Across
- 4. the predictable time an element takes to decay
- 7. Era that saw the rise of marine plants and invertebrates, fish, ferns, and amphibians
- 8. largest division in the Geologic Time Scale
- 9. sedimentary rock layers
- 12. era that was the time of the dinosaurs and the development of small mammals, birds, conifers, and flowering plants
- 13. the smallest and most specific division in the Geologic Time Scale
- 14. special fossils that indicate to geologists the boundaries in geological time
- 15. the largerst eon in the Geologic Time Scale
- 17. the next to the smallest division of the Geologic Time Scale
- 18. branch of geology dealing with the arrangement of sedimentary rock layers
- 19. history of life as documented by all fossils, preserved in sedimentary rock strata
Down
- 1. a scientist who studies the Earth’s crust as well as the processes and history that shaped it
- 2. a scientist that studies fossil remains found on the Earth’s surface in order to study primitive life forms
- 3. determines the order of past events but not the absolute age.
- 5. era in which we live, as well as large mammals and periodic ice ages
- 6. the assumption that the newest rock layers are on top of the older ones, unless some type of disturbance occurs
- 10. most accurate form of dating, also call radiometric dating
- 11. preserved remains or traces of animals, plants, and other organisms from the remote past
- 16. division in the Geologic Time Scale in which the eon is divided