塔里木盆地地震剖面地质解释及其构造演化

Geological interpretation of the seismic profile in Tarim Basin and tectonic evolution of this area

从地震剖面显示塔里木盆地发育为手风琴式演化史,大体上形成三层"断-坳"结构:(l)震旦系的"断",古生界—三叠系的"坳";(2)侏罗系的"断",白垩系的"坳";(3)古近系的"断",新近系的"坳"。断陷与坳陷分别由拉张与挤压应力场所致,这种应力场的变化是由相邻洋壳板块俯冲倾角由小到大的变化所引起的。由于地壳的多旋回运动,多次发生构造沉积演变,构成了多套生储盖组合,多领域、多种圈闭类型的油气藏,从震旦系—古生界—中生界—新生界,各断陷-坳陷结构的盆地都具有可能形成油气藏的地质条件。

Seismic Profile shows that the Tarim Basin has experienced a violin-style evolutionary process formation of the three-layer （fault subsidence-depression “ structure： （1） Sinian”fault subsidence which has led to the and Paleozoic-Triassic ＂depression＂ ; （2） Jurassic ＂fault subsidence＂ and Cretaceous ＂depression＂; （3） Paleogene ＂fault subsidence＂ and Neogene ＂depression＂. The fault subsidence and the depression resulted respectively from the pull-apart and the squeezing stress field, and the variation of such a stress field was caused by the subduction dip angle variation of the neighboring ocean crust plate from small to large. The polycyclic movement of the earth＇s crust led to the repeated tectonic-sedimentary evolution and produced quite a few oil-generating-oil-bearing-covering assemblages which formed oil-gas accumulations characterized by varied fields and varieties of trap styles. From Sinian through Paleozoic, Mesozoic to Cenozoic, basins with the fault subsidence-depression ＂ structure were all likely to have geological conditions favorable for the formation of oil-gas accumulations.