What Causes Granite To Turn Into Gneiss

Granite turns into gneiss.

What causes granite to turn into gneiss.

Short succinct and correct answer. Granite turns into gneiss. There are no chemical changes but structural. The change from granite to gneiss is not mineralogical i e.

If the granite gets buried deep in the crust it often changes to a gneiss. This is due to the long minerals in the original granite lining up perpendicular to a regional stress field. The appearance of granular minerals is what marks the transition into gneiss. By heat or pressure sometimes both.

With still more metamorphism gneisses can turn to migmatite and then totally recrystallize into granite. Well gneiss dosent turn into granite. Minerals are seen arranged in bands in gneiss. These minerals are then transported in streams and rivers and often end up as sediments in the oceans.

Intense heat and pressure can also metamorphose granite into a banded rock known as granite gneiss this transformation is usually more of a structural change than a mineralogical transformation. If it is part of a mountain it gets weathered eroded and transported to the ocean. Well gneiss dosent turn into granite. Not all gneiss is obtained from granite and there are also diorite gneiss biotite gneiss garnet gneiss and so on.

The mineral composition of both granite and gneiss is same but alteration of granite because of very high pressure and temperature leads to the formation of gneiss. When subjected to intense heat and pressure granite will. By heat or pressure sometimes both. Granites at the surface are exposed to weathering in which they break down into mostly quartz and feldspars.

Metamorphic rocks form from heat and pressure which changes the original or parent rock into a completely new rock. Gneiss is a metamorphic rock granite is an igneous rock and sandstone is a sedimentary rock. Another important structural change is the development of foliation or linear appearance in a gneiss. All rocks undergo a series of processes called the rock cycle where one type of rock changes into another.

Heat and pressure cause granite to become gneiss and change sandstone into quartzite. These rocks primarily consist of quartz feldspar and mica.