IODP

doi:10.14379/iodp.sp.352.2013

Site summaries (continued)

Proposed Site BON-6A

Priority: Alternate
Position: 28°25.63′N, 142°43.50′E
Water depth (m): 4452
Target drilling depth (mbsf): 1020 (270 m sediment, 750 m basement)
Approved maximum penetration (mbsf): 1520 (pending EPSP approval)
Survey coverage: Line IBr11 CDP 68100
• Track map (Fig. AF1)
• Seismic profiles (Figs. AF4, AF9)
Objective: Characterize lower volcanic stratigraphy at Bonin fore arc to investigate subduction initiation processes and test supra-subduction zone ophiolite models
Drilling, coring, and downhole measurements program: • Hole A: jet-in test
• Hole B: APC/XCB to basement (270 mbsf)
• Hole C: reentry system (16 and 10-3/4 inch casing to 275 mbsf)
• Hole C: drill without recovery to 280 mbsf, RCB from 280 to 1020 mbsf
• FlexIT core orientation measurements
• Wireline logging (triple combo, FMS-sonic)
Nature of rock anticipated: Pelagic carbonate with thin ash layers, basaltic lavas, and sheeted dikes