2022 JUN 18
Geography > Places in news > Places in news
About Theri Desert:
- Most of us may not know the small desert situated in the state of Tamil Nadu. It consists of red sand dunes and is confined to the Thoothukudi district.
- The red dunes are called theri in Tamil.
- They consist of sediments dating back to the Quaternary Period and are made of marine deposits.
- They have very low water and nutrient retention capacity.
- The dunes are susceptible to aerodynamic lift.
- This is the push that lets something move up. It is the force that is the opposite of weight.
Mineral composition of Theris
- The analysis of the red sand dunes reveal the presence of heavy and light minerals.
- These include ilmenite, magnetit, zircon, hematite, quartz etc.
- The iron-rich heavy minerals like ilmenite, magnetite and rutile present in the soil had undergone leaching by surface water.
- They were then oxidised because of the favourable semi-arid climatic conditions.
How did they form?
- Theris appear as gentle, undulating terrain.
- The lithology of the area shows that the area might have been a paleo (ancient) coast in the past.
- The presence of limestone in many places indicates marine transgression.
- The present-day theris might have been formed by the confinement of beach sand locally, after regression of the sea.
- When high velocity winds from the Western Ghats blew east, they induced migration of sand grains and accumulation of dunes.
Theri Desert is located in which of the following states in India?
(c) Tamil Nadu