地学前缘 ›› 2010, Vol. 17 ›› Issue (4): 128-139.

• 论文 • 上一篇    下一篇

前陆盆地的三维挠曲数值模拟: 以怀俄明西南上白垩统研究为例

Hongjun Luo,Dag Nummedal,Shaofeng Liu   

  1. 1BP America Inc., 501 WestLake Park Blvd, Houston, Texas, USA
    2Colorado Energy Research Institute, Colorado School of Mines, Golden, Colorado, USA
    3School of Earth Science and Resources, China University of Geosciences(Beijing), Beijing 100083, China
  • 收稿日期:2010-01-12 修回日期:2010-05-20 出版日期:2010-07-01 发布日期:2010-07-01
  • 作者简介:Hongjun Luo(罗红军)(1973—),男,博士,地质工程师,含油气系统、地层学专业。Email: Luo.Hongjun@bp.com

3D flexural numerical modeling of foreland basins: An example from the Upper Cretaceous across the Southwestern Wyoming.

Hongjun Luo,Dag Nummedal,Shaofeng Liu   

  1. 1BP America Inc., 501 WestLake Park Blvd, Houston, Texas, USA
    2Colorado Energy Research Institute, Colorado School of Mines, Golden, Colorado, USA
    3School of Earth Science and Resources, China University of Geosciences(Beijing), Beijing 100083, China
  • Received:2010-01-12 Revised:2010-05-20 Online:2010-07-01 Published:2010-07-01

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摘要：

前陆盆地的三维挠曲数值模拟是预测盆地三维格架和关键构造要素分布的强有力工具, 如在预测前隆分布方面(低隆起幅度、大范围分布的前隆很难从地下资料中识别)。为了解释详细地层对比中发现的前隆迁移,对怀俄明西南晚白垩世前陆盆地做了三维挠曲数值模拟。模拟过程中采用弹性地壳模型,并以详细的年代地层资料作为基本的输入数据。挠曲负载的估计来源于公开发表的怀俄明逆冲带的横剖面资料和风河逆冲带的缩短速率。模拟结果表明,由于逆冲负载的分布,前隆只局限分布在盆地的南部。随负载的迁移,前隆随时间向东南方向迁移。由于怀俄明逆冲带和风河逆冲带的相互作用,弹性地壳形成三维“前缘穹隆”而不是二维“前缘隆起”。三维挠曲模拟是理解怀俄明西南晚白垩世前隆迁移的关键。

关键词: 挠曲模拟, 前陆盆地, 上白垩统, 怀俄明

Abstract:

3D flexural numerical modeling of foreland basins provides a strong supportive tool to help predict 3D basin configuration and distribution of key structural elements, such as forebulges, which are very difficult to recognize  the subsurface due to its low amplitude and wide extent. To explain the forebulge migration observed from detailed stratigraphic correlation, 3D flexural modeling was applied for the Late Cretaceous foreland basin across the Southwestern Wyoming. An elastic lithosphere model was assumed, and detailed chronostratigraphy was used as fundamental framework input in the modeling. Flexural load was estimated from published cross sections across the Wyoming thrust belt and shortening rate of the Wind River thrust. Modeling results indicate that the forebulges were limited in their extent to only the southern part of the basin due to the distribution of the thrust loads. The forebulge shifted southeastward over time due to migration of this load. Because of the interaction of the Wyoming thrust belt and the Wind River Range, the elastic lithosphere formed a 3D “foredome” rather than a 2D “forebulge”. 3D flexural modeling is critical to the understanding of the Late Cretaceous forebulge migration across the Southwestern Wyoming.

Key words: flexural numerical modeling, foreland basins, Upper Cretaceous, Wyoming
CLC number：P5444;P53453Document code：AArticle ID：10052321(2010)04012812