Heterogeneous hydrofracture development and accretionary fault dynamics

Abstract

Research Article| March 01, 1994 Heterogeneous hydrofracture development and accretionary fault dynamics Kevin M. Brown; Kevin M. Brown 1Scripps Institution of Oceanography, La Jolla, California 92093-0220 Search for other works by this author on: GSW Google Scholar Barbara Bekins; Barbara Bekins 2Earth Sciences Department, University of California, Santa Cruz, California 95064 Search for other works by this author on: GSW Google Scholar B. Clennell; B. Clennell 3University of Birmingham, Birmingham, United Kingdom Search for other works by this author on: GSW Google Scholar D. Dewhurst; D. Dewhurst 3University of Birmingham, Birmingham, United Kingdom Search for other works by this author on: GSW Google Scholar G. Westbrook G. Westbrook 3University of Birmingham, Birmingham, United Kingdom Search for other works by this author on: GSW Google Scholar Geology (1994) 22 (3): 259–262. https://doi.org/10.1130/0091-7613(1994)022<0259:HHDAAF>2.3.CO;2 Article history first online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Kevin M. Brown, Barbara Bekins, B. Clennell, D. Dewhurst, G. Westbrook; Heterogeneous hydrofracture development and accretionary fault dynamics. Geology 1994;; 22 (3): 259–262. doi: https://doi.org/10.1130/0091-7613(1994)022<0259:HHDAAF>2.3.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 SocietyGeology Search Advanced Search Abstract Ocean Drilling Program observations at many accretionary wedges indicate that fluid flow in low-permeability sediments is focused along faults rich in clay minerals. Recent ring-shear experiments show that shear failure generally reduces permeability in muddy faults to values well below the surrounding sediments and that very little increase occurs in the fault permeability even when continued failure proceeds under steadily reduced effective loads. It is, thus, unlikely that observed focused flow occurs through the matrix of muddy faults, and we suggest that focused flow can only be explained by the development of open fracture systems. The lithostatic fluid pressures necessary for hydrofracturing in weak sediments cannot, however, exist throughout the imbricate thrust system and basal decollement zone because a zero basal shear stress condition would result in regional instability and accretionary wedge collapse. We propose that the regional hydrofracture networks must propagate heterogeneously, leaving relatively strong asperity regions at sublithostatic fluid pressures to balance forces in the wedge in three dimensions. This content is PDF only. Please click on the PDF icon to access. 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.