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Structural features of sedimentary rocks

structural features of sedimentary rocks

Sedimentary rocks constitute about 75% of the total exposed rocks on the earth’s crust. They are found in different forms/structures. The important structural features of sedimentary rocks are stratification, lamination, graded bedding, current bedding, ripple marks. Besides these, there are some minor structures such as mud cracks, rain prints, tracks of terrestrial animals, etc. These …

Texture of the Sedimentary Rocks

The Texture of sedimentary rocks

The texture of the sedimentary rocks is studied like that of the igneous rocks. Texture means the size, shape, and arrangement of grains in a rock. The particles of the sedimentary rocks are known as the ”Sediments”. As sediments contain particles of various sizes, grain size is an important factor in the description of sedimentary …

Classification of the Sediments

Classification of the sediments (that form the sedimentary rocks) is made on the basis of the sources of the sediments. Some of the rocks are formed from the sediments obtained from pre-existing rocks, while some are formed from the sediments sourced from the minerals precipitated from water. On the basis of the above mentioned two …

Sedimentary Rocks and their formation

Sedimentary rock formation

Sedimentary Rocks The upper 16 km thick earth’s crust contains only 5% of the sedimentary rocks, while the percentage of the sedimentary rock in the exposed rocks is about 75%. These rocks are found chiefly as an extensive cover over the continental crust. In the subject of rock formation, sedimentary rocks and their formation is …

Types of igneous rocks

There are two basic types of igneous rocks i.e. Intrusive Igneous rocks and Extrusive igneous rocks. Intrusive igneous rocks are those, which crystallize below the earth’s surface, and remain buried until the earth’s surface is eroded, while the extruded igneous rocks are those, which erupt onto the surface, where they cool quickly to form small …

Origin of the Igneous Rocks

We can find the mineral composition of igneous rocks by means of studying the chemical composition of the magma from which the rock has been crystallized. Because there is a large variety of igneous rocks, thus it was originally thought an equally large variety of magma also existed. But the later research found out that there are only two types of magma existed and all types of igneous rocks were derived from them.

Differentiation of Magma while cooling and solidification

Differentiation of Magma while cooling and solidification: Magmatic differentiation means the split of magma into various parts due to the presence of different types of chemicals in it. These parts of magma on cooling and solidification produce rocks of different types. As the chemical composition of magma differs in its different parts and layers, the …

Formation of Igneous Rocks

Differentiation of Magma while cooling/ solidification

Formation of Igneous Rocks: The igneous rocks are formed from the cooling and solidification of the Magma/Lava. The minerals and the chemical makeup of igneous rocks are important in order to understand their formation. Experimental studies of the crystallization sequence of minerals from a melt have helped greatly in understanding the origin of igneous rocks. …

Mechanics of Intrusion

Source of Magma:  Magma is originated from the upper mantle, which lies just under the crust, and is nearly molten. A slight drop in pressure caused by dee faulting etc, completes the melting process. The basaltic magma originates in this manner, while the “granitic magma” can be produced in two ways: (a) from melting of …