Characteristics Of Transport Pathways In Component Units Of Source To Sink Systems And Quantitative Prediction On Sedimentary Bodies Under Its Control

Transport pathways in source,conduit and sink units of source-to-sink systems(S2S)are the important bond connecting the three units.By the research about transport pathways in ancient and modern S2 S in qualitative and quantitative analysis,the main features of transport pathways have been defined and finely described in this paper,and the quantitative prediction of sedimentary bodies with parameters related to transport pathways has been discussed,which provides important reference value for the future quantitative analysis.For the chosen modern S2 S,on the one hand,the characteristics of transport pathways in modern S2 S have been analyzed in two aspects——types and scales.On the other hand,with the comprehensive research of recognition about sediment transport channels and the analysis of seismic facies,seismic attributes and sedimentary models,the transport pathways in the three units have been described specifically in ancient S2 S.Based on this analysis,by using the statistical analysis of transport pathways,the method of the quantitative prediction about the sedimentary bodies has been discussed with examples.The main results obtained in this paper as followings:1)For transport pathways in modern S2 S,in the first stepped terrain of China,transport pathways in the three units show different characteristics:(1)Transport pathways in the source unit are mainly shapes of convergence and parallel,of which the former has the wider channel about tens to hundreds of meters while the later has the narrower channel about only tens of meters.(2)Transport pathways in the conduit unit are mainly shapes of trunk,parallel or pinnate,which can be divided into two types in scales——long and short distances,the differences of which show typically on the main stream,river sinuosity and tributary,which are proved to have obvious links to longest channel with the multivariate regression analysis.(3)Transport pathways in the sink unit has the simple shapes,of which the most show dendritic,and the scales behave uniformly for many factors.2)For transport pathways in ancient S2 S,the analysis of seismic data in BZ12 Block shows that:(1)In the source unit,incised valleys and channels are the main transport pathways;(2)In the conduit unit,incised valleys,faulted troughs and structural transfer zones are the main transport pathways;(3)In the sink unit,the characteristics of transport pathways include four aspects: the widest progradation angle of the main stream,the farthest distance of the main stream,the thickest deposition and the mound seismic reflection configuration in vertical profile.3)Based on the parameters of transport pathways statistic from the geological field,the quantitative relation has been defined in the first stepped terrain between the sedimentary bodies and catchment area,longest channel and width of river estuary by the regression analysis.The majority of the S2 S have been proved that the statistics of fan area are consistent with the predicted values.The validity has been further verified with the examples of Ayakekumu Lake,Qinghai Lake,Issyk-Kul Lake and Erhai.