150kaBP以来巴丹吉林沙漠东南区域地层序列的新研究

A Recent Study on Sedimentary Sequence of Southeastern Badain Jaran Desert since 150 ka BP

巴丹吉林沙漠东南部边缘查格勒布鲁剖面中更新统/上更新统下部、上更新统下部/上更新统上部和上更新统上部/全新统的地质界线依次发生在59AGS/60L、39FD/40G和9L/10FD之沉积界面上。其时限依次大致为150kaBP、75kaBP和10kaBP,该剖面记录了150kaBP以来25个旋回的沙漠与湖相等沉积交替变更的历史过程。通过该剖面粒度和SiO2、Al2O3、Fe2O3、FeO在地层中的分布特征、软体动物化石指示的古生态等综合研究表明,所述这些沉积旋回是自那时以来,在北半球冰期间冰期气候波动影响下,冬夏古季风往复更迭所导致的非季风沙区沙漠期与间沙漠期多次正逆交替演变的结果。

The geological boundaries of the-Middle-Pleistocene/the-Upper-Pleistocene, Lower the-Upper-Pleistocene/Upper the-Upper-Pleistocene and Upper the-Upper-Pleistocene /Holocene in Chagelebulu section, situated at the southeastern of the Badain Jaran Desert, take place at the deposition interfaces of 59AGS/60L, 39FD/40G and 9L/10FD respectively and their time boundaries are roughly at 150 ka BP, 75 ka BP and 10 ka BP in turn. The study shows that the section has recorded 25 cycles of alternative change processes between desert and lacustrine depositions since 150 ka BP. Comprehensive study shows, by distribution characteristics of the grain-size and SiO_(2), Al_(2)O_(3), Fe_(2)O_(3), FeO in layers in the section and palaeoecology indicated by fossil mollusks, that the sedimentary cycles were products of many times of normal and reversal alternation evolutions between desert and inter-desert periods in the non-monsoon sandy land caused by vicissitudinary winter and summer monsoons under influence of glacial and interglacial climates in the Northern Hemisphere from that time on.