What are Metamorphic Rocks?

Metamorphic rocks are a type of rock that forms from the transformation of pre-existing rock types through a combination of heat, pressure, and chemical reactions. These rocks undergo changes in mineral composition, texture, and structure, resulting in the formation of new characteristics.

Formation of Metamorphic Rocks

Metamorphic rocks are formed deep within the Earth's crust where high temperatures and pressures cause existing rocks to undergo metamorphism. This process can occur in response to tectonic movements, burial deep within the Earth, or when rocks come into contact with magma.

Types and Examples

There are two main types of metamorphic rocks: foliated and non-foliated. Foliated metamorphic rocks, such as schist and gneiss, have a layered or banded appearance due to the alignment of mineral grains. Non-foliated metamorphic rocks, like marble and quartzite, do not have a layered structure.

Examples of metamorphic rocks found in nature include slate, formed from shale; marble, formed from limestone; and quartzite, formed from sandstone.

Processes and Characteristics

Metamorphic rocks undergo processes such as recrystallization, phase change, and neocrystallization, leading to the development of unique characteristics. These rocks exhibit increased hardness, density, and resistance to weathering compared to their parent rocks.

In conclusion, metamorphic rocks play a crucial role in the rock cycle, showcasing the dynamic processes that shape the Earth's crust and contribute to the formation of diverse rock types.