1. Chapter 29 Studying the Past Paleontology Fossils Let’s talk about the types……… The study of life that existed in prehistoric times Preserved remains of a plant or animal

2. Original remains Replaced remains Original and unchanged remains of a plant or animal preserved in a rock – Amber is an example (animals caught in sticky tree sap Minerals in groundwater replace the decaying plant or animal – like petrified wood!

3. Cast Mold A copy of the original fossil A depression in a rock of the original fossil

4. Trace fossilsImpressions such as footprints, tracks, burrows or bite marks

5. Relative Time Relative dating Strata - Placing events in a sequence in which they occurred Layers of the Earth

6. Basics….. Law of SuperpositionThe oldest layers of rock will be on the bottom and the youngest strata or layers will be on top

7. Principle of Cross Cutting Relations The igneous intrusion that cuts across layers of rock is always younger than the layers it cuts

8. Law of Embedded Fragments The fossils or fragments of rock that are embedded in a layer are OLDER - because they existed before

10. CorrelationThe matching of rock layers

11. CorrelationThe matching of rock layers

12. UnconformityA missing layer in the rock strata

13. Absolute Time Radioactive Decay Half-Life Radiocarbon Decay – Carbon – 14 dating The decay of radioactive isotopes, emitting tiny particles The time it takes ½ of a radioactive atoms to decay Using the isotope Carbon 14 to date organic material; half life of c-14 is 5,730 years