Question

Most metamorphic rocks exposed at the surface are believed to have been formed

A. in the stable platforms from deep burial under sedimentary rocks
B. on the flanks of the oceanic ridge systems
C. in the deep roots of developing mountain systems (folded mountain belts) in ancient times
D. from heat and pressure along the margins of igneous intrusions

Answer 1

Most surface-exposed metamorphic rocks are formed in the deep roots of ancient mountain systems due to high pressure and heat during mountain building, later exposed by erosion.

Correct option is c. in the deep roots of developing mountain systems (folded mountain belts) in ancient times

Step-by-step explanation:

Most metamorphic rocks exposed at the surface are believed to have been formed in the deep roots of developing mountain systems (folded mountain belts) in ancient times. This is because during the process of mountain building, known as orogeny, intense pressure and heat metamorphose rocks deep within the Earth. The Barrovian sequence shows a predictable pattern of metamorphic rock formation during a continental collision, where high-grade metamorphic rocks become exposed due to erosion of the overlying rocks. Mountains like the Alps were formed by the collision of tectonic plates, driving some rocks deep beneath the surface while uplifting others. Erosion eventually wears down the mountains, exposing the high-grade metamorphic rocks within.

Thus, the most likely answer to the student's question is 'C. in the deep roots of developing mountain systems (folded mountain belts) in ancient times'.