Simulation experimental study on sand sedimentation in braided river delta:A case study of Sangonghe Formation in Shawan Sag
Previous studies have shown that Sangonghe Formation in Shawan Sag is a braided river delta sedimentary system,the sedimentary system is characterized by a gentle slope,extensive distribution of sand bodies,and long-distance extension,distinguishing it from the conventional braided river delta sedimentary system.In order to comprehensively investigate the sedimentary sand bodies of Sangonghe Formation in Shawan Sag and elucidate their sedimentary laws and controlling factors,we conducted sedimentary simulation experiments using a dedicated experimental platform.The simulation results demonstrate that the braided river delta sand bodies of Sangonghe Formation in Shawan Sag showed three distinct stages:vertical elongation,horizontal and vertical equilibrium,and horizontal widening.A balance point exists during the sedimentary sand body development process.The vertical connectivity and horizontal continuity of these sand bodies exhibit a close correlation with distance of source,while their superposition and connectivity can be categorized into nine different types.Under specific conditions and within a particular timeframe,a novel type of temporary channel devoid of erosion surfaces can form.The development of these sand bodies is primarily controlled by five factors:topographic slope,hydrodynamic conditions,source supply,lake level fluctuations,and tectonic forces,each factor mutually influences one another.
simulation experimentssedimentary characteristicsbraided river deltaSangonghe FormationShawan Sag
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