Formation of folds, boudinage, and mullions in non-Newtonian materials

Abstract

Research Article| February 01, 1977 Formation of folds, boudinage, and mullions in non-Newtonian materials R. B. SMITH R. B. SMITH 1Department of Astro-Geophysics, University of Colorado, Boulder, Colorado 80309 Search for other works by this author on: GSW Google Scholar GSA Bulletin (1977) 88 (2): 312–320. https://doi.org/10.1130/0016-7606(1977)88<312:FOFBAM>2.0.CO;2 Article history first online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share MailTo Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation R. B. SMITH; Formation of folds, boudinage, and mullions in non-Newtonian materials. GSA Bulletin 1977;; 88 (2): 312–320. doi: https://doi.org/10.1130/0016-7606(1977)88<312:FOFBAM>2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract Previous work has suggested that the formation of folds, boudins, and mullions by creep is caused by the same general type of instability. The results of Newtonian flow models of this process compare poorly with observation, however. The study reported here extends the analysis to include a general class of non-Newtonian materials restricted only to being incompressible, anelastic (that is, without memory), isotropic, and homogeneous. Although the material is isotropic, the perturbation flow associated with growing structure is found to obey an anisotropic type of flow law. In a strain-rate softening material undergoing pure shear, resistance to additional normal straining is significantly reduced from the background level, whereas resistance to tangential straining is unchanged. This has a profound effect on the formation of geologic structures, increasing the growth rates and altering the dominant wavelengths. Non-Newtonian behavior turns out to be necessary for the formation of boudins and mullions and plays an important role, but not a necessary one, in the formation of folds. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.