Earth History & Fossil Formation

16. This is a type of fossil where minerals seeped into the open pores or wood and become solid

19.Our current era is?

6. This is a type of tree sap that hardens and cool

24. What period occurred around  210 my ago?

11.Pangaea is

9. Half life is the amount of time it take for half the atoms in an isotope to decay.

25.What era did land plants first appear on land?

22. Stromatolites are made up of a type of bacteria called

23.Who is this person?

10. Uniformitarianism states that

7. What type of rock do fossils commonly form in? What rock are they less likely to form in?

14. Dinosaurs developed during the Paleozoic era

4. Which type of fossil shows an impression of the organism in rock?

2. A _____________________ studies fossils and other living things from long ago.

15. Tree rings and ice cores can tell us

17. The actual age of an event or object is called its 

5. Original remains can be found in

1.______________________________ are the preserved remains or traces of once living things.

20.What was the worlds greatest mass extinction?

8. What is relative dating?

18. A rock has %25 of its original Uranium-235. Each half-life is 1.4 my. How old is the rock?

21." The size of the footprint tells me it could be as big as 2 tons." Is this an inference?

12.Geologic time is divided up based on when major events or changes occured

13. What layer of rock is the oldest?

3. Which type of fossil show evidence of movement or activity?