Affiliations: [a] School of Resources and Geoscience, China University of Mining and Technology, Xuzhou, Jiangsu, China
| [b] General Prospecting Institute China National Administration of Coal Geology, Beijing, China
| [c] College of Geoscience and Surveying Engineering, China University of Mining and Technology, Beijing, China
| [d] Petrochina Huabei Oilfield Company, Renqiu, Hebei, China
| [e] China National Offshore Oil Corporation Research Institute, Beijing, China
| [f] University of Calgary, Calgary, Alberta, Canada
Abstract: Various analogue models are applied to research the structural evolution of fold-and-thrust wedges. Numerical models are used to explore the fold-thrust wedges and some enlighting research has been made. But combination of the two models have rarely been given sufficient attention. Up to now, landward-vergent thrust wedges, which are uncommon in nature, have not yet been adequately explained and can only be reproduced in a few analogue models under particular conditions. In order to look closer at the formation conditions of fold-and-thrust wedges and to explore the origin of landward-vergent thrust wedges, we conducted a series of analogue and numerical models under different conditions of substrate. Results of our models revealed that in the frictional basal substrate, and under conditions of a large coefficient of frictional basal, it deformed the fold-and-thrust wedges. Purely landward-vergent thrusting wedge has formed, in the presence of an extremely weak or ductile basal décollement. The number of Landward-fault and fault displacement decreased, when the thickness of the ductile basal increased or the velocity decreased.
