An important form of basin-mountain coupling: Orogenic belt and flank basin

摘要

Orogeny is always associated with the erosion and sediments carried by both transverse and longitudinal river systems. Those two river systems transport sediments into foreland or hinterland basin and flank basin. Longitudinal river systems prevail in and around the Tibetan Plateau due to the fact that they flow parallel to the strike of structures within the developing mountain belt. The flank basins surrounded the Tibetan Plateau and adjacent areas are developed in different tectonic settings, including inland, continental margin and deep ocean, most of them containing oil and natural gas. Those basins not only have longer evolution histories than foreland basins but also are more complete in their records of deposition. Coupling of orogeny and flank basin deposition also occurred widely in pre-Cenozoic time, in particular, the coupling between the Qinling orogenic belt and Songpan-Ganzi flysch flank basin is the most distinctive. The evolution of ancient latitudinal rivers derived from the Qinling orogenic belt during periods of mountain building was controlled not only by landforms but also by the lateral extrusion of the crustal fragments.