THE ROLE OF THE PRE-RIFT STRUCTURE IN THE ARCHITECTURE OF THE DAMPIER BASIN AREA, NORTH WEST SHELF, AUSTRALIA
THE ROLE OF THE PRE-RIFT STRUCTURE IN THE ARCHITECTURE OF THE DAMPIER BASIN AREA, NORTH WEST SHELF, AUSTRALIA
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DOI：
10.1071/aj93046
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发表时间：
1994
期刊：
影响因子：
--
通讯作者：
Geoff Hill
中科院分区：
文献类型：
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作者：
Geoff Hill
丹皮尔次盆地显示出许多与盆地轴线倾斜的断层。先前对此的解释范围从同裂谷传输系统到深部扭转。该地区历史上曾发生过多次具有不同应力方向的裂谷事件，每次都利用了预先存在的断层模式。由于厚厚的沉积层之下的基底很难解释，因此最初的建筑是从构造环境来解释的。该次盆地毗邻太古代皮尔巴拉克拉通，这是一个被古代移动带包围的稳定地壳块。东非裂谷系统也在克拉通边缘环境中形成。在东非，地震数据和详细的地震解释显示，裂谷利用了移动带系统内的断层。在丹皮尔地区，三个不同的伸展向量与裂谷前结构和东非类似物相结合，用于建立盆地成因的替代模型。二叠纪-石炭纪延伸形成了由前寒武纪构造分隔的裂谷系统。侏罗纪伸展重新激活了这些断层，但新的伸展方向引起了斜滑和倾滑运动。这种倾斜滑动导致盖层区域内出现复杂的新断层分支阵列。白垩纪的第三个延伸矢量随后改变了结构。丹皮尔次盆地被视为利用前寒武纪构造结构的复杂失败裂谷。每个裂谷期裂谷前组构的结构继承影响了次盆地含油气结构的几何形状。
The Dampier Sub-basin shows many faults oblique to the basin axis. Previous explanations for this range from syn-rift transfer systems through to deep seated wrenching. Multiple rift episodes, with differing stress directions, occur in the area's history, each utilising the pre-existing fault patterns. As basement is difficult to interpret beneath thick sedimentary cover, the initial architecture is interpreted from the tectonic setting. The sub-basin lies adjacent to the Archean Pilbara Craton, a stable crustal block surrounded by ancient mobile belts. The East Africa rift system has also formed in a Craton margin setting. In East Africa earthquake data and detailed seismic interpretation show the rift utilises faults within the mobile belt systems. In the Dampier area, the three different extension vectors combined with the pre-rift fabric and the East Africa analogue, are used to build an alternate model for the basin genesis. Permo-Carboniferous extension sets up a rift system partitioned by the Precambrian fabric. Jurassic extension reactivates these faults but with oblique slip and dip slip movement caused by the new extension direction. This oblique slip causes complex branching arrays of new faults within the cover section. A third extension vector in the Cretaceous subsequently modifies the fabric. The Dampier Sub-basin is seen as a complex failed rift utilising a Precambrian tectonic fabric. The structural inheritance of the pre-rift fabric by each rift episode has affected the geometry of hydrocarbon-bearing structures of the sub-basin.