Abstract: A Survey on Groundwater Resources under the Southern Marginal Zone of Tarim Basin, Xinjiang was carried out by Xinjiang Institute of Geologic Survey in 2001.A bore (TK 17) of 400.22 m in depth was drilled so as to carry out the aging of the Quaternary strata in the Qarqin River watershed and even the southern marginal zone of Tarim Basin and reveal the relationship between the palaeogeography and the change of chemical composition of groundwater in this region by researching the palaeostratigraphic, palaeomagnetic and palaeoclimatic characteristics of the strata. The results show that the palaeomagnetic aging data accord basically with the sporo-pollen aging data, and the evolution processes of the strata formed from late-Pliocene Epoch to Holocene Epoch are revealed. Based on the palaeomagnetic aging data of the study area and the Quaternary aging data of the neighboring regions, the Quaternary strata under the Qarqin River Plain are aged as：the strata of 0～7. 0 m, 7. 0～46.6 m, 46.6～124.1 m, 124.1～368. 7 m and 368. 7～400.22 m in depth are Holocene Series, Upper Pleistocene Series, Mid-Pleistocene Series, Lower Pleistocene Series and Pliocene Series respectively, and the bottom ages of the first four strata are 0.011 Ma, 0.128 Ma, 0.78 m. a and 2.6 Ma respectively.

Key words: Qarqin River watershed, Quaternary aging, stratum, Xinjiang