What are Petrogenetic processes?

Petrogenesis, also known as petrogeny, is a branch of petrology dealing with the origin and formation of rocks. While the word petrogenesis is most commonly used to refer to the processes that form igneous rocks, it can also include metamorphic and sedimentary processes, including diagenesis and metamorphic reactions.

What is mean petrogenesis?

the origin or formation of rocks
Definition of petrogenesis : the origin or formation of rocks.

How granite is formed?

Granites are generally formed as “batholiths” at great depth and when exposed by erosion or other tectonic activity, these rocks occupy huge areas of the Earth’s surface, often as series of domes (Fig. 4.8) and valleys. The central cores of major mountain ranges consist of intrusive igneous rocks, usually granites.

What is the difference between petrography and petrogenesis?

The main difference between petrography and petrogenesis is that petrography involves the description and classification of rocks, especially by microscopic examination, while petrogenesis focuses on the origin and formation of rocks, especially igneous rocks.

How does granite change into sandstone?

Slowly, water and weather wore away granite through the process of erosion. These granite particles became sand, carried by streams to the ocean. Over millions of years, layers of sandy sediment piled up on the ocean floor. Slowly, the sediments were pressed together and cemented to form sandstone, a sedimentary rock.

What elements make up granite?

The chemical composition of granite is typically 70-77% silica, 11-13% alumina, 3-5% potassium oxide, 3-5% soda, 1% lime, 2-3% total iron, and less than 1% magnesia and titania. Volcanic rock of equivalent chemical composition and mineralogy is called rhyolite.

How is petrology helpful and necessary for geologists?

Petrology plays an important role in ascertaining the physical and chemical composition of rocks and the different conditions that influence their formation. Modern petrologists rely on knowledge in mineralogy to help in mapping and sampling of rocks.

What are the three processes of metamorphism?

The three types of metamorphism are Contact, Regional, and Dynamic metamorphism. Contact Metamorphism occurs when magma comes in contact with an already existing body of rock. When this happens the existing rocks temperature rises and also becomes infiltrated with fluid from the magma.

What are the two processes of metamorphism?

Equally as significant are changes in chemical environment that result in two metamorphic processes: (1) mechanical dislocation where a rock is deformed, especially as a consequence of differential stress; and (2) chemical recrystallization where a mineral assemblage becomes out of equilibrium due to temperature and …