provides an undeformed reference site of the incoming sedimentary sequence (Shipboard

Scientific Party, 2001). Site 1174 is located about 1.8 km landward of the deformation

front and penetrates the decollement within the proto-thrust zone (Figure 2-3). Site 1177

was drilled approximately 18 km seaward of the deformation front as the reference site

for the Ashizuri Transect (Shipboard Scientific Party, 2001). At both Sites 1173 and

1174, the hemipelagic sediments of the upper and lower Shikoku Basin are overlain by

the turbidite-rich trench-wedge facies, which was not tested for permeability. At Site

1177, the trench-wedge facies was not cored.

Peru

 The Peru accretionary complex is formed by the northeastward subduction at

approximately 6.1 cm/yr of the Nazca plate (Hampel, 2002) below the Andean

continental margin along the Peru Trench (Figure 2-4). During ODP Leg 201, seven sites

were drilled into a wide range of subsurface environments in both open-ocean (Sites

1225, 1226 and 1231) and ocean-margin provinces (Sites 1227 and 1230) of the eastern

tropical Pacific Ocean. These subsurface environments include carbonates and siliceous

oozes typical of the equatorial Pacific, clays and nannofossil-rich oozes of the Peru

Basin, biogenic and terrigenous-rich sediments of the shallow Peru shelf, and clay-rich

deepwater sequences of the Peru slope (Shipboard Scientific Party, 2003).