Tectonic Uplifting and Gas Pool Formation since Late Cretaceous Epoch, Sichuan Basin
四川盆地晚白垩世以来的构造隆升作用与天然气成藏

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.