作者:CHENG Rihui WANG Pujun LIU Wanzhu TANG Huafeng BAI Yunfeng KONG Qingying SONG Weihai
摘要:The characteristics of the Triassic sequences developed in the Lower Yangtze area display some great changes in both environment and climate. The change of environment was a transition from marine to continent via alternating environments. The change of climate was a transition from tropic (torrid) to warm and wet climate via subtropic dry climate. The type variations of the sequences were from the marine sequences to the continental sequences, corresponding to the changes of environments and climates.Sequence 1 is a type Ⅱ of sequence of mixed clastic and carbonate sediments; sequence 2 is a type Ⅰ of sequence of carbonate platform; sequence 3 is a type Ⅰ of sequence of carbonate tidal flat-salt lagoon,sequence 4 is a type Ⅱ of sequence of lacustrine within marine layers, and sequence 5 is a sequence of lacustrine-swamp. The development, distribution and preservation of those sequences reveal the tectonic controls and their changes in the background. The collision between the Yangtze plate and the North China plate was a great geological event in the geological history, but the timing of the collision is still disputed.However, the characteristics of Triassic sequence stratigraphy and sea level changes in the Lower Yangtze area responded to this coliision. The collision started at the beginning of middle Triassic and the great regression in the Lower Yangtze area started 22Ma earlier than those in the world. The tectonic conditions occurred before and during the collision controlled the development of sequences and type changes.
发文机构:College of Earth Sciences
关键词:三叠纪序列气候构造运动沉积岩Yangtze plateNorth China plateLower Yangtze areaTriassicsequenceresponse
分类号: P542[天文地球—构造地质学][天文地球—地质学]P588.2[天文地球—岩石学][天文地球—地质学]