Test Preparation on IAS Prelims Sample Paper -34

1.

Consider the following statements about Sea floor spreading.1. It is caused by a sinking mantle.2. It is verified by the observation that ocean crust rocks are much younger than the continental rocks.3. The sediments on the ocean floor get unexpectedly very thick due to sea floor spreading.Select the correct answer using the codes below.

Constant eruptions at the crest of oceanic ridges cause the rupture of theoceanic crust and the new lava wedges into it, pushing the oceanic crust on either side. The ocean floorthus spreads, known as sea floor spreading. Sea floor spreading is verified using these phenomena- It wasrealised that all ^ong the mid-oceanic ridges, volcanic eruptions are common and they bring huge amountsof lava to the surface in this area. The sediments on the ocean floor are unexpectedly very thin The age ofthe rocks increases as one moves away from the crest. The ocean crust rocks are much younger than thedeeoT t ri rt'h L thin. The deep trenches havedOBepotthsh.s ITt rmnetarn s lI ava is in close vicinity. i" the mid-oceanic ridge areas, the quake foci have shallowQ Source; Page 30: Fundamentals of Physical Geography: 11th NCERT
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