Tectonics, fluid migration, and fluid pressure in a deformed forearc basin, Cook Inlet, Alaska

Research Article| April 01, 2000 Tectonics, fluid migration, and fluid pressure in a deformed forearc basin, Cook Inlet, Alaska R. L. Bruhn; R. L. Bruhn 1Department of Geology and Geophysics, University of Utah, Salt Lake City, Utah 84112, USA Search for other works by this author on: GSW Google Scholar W. T. Parry; W. T. Parry 1Department of Geology and Geophysics, University of Utah, Salt Lake City, Utah 84112, USA Search for other works by this author on: GSW Google Scholar M. P. Bunds M. P. Bunds 1Department of Geology and Geophysics, University of Utah, Salt Lake City, Utah 84112, USA Search for other works by this author on: GSW Google Scholar Author and Article Information R. L. Bruhn 1Department of Geology and Geophysics, University of Utah, Salt Lake City, Utah 84112, USA W. T. Parry 1Department of Geology and Geophysics, University of Utah, Salt Lake City, Utah 84112, USA M. P. Bunds 1Department of Geology and Geophysics, University of Utah, Salt Lake City, Utah 84112, USA Publisher: Geological Society of America Received: 22 Jun 1998 Revision Received: 12 Mar 1999 Accepted: 12 May 1999 First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (2000) 112 (4): 550–563. https://doi.org/10.1130/0016-7606(2000)112<550:TFMAFP>2.0.CO;2 Article history Received: 22 Jun 1998 Revision Received: 12 Mar 1999 Accepted: 12 May 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 R. L. Bruhn, W. T. Parry, M. P. Bunds; Tectonics, fluid migration, and fluid pressure in a deformed forearc basin, Cook Inlet, Alaska. GSA Bulletin 2000;; 112 (4): 550–563. doi: https://doi.org/10.1130/0016-7606(2000)112<550:TFMAFP>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 Faulting controls fluid migration within transpressive fault-propagation folds in the Cook Inlet forearc basin of south-central Alaska. Na-Ca-Cl brine migrates out of Mesozoic rocks through reverse and oblique-slip faults into the cores of anticlines, where the fluid spreads laterally outward into lower Tertiary strata by flow through cross faults and permeable beds. Precipitation of zeolite and carbonate cement and veins reduces the permeability of folded bedding and faults. Zeolite minerals are formed by chemical reactions between Na-Ca-Cl brine and sedimentary rocks. Carbonate minerals are precipitated when Na-HCO3 connate fluid in the Tertiary section reacts with rocks during diagenesis, and by mixing of migrated Na-Ca-Cl brine with the Na-HCO3 pore fluid. Carbonate cement is also precipitated by fluctuations in PCO2 during faulting and jointing.High fluid pressure is encountered while drilling through lower Tertiary and Mesozoic strata in some anticlines. High-pressure fluid is contained within porous beds that are intercalated with strata cemented by carbonate and zeolite minerals. Zeolite and carbonate cemented beds retard the dissipation of high fluid pressure, and channel fluid flow parallel to bedding within the anticlines. High fluid pressure may be generated by several processes, acting either alone or together. The evidence for fault-controlled migration of fluid out of the basement suggests that volumetric strain related to deformation is most important, but may be augmented by dynamo-thermal metamorphism, sedimentary compaction, alteration of organic-rich rock and hydrocarbons, and possibly glacial loading. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.