Mountain, G.S., Miller, K.G., Blum, P., et al., 1994 Proceedings of the Ocean Drilling Program, Initial Reports, Vol. 150 3. EXPLANATORY NOTES 1 Shipboard Scientific Party 2 INTRODUCTION This chapter outlines methods used to obtain and process data collected by Leg 150 participants. Methods used by various investi- gators for shore-based analyses of Leg 150 data will be described in the individual scientific contributions to be published in the Scientific Results volume. Authorship of Site Chapters The separate sections of the site chapters were written by the following shipboard scientists (authors are listed in alphabetical or- der, no seniority is implied): Site Summary: Miller, Mountain Background and Objectives: Miller, Mountain Operations: Blum, Foss Lithostratigraphy: Damuth, Deconinck, Hesselbo, Kotake, McCracken, McHugh, Saito, ten Kate Biostratigraphy: Aubry, Burckle, Christensen, de Verteuil, Gartner, Katz, Snyder Paleomagnetism: Urbat, van Fossen Sedimentation Rates: Aubry, Christensen, Miller Organic Geochemistry: Quayle Inorganic Geochemistry: Compton Physical Properties: Fulthorpe, Hoppie, Lorenzo, Vecsei APC Downhole Temperature (ADARA): Blum Downhole Measurements: Aim, Guerin Seismic Stratigraphy: Miller, Mountain Summary and Conclusions: Miller, Mountain Summary core descriptions ("barrel sheets") and photographs of each core are included in Section 3. Downhole log measurements prepared onshore by the Borehole Research Group appear at the end of each site chapter. The Ocean Drilling Program (ODP) is in the process of replacing the bulk of the "Explanatory Notes" chapters in each Initial Reports volume with a chapter entitled "Annual Explanatory Notes to Initial Reports Volumes." These complete, detailed, and annually updated notes will reduce redundancy and help keep the printing costs of the Initial Reports at reasonable levels. In anticipation of this change, we have omitted some of the general information that has been reprinted repeatedly in past Initial Reports volumes; where appropriate, refer- ence is made to other Initial Reports volumes for detailed descriptions of methods. Drilling Operations Three coring systems were used during Leg 150: the advanced hydraulic piston corer (APC), the extended core barrel (XCB), and 1 Mountain, G.S., Miller, K.G., Blum, P., et al., 1994. Proc. ODP, Init. Repts., 150: College Station, TX (Ocean Drilling Program). 2 Shipboard Scientific Party is as given in the list of participants preceding the Table of Contents. the rotary core barrel (RCB). Any one of these systems was applied to maximize core recovery in the lithology being drilled. Drilling systems and their characteristics, such as drilling-related deforma- tion, are eloquently summarized in the "Explanatory Notes" chapter of the Leg 139 Initial Reports volume, and various versions are found in all previous volumes. Shipboard Scientific Procedures Numbering of sites, holes, cores, and samples followed standard ODP procedures. Afull identification number for a sample consists of the following information: leg, site, hole, core number, core type, sec- tion number, piece number (for hard rock), and interval in centimeters measured from the top of the section. For example, a sample identifi- cation of "150-903A-10H-1, 10-12 cm" would be interpreted as rep- resenting a sample removed from the interval between 10 and 12 cm below the top of Section 1, Core 10 ("H" designates that this core was taken during hydraulic piston coring) of Hole 903 A during Leg 150. Cored intervals are referred to in meters below seafloor (mbsf); these are determined by subtracting the rig floor height above sea level (as determined at each site) from the drill-pipe measurements from the drill floor. Note that this measurement usually differs from precision depth recorder (PDR) measurements by a few to several meters (see Chapter 4, this volume). General core handling procedures are described in previous Initial Reports volumes and the Shipboard Scientists Handbook, and are summarized here. As soon as cores arrived on deck, core-catcher samples were taken for the biostratigraphic laboratory, and gas void samples were taken with a vacutainer for immediate analysis as part of the shipboard safety and pollution prevention program. When the core was cut in sections, whole-round samples were taken for shipboard interstitial-water examinations and, from some cores, for shore-based consolidation tests. In addition, headspace gas samples were immedi- ately scraped from the ends of cut sections and sealed in glass vials for light hydrocarbon analysis. After we allowed the core to equilibrate for a minimum of 4 hr on deck, we ran whole-round sections through the Multisensor Track (MST; see "Physical Properties" section, this chapter) and performed thermal conductivity measurements. The cores were then split into working and archive halves. Cores were split from the bottom to top, so investigators should be aware that older material could have been transported upward on the split face of each section. The working half of each core was sampled for both shipboard and shore-based labora- tory studies, whereas the archive half was described visually and by means of smear slide examination. Where needed and possible, thin sections were taken from the working half. Most archive sections were run through the cryogenic magnetometer. The archive half was then photographed with both black-and-white and color film, a whole core at a time, and close-up photographs (black-and-white) were taken of particular features for illustration in the summary of each site, as requested by individual scientists. Both halves of the core were then put into labeled plastic tubes, sealed, and transferred to cold storage space aboard the drilling ves- sel. At the end of the leg, in St. John's, the cores were transferred from the ship into refrigerated vans that went by means of sea freight to Norfolk, Virginia, and then by truck to cold storage at the East Coast 21