Unit 4 vocab

2. when one geologic structure cuts through another
3. the action or process of flowing or flowing out
4. a non-living part of an ecosystem that shapes its environment
5. depicts layers of different rocks, with the oldest at the bottom and the youngest at the top
7. the numeric age of a layer of rocks or fossils
8. a fossil of a footprint, trail, burrow, or other trace of an animal rather than of the animal itself.
12. a supply or source of something
14. a living organism that shapes its environment
16. any animal or plant preserved in the rock record of the Earth
17. one of the principles of geology scientists use to determine the relative ages of rock strata, or layers
19. a process of continuous change from a lower, simpler, or worse to a higher, more complex, or better state
20. the synthesis of organic compounds by bacteria or other living organisms using energy derived from reactions involving inorganic chemicals, typically in the absence of sunlight.

1. A mass extinction is a short period of geological time in which a high percentage of biodiversity, dies out.
6. The time required for one-half of the radioactive (parent) isotopes in a sample to decay to radiogenic (daughter) isotopes
9. a surface of contact between two groups of unconformable strata.
10. the remains or impression of a prehistoric organism preserved in petrified form or as a mold or cast in rock.
11. the theory that changes in the earth's crust during geological history have resulted from the action of continuous and uniform processes.
12. Radiometric dating calculates an age in years for geologic materials by measuring the presence of a short-life radioactive element
13. the branch of science concerned with fossil animals and plants.
15. the approximate age of a specific rock layer
18. the process by which green plants and some other organisms use sunlight to synthesize foods from carbon dioxide and water