Quantitative reconstruction, hierarchical division and coupling mode establishment for ancient source-to-sink systems in continental basins

Quantitative reconstruction, hierarchical division and coupling mode establishment are important means to restore the erosion and sedimentation processes for depth-time ancient source-to-sink systems in continental basins. The main difficulties in quantitative reconstruction of provenance lie in paleo-geomorphology reconstruction and paleo-drainage reconstruction. New techniques for paleo-geomorphology reconstruction use a “three-zone and five-step” restoration method based on the framework of denudation, overlap-denudation and overlap zones as well as steps of residual geomorphology reconstruction, differential subsidence correction, overlap-denudation zone restoration, denudation zone restoration and depositional paleo-geomorphology restoration. In terms of paleo-drainage system reconstruction, a quantitative restoration and picking method is resorted to based on the ArcGIS system. The division of ancient source-to-sink systems in continental basins is usually realized by using the “three-line and three-level” method, of which, picking up watersheds, water dividing lines and ridge lines are very critical before a further division of first-order, second-order, and third-order source-to-sink systems. According to the area, geometric configuration and coupling relationship of the drainage unit and sedimentary body within the reconstructed ancient source-to-sink system, this paper puts forward four types of source-sink coupling modes, i. e., “dumbbell”, “racket”, “trophy” and “javelin” modes, and thus may serve as a valuable reference for quantitative study of source-to-sink system and prediction of deep exploration targets.