Paleotectonics，paleoclimate and base level fluctuation control the attribute of basin activity，provenance system and sediment grain size，and thus determining the type and distribution of delta and beach bar sand body. Based on the systematic analysis of cores from 123 wells （total length of 4 600 m），26 outcrops and logging data of 1 078 wells，we found that delta sand body were developed in the 1st，3rd and 5th Member of the Upper Triassic Xujiahe Formation，and beach bar sand body were developed in the 2nd，4th and 6th Member of Xujiahe Formation. Delta sand body can be subdivided into fan delta，braided river delta and meandering river delta sand body；beach bar sand body can be subdivided into reverse graded and normal graded sand body. Paleotectonics，paleoclimate and base level fluctuation control the type and distribution of delta and beach bar sand body. Flat paleotopography results in the increase of seaboard width and bed form friction，due to which the seaboard water energy is low and the delta sand body is easily preserved. Basin structure controls the provenance supply，topographical gradient and flow properties，thereby determining the type and distribution of delta sand body. Episodic movement causes the alternation of tectonic quiet period and active period，thus the change of provenance properties and topographical gradient，resulting in the alternation of delta and beach bar sand body. Paleoclimate change leads to the variation of monsoon properties and vegetation：Water energy is high，delta sand body is strongly reformed and beach bar sand body is developed in a large area during the dry monsoon period；water energy is low，provenance supply is low and delta sand body is easily preserved during the mild non-monsoon period. When the base level descends，basin water covers a smaller area and delta sand body advances toward the basin；when the base level ascends，basin water has a stronger reforming capacity and the beach bar sand body is well developed.
Shi Zhensheng Qiu Zhen Dong Dazhong Zhang Chenchen Xie Wuren Hao Cuiguo. Controls of paleotectonics，paleoclimate and base level fluctuation on the type and structure of delta front：A case study of the Upper Triassic in the Sichuan Basin，China[J]. Chinese Journal of Geology, 2017, 52(1): 270-284.