ow igneous rocks are formed?What are the different types of igneous rocks

Igneous rocks are formed through the cooling and solidification of magma or lava. The process can occur below the surface of the Earth, forming intrusive igneous rocks, or on the surface, forming extrusive igneous rocks. Here are the steps:

1. Magma Formation: Magma, which is molten rock beneath the Earth's surface, is formed when temperatures are high enough to melt rock, or when pressure decreases enough to allow solid rock to melt, or when water is added to hot solid rock.

2. Magma Ascent: The magma rises through the crust because it is less dense than the surrounding rock. It can rise through cracks or it can melt the rock it comes into contact with to create a path.

3. Magma Eruption or Intrusion: If the magma reaches the surface, it erupts as lava. If it cools and solidifies before reaching the surface, it forms an intrusion.

4. Cooling and Solidification: The magma or lava cools and solidifies, forming igneous rock. If it cools slowly, beneath the surface, it forms coarse-grained intrusive igneous rocks like granite. If it cools quickly, on the surface, it forms fine-grained extrusive igneous rocks like basalt.

There are two main types of igneous rocks:

1. Intrusive Igneous Rocks: These rocks form from magma that cools and solidifies within the crust of the planet. Granite is the most common type of intrusive igneous rock.

2. Extrusive Igneous Rocks: These rocks form from lava that cools and solidifies on the planet's surface. Basalt is the most common type of extrusive igneous rock.