کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4679480 1634884 2008 12 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Serpentinization pulse in the actively deforming Central Indian Basin
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات علوم زمین و سیاره ای (عمومی)
پیش نمایش صفحه اول مقاله
Serpentinization pulse in the actively deforming Central Indian Basin
چکیده انگلیسی

Heat flow in the actively deforming Central Indian Basin is on average 30 mW/m2 higher than the theoretical 55 mW/m2 heat flow expected from plate cooling of a Cretaceous oceanic lithosphere. Strong spatial correlation between the anomaly and the active thrust fault network at local (faults) and regional scales suggests two potential tectonically driven mechanisms activated at the time of initiation of deformation: friction-to-heat conversion or exothermic serpentinization. We quantitatively examine both processes using an updated geometry of the thrust fault network and simple thermal models. Friction generated heat is limited in all cases: at shallow levels, shear stresses remain small, while heat generated at deeper levels does not contribute significantly to the surface heat flow since permanent regime is not reached. In the exothermic serpentinization model, a maximum anomaly of 20 to 30 mW/m2 is reached 2 to 6 Myr after the onset of widespread serpentinization, depending on the efficiency of the water circulation. The amount and timing of heat release can fully explain the present-day surface heat flow of the Central Indian Basin, provided vigorous hydrothermal circulation closely followed the onset of deformation. Based on a reprocessed multichannel seismic line, we suggest that faults cutting through the entire crust and across the Moho discontinuity drive water at mantle levels and trigger the exothermic serpentinization reaction. We interpret sub-Moho reflectors imaged at depths of 8 to 15 km below the top of the crust – and coinciding with the location of the maximum reaction rate coefficient of serpentinization – as serpentinization fronts. We discuss the significance of this pulse of serpentinization in terms of timing of deformation, weakening and transient rheology of the oceanic lithosphere.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Earth and Planetary Science Letters - Volume 276, Issues 1–2, 30 November 2008, Pages 140–151
نویسندگان
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