSILS