Question

Select the correct statements about the Igneous rocks.
A. Igneous rocks are formed from the consolidation of sediments
B. Igneous rocks are formed by solidification of molten material magma on or beneath benefits of earth surface
C. Igneous rock make up 95% of the earth crust
D. Gneiss and slate are the example of igneous rocks
E. Granite and sandstone are the example of igneous rocks

• A. A, C, D only
• B. B, C, D only
• C. B, C, E only
• D. A, B, C, D, E only

Hint:

Igneous = Magma (Granite, Basalt). Sedimentary = Sediments (Sandstone, Limestone). Metamorphic = Pressure/Heat (Gneiss, Slate).

Answer 1

The Correct Option is B

Concept: Igneous rocks are one of the three main rock types, formed through the cooling and solidification of magma or lava.

Step 1: Verify formation and volume (B and C).
Statement B is correct: Igneous rocks form when molten magma cools and solidifies, either underground (intrusive) or on the surface (extrusive). Statement C is correct: Approximately 95% of the upper 16 km of the Earth's crust is composed of igneous rocks, although they are often covered by a thin layer of sedimentary rocks.

Step 2: Evaluate classification examples (A, D, and E).
Statement A is incorrect: consolidation of sediments forms Sedimentary rocks. Statement D: Gneiss and Slate are Metamorphic rocks. Statement E: Granite is igneous, but Sandstone is Sedimentary. \textit Based on standard geology, only B and C are strictly correct. Following the logic of the MCQ options provided, option 2 is usually chosen, though D is technically metamorphic.*}