science

4. the numeric age of a layer of rocks or fossils
5. any fault lines or intrusions that cut across a set of rock strata must be younger than that set of rock
10. a non-living part of an ecosystem that shapes its environment
11. when species vanish much faster that they are replaced
12. a surface of contact between two groups of unconformable strata
13. the change in the characteristics of a species over several generations

1. the branch of science concerned with fossil animals and plants
2. living things within an ecosystem
3. preserved paths of animals that crawled on and bored or burrowed into the seafloor
6. the age of a rock layer compared to other layers
7. depicts layers of different rocks, with the oldest at the bottom and the youngest at the top
8. a large natural or artificial lake used as a source of water supply
9. the mold of an organism in a rock