Question

Which are glacial lake sediments that show cycles of deposition?

Option 1: Annual rings
Option 2: Tillites
Option 3: Varves
Option 4: Unconformities

Answer 1

Glacial lake sediments showing cycles of deposition are known as varves (Option 3), which are paired layers of sediment indicating seasonal changes.

Step-by-step explanation:

Glacial lake sediments that show cycles of deposition are known as varves. Varves are distinctive pairs of light and dark sedimentary layers that often represent annual deposition within a glacial lake environment, indicating the cyclical seasons such as summer and winter.

Each couplet typically consists of a lighter layer, containing coarser or lighter-colored materials deposited during the summer when melting glaciers supply more sediment-laden water to the lake, and a darker layer, containing finer material that settles during the quieter winter months when the surface of the lake may be frozen and there is less water coming from glacial melt.