Controls on the geometry and evolution of thin-skinned fold-thrust belts, and applications to the Makran accretionary prism and Indo-Burman Ranges
Controls on the geometry and evolution of thin-skinned fold-thrust belts, and applications to the Makran accretionary prism and Indo-Burman Ranges
复制标题
薄皮褶皱冲断带几何形状和演化的控制及其在莫克兰增生棱柱和印缅山脉的应用
DOI：
10.1093/gji/ggz139
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发表时间：
2019
影响因子：
2.8
通讯作者：
Ball T
中科院分区：
文献类型：
--
作者：
Ball T
会聚边缘褶皱冲断带的形成是一个动态过程。弱沉积物在逆冲板块前部的堆积导致地壳增厚和俯冲板块的持续挠曲下沉。褶皱推覆带通常被视为具有自相似几何形状的库仑楔体，具有一个临界锥度，以及一个刚性或均衡补偿的底座。在这项工作的基础上，我们建立了一个新的动力学模型，研究了来水沉积物的厚度和物质性质以及俯冲板块中的挠曲在控制褶皱冲断带的行为和演化中的作用。我们的分析表明，褶皱冲断带的演化可以由重力扩张或垂直增厚主导，这取决于沉积物通量、物质性质和挠曲的相对重要性。我们将我们的模型应用于Makran增积棱柱和印度-缅甸山脉，结果表明，对于Makran挠曲，必须考虑Makran挠曲，才能从地震反射剖面解释沉积-基底界面的倾角。在印缅山脉中，输入沉积物厚度对锡隆高原自北向南地形特征的变化具有一级控制作用。
The formation of fold-thrust belts at convergent margins is a dynamic process. Accretion of weak sediments to the front of the overriding plate results in crustal thickening and continued flexural subsidence of the underthrusting plate. Fold-thrust belts are often treated as a Coulomb wedge having self-similar geometries with a critical taper, and either a rigid or isostatically compensated base. In this paper, we build upon this work by developing a new dynamic model to investigate both the role of the thickness and material properties of the incoming sediment, and the flexure in the underthrusting plate in controlling the behaviour and evolution of fold-thrust belts. Our analysis shows that the evolution of fold-thrust belts can be dominated by either gravitational spreading or vertical thickening, depending on the relative importance of sediment flux, material properties and flexure. We apply our model to the Makran accretionary prism and the Indo–Burman Ranges, and show that for the Makran flexure must be considered in order to explain the dip of the sediment–basement interface from seismic reflection profiles. In the Indo–Burman Ranges, we show that incoming sediment thickness has a first-order control on the variations in the characteristics of the topography from north to south of the Shillong Plateau.