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通过对西藏札达盆地古格组剖面的实际调查以及沉积物粒度、磁化率、碳酸盐等环境指标的分析,结合古地磁和ESR法测年资料,探讨了古格组4.4-2.74Ma的沉积环境变化。分析结果表明4.4Ma象泉运动以后,札达盆地沉积环境发生了显著变化,沉积环境由前期河流相沉积向湖相沉积转变。形成了厚度达500余米的古格组沉积,反映札达古湖沉积由滨湖-浅湖-半深湖-滨浅湖阶段的变化,即湖泊产生-发展-消亡的全过程。其发育过程与晚新生代以来高原隆升以及气候、环境变化密切相关。
Based on the actual investigation of the Guge formation in Zanda Basin, Tibet, and the analysis of the sediment grain size, magnetic susceptibility and carbonate environmental indicators, the paleomagnetic and ESR dating data are used to investigate the characteristics of the Guge formation from 4.4-2.74 Ma Depositional environment changes. The results show that the sedimentary environment of Zanda Basin changed significantly after 4.4Ma spring movement, and the sedimentary environment changed from previous river facies deposition to lacustrine deposition. The sedimentation of the Guge Formation with a thickness of more than 500 meters is formed, which reflects the whole process of sedimentation of the Zanda Lake from lakeside to shallow lake to semi-deep lake to shore-shallow lake. Its development is closely related to the uplift of the plateau and the climate and environment since the Late Cenozoic.