Focused fluid flow along faults in the Monterey Formation, coastal California

Research Article| November 01, 2000 Focused fluid flow along faults in the Monterey Formation, coastal California Peter Eichhubl; Peter Eichhubl 1Department of Geological Sciences, University of California, Santa Barbara, California 93106, USA Search for other works by this author on: GSW Google Scholar James R. Boles James R. Boles 1Department of Geological Sciences, University of California, Santa Barbara, California 93106, USA Search for other works by this author on: GSW Google Scholar Author and Article Information Peter Eichhubl 1Department of Geological Sciences, University of California, Santa Barbara, California 93106, USA James R. Boles 1Department of Geological Sciences, University of California, Santa Barbara, California 93106, USA Publisher: Geological Society of America Received: 20 Aug 1998 Revision Received: 22 Jul 1999 Accepted: 18 Nov 1999 First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (2000) 112 (11): 1667–1679. https://doi.org/10.1130/0016-7606(2000)112<1667:FFFAFI>2.0.CO;2 Article history Received: 20 Aug 1998 Revision Received: 22 Jul 1999 Accepted: 18 Nov 1999 First Online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation Peter Eichhubl, James R. Boles; Focused fluid flow along faults in the Monterey Formation, coastal California. GSA Bulletin 2000;; 112 (11): 1667–1679. doi: https://doi.org/10.1130/0016-7606(2000)112<1667:FFFAFI>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 Fluid flow in fractured siliceous mudstone of the Miocene Monterey Formation of California is inferred to be highly focused toward map-scale faults that locally contain extensive amounts of carbonate and minor silica cement. The distance of cross-stratigraphic flow, as inferred based on the strontium isotopic composition of carbonate fault cement, is close to the thickness of the Monterey Formation of 700 m in one of two study locations, Jalama Beach, and less than the formation thickness at another location, Arroyo Burro Beach. Fluid is thus derived from within the Monterey Formation rather than from underlying older units. Based on mass-balance estimates of the fluid volume required for fault cementation at Jalama Beach, the minimum distance of formation-parallel flow into the fault zone is 4 km and possibly >12 km. The inferred distance of flow parallel to the formation into this fault thus exceeds the distance of cross-formational upward flow along the fault by at least a factor of six. The mass-balance estimate requires that fluid flow along the fault is channeled into a pipe-shaped conduit rather than distributed along fault strike. Fluid flow from the surrounding formation into fault pipes is inferred to follow a radial rather than uni- or bilateral flow symmetry, using bedding-confined sets of extension fractures and stratabound breccia bodies. Radial fluid flow toward fault pipes requires fairly isotropic fracture permeability for flow along bedding and a low permeability across bedding. The inferred flow geometry illustrates the combined effect of fault permeability structure, permeability anisotropy of the surrounding formation, and hydraulic head distribution in controlling basinal fluid flow in faulted sequences. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.