Earth Science

4. / Hadean, Archean, Proterozioc Eons are commonly referred to as this
6. / The largest time units
7. / This Era contains fossils of early life forms, such as invertebrates, fishes, amphibians, reptiles & ferns
9. / A nearly complete composite record of geologic time
10. / Sedimentary rocks deposited without interruption
11. / The process of determining the absolute age of rocks, minerals & fossils.
12. / Unconformity in which sedimentary rocks lie on igneous rocks.
13. / Age in years
17. / Correlated rocks from many localities around the world.
19. / Eons divide into ______

1. / Thin, widespread sedimentary layer that deposited rapidly.
2. / The time it takes for half of the atoms in a radioactive sample to decompose
3. / Measurement refers only to the order in which events occurred
4. / Eras that are subdivided
5. / Remains and other traces of prehistoric life preserved in rocks.
8. / Tectonic activity titled older sedimentary rock layers, & erosion planed the off, before younger sediment accumulated
14. / States that life forms have changed throughout geologic time
15. / Atoms of the same element with different numbers of neutrons.
16. / This Era is when mammals and grasses became abundant.
18. / Matched rocks of the same age from different localities