Using 90–125 μm grains of quartz extracted from sediments, the equivalent dose absorbed since burial was derived by exposing aliquots of quartz to a sunlamp, regenerating the TL growth curve by artificial irradiation and comparing the natural TL of the sample being dated, as well as that of an adjacent surface sample, to this curve.The age can then be calculated once the dose rate is known.
A review of the aeolian sedimentary record of the Thar desert is presented.
This includes a regional survey of the major dune forms, their genesis and their relationship to climate and other regional landforms.
, accumulated at various depths in a stabilised dune at Budha Pushkar, Rajasthan, show inversion with respect to ‘stratigraphy’.
Occurrence of younger carbonates overlain by older ones at various levels, is interpreted in terms of a shift in climatic conditions causing pedogenic carbonates to be leached to greater depths.
The TL dates at Amarpura suggest that the dune building activity at Amarpura in the Rajasthan desert terminated at around 13,000 years B.
Mejdahl, Risoe National Laboratory, DK-4000 Roskilde, Denmark.
Loess of late Quaternary age mantles most of Nebraska south of the Platte River Valley.
At least five late Quaternary loesses are recognized: from oldest to youngest, one or more undifferentiated pre-Illinoian loesses, the Loveland Loess, the Gilman Canyon Loess, which exhibits a well developed soil and rests unconformably on the Sangamon soil, the Peoria Loess capped by the Brady soil, and the Bignell Loess, which is distributed discontinuously.
A key aspect of this work is the chronometry of the dunes using luminescence methods.