石油与天然气地质 ›› 1998, Vol. 19 ›› Issue (2): 99-105.doi: 10.11743/ogg19980203

• 论文 • 上一篇    下一篇

吉尔嘎朗图凹陷沉积层序几何构型

樊太亮1, 朱玲2   

  1. 1. 中国地质大学, 北京100083;
    2. 中国科学院地球物理研究所, 北京100083
  • 收稿日期:1998-02-19 出版日期:1998-06-25 发布日期:2012-01-18

GEOMETRIC ARCHITECTURE OF SEDIMENTARY SEQUENCE IN JIRGALONGTU DEPRESSION

Fan Tailiang1, Zhu Ling2   

  1. 1. China University of Geoseciences, Beijing;
    2. Institute of Geophysics, Chinese Academy of Sciences, Beijing
  • Received:1998-02-19 Online:1998-06-25 Published:2012-01-18

摘要:

断陷湖盆沉积层序的几何学特征是层序地层分析的基本线索和重要内容。据此将二连盆地吉尔嘎朗图凹陷侏罗系至白垩系的赛汉塔拉组划分为10个三级地震层序,组合成3个超层序。层序外部形态由下向上依次由箱状、楔状演变至席状披覆;边界终止方式由双断中止型、单断中止超覆型演变至周缘超覆型,分别对应于盆地的裂陷期、坳陷期和快速充填萎缩期。作为一个箕状断陷盆地,吉尔嘎朗图凹陷由低水位期沉积构型、水进期沉积构型和高水位期沉积构型组成,可识别出陡岸水下扇体系、进积型扇三角洲浊积扇体系和盆缘小型扇三角洲体系。三级层序间的组合型系可分为退积叠置、进积叠置、加积叠置三种类型,对应于密集段厚度的减薄、增厚、稳定和有机质丰度的减小、增大、基本不变的变化规律。由上表明,层序几何构型是层序动力学过程的反映,可揭示盆地的沉积特征和演化过程。

关键词: 层序地层, 几何构型, 沉积体系, 密集段

Abstract:

The geometric architectures of depositional sequences in fault-depressions play an important role in the analysis of sequence stratigraphy.According to its geometric architectures,the Sahantala Formation of the Jurassic Cretaceous in Jirgalangtu Depression,Erlian Basin could be classified into ten seismic sequences of third grade,which in turn constitute three supersequences.The shapes of the sequences are box-like,wedge shape and sheet drape in ascending order.The sequence boundaries varied from bilateral fault monoclinal fault overlap marginal overlap types,correspounding respectively to the fracture subsidence,depression and filling stages of the basin.The Jirgalangtu Depression is composed of low level,water inflow and high level configurations and contains abrupt slope subaqueous fan system,prograding fan delta-turbidite fan system and marginal minor fan delta system.The combination of the three sequences includes retrograding,prograding and aggrading types.It is proposed in this paper that the geometric architectures of sequences could reveal the process of sequence dynamics,the deposition property and evolution process of the basin.