The optimal combination structure of the index (R) of eroding force of rainfall in hilly areas of northwest Sichuan is that the product of the total kinetic energy (∑ E) of rainfall and its maximum intensity for 40 minutes (I_(40)) is R = ∑ E ·I_(40).
The main depositional systems identified in No 1 member of Xujiahe formation, which developed in early late-Triassic gulf of NW Sichuan basin, include carbonate platform, bartier island-lagoon, and braid delta, etc.
The Markam block (I), the northwestern Sichuan sub-block (ll1), and middle Yunnan sub-block (ll2) have a southeastward horizontal sliding rate of 1-5 mm/a, clockwise rotating angular rate of 1.4-4°/Ma, and uplifting rate of about 1 mm/a.
The results indicate: 1) The landslides and debris flows are mainly in the eastern and southern area of Sichuan Province, however, there are few landslides and debris flows in the western particularly the northwestern Sichuan.
Finally, the anomalous area was concentrated to Lijiang and Yongsheng located northwestern Sichuan-Yunnan region on December 1995, and the epicenter area in future is drawn out clearly.
A few isolated earthquake type (IET) mainly occurred in northwestern Sichuan and there is no IET occurred in Yunnan region.
Carnian (upper triassic) sponge mounds of the Northwestern Sichuan Basin, China: Stratigraphy, facies and paleoecology