کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
6433336 1636709 2016 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Seismic imaging of a megathrust splay fault in the North Chilean subduction zone (Central Andes)
ترجمه فارسی عنوان
تصویربرداری لرزه ای از گسل شتاب دهنده مگاتراست در ناحیه فرونشانی شمال شیلی (آندورای مرکزی)
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات فرآیندهای سطح زمین
چکیده انگلیسی


- Imaging of a predicted megathrust splay fault using pre-stack depth migration.
- Hypocenters located by Bloch et al. (2014) accomplish that structure.
- Imaging of steeply dipping Uyuni-Kenayani Fault (Altiplano) at 0-20 km depth.
- Imaging the Moho at approximately 60 km depth beneath the Altiplano.

Prominent trench-parallel fault systems in the arc and fore-arc of the Chilean subduction zone can be traced for several thousand kilometers in north-south direction. These fault systems possibly crosscut the entire crust above the subduction megathrust and are expected to have a close relationship to transient processes of the subduction earthquake cycles. With the motivation to image and characterize the structural inventory and the processes that occur in the vicinity of these large-scale fault zones, we re-processed the ANCORP'96 controlled-source seismic data set to provide images of the faults at depth and to allow linking geological information at the surface to subsurface structures. The correlation of the imaging results with observed hypocenter locations around these fault systems reveals the origin and the nature of the seismicity bound to these fault systems. Active and passive seismic data together yield a picture of a megathrust splay fault beneath the Longitudinal Valley at mid-crustal level, which can be observed from the top of the subduction plate interface and which seems to be connected to the Precordilleran Fault System (PFS) known at the surface. This result supports a previously proposed tectonic model where a megathrust splay fault defines the Western Altiplano as a crustal-scale fault-bend-fold. Furthermore, we clearly imaged two branches of the Uyuni-Kenayani Fault (UKF) in a depth range between 0 and 20 km. In summary, imaging of these faults is important for a profound understanding of the tectonic evaluation and characterization of the subduction zone environment, for which the results of this study provide a reliable basis.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Tectonophysics - Volume 689, 15 October 2016, Pages 157-166
نویسندگان
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