Sedimentary Provenance Analysis of the Chang 9–Chang 10_1 Depositional Stages of the Late Triassic Yanchang Formation of the Ordos Basin

The determination of the provenance of sedimentary material is an important step in determining the paleogeography of sedimentary basin;this article presents new data for Late Triassic sedimentation associated with the Yanchang formation in the giant inland Ordos basin catchment.Analysis of paleocurrent directions,composite characteristics,and the spatial distribution of heavy and light minerals within the Chang 101 and Chang 9 depositional stages of the Yanchang formation indicates that sediments within the basin have four distinct provenances,being derived from the northeast,east,south and northwest.Of these 4 provenance directions,the majority of sediment was derived from the northeast and northwest,with sediments derived from the east and south only present in localised areas of the basin.In terms of temporal changes between the Chang 101 and Chang 9 depositional stages,an increase in material with an eastern provenance is coincident with a decrease in material derived from the west,in addition to a change in provenance direction from southwest to more directly south.