Far-field lithospheric deformation in Tibet during continental collision
Far-field lithospheric deformation in Tibet during continental collision
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DOI：
10.1029/2008tc002344
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发表时间：
2009-12-03
期刊：
影响因子：
4.2
通讯作者：
Houseman, Gregory A.
中科院分区：
文献类型：
--
作者：
Dayem, Katherine E.;Molnar, Peter;Houseman, Gregory A.
自始新世中晚期以来，即印度与欧亚大陆碰撞后不久，沿着现今青藏高原北缘的地壳变形就发生了。假设在这些距离和时间尺度上，可以使用薄粘性片来近似岩石圈，我们表明，由凹进边界引起的远场岩石圈变形预计将在碰撞开始后不久开始。当计算塔里木盆地等类似克拉通岩石圈的强区时，剪切率和垂直应变率集中在强区南缘，导致该处变形增强。在按印度和青藏高原尺寸进行计算时，高原北缘的剪切率和垂直应变率在碰撞开始后不久就会增加。在计算后期，地壳增厚会加速。我们认为，10 Ma 左右明显增加的折返（或许还有地表隆起）可能预示着增厚锋面的到来。引用：Dayem, K. E.、P. Molnar、M. K. Clark 和 G. A. Houseman (2009)，大陆碰撞期间西藏的远场岩石圈变形，Tectonics，28，TC6005，doi:10.1029/2008TC002344。
Crustal deformation along the present-day northern margin of the Tibetan Plateau has occurred since mid to late Eocene time, soon after India collided with Eurasia. Assuming that on these distance and time scales the lithosphere can be approximated using a thin viscous sheet, we show that far-field lithospheric deformation caused by an indenting boundary is expected to start shortly after collision begins. When a strong region analogous to cratonic lithosphere like that of the Tarim Basin is included in the calculations, shear and vertical strain rates concentrate along the southern edge of the strong region, resulting in enhanced deformation there. In calculations scaled to the dimensions of India and the Tibetan Plateau, shear and vertical strain rates on the northern edge of the plateau increase soon after collision begins. Crustal thickening accelerates later in the calculations. We propose that the apparent increased exhumation (and perhaps surface uplift) around 10 Ma may signal the arrival of the thickening front. Citation: Dayem, K. E., P. Molnar, M. K. Clark, and G. A. Houseman (2009), Far-field lithospheric deformation in Tibet during continental collision, Tectonics, 28, TC6005, doi:10.1029/2008TC002344.