Leucogranite/Alaskite:

Leucogranite is an igneous rock dominated completely by the white colored minerals.

It lacks the abundance of black/dark minerals like biotite.

Neso-silicate minerals like garnet often replace the dark minerals.

Generally, granite is an intrusive igneous rock formed deep inside the earth’s crust by the process of slow crystallization (slow cooling of magma).

But it is significantly different incase of the formation of leucogranite/alaskite.

It is generally derived from the anatexis process (partial melting of the rocks).

When the metamorphosed fine grained sedimentary rocks like mudstone, siltstone also known as “pelitic rocks” undergoes the partial melting due to the maximum pressure and temperature results in the formation of leucogranite.

The partial melting of the pelitic rocks is further followed by deformation and again by metamorphism.

The heat involved in the metamorphism is produced by shear heating in the shear zone.

In case of tertiary leucogarnite/ Manaslu granite located at the Higher Himalaya Crystalline (HHC) is believed to be derived from partial melting of quartzo- feldspathic gneiss of Higher Himalaya.