| PDF: | |
| Time: | 2004 |
| Journal: | Geotectonica et Metallogenica |
| Volumn: | 28 |
| Issue: | 2 |
| Pages: | 134-141 |
| Type: | Other |
| Author: | Rihui Cheng,Pujun Wang,Wanzhu Liu,Huafeng Tang,Yunfeng Bai,Qingying Kong,Weihai Song |
Abstract: | The characteristics of sequences developed during Triassic in Lower Yangtze area reflect a great change in environment and climate.The change of environment was a transition from marine to continental via a marine-continental alternating environment.The change of climate was a transition from tropic (torrid)to warm and wet through a subtropic dry climate.The type variations of sequences corresponding to the changes of environment and climate were from type II sequence of mixed clastic and carbonate rocks, type I sequence of carbonate platform and type I carbonate tidal flat-salt lagoon to type II sequence of lacustrine within marine layers and sequence of lacustrine-swamp.The development, distribution and preservation of those types of sequences reveal the tectonic controls and their changes in the background.Collision between Yangtze Plate and North China Plate was a great geological event in geological history, but the timing of the collision is still disputed.However, the characteristics of Triassic sequence stratigraphy respond to this collision .The collision started at the beginning of middle Triassic and the great regression in the Lower Yangtze area started about 22Ma earlier than that in the world.The tectonic conditions before and during the collision control the sequence development and the type changes. |