• RSS
  • E-mail Alert
  • 收藏主页

古地理学报 ›› 2000, Vol. 2 ›› Issue (1): 70-76. doi: 10.7605/gdlxb.2000.01.008

• 构造古地理学及古构造 • 上一篇    下一篇

广西加里东运动构造古地理问题

吴浩若   

  1. 中国科学院地质与地球物理研究所 北京 100029
  • 出版日期:2000-02-01 发布日期:2000-02-01
  • 作者简介:吴浩若，男，1940年生，1962年毕业于北京地质学院，1966年中科院地质研究所研究生毕业，现为中科院地质与地球物理研究所研究员，主要从事地层学和古生物学研究工作。

A DISCUSSION ON THE TECTONIC PALAEOGEOGRAPHYRELATED TO THE CALEDONIAN MOVEMENT IN GUANGXI

Wu Haoruo   

  1. Institute of Geology and Geophysics Chinese Academy of Sciences, Beijing 100029
  • Online:2000-02-01 Published:2000-02-01
  • About author:Wu Haoruo, born in 1940, graduated from the Beijing College of Geology in 1962. Now he is a professor in the Institute of Geology and Geophysics, Chinese Academy of Sciences, and is engaged in palaeontology and stratigraphy.

摘要：

广西历来被认为是我国加里东运动的典型地区，志留纪末的造山运动使早泥盆世莲花山组砾岩不整合于下伏地层之上。但是，实际上莲花山组只分布于广西中部的大明山－大瑶山地区和东北部扬子地块边缘，并且，它不具备同造山期磨拉石沉积特征，而是古陆剥蚀面上新海侵序列底部的滨海相沉积。广西西部的晚古生代台地相区，泥盆系底部为泥岩或粉砂岩，超覆于寒武系台地相沉积层之上。滇东南和越南北部邻区情况类似。推测在早古生代时它们属于一个地块，可称为“桂滇－北越地块”。早奥陶世云开地块和桂滇－北越地块、扬子地块的会聚和挤压，形成了大明山－大瑶山地体寒武系东西向的线形褶皱带。这是广西加里东运动的主幕。晚奥陶世—早志留世华夏地块和扬子地块的碰撞带在广西仅限于它的东北部，表现为震旦系—下志留统近南北向的线形褶皱带。志留纪末并无造山运动的证据。早泥盆世开始，可能由于地幔柱活动而使桂滇－北越地块裂解，形成北越地块、靖西台地和其他更小的块体。

Abstract:

Guangxi is usually regarded as a typical area of the Caledonian Movement in China, where the orogeny at the end of Silurian caused the conglomerates of the Early Devonian Lianhuashan Formation to rest unconformably on the underlying strata. However, the distribution of the Lianhuashan Formation is limited in the DamingshanDayaoshan area in central Guangxi and the marginal area of the Yangtze platform in northeastern Guangxi. Furthermore,these conglomerates don't display any characteristics of the synorogenic molasse deposits but have evidences of littoral deposits which are preserved as the basal part of a new transgression sequence on the erosional surface of an ancient land.In the Late Palaeozoic shallowmarine platform area of the western Guangxi,the Lower Devonian mudstones or siltstones onlap to the Cambrian platform strata. The same situation can be found in the adjacent areas such as southeastern Yunnan and North Vietnam. This means that during the Early Palaeozoic these areas belonged to a same block. The name“GuangxiYunnanNorth Vietnam Block” or “GYNV Block” in brief is suggested here. The convergence and compression between the Yunkai Block and the GYNV Block as well as the Yangtze Block during the Early Ordovician led to the formation of the EW oriented Cambrian linear fold belts in the DamingshanDayaoshan terrane. This was the main phase of the Caledonian Movement in Guangxi. The Late Ordovician—Early Silurian collision belt in Guangxi, between the Cathaysian and Yangtze blocks, can only be seen in its northeastern part, and this belt is presented as  the NS oriented Sinian—Early Silurian linear fold belt. There is no evidence on the orogenic process at the end of the Silurian. Since the Early Devonian, due to plume activity the GYNV Block had disintegrated into the North Vietnam Block, Jingxi Platform and the other smaller blocks.