石油与天然气地质 ›› 1983, Vol. 4 ›› Issue (3): 236-245.doi: 10.11743/ogg19830301

• 论文 •    下一篇

贺兰坳拉槽与前渊盆地及其演化

孙国凡, 刘景平   

  1. 地质矿产部第三普查勘探大队
  • 收稿日期:1982-11-29 出版日期:1983-09-25 发布日期:2012-01-16

HELAN AULACOGEN AND FRONT BASIN AND THEIR EVOLUTION

Sun Guofan, Liu Jingping   

  1. The 3rd Brigade of Petrolenum Prospecting and Exploration, Ministry of Geology and Mineral Resources
  • Received:1982-11-29 Online:1983-09-25 Published:2012-01-16

摘要:

鄂尔多斯西缘在大地构造属性上往往被认为具地槽、地台过渡带性质,并给以"鄂尔多斯西缘过渡带"、"鄂尔多斯台缘坳陷"等称谓。但是,南北方向的鄂尔多斯西缘过渡带与北西西方向的祁连加里东褶皱带几乎近直角相交,二者显得极不协调;并且这一南北方向的过渡带北段,被夹持于鄂尔多斯地台与阿拉善地块之间,因而仅用"过渡带"来简单解释鄂尔多斯西缘地区的大地构造性质似嫌不足。笔者认为以坳拉槽(Aulacog-en)(中元古代-古生代)及前渊盆地(中生代)的形成发育机制阐明该区的大地构造性质较为合理。为此,本文对该坳拉槽与前渊盆地的发育及演化特征试作一初步分析。

Abstract:

In this paper,a systematical description of tectonic attributes and history of evolution of the western Ordos margin is made from the viewpoint of plate tectonics. It is considered that the margin evolved from pre-Caledonian aulacogen through post-Caledonian aulacogen,via Mesozoic front depression to Cenozoic graben. An relative account of tectonic patterns,sedimentary characteristics,transgressive direction,magmatic activities and stress action of defferent times are given. The authors point out that the development mechanism of the above structures depends mainly on long-term convergence of north Qilian geosyncline and the adjacent Alashan block as well as dextral shearing of BaojiQingtongxia deep fault.The present area is characterized by sediments of huge thickness which formed a good few sedimentary cycles favourable to oil generation and preservation. Oil prospects of this area could not be underestimated though intensive reformation has later occurred in this area. The authors suggested that the hinge zone lying in between the area studied and Ordos platform,i. e.,the thrustclad area,should be promissing for oil and gas,when the middle Ordovician and the middle-upper Carboniferous are considered as rock sequences favourable to oil generation.