کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
8908710 1636680 2018 54 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Foreland uplift during flat subduction: Insights from the Peruvian Andes and Fitzcarrald Arch
ترجمه فارسی عنوان
بلند شدن فرلند در حین فروپاشی صاف: بینش از آند و پرو پروین و آرک فیتزکرارالد
کلمات کلیدی
برش پایه، اسلب تخت، آند ضخیم شدن پوست، لیتوسفر، آرک فیتزکرارال،
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات فرآیندهای سطح زمین
چکیده انگلیسی
Foreland deformation has long been associated with flat-slab subduction, but the precise mechanism linking these two processes remains unclear. One example of foreland deformation corresponding in space and time to flat subduction is the Fitzcarrald Arch, a broad NE-SW trending topographically high feature covering an area of >4 × 105 km2 in the Peruvian Andean foreland. Recent imaging of the southern segment of Peruvian flat slab shows that the shallowest part of the slab, which corresponds to the subducted Nazca Ridge northeast of the present intersection of the ridge and the Peruvian trench, extends up to and partly under the southwestern edge of the arch. Here, we evaluate models for the formation of this foreland arch and find that a basal-shear model is most consistent with observations. We calculate that ~5 km of lower crustal thickening would be sufficient to generate the arch's uplift since the late Miocene. This magnitude is consistent with prior observations of unusually thickened crust in the Andes immediately south of the subducted ridge that may also have been induced by flat subduction. This suggests that the Fitzcarrald Arch's formation by the Nazca Ridge may be one of the clearest examples of upper plate deformation induced through basal shear observed in a flat-slab subduction setting. We then explore the more general implications of our results for understanding deformation above flat slabs in the geologic past.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Tectonophysics - Volumes 731–732, 22 April 2018, Pages 73-84
نویسندگان
, , , , , ,