The fabric of fine-grained sediments from the deep-sea terrace on the landward side of the Japan Trench, cored during Ocean Drilling Program Leg 186, was analyzed using the anisotropy of magnetic susceptibility. The purpose of this study was to document the magnetic fabrics formed in a tensional environment. Faults and joints (healed fractures) were found in the lower portion of recovered core. Analysis of these structures suggests an east-west tensional direction. The general shape of the magnetic fabric ellipsoid is fairly oblate. Bedding planes dip to the east in Hole 1151, and the magnetic fabric is completely controlled by the bedding plane. The magnetic fabric in the interval highly affected by fracturing, however, shows higher anisotropy. Magnetic foliations, which have been reorientated using paleomagnetic north, incline eastward and westward.

Supplement to: Kanamatsu, Toshiya; Matsuo, Kazue (2003): Rock magnetic study of sediments from the Japan Trench, ODP Leg 186: implications for deformation of sediments. In: Suyehiro, K; Sacks, IS; Acton, GD; Oda, M (eds.) Proceedings of the Ocean Drilling Program, Scientific Results, College Station, TX (Ocean Drilling Program), 186, 1-21