Record Details
Refinement of a high-resolution, continuous sedimentary section for studying Equatorial Pacific Ocean paleoceanography, Leg 138
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | Refinement of a high-resolution, continuous sedimentary section for studying Equatorial Pacific Ocean paleoceanography, Leg 138 |
| Names |
Hagelberg, T. K.
(creator) Pisias, Nicklas G. (creator) Shackleton, N. J. (creator) Mix, Alan C. (creator) Harris, Sara E. (creator) |
| Date Issued | 1995 (iso8601) |
| Abstract | Ocean Drilling Program (ODP) Leg 138 was designed to study the late Neogene paleoceanography of the equatorial Pacific Ocean at time scales of thousands to millions of years. Crucial to this objective was the acquisition of continuous, high-resolution sedimentary records. It is well known that between successive advanced piston corer (APC) cores, portions of the sedimentary sequence often are absent, despite the fact that core recovery is often recorded as 100%. To confirm that a continuous sedimentary sequence was sampled, each of the 11 drill sites was multiple-APC-cored. At each site, continuously measured records of magnetic susceptibility, gamma-ray attenuation porosity evaluator (GRAPE), wet-bulk density, and digital color reflectance were used to monitor section recovery. These data were used to construct a composite depth section while at the site. This strategy often verified 100% recovery of the complete sedimentary sequence with two or three offset piston-cored holes. Here, these initial efforts have been extended to document the recovery of a complete sediment section and to investigate sources of error associated with sediment density measurements and changes in local sedimentation rates. At Sites 846 through 852, fine-scale correlation (on the order of centimeters) of the GRAPE records was accomplished using the inverse correlation techniques of Martinson et al. (1982). Having a common depth scale for all holes at each site facilitated comparison of high-resolution data from different holes. After refining the interhole correlation, GRAPE records from adjacent holes were "stacked" to produce a less noisy estimate of sediment wet-bulk density for Sites 846 through 852. The continuity of the stacked GRAPE record is confirmed with reflectance and susceptibility records. The resulting stacked GRAPE records have a temporal resolution of less than 1000 yr for the past 5 m.y. Moreover, the stacking procedure allows for development of error estimates for measurements present in more than one hole. An important advantage provided by this framework is that one can determine the range of sedimentation variability between adjacent holes at a given site. This variability is caused by local sedimentation variability and by artifacts of the coring process. We demonstrate that the depth domain changes in sedimentation variability required to correlate among adjacent holes are larger than the changes induced by time-scale tuning procedures. |
| Genre | Article |
| Identifier | Hagelberg, T., Pisias, N., Shackleton, N., & Mix, A. (1995). Refinement of a High-Resolution, Continuous Sedimentary Section for Studying Equatorial Pacific Ocean Paleoceanography, leg 138. < http://www.coas.oregonstate.edu/facultypages/Mix/Hagelberg_etal_1995_ODP138sr_refinement.pdf > In: Pisias, N.G., Mayer, L.A., Janecek, T.R., Palmer-Julson, A., and van Andel, T.H. (eds). /Proceedings of the Ocean Drilling Program, Scientific Results,/ 138, College Station, TX (Ocean Drilling Program), 31-46. |
