Decompression melting at a divergent boundary produces which type of magma and forms which rocks?

Prepare for your Introduction to Physical Geology Exam. Tackle diverse topics with multiple-choice questions and detailed explanations. Equip yourself with knowledge about Earth's physical processes and surface features. Ace your exam with confidence!

Multiple Choice

Decompression melting at a divergent boundary produces which type of magma and forms which rocks?

Explanation:
At divergent boundaries, mantle material rises and pressure drops, causing decompression melting. This melting produces basaltic magma, which is mafic in composition (rich in Mg and Fe, relatively low in silica). As this magma moves upward, it can crystallize underground to form gabbro (an intrusive rock) or erupt at the surface to form basalt (an extrusive rock). So the magma is mafic, and it forms both extrusive and intrusive rocks.

At divergent boundaries, mantle material rises and pressure drops, causing decompression melting. This melting produces basaltic magma, which is mafic in composition (rich in Mg and Fe, relatively low in silica). As this magma moves upward, it can crystallize underground to form gabbro (an intrusive rock) or erupt at the surface to form basalt (an extrusive rock). So the magma is mafic, and it forms both extrusive and intrusive rocks.

Subscribe

Get the latest from Examzify

You can unsubscribe at any time. Read our privacy policy