IODP

doi:10.14379/iodp.sp.352.2013

Site summaries (continued)

Proposed Site BON-5A

Priority: Alternate
Position: 28°24.54′N, 142°37.04′E
Water depth (m): 3152
Target drilling depth (mbsf): 910 (160 m sediment, 750 m basement)
Approved maximum penetration (mbsf): 1410 (pending EPSP approval)
Survey coverage: Line IBr11 CDP 66380
• Track map (Fig. AF1)
• Seismic profiles (Figs. AF4, AF5, AF8)
Objective: Characterize upper 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 (160 mbsf)
• Hole C: reentry system (16 and 10-3/4 inch casing to 165 mbsf)
• Hole C: drill without recovery to 170 mbsf, RCB from 170 to 910 mbsf
• FlexIT core orientation measurements
• Wireline logging (triple combo, FMS-sonic)
Nature of rock anticipated: Pelagic carbonate with thin ash layers, boninite, and basaltic lavas