Luminescence chronology of aeolian deposition during the Late Quaternary on the southern margin of Thar Desert, India

• Published in: Quaternary international 2003, Vol.104 (1), p.87-98
• Main Authors: Juyal, N, Kar, A, Rajaguru, S.N, Singhvi, A.K
• Format: Article
• Language: English
• ISSN: 1040-6182; 1873-4553
• DOI: 10.1016/S1040-6182(02)00137-4

Aeolian deposits constitute the uppermost lithostratigraphic unit in the southern margin of the Thar desert. They occur as poorly organized dunes resting on the upper part of a major fluvial sequence. Considerable evidence exists to show that the southern margin witnessed fluvial aggradation before the onset of dune accretion. Transition from a dominantly fluvial phase to aeolian deposition was gradational. Blue-green light stimulated luminescence chronometry of six fossil dunes indicates that the dune building activity started around 26 ka and continued episodically until around 5 ka . Evidence of a phase of landscape stability is seen corresponding to the interval 11– 9 ka . This is also reflected by the presence of Stone Age artifacts (microliths) and fluvially reworked aeolian sand, and corresponds to the strengthening of the southwest monsoon in the region. A progressive northward shift through time in the parameters controlling dune building activity is seen. Aeolian accretion in the southern part (Mahi basin) ended around 10 ka , whereas in the northern Sabarmati it continued until around 5 ka and in the case of core regions of Thar, it continued until 0.6 ka . The southern margins of the Thar Desert thus have not experienced any major aeolian deposition since 5 ka .