Structure of the Earth

Structure of the Earth - Inside our earth

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• published: 19 Mar 2013
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Inside of earth Interior of the earth. The earth our home planet is a dynamic planet that undergoes lots of changes inside and outside especially the deepest interiors. The earth is made up of several concentric layers with one inside the other. The outer most layer is the crust, which is the thinnest of all layers with a thickness of 35 km on the continental masses and 5 km on the oceanic floors. The main consistent of the continental masses is the silica and aluminum which is also referred as SILA where as the oceanic crust mainly consists of silica and magnesium and is therefore called as SIMA. Beneath the crust there is a 2nd layer, the mantle which extends up to a depth of about 2900 km and a radius of about 3500 km. The minerals that are mostly found in this layer are Nickel and ferrous which account for very high temperature in the interiors of the earth Rocks and minerals A natural mass of mineral matter that constituents the earth crust consists of rocks of different colours, sizes and textures. There are three major types of rocks 1. Igneous 2. Sedimentary 3. Metamorphic The formation of these igneous rocks or primary rock as they are also called occurs when the molten magma cools and becomes solid. There are two types in these igneous rocks. They are Intrusive and extrusive rocks. The lava which is fiery molten magma that comes out of the volcanoes become hard when it touches the crust forming extrusive igneous rocks. They have a very fine grained structure. One the example is Basalt. The deccan plateau is primary made up of basalt rocks. when the magma cools down inside the crust, really hard and solid rocks are formed which are called intrusive igneous rocks. An example of this type of rock is granite which is used to make grinding stones. Sedimentary rocks are formed by a process when rocks roll down and hit other and crack forming sediments. These sediments are transported and deposited by wind, water etc. They are in the form of layers of rock called the sedimentary rocks. Sandstone is formed by these grains of sedimentary rocks. Under great heat and pressure the sedimentary and igneous rocks are transformed into Metamorphic rocks just the way in which clay changes into slate and slate into marble. Rocks as we all know are used to make roads, buildings and houses. You can look around you and see the different types, shapes and sizes of rocks. As we learnt before, rocks changes its types under external conditions and this process of transformation is called the rock cycle. The first step of the cycle starts when molten magma cools and solidifies into igneous rocks. Next when these igneous rocks are broken down they transform into sedimentary rocks. The cycle continues till igneous and sedimentary rocks that are subjected to heat and pressure change into metamorphic rocks. If these metamorphic rock continue to be under heat and pressure, they melt to form molten magma thus completing the rock cycle. Rocks also constitute minerals which are naturally occurring substances of different physical properties and definite chemical structure. They are used as petroleum, gas, aluminium, granite etc