Geological Record CW 1

4. a solid copy of the shape of an organism
5. fossils in which minerals replace all of an organism, or a part, such as a dinosaur bone
8. the geologic principle that states that in horizontal layers of sedimentary rock, each layer is older than the layer above it and younger than the layer below it
10. a standard time scale of the geologic events and life forms in Earth’s history
11. a break in Earth’s crust long which rocks move
12. the process of measuring the absolute age of geologic material by measuring the concentrations of radioactive isotopes and their decay products
13. a hollow area in sediment in the shape of an organism or part of an organism
14. a drill core of ice that can help tell the climates of the past
15. fossils of widely distributed organisms that lived during a geologically short period
16. the time it takes for half of the atoms of a radioactive element to decay
19. these fossils provide evidence of the activities of ancient organisms
22. the age of rock compared to the ages of other rock
23. rock that forms when melted material hardens inside Earth or on the surface
24. type of fossil that is an extremely thin coating of carbon on rock

1. when many types of living things become extinct at the same time
2. an igneous rock layer formed when lava flows onto Earth’s surface and hardens
3. a gap in the geologic record that shows where rock layers have been lost due to erosion
6. the age of a rock given as the number of years since the rock formed
7. scientists who study fossils
9. A description of surface features of land.
17. a bend in rock that forms where part of Earth's crust is compressed
18. an igneous rock layer formed when magma hardens beneath Earth’s surface
20. a term referring to all water that is temporarily frozen in polar ice caps, snow, permafrost, and glaciers
21. the process in which the nuclei of radioactive elements break down, releasing fast-moving particles and energy