论华南的板溪群及其有关的大地构造问题

On the Banxi Group and Its Related Tectonic Problems in South Chinab

研究认为板溪群为雪峰一武陵山区的一个岩石地层单位，由马底驿组和五强溪组组成，是一套正常的沉积地层而不是构造杂岩；华南不存在“华南阿尔卑斯”证据的飞来峰和构造窗；原带状大“板溪群”中含蛇绿岩外来岩块的变质岩系形成于前震旦纪。

In South China,the Banxi Group is a stratigraphic unit.It has attracted wide attentionsince K. J. Hsu et al interpreted it as a Banxi Melange in their tectonic model of“ HuananAlps”in the 1980’s. The geological studies make us believe that it is reasonable to redefine theBanxi Group as a lithostratigraphic unit composed of Madiyi and Wuqiangxi Formations in theXuefeng- Wuling mountain area. The meaning of Banxi Group in Hsu’s Banxi Melange isthat of the large“Banxi Group”used in the 1960’s and 1970’s,The stratigraphic,tectonic,isotopic and paleontologic data make it clear that:(1)the Banxi Group has a normalsedimentary sequence;(2)the subgroup of the former large“Banxi Group”is a set ofmetamorphic rocks with ophiolite blocks and was formed be fore Sinian but not in Mesozoiccollision orogeny in South China(Huanan Alps);(3)there is no structural window or klippethat can be taken as the evidence for Huanan Alps and Hsu’s concept of Banxi Melange. Asaresult,Hsu’s concept is untenable,and there is no Huanan Alps or Mesozoic collision orogenybetween the Yangtze and Huanan blocks.