Crust example sentences

95% of the earth's crust is made up of silica and silicates.It also occurs extensively in the combined form in the Earth's crust as well as also in the air in the form of carbon dioxide.According to this theory, the crust (upper part) of the earth has been formed out of seven major and some minor plates.The abundance of boron in earth crust is less than 0.The total volume of workable mineral deposits is an insignificant fraction i.e. one per cent of the earth s crust.Petrol, diesel and kerosene oil are obtained by the fractional distillation of petroleum found under the earth's crust.Antennal glands or green glands perform the excretory function in crustaceans like prawns.The convectional currents split the crust into a number of pieces, thus leading to the drifting of the Indo-Australian plate after being separated from the Gondwana land, towards north.There are at least 2,000 minerals that have been named and identified in the earth crust; but almost all the commonly occurring ones are related to six major mineral groups that are known as major rock forming minerals.The amount of carbon present in the earth's crust and in the atmosphere is quite meagre.Metamorphism occurs when rocks are forced down to lower levels by tectonic processes or when molten magma rising through the crust comes in contact with the crustal rocks or the underlying rocks are subjected to great amounts of pressure by overlying rocks.Carbon (C), silicon (Si), germanium (Ge), tin (Sn) and lead (Pb) are the members of group 1 Carbon is the seventeenth most abundant element by mass in the earth's crust.Where do these metals come from? You have studied that the earth s crust is made up of different minerals embedded in the rocks.The crustal rocks (igneous, metamorphic and sedimentary) once formed may be carried down into the mantle (interior of the earth) through subduction process (parts or whole of crustal plates going down under another plate in zones of plate convergence) and the same melt down due to increase in temperature in the interior and turn into molten magma, the original source for igneous rocks.Silicon is the second (2 7 % by mass) most abundant element on the earth's crust and is present in nature in the form of silica and silicates.