滇西昌宁—孟连带西区两个地层问题——兼论昌宁—孟连带的闭合造山过程  

A Discussion on Two Problems Concerning the Stratigraphy of the West Zone in the Changning-Menglian Belt, Western Yunnan, China

作　　者：方宗杰[1] 王玉净[1] 周志澄[1] 王成源[1] 郭震宇[1] 肖荫文 

机构地区：[1]中国科学院南京地质古生物研究所,江苏南京210008 [2]云南省地质矿产局区调所,云南玉溪653100

出　　处：《地层学杂志》2000年第3期182-189,共8页Journal of Stratigraphy

基　　金：国家自然科学基金项目!( No.49672 14 7)研究成果之一。

摘　　要：对昌宁—孟连带西区的两个地层问题进行了讨论。根据牙形刺和放射虫的发现将原定为拉巴组的塔拉弄—南雅条带的时代厘定为晚泥盆世至早石炭世 ,时代大致与南皮河群的弄巴组或“中区”的“上泥盆统”相当 ,它们之间的确切关系仍有待进一步研究。怕拍组实际上主体属晚二叠世晚期 ,仅顶部可能包含有少量下三叠统印度阶最底部的沉积。对怕拍组的研究证实了澜沧运动的存在 ,昌宁—孟连带自此开始了由海洋盆地向造山带的演变进程 ,这一过程持续达七千万年之久。The “Pseudo Laba Formation” of the Talalong Nanya outcrop belt of the west zone in the Changning Menglian belt was formerly classed as Permian, but now because of the discovery of conodonts and radiolarians, the age of this outcrop belt can be closely estimated as Late Devonian (Famennian) to Early Carboniferous. We determine the main part of the Papai Formation by radiolaria to be Upper Permian and probably upper Changhsingian in age. However, the uppermost of the Papai Formation has a Claraia fauna and is assigned to the Griesbachian of Uppermost Permian to Lowermost Triassic age. The sedimentary features of the Papai Formation indicate the style of syndepositional tectonism and can be comparable to the piggyback basin in mechanism. This marks the beginning of the Lancang Orogeny that 1asted for 70 Ma until the Middle Jurassic.

关 键 词：泥盆纪 石炭纪 二叠纪 三叠纪 闭合造山过程 

分 类 号：P534.4[天文地球—古生物学与地层学] P534.51[天文地球—地质学]