Table T1 (continued).
Polarity chron/subchron
Reversal type
Age
(Ma)
Range
(mbsf)
Best estimate (mbsf)
Best estimate core,
section, interval (cm)
Measurement type
Range
(mbsf)
Best estimate (mbsf)
Best estimate hole, core,
section, interval (cm)
Measurement
type
C4r.2r-1 (o) RN 8.651



404.81-404.88 404.85 1095B-34X-6, 5 Discrete/Split-core
C4An (t) NR 8.699



411.70-411.74 411.72 1095B-35X-4, 62 Split-core
C4An (o) RN 9.025



445.98-446.02 446.00 1095B-39X-1, 90 Split-core
C4Ar.1n (t) NR 9.230



460.70-461.04 460.87 1095B-40X-5, 7 Split-core
C4Ar.1n (o) RN 9.308



485.40-485.65 485.53 Between 1095B-43X-2 and 43X-CC Split-core
C4Ar.2n (t) NR 9.580



504.74-522.88 520.50 Between 1095B-46X-2 and 48X-1 Split-core

Notes: Ages for chrons are from Cande and Kent (1995). (o) = onset, (t) = termination of a polarity chron. NR = a reversal where the polarity of the field changed from normal to reversed, RN = a reversal where the polarity of the field changed from reversed to normal. * = the reversal boundary is the same as identified by Shipboard Scientific Party (1999a), but the location of the boundary has been adjusted slightly. † = identification of chron and reversal boundaries is speculative; therefore, these reversal boundaries are not used in the sedimentation rate plots. ‡ = the reversal boundary is identical to that given by Shipboard Scientific Party (1999a). Comments: (1) = depth to mudline in mbsf agrees to within 2 cm for the first core from Holes 1095A, 1095B, and 1095C. (2) = our interpretation places Chron C2n ~20 m higher in the section than that by Shipboard Scientific Party (1999a). (3) = the polarity subzone interpreted to represent Subchron C2r.1n is speculative. Rather than a geomagnetic origin, the subzone could be caused by coring disturbance at the top of Core 178-1095D-6H. We place the C2r.1n (t) reversal at the very top of Core 178-1095D-6H. This subchron was thought to be lost in a hiatus based on the interpretation of Shipboard Scientific Party (1999a). (4) = this reversal was interpreted to represent C2n (t) by Shipboard Scientific Party (1999a) and was thought to occur above a hiatus that removed reversals C2n (o) to C2An.1n (t). (5) = placing Subchron C2An.1n (o) at this locality produces a subchron (C2An.1r) that is short, with resulting sedimentation rates exceptionally slow relative to sedimentation rates above and below. (6) = average mcd depth taken from the best estimates from Holes 1095A and 1095D, which are 77.98 and 77.92 mcd. (7) = this reversal could be C2An.1n (o) instead of C2An.2n (o), in which case no Subchron C2An.2n appears to be recorded. (8) = average mcd depth taken from the best estimates for Holes 1095A and 1095B, which are 84.58 and 85.54 mcd. (9) = the reversal occurs within an interval that has some drilling disturbance. The best estimate for the location agrees with noisy discrete data. (10) = this is possibly a newly identified cryptochron, which we refer to as C3n.1r-1. (11) = Subchron C3n.3n was not previously identified by Shipboard Scientific Party (1999a). (12) = this poorly constrained reversal, C3n.4n (t), occurs somewhere within a broad zone of shallow inclinations. (13) = this is possibly a newly identified cryptochron, which we refer to as C3r-1. (14) = Subchron 3An.1n (o) is placed in the lower part of the coring gap (top of Core 178-1095B-16X) rather than the middle. (15) = reversals C4r.1n (t) and C4r.1n (o) possibly occur in a zone of shallow inclinations near 364 and 369 mcd, respectively. (16) = the transition zone for Subchron C4r.2r-1 (t) is from 393.94 to 394.48 mcd in discrete samples. This is a zone that is weakly magnetized. (17) = the transition zone for C4r.2r-1 (o) can only be limited to between Sections 178-1095B-34X-5 and 34X-6 in split-core data. (18) = the reversal C4Ar.2n (t) is arbitrarily placed near the top of Core 178-1095B-48X to better agree with logging estimate.