کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
9536113 1357079 2005 18 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Propagation of strike-slip faults across Holocene volcano-sedimentary deposits, Pasto, Colombia
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات زمین شناسی
پیش نمایش صفحه اول مقاله
Propagation of strike-slip faults across Holocene volcano-sedimentary deposits, Pasto, Colombia
چکیده انگلیسی
This study contributes to the understanding of shear failure development on the basis of macroscopic field data collected in latest Pleistocene-Holocene pyroclastic and fluvio-lacustrine deposits in the Pasto Valley, SW Colombia. Here there is a pervasive system of microfaults and joints. Right-lateral strike-slip microfaults strike N065°, whereas left-lateral strike-slip microfaults strike N120°. Three main joint sets strike N, N065° and N020° in decreasing order of frequency. Stress computation gives a horizontal σ1 trending ∼N060° and a horizontal σ3 trending ∼N150°, consistent with earthquake focal mechanisms and stress inversion of main faults. Synthetic shears dominate resulting from nucleation of older cracks. In the basement cropping out northeast of Pasto, the NE- to ENE-striking Buesaco, Aranda and Pasto Faults show evidence of latest Pleistocene-Holocene right-lateral strike-slip motions. The structures in the Pasto Valley can be interpreted as a Mode III damage zone representing the up-dip propagation of the main faults across the young volcano-sedimentary deposits.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Structural Geology - Volume 27, Issue 10, October 2005, Pages 1838-1855
نویسندگان
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