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Correct Option is 4 3 2 1

Crust is the outer thin layer with a total thickness normally between 50-100 km. Oceanic crust is thinner (5-30 km thick) as compared to the continental crust (50-100 km thick). The outer covering of the crust is of sedimentary material (granitic rocks) and below that lie crystalline, igneous and metamorphic rocks which are acidic in nature. The lower layer of the crust consists of basaltic and ultra-basic rocks. The continents are composed of lighter silicates—silica + aluminium (also called ‘sial’) the oceans have the heavier silicates—silica + magnesium (also called ‘sima’). Avg. density : 2.7 g/Cm3 Mantle extends from Moho’s discontinuity  to a depth of 2,900 km (Moho-Discontinuity to the outer core). The lower mantle extends beyond the asthenosphere. It is in solid state. The avg. density of mantle 4.6 g/Cm3 It is composed of solid rock and magma. It forms 83 per cent of the earth’s volume. The outer layer of the mantle is partly simatic while the inner layer is composed of wholly simatic ultra-basic rocks Core Lies between 2900 km and 6400 km below the earth’s surfaceAccounts for 16 per cent of the earth’s volume. Core has the heaviest mineral materials of highest density. It is composed of nickel and iron [nife]. The outer core is liquid while the inner core is solid. A zone of mixed heavy metals + silicates separates the core from outer layers. Avg density : 11g/Cm3 Asthenosphere : Upper portion of the mantle below upper mantle Extending up to 400 km , Semi-liquid & solid . Main source of magma that finds out its way to the surface during volcanic eruption Density higher than crust The crust and the uppermost part of the mantle are called lithosphere. Its thickness ranges from 100-200 km.

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