Across
- 4. bones, teeth, and shells can be preserved this way
- 7. 'recent life', what earth looks like today
- 8. this happens when water dissolves the original solid material and replaces them with mineral matter such as calcite,silica, pyrite,and hematite
- 9. petrified wood is the most well known of this process
- 13. the earliest era between the three; where life first started on earth
- 15. special fossils called this indicate to geologists the boundaries in geologic time
Down
- 1. most accurate form of dating, also called radiometric dating
- 2. this law helps scientists determine the age of fossils,relatively speaking
- 3. the process by which all substances of plants and animals decay,except carbon
- 5. having no living members; no longer in existence
- 6. if two different rock strata in different areas on Earth contain the same index fossils,then the strata are probably the same age
- 10. this can trap animals and preserve their bodies to where we can see it today
- 11. provides indirect evidence of life in the past rather than the body of the animal itself
- 12. this is excreted from certain plants, which is thought to protect them from insects and seals off plant injuries
- 14. dinosaurs lived in this era