Question

Mention various types of rocks.

Answer 1

Hint:
Rocks form a major part of earth’s crust. Rocks are defined as the aggregate of minerals. Basically they are formed by erosion, weathering, volcanic eruption and transportation of Mountains. The rocks are broadly classified into three categories based on geological classification; Such as – Igneous Rock, Sedimentary Rock and Metamorphic Rock.

Complete answer:

Igneous Rock: Inside the portion of earth has high temperature so it causes fusion and makes the form of pasty or molten material that is called Magma. When it comes out of the earth’s surface through a weak portion of earth or old mountains that is called Lava, after cooling it converts into igneous rock. It is also known as Primary Rock or Parent Rock. There are also three types; Such as – Plutonic Igneous Rock (Intrusive Rock), Sub volcanic Rock, Volcanic Rock (Extrusive Rock). Examples: - Granite, Pegmatite, Gabbro, Serpentine, Dolerite, Basalt, Trap, Andesite, Scoria, etc.

Sedimentary Rock: It is derived from the consolidation of sediment of pre-existing rock like an igneous rock, under the influence of mechanical, chemical, organic activities of the denuding agents that is wind, water, rainfall, glaciers, etc. It is also known as secondary rocks. There are some examples of secondary rock, such as – Limestone, Sand stone, Shale (Mudstone), Chalk, Kankan, Gypsum, Gravel, Dolomite, etc.

Metamorphic Rock: The rocks formed from the pre-existing rock (igneous and sedimentary rock) by the process of metamorphism, under the influence of Heat, Pressure or both. It is also known as tertiary rock. There are some examples of tertiary rock. Such as – Gneiss, Marble, Quartzite, Slate, Schist, etc.

Note:
> There are various types of rocks based on Physical classification; such as – Stratified rock, Unstratified Rock and Foliated Rocks.
> There are various types of rocks based on chemical classification; such as – Siliceous rock, Calcareous rock and Argillaceous rock.