SAMPLING PLAN

 General
Much of the Neogene core material to be recovered during Leg 189 will be retrieved by APC and XCB coring, generally by triple coring. Sampling of the recovered cores will be subject to the rules described in the ODP Sample Distribution Policy (http://www-odp.tamu.edu/publications/policy.html). Sampling for high-resolution isotopic, sedimentologic, and micropaleontologic studies will be conducted after construction of the spliced composite section. High-resolution sampling is anticipated for most sites. Sampling schedules will be worked out to optimize stratigraphic coverage and to minimize duplication. Geochemical sampling, which calls for larger volumes, will be conducted on material from the third hole if it would otherwise interfere with first-pass micropaleontology and sedimentology sampling.

Most high-resolution sampling will be deferred until after the cruise; however, the upper few cores in each hole that contain high-porosity sediments, which may be disturbed during transport to the Gulf Coast Repository (Texas A&M University), will be sampled on board ship. High-resolution sampling is anticipated for most of the upper APC and XCB cores, depending on the abundance of microfossils (especially benthic foraminifers). Where appropriate, U-channel sampling for high resolution paleomagnetic studies will be conducted postcruise in the temporary archive half along the composite sampling splice.

Sampling for whole-round samples (e.g., physical properties, interstitial waters, etc.) will be undertaken so as not to interfere with stratigraphically sensitive sampling sequences and to take advantage of available continuous nondestructive measurements where possible.

The large amount of material to be rotary cored will largely be Eocene and lower Oligocene detrital sediments, but will also probably include the older Neogene sequences in places. The sampling density will be much lower in the detrital sequences.

Ultra-High-Resolution Sites
Should particularly thinly laminated sediments be encountered, or some other factor necessitate it, detailed very high-resolution sampling may be approved. The sampling allocation committee (SAC) will determine details of the sampling pattern in such instances.

Sampling Timetable
Detailed sampling of cores from a given site will proceed only after a composite stratigraphy is constructed from cores from the two or more holes drilled at the site. The splice will be constructed, and the stratigraphic information will be distributed to the scientific party, in advance of postcruise sampling to facilitate planning and scientific collaboration. Requests to sample on board, for pilot studies or for projects requiring lower stratigraphic resolution, will be considered by the SAC.

Archives
The permanent archive will be the ODP-defined "minimum permanent archive." Once the working half of a core section is depleted, the temporary archives for that section will be accessible for sampling. Wherever possible, one-quarter of such temporary archives should be preserved by sampling off-center. The archive-half cores (permanent and temporary) for all holes will not be sampled aboard ship, and the permanent archive will be designated postcruise.

Final Comment
All sampling for Leg 189, and the final sampling plan, will be approved by the SAC, consisting of the Co-Chief Scientists (Exon and Kennett), Staff Scientist (Malone), and the Curator (or his representative). The initial sampling plan will be preliminary and may be modified during the cruise, depending upon actual material recovered and collaborations that may evolve between scientists.


To 189 References

To 189 Table of Contents