TECTONIC EVOLUTION AND PALEO-PLACER GOLD PROSPECT OF JIAODONG AREA
Sun Yan Tan Qixin Han Chunrui Liu Xiqing Liu Qirong(Institute of Marine Geology,MGMR,Qingdao,266071,China)
Jiaodong massif,a product of the coaction of subduction-obduction and nappe-shear-ing translation-shearing during land-land collision of North China landmass and LowerYangtze landmass,is composed of 3 secondary tectonic elements,namely,Jiaobei massif,Jiao-Rong terrane and Wu-Rong juncture.And the massif has experienced 4 evolutionarystages,that is,isolation,collision-combination, basin development and post-basin re-working.This paper is an approach to sedimentary formations,teconic changes,magmat-ic activity,lithofacies and paleogeography of the 4 evolutionary stages,and their rela-tions with placer gold are analyzed. Structural layers formed during the latter two evolu- tionary stages are placer-gold targets,represented by Laiyang Formation and WangshiFormation of Cretaceous and Huangxian Formation and Yaoshan Formation of Ceno-zoic. We should pay special attentions to ancient channels,lake deltas and ancientresidues in the formations. And prospect areas are north edge of the Laiyang Basin,south edge of the Huangxian Basin and the transitional zone to the Jiaobei uplift.