【摘要】 昌宁-孟连构造带属于滇西古特提斯造山带的一部分,代表了古特提斯多岛洋的主洋盆沉积地层记录.空间上,它向南与泰国西北部的清迈构造带相连,向北可以与青藏地区的改则-碧土构造带对比.在清迈构造带,已经发现早泥盆世至晚三叠世含放射虫硅-泥质岩地层记录;在改则-碧土构造带,也已经报道有拉丁期和卡尼期含放射虫硅-泥质岩地层序列.在昌宁-孟连构造带,已知最年轻的放射虫组合时代为安尼期.最近,笔者在昌宁-孟连构造带中部耿马地区拉巴群样品中发现新的放射虫组合,可以与Oertlispongus inaequispinosus亚带对比,其地质时代为拉丁期早期.因此,昌宁-孟连构造带深水盆地的封闭时代应在拉丁期之后.该成果为研究昌宁-孟连古特提斯盆地演化提供了新的资料.更多还原

【Abstract】 As a part of the Paleo-Tethyan orogenic belt in west Yunnan,the Changning-Menglian belt holds the sedimentary records formed by the main branch of the Archipelagic Paleo-Tethyan Ocean.It can be linked with the Chiang Mai belt southwardly and with the Gertse-Bitu belt northwardly.The Early Devonian-Late Triassic pelagic sedimentary strata with radiolarians have been discovered in the Chiang Mai belt and the Ladinian and Carnian radiolarian fauna have also been found in the Gertse-Bitu belt.But youngest radiolarian zone from the Changning-Menglian belt is the Anisian Triassocampe deweveri Zone.Recently,the Ladinian Oertlispongus inaequispinosus Subzone was gotten from chert in Gengma area,the middle ChangningMenglian belt.The fauna shows that the Changning-Menglian Paleo-Tethyan basin was closed after the Ladinian.Younger radiolarian fauna should be further investigated in the Changning-Menglian belt.更多还原