Rock Melting and Magma Formation

The video tutorial explains three main ways rocks can melt: heat transfer, decompression melting, and flux melting. Heat transfer occurs when rocks are near hot sources like magma chambers, common at hot spots, producing mafic magma. Decompression melting happens at divergent plate boundaries, creating silica-rich basaltic magma. Flux melting occurs at subduction zones, resulting in silica-rich andesite. The tutorial also covers magma compositions: mafic from mid-ocean ridges and hot spots, intermediate from convergent boundaries, and felsic from partial melting of continental rocks.

What is the primary mechanism by which heat transfer causes rocks to melt?

• Pressure decrease

• Introduction of water

• Increase in temperature

• Chemical reaction

In the context of rock melting, what is a common feature of hot spots?

• Presence of water

• High pressure

• Mantle plumes

• Cold temperatures

What is the primary composition of magma produced at mantle hot spots?

• Mafic

• Silica-rich

• Felsic

• Intermediate

What type of magma is produced by decompression melting at divergent plate boundaries?

• Intermediate andesite

• Ultramafic magma

• Silica-rich basaltic magma

• Felsic magma

Which process is responsible for the most voluminous production of magma on Earth?

• Decompression melting

• Heat transfer

• Flux melting

• Partial melting

What is the role of water in flux melting at subduction zones?

• It decreases temperature

• It cools the magma

• It increases pressure

• It facilitates rock melting

What type of magma is associated with flux melting?

• Mafic magma

• Silica-rich and acidic magma

• Ultramafic magma

• Basaltic magma

Which type of rock is typically formed at mid-ocean ridges and hot spots?

• Sedimentary rocks

• Felsic rocks

• Intermediate rocks

• Mafic rocks

Where do felsic rocks typically originate from?

• Hot spots

• Partial melting of young crustal rock

• Mid-ocean ridges

• Subduction zones

What is the primary source of intermediate rocks?

• Convergent boundaries

• Transform boundaries

• Divergent boundaries

• Hot spots