pg. 249 ?'s 1-5

1) Describe they typical conditions necessary for fossil formation. one way is for a dead organism to become a fossil is they have hard parts such as bones, shells, or teeth.

2) Explain how a fossil mold is different from a fossil cast. mold- the cavity in the rock. cast- a mineral rich water of other sediments might enter the cavity, form a new rock, and produce a copy

3) How are the characteristics of an index fossil are useful to geologists. it is a way to approximate the ages of rock layer.

4) Describe how carbon films form. Fossils usually form when sediments bury a dead organism. As sediment piles up, the organism's remains are subjected to pressure and heat. These conditions force gases and liquids from the body. A thin film of carbon residue is left, forming a silhouette of the original organism.

5) What can you say about the ages of two widely separated layers of rock that contain the same type of fossil? I think that maybe history repeated its self and there was another ice age or some other period of time where the same kind of animal or organism died and the remains were left in the ground.