...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of geophysical research. Solid earth: JGR >Relationship between structural style, overpressures, and modern stress, Baram Delta Province, northwest Borneo
【24h】

Relationship between structural style, overpressures, and modern stress, Baram Delta Province, northwest Borneo

机译：婆罗洲西北部巴拉姆三角洲地区结构样式，超压和现代应力之间的关系

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The Baram Delta differs from most large (passive margin) deltas because of its location on an active postcollisional margin. Structural style and evolution is influenced both by gravity-driven deformation and regional stress. Key structural features of the delta include (1) late development of the toe fold and thrust belt (latest Miocene-Recent) with respect to 17 Ma recent development of growth faults on the shelf; (2) a narrow active region of extension on the outer shelf upper slope; (3) absence of well-developed shale diapirs; and (4) inner shelf onshore folding, thrusting, and growth fault inversion. Overpressure magnitude, type, distribution, and principal stress orientation and magnitude for the shelfal area were determined from well data. The inner shelf onshore area of inversion displays decreasing vertical stress gradient offshore and pronounced transfer of disequilibrium compaction overpressure from the Setap (shale) Formation into the overlying Belait Formation. This loss of overpressure permitted partial recoupling of once detached deltaic sediments with basement. Evidence for partial recoupling includes decreasing minimum horizontal stress gradient from NE (area of maximum inversion) to SW across the shelf and coast-perpendicular inner shelf Shmax directions appropriate for inversion, but with stress magnitudes insufficient to cause deformation. These observations constrain models to explain why toe fold-thrust belt activity occurred relatively late, while inner shelf folding developed early and is inactive today. During delta progradation disequilibrium compaction overpressures developed in the outer shelf slope area and helped decouple the section from basement late in the delta history, hence compressional deformation shifted further offshore. Conversely onshore inner shelf inversion caused late overpressure loss, resulting in partial recoupling of the deltaic section with basement.
机译：Baram三角洲不同于大多数较大的（被动边界）三角洲，因为它位于活动的碰撞后边缘。结构样式和演化受重力驱动的变形和区域应力的影响。三角洲的主要结构特征包括：（1）相对于17 Ma陆架上最近发育的断层，趾褶和逆冲带的发育较晚（最新中新世）。 （2）在外货架上斜坡上的狭窄有效延伸区域; （3）缺乏发达的页岩底泥; （4）陆架内陆褶皱，逆冲和生长断层反转。根据井的数据确定了陆架的超压强度，类型，分布，主应力方向和强度。反演的内陆陆架区域显示出近海垂直应力梯度减小，不平衡压实超压从塞塔普（页岩）地层到上覆贝拉伊特地层的明显转移。这种超压的损失使得曾经分离的三角洲沉积物与地下室部分重新耦合。部分重新耦合的证据包括在整个大陆架和垂直于海岸的内大陆架Shmax方向上，从NE（最大反演区域）到SW的最小水平应力梯度减小，适合于反演，但应力大小不足以引起变形。这些观察结果约束了模型，以解释为什么脚趾褶皱-冲断带活动发生得相对较晚，而内部层架褶皱发展得较早，而今天却不活跃。在三角洲发育期间，在外陆架斜坡区域出现了不平衡压实超压，并在三角洲历史后期帮助断面与基底脱开，因此，压缩变形进一步向海上移动。相反，陆上内陆架反转导致后期超压损失，导致三角洲部分与地下室部分重新耦合。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号