Solution :
The type of melting that is responsible for the mafic magmas for the following plate tectonic settings :
a). Mid - ocean ridges
At the mid oceanic ridges, the two plates diverges away and the new oceanic crust is formed by the effusion of the magma. The earth's interior is exposed as the two plates are moved away.
b). Continental rift :
A new oceanic crust is formed by the effusion of the magma and the two plates diverges away. Thus it causes the formation of the melt in the continental drift. As a result, the crustal thickness decreases.
c). Oceanic and continental volcanic arc :
The oceanic arc and the volcanic arc are the locations of the convergence. The denser plate of the arcs subducts under the less denser plates or the lighter plates and it moves downwards into the mantle, which causes the increase in temperature of the surroundings.
Answer:
The Solomon Islands, island of narato and nuatambu Island
It has been accreated and developed in it's core it is retianed
330 million, 500 million, 20K meters squated, dont get the last 2.