Acoustic and elastic properties of calcareous sediments across a siliceous diagenetic front on the eastern US continental slope

Publication Type  Journal Article
Year of Publication  1996
Authors  Guerin, G.; Goldberg, D.
Journal Title  Geophysical Research Letters
Volume  23
Issue  19
Pages  2697-2700
Journal Date  Sep 15
ISBN Number  0094-8276
Accession Number  ISI:A1996VH16900031
Key Words  marine-sediments

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.


Vh169Times Cited:6Cited References Count:12

URL  <Go to ISI>://A1996VH16900031