8. occurs at ocean ridges, whereas occurs at subduction zones.

a. flux melting; decompression melting

b. decompression melting; flux melting

c. formation of intrusive rocks; formation of extrusive rocks

d. formation of extrusive rocks; formation of intrusive rocks

The correct answer is option b. Decompression melting; flux melting.

Explanation:

The Decompression melting process takes place in mid-ocean ridges.

What happens here is that two plates are separated, and the space between them is filled with hot rock that emerges from below. If this rock rises quickly before it can cool, it melts as the pressure drops as the rock approaches the surface.

Flux melting occurs when a solid rock is hot and receives water or other volatile components. This process is found in the subduction zones, where the rock of the upper mantle is melted by the addition of these materials that come from the descending plate.

since there isn't any suggested answers i will give you the reason and hopefully you can figure it

south africa, or rather all of africa, has not been in the location in which it is nowadays throughout the geological past. after the super-continent pangaea started to break apart, gondwanaland, in which was africa, moved further south, and parts of it came to be very close to the south pole. because the climate in this part of the world is very cold due to the very dispersed sun rays in there, what is now south africa, started to freeze, and the conditions were right for the formation of glaciers. the glaciers existed up until the period when gondwanaland started to break apart and what is now africa started to move towards north, sp it warmed up and the glaciers melted.