IODP Expedition 320/321 Scientific Prospectus

doi:10.2204/iodp.sp.320321.2008

Site summaries (continued)


PEAT-3 Line 6:	2006 JD 095 00:43:29 UTC, SP 22721
Nearest crossing:	PEAT-3 Line 3 at 2006 JD 094 21:18:15 UTC, SP 21487
Estimated crustal age (Ma):	46
Ship location:	SP 22721: 10°32.772’N, 138°20.183’W
Basement depth (m):	4889 (6.519 s TWT)
Sediment thickness (m):	181 from Site 574 velocity profile (0.229 s TWT)
Velocity (Mayer et al., 1985):	Depth (mbsf)	TWT (ms)	Velocity (m/s)
	0–76	0–100	1520
	76–151	100–193	1613
	151–330	193–410	1650
	>330–TD	>410	1970
Site PEAT-3D was chosen as an alternate site, ~2 km north of the cross between Lines 6 and 3 along Line 6. This site has a slightly thinner basal section, although the total sediment column is slightly thicker. Subbottom profiling occasionally reveals indistinct horizons to ~60 m subsurface. However, over most of the area few or no subsurface horizons can be distinguished.