Dunes
–Longitudinal Dunes
–Crescent Shaped Dunes
–Transverse Dunes
1. Longitudinal Dunes
- These are mostly run from south west to north east
- Parallel to the prevailing winds & mostly sword-shaped type.
- Its Longer axis is parallel to the direction of wind
2. Transverse Dunes
- These types of dunes are formed across the wind direction.
- Commonly found in eastern & northern parts of Marusthali.
- Windward side is long & gently sloping, while leeward side is steep and abrupt.
- These are also called U-shaped dunes.
3. Crescent Shaped Dunes
- The Width of these types of dunes varies from 100 m to 200 m height of dunes-10 m to 20 m.
- The dunes have a gently sloping convex windward side & steep leeward
- These are found in isolation or occasionally side by side in lines.
2. Dune Free Tract
- It is rocky but dune free tract.
- Bikaner, Jaisalmer, Phalodi & Pokhran are known as dune free areas.
- Limestone & Sandstone rocks exposes here belong to Jurassic & Eocene formations.
- Gneiss, Grid conglomerate, schist & granite rocks are also exposed at places.