The integated study of sediment sources in sedimentary basins:an example from the Eogene Nanpu rift subbasin

The conventional heavy mineral techniques are effective tools for determining prove-nance orientations and properties of parent rocks,but there exist limitations because:(1) it is difficult to discriminate the source areas of limestones,dolostones and part of clastic sedimentary rocks without or with minor amount of heavy minerals,and(2)Heavy minerals cann't be used to determine accurately the main channels along which the sediments were transported.In this respect,the authors suggested that particular attention should be drawn to:(l)mineralogy and associations of heavy minerals in order to determine the types and lithologic evolution of parent rocks in the source areas;(2)mineral compositions and textures and structures of sedimentary rocks so as to ascertain whether there are unknown parent rock types and transport distance of sediments in the source areas,which cann't be recognized by means of heavy mineral analysis;(3)the analysis of depositional systems, particularly the compilation of sandstone distrbution maps aiming at effectively delimiting the position and extent of the source areas;(4)the application of palaeostructural maps to the identification of the migration channels and directions of the sediments,and(5)the com-pilation of palaeoenvironmental maps of sedimentary basins and provenances.