precambrian geology - exam 3

Question 1

archean granite

Answer 1

greenstone formation

Question 2

granite and gneiss

Answer 2

continental material

Question 3

greenstone

Answer 3

metamorphosed basalts

Question 4

differences between modern and precambrian plate tectonics?

Answer 4

-heat production
-more melting
-smaller continental blocks
-faster mantle convection

Question 5

differences between modern and precambrian conditions?

Answer 5

organisms (w/o hard parts), archean had oxygen poor atmosphere, formations of banded iron (bif)

Question 6

the most early evidence of life

Answer 6

stromatolites (algae)

Question 7

the first large, complex, multicellular, soft bodied organisms were discovered in the

Answer 7

ediacaran period (latest precambrian)

Question 8

-ice covers the entire earth
-multiple neoproterozoic glaciations
-prior to the ediacaran period

Answer 8

snowball earth

Question 9

ice covers the entire earth

Answer 9

snowball earth

Question 10

equatorial waters contain ice but not frozen solid

Answer 10

slushball earth