A complete structural model and kinematic history for distributed deformation in the Wharton Basin
A complete structural model and kinematic history for distributed deformation in the Wharton Basin
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DOI：
10.1016/j.epsl.2020.116218
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发表时间：
2020-05
影响因子：
5.3
通讯作者：
Duncan E. Stevens;L. McNeill;T. Henstock;M. Delescluse;N. Chamot‐Rooke;J. Bull
中科院分区：
文献类型：
--
作者：
Duncan E. Stevens;L. McNeill;T. Henstock;M. Delescluse;N. Chamot‐Rooke;J. Bull
赤道东印度洋有一个扩散板块边界，广泛的变形适应了印度、澳大利亚和摩羯座亚板块之间的相对运动。我们整合了 IODP Expedition 362 钻孔数据，该数据首次提供了九十东岭 (NER) 以东沉积层序的精确、真实的年代地层学，与二维地震反射剖面和多波束测深，以评估 NER 和巽他俯冲带之间的断层类型、活动时间以及与物理和流变特性的比较。我们在沃顿盆地北部的 NER 以东确定了四个不同的断层组。 N-S (350-010°) 定向断层与现已灭绝的沃顿扩张中心形成的 N-S 断裂带相关，仍然活跃，并且至少自 10 Ma 以来一直持续活跃。 NNE 和 WNW 走向的断层结构在断裂带之间发育。这三组断层的方向和可能的位移方向定义了一个 Riedel 剪切系统，该系统响应深度上的～NNE-SSW 左旋走滑活动，最近 2012 年发生的板内大地震证明了这一点。我们还发现了∼NE-SW反向断层的证据，其类型与在NER以西观察到的东西向反向断层类似，其中反向断层更为占主导地位。我们表明该走滑系统的活动增加了约。 7-9 Ma，与 NER 西部的逆断层作用和板内变形同时发生。
The equatorial eastern Indian Ocean hosts a diffuse plate boundary, where widespread deformation accommodates the relative motion between the Indian, Australian and Capricorn sub-plates. We integrate IODP Expedition 362 borehole data, which for the first time provides an accurate, ground-truthed chronostratigraphy of the sedimentary sequence east of the Ninety East Ridge (NER), with 2D seismic reflection profiles and multibeam bathymetry to assess the styles of faulting between the NER and the Sunda subduction zone, timing of activity and comparison with physical and rheological properties. We identify four distinct fault sets east of the NER in the northern Wharton Basin. N-S (350-010°) orientated faults, associated with the N-S fracture zones formed at the now extinct Wharton spreading centre, are still active and have been continuously active since at least 10 Ma. NNE- and WNW-trending fault fabrics develop between the fracture zones. The orientations and likely sense of displacement on these three sets of faults defines a Riedel shear system responding to ∼NNE-SSW left-lateral strike-slip activity at depth, demonstrated by the recent 2012 great intraplate earthquakes. We also find evidence of ∼NE-SW reverse faults, similar in style to E-W reverse faults observed west of the NER, where reverse faulting is more dominant. We show that the activity of this strike-slip system increased ca. 7-9 Ma, contemporaneous with reverse faulting and intraplate deformation west of the NER.