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How Rocks Are Formed? Best Explanation | Gurugrah. in

How Rocks Are Formed? |

Formation of rocks –

Rocks –

In general, plants and organic matter are considered separate from rocks. Although minerals are found only in rocks, minerals are also considered separate from rocks. All the different types of material that make up the crust – such as stone, sand, and clay – are known as rocks. That is, except for minerals, all the substances found on the earth’s crust are called rocks. They can be hard as a rock and as soft as a clay pot.

Rocks and minerals were formed as part of the Earth’s formation process. Hence these two elements are found together. Most rocks have one or more rocks on or near them. For example, granite contains a variety of minerals. Some examples of gemstones are crystal, feldspar, and mica. Whereas the same mineral calcite is present in marble. He will be Rocks may contain one or more minerals. Furthermore, most rocks are a mixture of minerals.

Types of rocks There are three types of rocks-

1. Igneous Rocks

2. Sendimentaty Rocks

3. Metamorphic Rocks

1. Igneous Rocks –

Igneous rocks are also called primary rocks or base rocks because they were the first to form. The rocks you see here are the result of molten rock that has cooled over time. That is why it is said that “igneous rocks” are rocks formed by the cooling of lava or magma. These rocks include granite, gabbro, basalt, and more.

The interior of the Earth is very hot because due to extreme heat in many parts, all the elements there become molten states. This molten material is called magma. When the heat released from the volcano comes to the surface, it is called lava. Minerals and other elements in lava remain in the molten state, so the rock formed from lava contains many mixed minerals.

Characteristics of igneous rocks

1. Igneous rocks are formed from molten hot material, so they are extremely hard and solid.

2. They are fibrous, and the number and size of the sieves are not fixed. Generally, the intrusive rocks have large ravines and small ravines are found in the outer rocks.

3. They do not have layers, but a rock can have many joints.

• Organic remains are not found in these rocks.

• Igneous rocks do not have pores or pores as are found in layered rocks.

4. These rocks are found only on the surface in volcanic areas.

2. Flaky Rocks –

Rocks arranged in layers on the surface are called sedimentary rocks. They are formed by the elements of erosion, such as rivers and wind. This is due to the accumulation of ingested substances. Igneous rocks are destroyed by various agents such as rivers, wind, ocean waves, glaciers, and underground water. This substance is formed when there is the erosion of land. This sediment gets deposited at the bottom of water bodies. Sedimentary layers are deposited annually.

Many years ago, layers could be distinguished. After being subjected to thousands of years of extreme pressure and heat, layers of rocks are exposed. These are the only depressions and are called sandy rocks. Some rocks break easily, such as sandstone and limestone. Other rocks are less brittle, such as chalk and clay. Finally, there are rocks that are very fragile and can break easily, such as shale and shale.

Features of sedimentary rocks

1. These rocks have been formed by the deposition in the form of layers by rivers etc., hence layers are found in them. This is their main feature because other rocks do not have layers.

2. Flaky rocks are formed from fragments of igneous and metamorphic rocks and dust remains of flora, fauna, etc. Therefore, the remains of animals and fragments of parent rocks are found in them.

3. Most of the flaky rocks are formed at the bottom of the sea, so there are signs of sea waves, etc.

4. These rocks are relatively less hard, so weathering and erosion happen quickly.

5. They do not contain ravines as are found in igneous rocks.

6. It is porous and permeable. That is why deposits of water and mineral oil are also found in them.

7. Most of the layered rocks are found horizontally.

8. There are cracks, joints, etc. in the flaky rocks, so they are easily fragmented.

3. Metamorphic Rocks –

Metamorphic rocks are rocks that change color, form, and structure due to extreme pressure on them. These rocks change color and form only when heated, and they do not undergo decomposition or dissolution. The minerals present in these rocks change their properties, making the rocks hard.

With extreme transformation, it can be difficult to remember what the original look looked like. Conversion in plants can happen quickly or slowly. Examples of metamorphic rocks include limestone, marble shale, and slate. These rocks change from one form to another over time.

Changes in parent rocks occur in five ways:

1. Thermal Conversion

2. Aqueous Conversion

3. Thermo-aqueous conversion

4. Dynamic Conversions

5. Static Conversion

1. Thermal Conversion –

The shape of rocks changes due to the interaction of molten rock located inside the earth. Thus heat is converted from one form to another. This type of change is usually caused by a flame. Occurs at the time of ejaculation.

Limestone is converted by contact with molten rock. Similarly, quartzite is formed from sandstone. The part of the rock that is in contact with the magma changes more than the rest.

2. Aqueous Conversion –

Due to the weight of the huge amount of water in the oceans, there is a change in the rocks at the bottom, this is called hydrological transformation. This type of change occurs in limited areas and is very rare.

3. Thermo-aqueous conversion –

This conversion is due to heat and water load. In general, the effect of this conversion is rarely visible.

4. Dynamic Conversion –

This transformation takes place due to friction and heat generated by the horizontal or vertical movement of rocks within the crust. This conversion takes a lot of time. Example- Formation of granite from slate coal from shale. Generally, this transformation takes place only in mountainous areas.

5. Static Conversion –

Due to the pressure of upper rocks, there is a change in the rocks below, then it is called static transformation. It can also be called pressure conversion. Many rocks of the crust are transformed in this way.

Reason for conversion –

1. Thermal –

The metamorphic rocks forming the crust are mostly composed of this element. Due to the heat, the parent rock melts, causing a complete change in its appearance and composition. Conversion takes place. The heat inside the crust comes from magma. The effect of this element is more pronounced when a volcano erupts.

2. Pressure –

Due to extreme pressure, the rocks below changed. When there is pressure from both sides, the rocky part in the middle can sometimes metamorphose. The change of type is caused by the continental formation and mountain-building movements.

3. Solution –

Due to the interaction of various chemicals, the substances in the rocks get dissolved and changed. For example, when carbon dioxide and oxygen gas are mixed together, their chemical reactions increase. When I came in contact with this water, the rocks around me changed their shape and organization.

Major metamorphic rocks –

(i) Metamorphic forms of igneous rocks:-

1. Granite to Nice

2. Gabrones and Serpentines from Gebro

(ii) Metamorphic forms of sedimentary rocks:-

1. Quartzite from sandstone

2. Shell to Slate

3. Cysts and mica from the shell

4. Marble to Limestone

5. Coal to Diamond

6. Bituminous to Anthracite

7. Marble from dolomite and alabaster

Geological rocks found in India -

The rocks found below the surface are called geological features. Since the cooling of the Earth, six different types of rocks have been formed. Their construction belongs to a different era. Different types of rocks are found in different parts of India. There are rocks from the mountains, rocks from the plains, and rocks from the coast. Metals are found in different amounts in all these rocks. The main rocks found in India are as follows:

1. Archean rocks

2. Dharwad Rocks

3. Cuddapah Rocks

4. Rocks of Vindhyan order

5. Rocks of Gondwana order

6. Deccan Trap


By Chanchal Sailani | September 27, 2022, | Editor at Gurugrah_Blogs.



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