1. Correlation and Fossils WOOHOO!

2. Applying Principles of Relative Dating to Determine Geologic History of an Area The process of matching rocks or geologic events occurring at different locations of the same age is called The process of matching rocks or geologic events occurring at different locations of the same age is calledCORRELATION

4. Correlation of rock layers often relies upon fossils William Smith (late l700’s) noted that rock layers in widely separated areas could be identified and correlated by their distinctive fossil content William Smith (late l700’s) noted that rock layers in widely separated areas could be identified and correlated by their distinctive fossil content This led to the "principle of fossil succession“ This led to the "principle of fossil succession“succession Fossils succeed one another in a definite and determinable order, and therefore any time period can be recognized by its fossil content Fossils succeed one another in a definite and determinable order, and therefore any time period can be recognized by its fossil content

5. Index Fossils Index fossils - any animal or plant that is characteristic of a particular span of geologic time or environment. Index fossils - any animal or plant that is characteristic of a particular span of geologic time or environment. 2 criteria must be met 2 criteria must be met Life form lived over a wide geographic area – horizontal distribution Life form lived over a wide geographic area – horizontal distribution Life form existed for a short period of time – short vertical distribution Life form existed for a short period of time – short vertical distribution

6. NYS Index Fossil

7. Again….Corellation… Correlation- or CO-RELATION (two or more things related) is a critical tool in the reconstruction of Earth’s history. Correlation- or CO-RELATION (two or more things related) is a critical tool in the reconstruction of Earth’s history. Geologists look for a sequence of rocks (an “order”) that is the same in two or more areas, and can therefore say they are the same age! Geologists look for a sequence of rocks (an “order”) that is the same in two or more areas, and can therefore say they are the same age! Let’s check it out!! Let’s check it out!!