Earth Science

The velocity of S-waves decreases in the asthenosphere due to the presence of partially molten rocks, which reduce the rigidity of the medium. This property indicates that the asthenosphere is a mechanically weak layer within the Earth’s upper mantle.

Connate water is the water that gets trapped within the pores of sedimentary rocks during their formation. It is ancient water, distinct from meteoric or underground water, and may contain high salinity due to its long isolation.

1. A watershed is an area of land that channels precipitation and snowmelt to a common outlet, such as a river or lake.
2. It is delineated by topographical divides that separate drainage basins.

Corundum has a hardness of 9 on the Mohs scale, making it one of the hardest natural minerals, second only to diamond.

- Feldspar is a silicate mineral (A - II).
- Gypsum belongs to the sulphate group (B - IV).
- Azurite is a carbonate mineral (C - III).
- Halite is classified as a halide (D - I).

Muscovite and Biotite are mica minerals with a platy crystal habit, characterized by their ability to split into thin, flexible sheets.

Rhyolite is an extrusive igneous rock, while granite is its plutonic equivalent, meaning it crystallizes below the Earth’s surface with similar mineral composition.