Environmental Evolution of the Lop Nur Region in Tarim Basin since Early Pleistocene.

Abstract

The K1 boring core was taken from the bottom of the dried up lake of Lop Nur, situated at the east margin of the Tarim Basin. This core, about 100m long, composed of mainly mud and sand with gypsum beds since the early Pleistocene, reveals an unconformity between the early Pleistocene and mid-Pleistocene. Pollen analyses made it clear that in the early Pleistocene, the forest-steppe vegetation was dominant in the region, but turned into alternation of desert steppe and desert since the mid-Pleistocene. The lake was developed probably as early as in the early Pleistocene. High percentages of Picea and total tree pollen suggest a comparatively wet condition and existence of forests near Lop Nur in the early Pleistocene. Arid environment started at the beginning of the mid-Pleistocene and it became extremely arid in the Holocene.