Clastic Rock Geochemical Properties and Its Trace to the Source Area Structures of Yanchang Formation in Lingtai County in Gansu Province

The characteristics of petrochemistries, microelements and rare earth elements of sandstone samples from Chang9-10 members of Yanchang Formation of ling1 well are systematically studied. By using structural distinguished figures of different macroelements and microelements, the source area structural attributes of ling1 well are analyzed and discussed. The results show that: The microelement content in sandstone samples of Yanchang Formation from ling1 well area is stable; In microelement distribution curves, light rare earth elements (LREE) are evidently concentrated but heavy rare earth elements(HREE) are depleted; According to the structural distinguished figures of different macroelements and microelements, the structural backgrounds of source area are mainly active continental margin and islands; The Ling1 well area is located in hinterland in Odors basin, its sediments are mixed provenance, and its evolution course is controlled by Qinling orogenis belt which results from combination Huabei plate with Yangtze plate. To late Triassic, Qinling orogenis belt became stable source area of Ling1 well.