کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4733105 1356988 2014 13 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Thrust initiation and its control on tectonic wedge geometry: An insight from physical and numerical models
ترجمه فارسی عنوان
آغاز رانش و کنترل آن بر هندسه گوه تکتونیکی: بینش از مدل های فیزیکی و عددی
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات زمین شناسی
چکیده انگلیسی


• Factors controlling the location of thrust initiation on a decollement.
• Dipping basal decollement localizes the first ramp away from the backstop.
• Location of ramp initiation determines the wedge geometry in collision zones.
• Mono-vergent wedge transform to bi-vergent geometry with increasing basal slope.

We performed a series of sandbox experiments to investigate the initiation of thrust ramping in tectonic wedges on a mechanically continuous basal decollement. The experiments show that the decollement slope (β) is the key factor in controlling the location of thrust initiation with respect to the backstop (i.e. tectonic suture line). For β = 0, the ramping begins right at the backstop, followed by sequential thrusting in the frontal direction, leading to a typical mono-vergent wedge. In contrast, the ramp initiates away from the backstop as β > 0. Under this boundary condition an event of sequential back thrusting takes place prior to the onset of frontal thrust progression. These two-coupled processes eventually give rise to a bi-vergent geometry of the thrust wedge. Using the Drucker-Prager failure criterion in finite element (FE) models, we show the location of stress intensification to render a mechanical basis for the thrust initiation away from the backstop if β > 0. Our physical and FE model results explain why the Main Central Thrust (MCT) is located far away from the Indo-Tibetan plate contact (ITSZ) in the Himalayan fold-and-thrust belts.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Structural Geology - Volume 67, Part A, October 2014, Pages 37–49
نویسندگان
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