What is burial metamorphism?

Burial metamorphism is specifically associated with low-grade metamorphism that occurs when sediments are deeply buried under thick layers of overlying material, such as other sediments. As sediments accumulate, the increase in pressure and temperature due to the weight of the overlying rock alters the minerals within the sediments. This process leads to the recrystallization and reorganization of mineral structures without reaching the high temperatures required for high-grade metamorphism.

This type of metamorphism typically occurs in sedimentary basins where significant thicknesses of sediment accumulate over time. The conditions under which burial metamorphism takes place—generally lower temperatures compared to those seen in higher-grade metamorphism—make it distinct in terms of the types of changes that occur in the rock.

The other options pertain to different processes or conditions, such as high-grade metamorphism, volcanic activity, or sedimentation, which do not accurately describe burial metamorphism.