1. DO NOW Geologic Time

2. DO NOW 1. Superposition –C–C 2. Absolute dating –B–B 3. Relative dating –A–A 4. Geologic column –D–D A. Finding if a rock layer is older or younger than the layers around it. B. Finding the exact age of an object using unstable atoms C. The idea that younger rock lies above older rock. D. Detailed series of rock layers of all known fossils and rock formations from around the world.

3. DO NOW 1. Explain the four features of an index fossil. – Found worldwide – Abundant – Easily recognizable – Alive for only a short period of geologic time 2. PURPOSE of an index fossil? – used to date the layer the index fossil is found in. 3. What is the index fossil of the Paleozoic Era? – Trilobite

4. DO NOW What do fossils show scientists? – 1. What Earth and its environment was like in the past. – 2. How Earth and its environment have changed over time. – 3. What organisms lived in the past. – 4. How organisms have changed with time.

5. DO NOW 1. What is a trace fossil? – Give three examples – Footprints, burrows, droppings 2. What is a body fossil? – Give three items that may become a body fossil Bones, teeth, shells

6. DO NOW – 1. Cast fossil F – 2. Mold fossil D – 3. Petrified fossil A – 4. Preserved remains C – 5. Carbon films G – 6. Fossil B – 7. Index fossil E A. When minerals replace all or part of an organisms tissues, such as bone or wood. B. The trace or remains of an organism that lived long ago, most commonly preserved in sedimentary rock. C. When animals are preserved in or close to their natural state as in amber, tar, or ice. D. An impression or imprint of an organism in sediment which turns to rock. E. A fossil that is used to establish the age of a rock layer F. Formed when sediment fills an impression made by an organism and becomes rock. G. Thin layer of carbon from the organism left behind in the rock.