Rock system and Classification of Rocks

Rocks are mineral assemblages with properties that blend all elements in traces. Any effects obtained from mineralogy, chemical makeup, texture, grain size, or other identifying qualities can be used to designate rock kinds. In addition, each major rock type has its classification. Natural rocks are available in a wide range of types and sizes. Real rocks usually have such basic features, and the scales used to assess changes usually indicate some variation in the set of attributes. This study will go into the specifics of the rock system, including its classification and formation.

What is the Rock System?

Because Indian rocks date back to the Eoarchean Era, the country’s geology is quite diversified. A few of the rocks have been distorted and altered significantly. Other deposits include alluvium, which has recently been deposited but has not yet undergone diagenesis. The Indian subcontinent has a large number of mineral resources of various types. India’s fossil record, which includes stromatolites, invertebrates, vertebrates, and plant fossils, is amazing. The  Dharwar System,  Archaean System, Vindhyan System, Cuddapah System, Deccan Trap; Gondwana System, Quaternary System, Tertiary System; divide India’s geographical land area.

The oldest rocks are the Archaean Gneisses. These Rocks developed as molten magma solidified – the earth’s surface was extremely hot at the time. The ‘Basement Complex’ is what it’s called. The formation of the Dharwar System occurred between 4 billion and 1 billion years ago. The Sedimentary rock system has been highly metamorphosed. They’re the earliest metamorphosed rocks on the planet. The Dharwar region of Karnataka has a lot of them.

Purana Rock System is a type of rock that is found in India. Synclinal basins deposited unfossiliferous clay, slates, sandstones, and limestones. 

The Cuddapah region of Andhra Pradesh has the best outcrops. 

Vindhyan System is a system named after  Vindhyan Mountains. Ancient sedimentary strata (4000 m thick) are piled on the Archaean basis in this system. They are Unfossiliferous in most cases. The Deccan trap covers a large portion of this belt.

What is the Classification of Rocks?

When molten rock magma and lava cool and harden, igneous rocks form. Sedimentary rocks form as particles fall out of air or water or when minerals precipitate out of water. They build up in layers. Existing rocks undergo metamorphism due to heat, pressure, or reacting fluids like hot, mineral-laden liquid. The most prevalent elements in the earth’s crust are silicon and oxygen, which make up the majority of rocks.

The 2 categories of igneous rock are as follows:

Intrusive igneous rock: As the earth cools slowly, these rocks crystallize below the surface, resulting in huge crystals. Intrusive igneous rocks include granite, diorite, and pegmatite.

Extrusive igneous rock: Such rocks erupt onto the surface and cool quickly, resulting in tiny crystals. Amorphous glass forms when a few rocks cool too quickly. Extrusive igneous rocks include tuff, basalt, and pumice.

The 3 kinds of sedimentary rocks are as follows:

Clastic sedimentary rocks were formed through the weathering of debris. Sandstone and siltstone are examples of clastic sedimentary rocks.

Chemical sedimentary rocks are formed when dispersed elements from a solution precipitate. Iron ore and limestones are examples of chemical sedimentary rocks.

Organic sedimentary rocks are made up of accumulated plant and animal debris. Coal and some dolomites are examples of organic sedimentary rocks.

The 2 categories of metamorphic rock are as follows:

Metamorphic rocks that have been foliated: These rocks have been foliated by heat and pressure, giving them a layered appearance. Foliated metamorphic rocks include gneiss and phyllite.

Metamorphic rocks that aren’t foliated: These rocks don’t have layers. Non-foliated metamorphic rocks include quartzite and marble.

What is the Formation of Rocks?

Sedimentary rocks are made up of fragments of other rocks or organic matter. Clastic, biological, and chemical sedimentary rocks are the three types of sedimentary rocks. Sandstone and other clastic sedimentary rocks are formed from clasts and debris of other rocks. Hard, biological elements such as plants, shells, and bones are compacted into the rock to form organic sedimentary rocks, such as coal.

Metamorphic rocks have been transformed by extreme heat or pressure from their initial state. There are two types of metamorphic rocks: foliated and non-foliated. When a rock containing flat or elongate minerals is subjected to extreme pressure, the minerals align in layers, forming foliation. Foliation occurs when elongate or platy minerals, such as hornblende or mica, align parallel to the pressure plane.

When molten hot stuff cools and hardens, igneous rocks form. There are a few distinct techniques to make igneous rocks. Intrusive or strictly platonic, igneous rocks form deep within the crust. Extrusive igneous rocks are often known as volcanic igneous rocks, originating above or on top of the earth’s crust.

Conclusion

The Himalayas, Assam, Madhya Pradesh, Bengal, Orissa, Bihar, and Rajasthan are known for their gneisses and schists. Quartzite is a hard rock found in Bihar, Rajasthan, Tamil Nadu, Madhya Pradesh, and the Delhi area. Marble can be found in Rajasthan around Ajmer, Alwar, Jaipur, and Jodhpur and areas of Madhya Pradesh’s Narmada Valley.