Compositional relationship between the source-to-sink segments and their sedimentary response to diverse geomorphology types in the intrabasinal lower uplift of continental basins

Abstract

Investigating on new method for Source-to-Sink study by integrating modern system and subsurface interpretation, establishment of the quantitative coupling model from source to sink, and form industrial application standard have long been the research trends of Source-to-Sink system in continental basins. Here the symmetrical and asymmetrical conceptual source-to-sink coupling models (i.e., Symmetrical Dumbbell Type and Asymmetrical Dumbbell Type) are proposed to respond to diverse geomorphology types (i.e., convergent and unitary incised type) based on the morphological and digital proportion between catchment-drainage unit of upstream and sediment-fan of downstream, then summarize and extract the two models by contrasting a modern source-to-sink system of Hovd Central Uplift in northwestern Mongolia as well as an ancient source-to-sink system of Huizhou-Lufeng Lower Uplift in Pearl River Mouth Basin, South China Sea. In the practical study, the satellite remote sensing and Google geological map are used to deconstruct the modern case and combine the Google-topographic-map, well log data, core data and seismic-geomorphology analysis to dissect the ancient case analogously. This paper mainly discusses morphological proportional ranges of catchment acreage (Asource) and sediment fan acreage (Ssink), the relativity between topographic gradient (Gsource) and the source ratio (Rsource=AsourceAsource+Ssink), and the physical properties of sedimentary sand-body associated with diverse geomorphologic types in continental lacustrine basins. Therefrom, it is concluded that the proportion (P=Asource:Ssink) between catchment-drainage segment of source area (Asource) and sediment-fan of depositional sink (Ssink) is over 1:1 in Symmetrical Dumbbell Type source-to-sink coupling model, which is commonly between 1:1.1 and 1:1.6; However, it is below 1:1 in Asymmetrical Dumbbell Type source-to-sink coupling model, which is generally between 1:0.6 and 1:0.9; and there is an evident negative correlation between topographic gradient (Gsource) and the source ratio (Rsource). Finally, these results reveal that the reservoir formed by Symmetrical Dumbbell Type source-to-sink coupling model performs much more superiority. In summary, the two coupling models have not only supplied a new insight into the research on sandy-sediments transport and distribution, but also defined the directions for better finding favourable sand bodies (reservoir) when exploring oil and gas.