INDIAN GEOGRAPHY

Detailed explanation-1: -Igneous rock makes up 95% of crustal rock and are one of the oldest types of rockthe main rocks that are formed from intrusion are Granite, diorite, gabbro and ultramafic Rocks. Of these the most common type is the granite rock which is composed of mainly potassium and silicon rich Feldspars and quartz.

Detailed explanation-2: -The top 20–25 km of the Earth’s crust consists of approximately 95% igneous rocks or their metamorphic equivalents, 4% shale, 0.75% sandstone, and 0.25% limestone. The average chemical composition of common rocks is given in Table 1.

Detailed explanation-3: -Igneous and metamorphic rocks make up 90–95% of the top 16 kilometres (9.9 mi) of the Earth’s crust by volume. Igneous rocks form about 15% of the Earth’s current land surface.

Detailed explanation-4: -Igneous rocks are formed when molten magma formed in the lithosphere cools and crystallizes into solid rock. Magma cools slowly inside the Earth, forming rocks like granite, which have large minerals that can be seen with the naked eye. These are called plutonic igneous rocks.

Detailed explanation-5: -A wide variety of igneous rocks occur in the continental lithosphere, a reflection of its heterogeneous nature compared to oceanic lithosphere.