Evolving strain partitioning in the Eastern Himalaya: The growth of the Shillong Plateau
Evolving strain partitioning in the Eastern Himalaya: The growth of the Shillong Plateau
复制标题
喜马拉雅东部不断变化的应变分配：西隆高原的增长
DOI：
10.1016/j.epsl.2015.10.017
复制
发表时间：
2016
影响因子：
5.3
通讯作者：
Najman Y
中科院分区：
文献类型：
--
作者：
Najman Y
西隆高原是喜马拉雅前陆唯一的隆起地形（海拔高达2000米）。有人建议有一个重大的影响，应变分区，从而在东喜马拉雅构造。此外，它在夏季风轨迹上的位置意味着它影响了区域气候，在其背风面的地质时间尺度上减少了侵蚀率。高原表面隆起的时间一直难以确定。在地质时间尺度上计算出了剥露率，但这些似乎与根据用GPS测量的现今速度场外推的估计值不一致，因此有人认为剥露和地表隆起是不相关的。我们确定的地表隆起的时间使用相邻的苏尔马盆地南部的沉积记录，它记录了从一个被动的边缘与向南增厚的沉积包的弯曲盆地与北增厚的地层，由于加载由隆起的高原的过渡。我们的方法涉及使用所有可用的二维地震数据的盆地，再加上良好的领带信息，以产生等容线图，并构建一个简单的模型，以评估的时间和幅度的弯曲载荷的西隆高原的苏尔玛盆地的沉降。我们的结论是，主要时期的弯曲载荷发生在沉积的Tipam组（3.5- 102马）向前，这可能是代表显着的地形增长的Shillong高原的时间。我们的等容线图和地震剖面也使我们能够限制相邻盆地边界印缅山脉南北走向背斜变薄的时间，因为在同一时间间隔内发生。西隆高原的隆起和印度-缅甸山脉向西侵入这一地区的综合作用，切断了喜马拉雅源和苏尔马盆地汇之间的古雅鲁藏布江流域连接，在Tipam形成时代结束时（102 Ma）。
Abstract The Shillong Plateau is the only raised topography (up to 2000 m elevation) in the Himalayan foreland. It is proposed to have had a major influence on strain partitioning and thus tectonics in the Eastern Himalaya. Additionally, its position on the trajectory of the summer monsoon means it has influenced the regional climate, with reduced erosion rates proposed over geological timescales in its lee. The timing of surface uplift of the plateau has been difficult to determine. Exhumation rates have been calculated over geological timescales, but these seem at variance with estimates based upon extrapolating the present day velocity field measured with GPS, and it has thus been suggested that exhumation and surface uplift are decoupled. We determine the timing of surface uplift using the sedimentary record in the adjacent Surma Basin to the south, which records the transition from a passive margin with southward thickening sedimentary packages to a flexural basin with north-thickening strata, due to loading by the uplifting plateau. Our method involves using all available 2D seismic data for the basin, coupled to well tie information, to produce isochore maps and construct a simple model of the subsidence of the Surma basin in order to assess the timing and magnitude of flexural loading by the Shillong Plateau. We conclude that the major period of flexural loading occurred from the deposition of the Tipam Formation (3.5–∼ 2 Ma) onwards, which is likely to represent the timing of significant topographic growth of the Shillong Plateau. Our isochore maps and seismic sections also allow us to constrain the timing of thinning over the north–south trending anticlines of the adjacent basin-bounding Indo–Burman Ranges, as occurring over this same time interval. The combined effect of the uplift of the Shillong Plateau and the westward encroachment of the Indo–Burman Ranges to this region served to sever the palaeo-Brahmaputra drainage connection between Himalayan source and Surma Basin sink, at the end of Tipam Formation times (∼ 2 Ma).
登录
查看更多内容
通过对不丹东部桑竹琼卡尔古雅鲁藏布江沉积物（西瓦利克群）的研究来限制西隆高原隆起的时间
DOI：
--
发表时间：
2015
期刊：
影响因子：
--
作者：
G. Govin;Y. Najman;D. Grujic;P. V. Beek;J. Davenport;P. Huyghe
通讯作者：
P. Huyghe
印度东北部的道基断层：重新激活大陆边缘的地壳规模逆冲褶皱
DOI：
--
发表时间：
2011
期刊：
影响因子：
--
作者：
E. K. Ferguson;L. Seeber;S. H. Akhter;M. Steckler;A. Biswas;B. Mukhopadhyay
通讯作者：
B. Mukhopadhyay
影响因子：
2.8
作者：
A. Sikder;M. Alam
通讯作者：
A. Sikder;M. Alam
孟加拉国东北部锡尔赫特海槽的沉积和构造
DOI：
--
发表时间：
1990
期刊：
影响因子：
--
作者：
S. Johnson;A. M. Alam
通讯作者：
A. M. Alam
影响因子：
4.2
作者：
Adams, B. A.;Hodges, K. V.;Wartho, J.
通讯作者：
Wartho, J.