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Diagenesis, sediment strength, and pore collapse in sediment approaching the Nankai Trough subduction zone

2006; Geological Society of America; Volume: 119; Issue: 3-4 Linguagem: Inglês

10.1130/b25920.1

1943-2674

G. A. Spinelli, Peter S. Mozley, Harold Tobin, Michael B. Underwood, N. W. Hoffman, G. M. Bellew,

Geological and Geochemical Analysis

Research Article| March 01, 2007 Diagenesis, sediment strength, and pore collapse in sediment approaching the Nankai Trough subduction zone Glenn A. Spinelli; Glenn A. Spinelli 1Earth & Environmental Science Department, New Mexico Institute of Mining and Technology, Socorro, New Mexico 87801, USA Search for other works by this author on: GSW Google Scholar Peter S. Mozley; Peter S. Mozley 1Earth & Environmental Science Department, New Mexico Institute of Mining and Technology, Socorro, New Mexico 87801, USA Search for other works by this author on: GSW Google Scholar Harold J. Tobin; Harold J. Tobin 1Earth & Environmental Science Department, New Mexico Institute of Mining and Technology, Socorro, New Mexico 87801, USA Search for other works by this author on: GSW Google Scholar Michael B. Underwood; Michael B. Underwood 2Department of Geological Sciences, University of Missouri, Columbia, Missouri 65211, USA Search for other works by this author on: GSW Google Scholar Nicole W. Hoffman; Nicole W. Hoffman 3Earth & Environmental Science Department, New Mexico Institute of Mining and Technology, Socorro, New Mexico 87801, USA Search for other works by this author on: GSW Google Scholar Glen M. Bellew Glen M. Bellew 4Department of Civil & Environmental Engineering, University of Missouri, Columbia, Missouri 65211, USA Search for other works by this author on: GSW Google Scholar GSA Bulletin (2007) 119 (3-4): 377–390. https://doi.org/10.1130/B25920.1 Article history received: 24 Oct 2005 rev-recd: 29 Sep 2006 accepted: 09 Oct 2006 first online: 08 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Glenn A. Spinelli, Peter S. Mozley, Harold J. Tobin, Michael B. Underwood, Nicole W. Hoffman, Glen M. Bellew; Diagenesis, sediment strength, and pore collapse in sediment approaching the Nankai Trough subduction zone. GSA Bulletin 2007;; 119 (3-4): 377–390. doi: https://doi.org/10.1130/B25920.1 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 A minor amount of opal cement inhibits consolidation of sediment approaching the Nankai Trough subduction zone at Ocean Drilling Program Sites 1173 and 1177. Secondary and backscattered electron images of sediments from Site 1173 reveal a low-density, silica phase (opal-CT) coating grain contacts. The grain-coating cement is more widespread in the upper Shikoku Basin facies than in the lower Shikoku Basin facies. Numerical models of opal-CT content display increases with depth through the cemented upper Shikoku Basin section. Once temperature increases above ∼55 °C, the rate of opal-CT dissolution outpaces precipitation, the cement can no longer support the overburden, and the open framework of the sediment begins to collapse. Cementation followed by cement failure is consistent with observed anomalies in porosity, seismic velocities, and shear rigidity. Porosity is anomalously high and nearly constant near the base of the upper Shikoku Basin facies, whereas seismic velocity increases with depth in the same interval. Across the boundary between the upper Shikoku Basin facies and the lower Shikoku Basin facies, there are step decreases in porosity from ∼60% to ∼45%, P-wave velocity from ∼1800 m/s to ∼1650 m/s, and S-wave velocity from ∼550 m/s to ∼300 m/s. Similar cementation and porosity collapse may be important in other locations where heating of hemipelagic deposits, with minor amounts of opal, is sufficient to trigger opal diagenesis. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.