Question

What are sills
What are dykes

Answer 1

Explanation:

sills are shelf or slab of stone or wood

or it is a strong horizontal beam forming a base in the frame of a timbered building

dykes means is a sheet of rock that formed in a fracture in a pre - existing rock body

Answer 2

Sills and Dykes

Explanation:

     1. Sills:-

• A sill is a sheet like igneous body which runs parallel to the bedding planes of the pre-existing strata.

• These may be horizontal, inclined or vertical that depends upon the attitude of the strata in which they are intruded.

• Sills vary in thickness from a few centimeters to several hundred metres but they are always thin as compared to their length along beds.

• Sills are commonly made up of dolerites and basalts.

   2. Dyke-  

• A dyke is a wall like igneous body that cuts across the strata of the pre-existing rocks.

• Dykes are often vertical or steeply inclined.

• Their thickness varies from a few centimeters to a hundred meter or more.