摘要
对取自1980—1986年的样品分析表明:云南断陷湖泊自上新世随着区域性隆起断裂拉张形成以来,经历了裂陷早期沼泽、深陷期深水、充填后期浅水的构造-沉积演化阶段,揭示了深水湖泊以重力流为特色;中等水深湖泊横向搬运以重力流、纵向搬运以三角洲为特色;浅水湖泊以河流三角洲为特色的沉积模式。
1. Lakes in Yunnan and Tibet plateaus, which developed along with regional deep-great belts during Pliocene and Early Pleistocene are of unity and synchronism in spacial and temporal distribution. These lakes were formed by tensional faults with regional upheaval and dissociation of Yunnan Plateau, as a result of collision of Indian Plate with Tibet Plate.2. According to the comprehensive analysis of spore-pollen, molluska, ostracoda, age dating of paleomagnetic, 14C and uranium series, and sedimentary sequence obtained from deep cores, it can be found that the strata may be regarded as a continue accumutation in 3.4Ma including the periods of upper Pliocene, Pleistocene and Holocene. The evolution process of lake basin shows a shallow-deep-shallow environmental change.3. The largest thickness and rate of sedimnt in fault basin are not located in their geometrical center, but in one side near the main fault. For the sedimentation pattern of the fault basin, there exist two transport systems, longitudinal and lateral, the latter can be divided into steep slope and gentle slope. All these features show that the sedimentary process was controlled by fault action in the lake basin.4. Tectonic-sedimentary evolution in fault basin has experienced the following general trend: limnology stage of preliminary tension, deep water stage of strongly sagging period and shallow water stage of late filling period, lithologically experienced: coarse-fine-coarse. Different models of sediment can be formed in each stages.
出处
《海洋与湖沼》
CAS
CSCD
北大核心
1991年第6期509-516,共8页
Oceanologia Et Limnologia Sinica
