Q. 3. Answer the following questions in one sentence each :
(1) What is called lower layer of the crust?
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(2) Out of which layer of the crust are the continents formed?
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(3) Out of which layer of the crust is most of the oceanic base formed?
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(4) What compounds does the mantle consists of ?
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(5) In which of the layers of the interior of the earth is magma formed?
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(6) What are the two parts of the core?
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Answer:
answer 1 In geology, sima (/ˈsaɪmə/) is an antiquated blended term for the lower layer of the Earth's crust. This layer is made of rocks rich in magnesium silicate minerals.
answer 2 The continental crust is the layer of granitic, sedimentary and metamorphic rocks which form the continents and the areas of shallow seabed close to their shores, known as continental shelves. It is less dense than the material of the Earth's mantle and thus "floats" on top of it.
Answer.3
Oceanic crust is continuously being created at mid-ocean ridges. As plates diverge at these ridges, magma rises into the upper mantle and crust. As it moves away from the ridge, the lithosphere becomes cooler and denser, and sediment gradually builds on top of it.
answer 4 In terms of its constituent elements, the mantle is made up of 44.8% oxygen, 21.5% silicon, and 22.8% magnesium. There's also iron, aluminum, calcium, sodium, and potassium. These elements are all bound together in the form of silicate rocks, all of which take the form of oxides.
answer 5 The core is the superheated center, the mantle is the thick, middle layer, and the crust is the top layer on which we live. Magma originates in the lower part of the Earth's crust and in the upper portion of the mantle.
answer 6
Explanation:
The core is made of two layers: the outer core, which borders the mantle, and the inner core. The boundary separating these regions is called the Bullen discontinuity. The outer core, about 2,200 kilometers (1,367 miles) thick, is mostly composed of liquid iron and nickel.