Across
- 2. dating a method used to determain the age of rocks by comparing them
- 4. Record The totality of fossilized artifacts and their placement within the earth's rock strata
- 5. ions, or molecules and having fixed distances between constituent parts
- 7. is the large span of time in Earth's history
- 10. explostion the relatively rapid appearance, around 542 million years ago, of most major animal phyla, as demonstrated in the fossil record
- 11. crystals A homogenous solid formed by a repeating, three-dimensional pattern of
- 12. the current Phanerozoic Eon
Down
- 1. time scale a system of chronological measurement that relates stratigraphy to time, and is used by geologists
- 3. tectonics The outermost crust of the Earth is cracked into several large pieces called plates that average 50 miles thick.
- 6. the earth
- 8. The gaseous mass or envelope surrounding a celestial body, especially the one
- 9. life the time taken for half of the atoms in a radioactive material to undergo decay