Which metamorphism forms metamorphic rock bodies spanning hundreds of square kilometers?

Which metamorphism forms metamorphic rock bodies spanning hundreds of square kilometers?

• A. Contact metamorphism
• B. Dynamic metamorphism
• C. Regional metamorphism
• D. Hydrothermal metamorphism

Answer: (C)

Scale of metamorphism determines how large the affected rock bodies become. Regional metamorphism happens when extensive portions of the crust are subjected to elevated temperatures and pressures during tectonic processes like mountain building and crustal thickening. This widespread action creates metamorphic belts that cover hundreds of square kilometers, producing rocks such as schist, gneiss, or mapped marble across large regions. In contrast, contact metamorphism is localized to zones surrounding heat sources like magma intrusions, so it affects relatively small areas. Dynamic metamorphism occurs along faults as rocks are crushed, forming narrow fault zones. Hydrothermal metamorphism alters rocks along fractures where hot fluids circulate, again typically in limited areas.

Scale of metamorphism determines how large the affected rock bodies become. Regional metamorphism happens when extensive portions of the crust are subjected to elevated temperatures and pressures during tectonic processes like mountain building and crustal thickening. This widespread action creates metamorphic belts that cover hundreds of square kilometers, producing rocks such as schist, gneiss, or mapped marble across large regions.

In contrast, contact metamorphism is localized to zones surrounding heat sources like magma intrusions, so it affects relatively small areas. Dynamic metamorphism occurs along faults as rocks are crushed, forming narrow fault zones. Hydrothermal metamorphism alters rocks along fractures where hot fluids circulate, again typically in limited areas.