Why are ultramafic volcanics rare in rocks that are much younger ...

[jasdeep_brar]

Why are ultramafic volcanics rare in rocks that are much younger than Archean in age?

Question 2

Which statement about caves is false?
 A)They form underwater.
 B)They are formed by deposition of calcium carbonate.
 C)They form naturally and are open to the surface.
 D)The majority of caves are small.
 E)They are commonly found in regions with karst topography.

[leeeep]

Answer to Question 1

Earth has cooled from its early stages because radiogenic heat production decreased. The Archean near-surface temperatures have not been high enough for ultramafic magma to reach the surface.

Answer to Question 2

B

[jasdeep_brar]

Thanks for the timely response, appreciate it

[alvinum]

Gracias!