Acoustic and elastic properties of calcareous sediments across a siliceous diagenetic front on the Eastern U.S. continental slope

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doi: 10.1029/96GL02188
Author(s): Guérin, Gilles; Goldberg, Dave
Author Affiliation(s): Primary:
Lamont-Doherty Earth Observatory, Borehole Research Group, Palisades, NY, United States
Volume Title: Geophysical Research Letters
Source: Geophysical Research Letters, 23(19), p.2697-2700. Publisher: American Geophysical Union, Washington, DC, United States. ISSN: 0094-8276 CODEN: GPRLAJ
Note: In English. 12 refs.; illus., incl. 2 tables
Summary: The Ocean Drilling Program drilled Hole 904A on the upper continental slope offshore New Jersey through 230 m of Eocene chalks and an opal-A/opal-CT diagenetic front. In addition to a suite of standard logging tools, a dipole sonic tool was deployed to determine the in situ shear sonic velocity and the elastic properties of these slow, highly porous, sediments. While porosity decreases by 20% across the diagenetic front, the compressional velocity and the density are observed to increase by 30%, the shear sonic velocity and the bulk modulus by about 60%, and the shear modulus by almost 300%. It is shown that shear and compressional velocities are both controlled by porosity and consolidation, and that existing models for the prediction of elastic properties and shear velocity from standard logs are still valid through the diagenetic front. The strong effect of diagenesis on rigidity makes the shear velocity log a highly sensitive indicator of pore shape and pore filling transformations. Copyright 1996 by the American Geophysical Union.
Year of Publication: 1996
Research Program: ODP Ocean Drilling Program
Key Words: 07 Marine Geology and Oceanography; 20 Geophysics, Applied; Acoustical logging; Acoustical methods; Bulk modulus; Calcareous composition; Carbonate rocks; Chalk; Clastic rocks; Consolidation; Continental slope; Diagenesis; Eastern U.S.; Elastic constants; Elastic properties; Framework silicates; Geophysical methods; Geophysical surveys; In situ; Leg 150; New Jersey; ODP Site 902; ODP Site 904; Ocean Drilling Program; Offshore; Opal; Opal-A; Opal-CT; Porcellanite; Porosity; Sedimentary rocks; Shear modulus; Silica minerals; Silicates; Surveys; United States; Well-logging
Coordinates: N385148 N385605 W0724605 W0724622
Record ID: 1996082006
Copyright Information: GeoRef, Copyright 2017 American Geosciences Institute.