Can metamorphic rocks form at Earth's surface?

Can metamorphic rocks form at Earth's surface?

• A. Yes
• B. No
• C. Only at high pressures at depth
• D. Only beneath the oceans

Answer: (B)

Metamorphism involves minerals recrystallizing and forming new minerals in response to higher temperature, higher pressure, and often fluids. These conditions occur mainly below Earth’s surface, where rocks are buried deep in the crust or heated by nearby magma. At the surface, pressures are essentially atmospheric and temperatures are not high enough to drive the mineral changes that define metamorphic rocks. You can get some metamorphism in localized zones near hot igneous intrusions (contact metamorphism), but that still happens beneath the surface rather than right at the open surface. So, under normal surface conditions, widespread metamorphic rocks do not form.

Metamorphism involves minerals recrystallizing and forming new minerals in response to higher temperature, higher pressure, and often fluids. These conditions occur mainly below Earth’s surface, where rocks are buried deep in the crust or heated by nearby magma. At the surface, pressures are essentially atmospheric and temperatures are not high enough to drive the mineral changes that define metamorphic rocks. You can get some metamorphism in localized zones near hot igneous intrusions (contact metamorphism), but that still happens beneath the surface rather than right at the open surface. So, under normal surface conditions, widespread metamorphic rocks do not form.