四川盆地晚白垩世以来的构造隆升作用与天然气成藏

四川盆地及其周缘地区在喜马拉雅期发生了强烈的隆升运动。除川西坳陷外四川盆地内部自晚白垩世后一直处于隆升阶段，但各地区有差异，主要的隆升期是新近纪（隆升速率超过100 m/Ma，隆升幅度超过4 200 m），隆升的阶段性明显, 可分成3个阶段：第1阶段（晚白垩世-古近纪），为差异隆升阶段，大部分地区处于隆升状态，但隆升的速率有差异； 第2阶段为整体隆升阶段，全盆地都处于隆升状态，整体隆升幅度大，速率一般大于40 m/Ma，隆升幅度超过1 000 m；第3阶段为快速隆升阶段，全盆地的隆升速率除川西坳陷外均大于100 m/Ma，隆升幅度超过1 500m。四川盆地周缘造山带自晚燕山期以来均是隆升状态，亦可分为3个阶段：第1阶段（120~65 Ma），隆升速率15~93 m/Ma，隆升幅度一般在1 000 m左右；第2阶段(65~25 Ma)，隆升较慢，速率一般在5~47m/Ma，隆升幅度为250~1 800 m；第3阶段（25 Ma至今）， 隆升速率高，为60~300 m/Ma，隆升幅度从1 300 m到大于 3 000 m。喜马拉雅期隆升作用一方面控制了现今构造的形成，另一方面引起能量场调整(压力和温度效应)，促使地层势能的转换和油气的再运聚，对于油气最终运聚成藏起了重要的作用。 四川盆地无论中下组合碳酸盐岩气藏还是上组合碎屑岩气藏的形成都与喜马拉雅期隆升作用息息相关, 大型天然气藏具有晚期定型、快速成藏、大量集中聚集的特征，即速度快、规模大、分布集中的天然气爆发式成藏。

Tectonic Uplifting and Gas Pool Formation since Late Cretaceous Epoch, Sichuan Basin

The strong tectonic uplifting took place since late Cretaceous epoch in the Sichuan Basin and its peripheral orogenic zones. Except the west Sichuan foreland basin, the whole Sichuan basin was in the state of uplifting since late Cretaceous epoch. However, the uplifting characteristics are diverse in different parts of the basin. The uplifting process could be divided into three stages. The first stage, namely differential uplifting stage, is from the late Cretaceous epoch to the Eogene period. Most of the basin was raised with differential uplift velocities in this stage. The second stage is called the whole basin uplifting stage, with the uplifting rate of more than 40m/Ma and the uplifting height of more than 1 000m. The third stage is the fast uplifting stage with the uplifting height of more than 1 500m and the velocity of more than 100m/Ma except the west Sichuan basin. The Himalayan uplifting is not only to control the formation of the modern structures, but also to adjust the energy field (temperature and pressure) in the basin. The adjustment of the energy made fluids re\|migrate and took an important part in the formation of the natural gas pools in the basin. The hydrocarbon accumulations there from Palaeozoic to Mesozoic, both carbonate and clastic rocks, are also related to the Himalayan uplifting. The big natural gas fields (pools) in the basin have the following characteristics: late finalization, fast formation of hydrocarbon pools, vast quantity accumulation of hydrocarbon, namely fast velocity, large scale and concentrated distribution.