石油与天然气地质 ›› 1997, Vol. 18 ›› Issue (4): 276-281.doi: 10.11743/ogg19970403

• 论文 • 上一篇    下一篇

下扬子区中生代溧水-南陵拉分盆地的厘定

林鹤鸣, 夏邦栋   

  1. 南京大学地球科学系 南京 210093
  • 收稿日期:1996-11-08 修回日期:1997-03-19 出版日期:1997-12-25 发布日期:2012-01-18

DEFINITION OF MESOZOIC LISHUI NANLING PULL APART BASIN IN LOWER YANGTZE REGION

Lin Heming, Xia Bangdong   

  1. Department of Earth Sciences, Nanjing University, Nanjing
  • Received:1996-11-08 Revised:1997-03-19 Online:1997-12-25 Published:2012-01-18

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摘要：

溧水南陵盆地是一具两个沉陷中心的中生代拉分盆地,两侧边界断裂为一对走向为NNE的左旋左阶的雁行走滑断裂,并与宁芜拉分盆地有着成因上的联系,两者组成一个拉分盆地系列。盆地具有以下沉积特征:(1)沉积物累积厚度达6000m,沉积速度大于690m/Ma;(2)沉积相在盆地平面上和横剖面上均表现出明显的不对称;(3)古水流方向在盆地的边缘指向盆地内部,在盆地轴部则与盆地走向一致,砾石含量和粒径顺古水流方向减少或变小;(4)盆地边界断裂的走滑作用造成扇体位移以及古水流的持续转向;(5)火山岩从钙碱性向碱性转变反映出盆地所处大地构造环境由挤压向引张的变化

关键词: 溧水-南陵, 拉分盆地, 下扬子区, 西横山组, 厘定

Abstract:

Lishui Nanling Basin is a Mesozoic pull apart basin which possesses two sedimentary depression.The boundary faults of the basin's two sides are left step sinistral en echelon strike slip faults with NNE strike.The basin has similar origin to that of Ningwu pull apart basin. They constitute a pull apart basin set.The basin has following features:(1)The stratigraphic thickness is up to 6 000 m,and the sedimentation rate is more than 690 m/Ma.(2)The sedimentary facies show evident asymmetry in basin's plane and cross sections.(3)The palaeocurrent directions of the basin margins point to intra basin,those in the axial region of the basin are accord with the basin axis.Along the palaeocurrent directions,the content and the size of the gravel decreases.(4)Strike slip movement of the boundary faults led to the fan/source displacement and the continuous change of the palaeocurrent directions.(5)Volcanic rocks changed from calc alkaline into alkaline into alkaline in the basin,indicating the change of it's tectonic background from compression to extension.