Provenance analysis of the Yanchang Formation in eastern Gansu,Ordos Basin

The synthetic analysis of REEs in mudstone,carbonate debris contents,light and heavy minerals and grain sizes of sandstone in the Chang-3 oil reservoirs shows that the sediments dominantly come from the northeast and southwest in eastern Gansu,Ordos Basin.The provenance boundaries are approximately arranged in the Nanliang-Huachi region in the northeast,and in the Yuele region in the southwest.