点苍山新生代推覆构造的确立及其地质意义

THE DETERMINATION OF CENOZOIC NAPPE STRUCTURES OF DIANCANG MTS AND THEIR GEOLOGICAL SIGNIFICANCE

点苍山地处三江构造带东缘 ,其东侧扬子陆块上的古生代地层 ,越过洱海断裂推覆到苍山西坡的中、新生代地层之上 :下泥盆统青山组推覆至下白垩统景星组之上 ;上二叠统乌龙坝组及红岩子组推覆在始新统宝相寺组之上。三江构造带中的上三叠统歪古村组及三合洞组推覆在上侏罗统坝注路组之上。推覆时期为始新世～上新世 。

The Diancang mountains are situated along the eastern margin of three river structural zone. The Palaeozoic strata in the eastern Yangzi landmass thrust across the Erhai fault and superimposed on the Mesozoic or Cenozoic ones on the western slope of Diancang mts, such as the Lower Devonian Qingshan Formation on the Lower Cretaceous Jingxing Formation; the Upper Permian Wulongba Formation and Hongyanzi Formation on the Eocene Baoxiangsi and the Upper Triassic Waigucun Formation and Sanhedong Formation in the three river structural zone on the Upper Jurassic Bazhulu Formation. The thrusting was caused by the continental convergent compression from Eocene to Pliocene.