The desert region of India has two parts-The Great Desert and the Little Desert. The Great Desert extends from the edge of the Rann of Kutch
beyond the Luni River northward. The Little desert extends from the Luni between Jaisalmer
upto the northern wastes. Between these two deserts lies a zone of absolutely sterile country consisting of rocky land and cut up by limestone ridges.
A prehistoric river channel, the Ghagger, passes through the desert. It can be traced for 600 miles from Punjab in India to Sindh in Pakistan. The Ghaggar basin once drained in to the Rann of Kutch, and probably formed a part of the Indus basin. The Rann of Kutch is now a salty marsh land inundated seasonally during the summer monsoon