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1401.5 mbsf (Hole C0002A; Expedition 314 Scientists, 2009a) and 0 to 980 mbsf (Hole C0002G; Expedition 332 Scientists, 2011). Coring at Site C0002 previously sampled 0-203.5 mbsf (Holes C0002C and C0002D) and 475-1057 mbsf (Hole C0002B) (Expedition 315 Scientists, 2009b). During riser operations, we expanded the data sets at Site C0002. Gas from drilling mud was analyzed in near real time in a mud-gas monitoring laboratory and was sampled for postcruise research. Continuous LWD/MWD data were collected in real time for quality control and for initial assessment of borehole environment and formation properties. Recorded-mode LWD data provided higher spatial sampling of downhole parameters and conditions. Cuttings were sampled for standard shipboard analyses and shore-based research. Riserless Methods 1

Drill core recovered at Ocean Drilling Program Site 808 (Leg 131) proves that the wedge of trench sediment within the central region of the Nankai Trough comprises approximately 600 m of hemipelagic mud, sandy turbidites, and silty turbidites. The stratigraphic succession thickens and coarsens upward, with hemipelagic muds and volcanic-ash layers of the Shikoku Basin overlain by silty and sandy trench-wedge deposits. Past investigations of clay mineralogy and sand petrography within this region have led to the hypothesis that most of the detritus in the Nankai Trough was derived from the Izu-Honshu collision zone and transported southwestward via axial turbidity currents. Shipboard analyses of paleocurrent indicators, on the other hand, show that most of the ripple cross-laminae within silty turbidites of the outer marginal trench-wedge facies are inclined to the north and northwest; thus, many of the turbidity currents reflected off the seaward slope of the trench rather than moving straight down the trench axis. Shore-based analyses of detrital clay minerals demonstrate that the hemipelagic muds and matrix materials within sandy and silty turbidites are all enriched in illite; chlorite is the second-most abundant clay mineral, followed by smectite. In general, the relative mineral percentages change relatively little as a function of depth, and the hemipelagic clay-mineral population is virtually identical to the turbidite-matrix population.Comparisons between different size fractions (<2 µm and 2-6 µm) show modest amounts of mineral partitioning, with chlorite content increasing in the coarser fraction and smectite increasing in the finer fraction. Values of illite crystallinity index are consistent with conditions of advanced anchimetamoΦhism and epimetamoΦhism within the source region. Of the three mica poly types detected, the 2Mj variety dominates over the IM and IMd polytypes; these data are consistent with values of illite crystallinity. Measurements of mica b o lattice spacing show that the detrital illite particles were eroded from a zone of intermediate-pressure metamoΦhism. Collectively, these data provide an excellent match with the lithologic and metamoΦhic character of the Izu-Honshu collision zone. Data from Leg 131, therefore, confirm the earlier inteΦ r etations of detrital provenance. The regional pattern of sediment dispersal is dominated by a combination of southwest-directed axial turbidity currents, radial expansion of the axial flows, oblique movement of suspended clouds onto and beyond the seaward slope of the Nankai Trough, and flow reflection back toward the trench axis.

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