کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4733170 1640522 2013 13 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
A geometric model for the formation of deformation band clusters
ترجمه فارسی عنوان
یک مدل هندسی برای تشکیل خوشه های باند تغییر شکل
کلمات کلیدی
نوارهای تغییر شکل سیاره، هندسه منطقه گسل، ماسه سنگ های تخلخل بالا، استحکام کششی، تضعیف فشار
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات زمین شناسی
چکیده انگلیسی


• Clusters of deformation bands arise from distributed strains common to all faults.
• Band clusters develop at fault geometric irregularities (e.g., bends, relays).
• Strain hardening not required to form band clusters and laboratory data are equivocal.
• Slip localisation, asperity removal and strain weakening account for band formation.
• A geometric model reconciles band distributions within complex fault zones.

Arrays of closely-spaced (approximately <70 mm) sub-parallel cataclastic deformation bands are common structures in deformed, high-porosity (∼10–35%) sandstones. The distribution of strain onto many small-displacement deformation bands is thought by some to result from strain-hardening of the cataclasite within individual bands. Examination of both normal and strike-slip faults with displacements ≤7 m from southeastern Utah, USA, and the North Island of New Zealand suggests, however, that clusters of deformation bands systematically develop at fault geometric irregularities (e.g., fault bends, steps, relays, intersections and zones of normal drag). The strain-hardening model does not account for clustering of deformation bands at fault geometric irregularities or the associated widespread coalescence of bands, and is not unequivocally demonstrated by post-peak macroscopic mechanical responses in laboratory rock deformation experiments. A geometric model is proposed in which individual bands within clusters develop sequentially due to migration of incremental shear strains at fault geometric irregularities as part of a slip localisation, asperity removal and strain weakening process. The geometric model, which does not require strain hardening of the fault rock, applies for the duration of faulting and a range of rock types in the brittle upper crust.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Structural Geology - Volume 55, October 2013, Pages 21–33
نویسندگان
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