کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4733314 1357017 2011 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
The neutral lines in buckle folds
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات زمین شناسی
پیش نمایش صفحه اول مقاله
The neutral lines in buckle folds
چکیده انگلیسی

The neutral line in a buckle fold, dividing areas of outer-arc extension from areas of inner-arc shortening, is a fundamental concept in structural geology. In the past, folds have been constructed kinematically from a given neutral line geometry using the tangential longitudinal strain pattern. In this study, a mechanical finite element model is used to numerically buckle single-layer folds with Newtonian and power-law viscous rheology. Two neutral lines can be distinguished, the incremental neutral line (zero layer-parallel strain rate) and the finite neutral line (zero finite layer-parallel strain). The former develops first and migrates through the layer from the outer towards the inner arc ahead of the latter. Both neutral lines are discontinuous along the fold and terminate either at the bottom or top interface of the layer. For decreasing viscosity ratio between layer and matrix and for decreasing initial amplitude, the neutral lines develop later during folding and, for some cases, no neutral line develops. The dynamical behaviour of the neutral lines is similar for Newtonian and power-law viscous rheology if the viscosity ratio is large, but substantially different for small viscosity ratios. The results are discussed in light of fold-related structures, such as outer-arc-extension structures and inner-arc-shortening structures.

Figure optionsDownload high-quality image (344 K)Download as PowerPoint slideHighlights
► The neutral lines in Newtonian and power-law viscous single-layer folds are studied.
► Two neutral lines can be defined: the finite and the incremental neutral line.
► During folding, both neutral lines migrate from the outer towards the inner arc.
► None of the two neutral lines is continuous along the fold.
► For small viscosity ratios the neutral lines do not develop.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Structural Geology - Volume 33, Issue 10, October 2011, Pages 1501–1508
نویسندگان
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