Site summaries (continued)

Proposed Site NT2-03B

  • Chikyu Expedition 314 (LWD)
  • Chikyu Expedition 315 (Megasplay Riser Pilot)
33°14.30′N, 136°42.65′E
Water depth (m):
Target drilling depth (mbsf):
1000 m
Approved maximum penetration (mbsf):
1250; approved by CDEX and TAMU safety panels based on EPSP Jan 2007 recommendation
Survey coverage:
CDEX 2006 3-D MCS; extensive survey data outlined in Proposal 603A-Full2 (
(see text for full details):
Sample forearc basin sediments and deformed prism
Preparatory site for 3.5 km deep Stage 2 riser site (Stage 2 will characterize megasplay fault zone system by intersecting it at intermediate depth of 3.5 km)
Integration with proposed Sites NT2-01A and NT3-01 is essential
Drilling, coring, and downhole measurement program:
Chikyu Expedition 314 (LWD):
  • Pilot hole using MWD
  • Hole A - MWD/LWD to 1000 m
Chikyu Expedition 315 (Megasplay Riser Pilot): Hole B:
  • Jet-in test
  • APC/XCB coring and downhole measurements (temperature, core orientation)
Hole C:
  • Install reentry cone and 20 inch casing
  • Drill without coring to depth of Hole B
  • RCB core to TD
  • Wireline logging (DSI, VSP)
  • Deploy reentry cone and 13-3/8 inch casing if required to achieve TD
  • Wireline logging only as contingency in case Chikyu Expedition 314 LWD is not successful
Hole D:
  • Initiate riser drill hole
  • Install 36 inch conductor casing
  • Drill 26 inch hole to 700 mbsf
  • Install and cement 20 inch casing
Anticipated lithology:
0–210 mbsf: slope sediments
210–800 mbsf: accretionary prism (deformed, compacted turbidites)