Meissl, Sandra et al. (2010): Data report; Preliminary assessment of Pleistocene sediment strength in the Ursa Basin (Gulf of Mexico continental slope) from triaxial and ring shear test data

Leg/Site/Hole:
IODP 308
IODP 308 U1322
IODP 308 U1324
Identifier:
2010-098056
georefid
10.2204/iodp.proc.308.211.2010
doi
Creator:
Meissl, Sandra
IFM-GEOMAR, Kiel, Federal Republic of Germany
author
Behrmann, Jonas
Albert-Ludwigs-Universitaet Freiburg, Federal Republic of Germany
author
Behrmann, Jan H.
University of California-Santa Cruz, United States
author
Identification:
Data report; Preliminary assessment of Pleistocene sediment strength in the Ursa Basin (Gulf of Mexico continental slope) from triaxial and ring shear test data
2010
In: Flemings, Peter B., Behrmann, Jan H., John, Cedric M., Iturrino, Gerardo J., Aizawa, Yasutaka, Nguyen Thi Thanh Binh, De Silva, Neil, Dugan, Brandon, Edeskar, Tommy M., Franke, Christine, Gay, Aurelien, Gilhooly, William Patrick, III, Gutierrez-Pastor, Julia, Shao Yongjiang, Li Qianyu, Long, Hui, Moore, J. Casey, Nunoura, Takuro, Pirmez, Carlos, Reichow, Marc, Sawyer, Derek E., Schneider, Julia, Shumnyk, Anatoliy V., Suzuki, Takahiro, Takano, Yoshinori, Urgeles, Roger, Yamamoto, Yuzuru, Zampetti, Valentina, Proceedings of the Integrated Ocean Drilling Program; Gulf of Mexico hydrogeology; Expedition 308 of the riserless drilling platform from Mobile, Alabama, to Balboa, Panama; Sites U1319-U1324, 30 May-8 July 2005
IODP Management International, Washington, DC, United States
308
We report the preliminary results of a triaxial and ring shear study on clay-rich, fine-grained Pleistocene sediments cored in Ursa Basin, Gulf of Mexico continental slope. Specimens from Integrated Ocean Drilling Program (IODP) Expedition 308 Sites U1322 and U1324 document friction coefficients in the range of 0.13-0.31, with internal angles of friction of approximately 7.4 degrees -17.2 degrees in ring shear experiments. At intermediate (7.624 MPa) to high (15.237 MPa) overburden pressure, the majority of the samples tested show velocity weakening, whereas lower overburden pressures do not give a clear trend regarding velocity weakening or strengthening of the samples. In consolidated-undrained triaxial tests, peak shear stresses observed are between 27 and 140 kPa, with the strongest sample by far coming from a core catcher section. We suspect that this is an effect of fabric changes induced during hydraulic piston coring. One sample coming from the base of a mass transport deposit at Site U1322 is the weakest one tested. Young's moduli calculated range from 2 to 17.4 kPa. Stress paths indicate slight overconsolidation of the samples, which is in line with the information gained from preconsolidation stresses in other studies. Permeability determined from consolidation data is in the range of 10 (super -16) to 10 (super -17) m (super 2) , and hydraulic conductivity is around 10 (super -9) to 10 (super -10) ms (super -1) . Grain density of the tested samples is around 2.7 g/cm (super 3) , and water content ranges from 18.3% to 30.7%.
English
Serial
Coverage:Geographic coordinates:
North:28.0600
West:-89.0800East: -89.0100
South:28.0500
Engineering geology; Atlantic Ocean; boreholes; Cenozoic; continental slope; cores; elastic constants; Expedition 308; experimental studies; friction angles; Gulf of Mexico; hydraulic conductivity; Integrated Ocean Drilling Program; IODP Site U1322; IODP Site U1324; laboratory studies; Louisiana; marine sediments; mechanical properties; North Atlantic; northern Gulf of Mexico; permeability; physical properties; Pleistocene; pore pressure; Quaternary; sediments; shear strength; shear tests; soil mechanics; strain; stress; triaxial tests; United States; Ursa Basin; Young's modulus;
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