What term refers to a large downward-protruding portion of the lithosphere under a craton?

Unlock all questions

This demo includes only 20 questions. Upgrade to access hundreds of questions, flashcards, exam simulations, and disable ads.

Full question bankExam simulationsFlashcards
From $25.99Unlock all

Prepare for the Gemological Institute of America's Graduate Diamonds Exam. Enhance your expertise with comprehensive quizzes and insightful explanations. Be ready to excel!

Multiple Choice

What term refers to a large downward-protruding portion of the lithosphere under a craton?

Explanation:
Mantle keel describes the large downward-protruding portion of the lithosphere beneath a craton. This thick, cold, rigid root extends deeper into the mantle and anchors the craton, contributing to its stability and unusually high seismic velocities. It is a structural feature of the lithospheric mantle, not molten material or a simple mineral. A magma body, a mineral, or a pipe does not capture this downward-extending lithospheric root, so the term that best fits is mantle keel.

Mantle keel describes the large downward-protruding portion of the lithosphere beneath a craton. This thick, cold, rigid root extends deeper into the mantle and anchors the craton, contributing to its stability and unusually high seismic velocities. It is a structural feature of the lithospheric mantle, not molten material or a simple mineral. A magma body, a mineral, or a pipe does not capture this downward-extending lithospheric root, so the term that best fits is mantle keel.

More Multiple Choice Questions
Subscribe

Get the latest from Passetra

You can unsubscribe at any time. Read our privacy policy