The western Sichuan fold and thrust belt ( WSFTB) extends the front of Longmen Shan mountain ( Figure 1), standing as an extremely important target for oil and gas exploration, and a region of high seismicity. The results also indicate that MD can alter the deformation partition in depth of any other multiple dГ©collement system. The modeled fold and thrust structures are comparable with the southern, central and northern WSFTB respectively, suggesting that varied MD may control the along-strike structural variations presented. Consequently, the fastest deformation propagation rate and farthest deformation front (in all the experiments) occurred in the middle structural level. Our experimental results illustrated that 1) Absence of MD facilitated decoupling on SD, forming the greatest contrast between subsurface deformation front and the blind one beneath SD 2) Frictional MD itself showed little decoupling, while its weakness reduced the bulk strength of deep structural level, lowering decoupling effect on SD and leading to approximating deformation fronts in the shallow and deep 3) The viscous MD, along with SD relieved the resistance on their interbed layer.

We conducted three sandbox experiments by varying this mid-level dГ©collement (MD) from absence to presence, and from frictional to viscous, to test the effect on diversity of regional structural configuration. In this paper, we focus on the third dГ©collement situated between them. The effect of regionally distributed shallow Triassic salt dГ©collement (SD) and the basal one (BD) has been well understood.

For both issues, the detailed structural configuration and deformation mechanism behind it are of great importance, but remain unclear due to the complexity created by the presence of multiple dГ©collements. It has received great attention due to high earthquake risks and rich resources of oil and gas. The WSFTB is located outboard of the eastern Tibetan Plateau, western China. 3Laboratory for Mineralogy and Petrology, Department of Geology, Ghent University, Ghent, Belgium.2Southern Marine Science and Engineering Guangdong Laboratory, Zhuhai, China.1Guangdong Provincial Key Lab of Geodynamics and Geohazards, School of Earth Sciences and Engineering, Sun Yat-Sen University, Guangzhou, China.Chuang Sun 1,2*, Zhigang Li 1,2*, Shimin Wu 1,2, Zhiyuan He 3, Shaotian Zhao 1 and Panfei Wang 1

The sandbox original author