Huepers, Andre; Kopf, Achim J. (2012): Consolidation properties of silty claystones and sandstones sampled seaward of the Nankai Trough subduction zone, IODP Sites C0011 and C0012. IODP Management International, Washington, DC, United States, In: Underwood, Michael B., Saito, Saneatsu, Kubo, Yu'suke, Sanada, Yoshinori, Chiyonobu, Shun, Destrigneville, Christine, Dugan, Brandon, Govil, Pawan, Hamada, Yohei, Heuer, Verena, Huepers, Andre, Ikari, Matt, Kitamura, Yujin, Kutterolf, Steffen, Labanieh, Shasa, Moreau, John, Naruse, Hajime, Oda, Hirokuni, Park, Jin-Oh, Pickering, Kevin T., Scudder, Rachel, Slagle, Angela, Spinelli, Glenn, Torres, Marta, Tudge, Joanne, Wu Huaichun, Yamamoto, Tomohiro, Yamamoto, Yuzuru, Zhao, Xixi, Proceedings of the Integrated Ocean Drilling Program; NanTroSEIZE Stage 2; subduction inputs; Expedition 322 of the riser drilling platform; Yokkaichi, Japan, to Shingu, Japan; Sites C0011 and C0012, 1 September-10 October 2009, 322, georefid:2012-098508

Abstract:

We conducted incremental loading and constant rate of strain consolidation tests on sediments recovered during Integrated Ocean Drilling Program (IODP) Expedition 322 from Sites C0011 and C0012, located seaward of the deformation front in the Nankai Trough subduction zone, southeast Japan. In total, five silty claystones and six sandstone samples from lithologic Units II-V were tested. The results document higher compressibilities for clay-rich specimens with compression indexes of C (sub c) =0.4829-0.6905, whereas sandstones are characterized by values of C (sub c) =0.2257-0.4357. Maximum past effective stresses of silty claystones from Units II and III suggest a normal to slightly overconsolidated state. Samples from Units IV and V are significantly overconsolidated with overconsolidation ratios of 2.06-2.51. Vertical effective stresses of approximately 10 MPa are needed to force yielding nonvolcanic sandstones. These yield stresses are significantly higher than the calculated value of in situ hydrostatic vertical effective stresses. In contrast, volcanic sandstones yield at stresses close to the in situ hydrostatic effective stress. For all tested specimens, the logarithm of hydraulic conductivity K shows a linear relationship with void ratio, with sandstones exhibiting higher K values. Calculated in situ intrinsic permeabilities for silty claystones decrease with depth from 1.8X10 (super -17) m (super 2) at 377.81 m core depth below seafloor (CSF) to 8.5X10 (super -20) m (super 2) at 749.38 m CSF. In situ intrinsic permeabilities of sandstones do not show a clear trend but scatter between values of 1.3X10 (super -15) and 4.0X10 (super -17) m (super 2) .

Coverage:

West: 136.5254 East: 136.5501 North: 32.4944 South: 32.4453

Relations:

Expedition: 319

Site: 319-C0011

Expedition: 322

Site: 322-C0011

Site: 322-C0012

Expedition: 333

Site: 333-C0011

Site: 333-C0012

Expedition: 338