Because of the water depth, the nature of the material being cored, and logging while drilling, the amount of core recovery was generally low. In addition, drilling through décollements and in accretionary prisms has historically been difficult. Hole problems were also encountered during this leg.

Technical support in the Chemistry, Physical Properties, X-ray, and Downhole Labs played key roles in supporting the leg's scientific objectives. Work in the chemistry lab was especially challenging because of the large number of interstitial water (IW) samples collected.

This was the last full leg of testing JANUS, the ODP database, before official implementation on 171B. A Tracor representative did not sail during the leg, but there was a full Tracor crew at the San Diego port call to install the latest build and demonstrate the system to the Steering Committee evaluators. The crew entered real data into the available JANUS applications for the entire cruise while double entry was still done to the old system. This was done in an effort to debug the program. Weekly test results were sent to Tracor.

Chemistry Lab

Due to the interest in gaining an understanding of the fluid-flow patterns in the Costa Rica margin accretionary wedge, a major effort was devoted to detailed pore-water analysis. A large number of IW's were squeezed (>3% of the total recovery for the leg).

Interstitial water shipboard analysis on Leg 170 included refractometric analysis for salinity; titrations for pH, alkalinity, chloride, calcium, and magnesium; ion chromatography for sulfate, potassium, sodium, calcium, and magnesium; and colorimetric analyses for silica, phosphate, and ammonium. Atomic absorption spectrophotometry was used to quantify concentrations of potassium in pore waters.

Solid core samples were analyzed for inorganic and total carbon (using the coulometer and the carbon, nitrogen, and sulfur [CNS] elemental analyzer ). Based on their organic carbon content, some samples were selected and analyzed with the Rock-Eval. The system was used to determine S1, S2, and S3.

Gas Chromatograph #3 (GC3) and National Gas Analysis (NGA) were used during this leg to provide real-time monitoring of the volatile hydrocarbons. A new version of Chemstation was installed. The initial testing of the chemistry input to the JANUS database began on this leg. Difficulties were noted and described and sent to the beach for modification in the new version due for Leg 171.

Computer Service

The technical staff entered real data into the available JANUS applications for the entire cruise, while double entry was still done on the old system. Double entry is time consuming, but necessary during this interim period. Weekly test results were sent to Tracor. This is the last time to test the JANUS applications before they go on line during Leg 171.

A Marisat-B system was borrowed from the UNOLS fleet to test high-speed data transmission, especially for logging data. Unfortunately we were not able to do much testing. Hopefully it will be used more on the next leg. This will ultimately be used to send e-mail to ODP.

The Novell/cc:Mail setup was enhanced with more hardware, software patches, system tuning, and reconfiguration. PC and Macintosh workstation software was upgraded and tuned, and standard installation sets created. The Appleshare server was retired and the files moved to Novell volumes. More memory was added to Grosbeck and Grubby so print queues, backups, and other utilities could work better together. GEOREF, the geology reference utility, was moved to a PC so more users could login. Another SCSI controller was added to Grosbeck, so tape drives and hard drives would be separated for better performance. Print queues were cleaned up. The cc:Mail post office was enlarged.

Core Lab

During the initial transit, new wooden book cases were built for the DSDP/ODP Initial Results and Scientific Results stored in the rear of the core lab. These beautiful wood book cases dramatically increased the storage area for books in the Core Lab. A half-core Multisensor system was bought from Geotek and left set up in the lab. This system has a line scan camera, a Cesium source for density measurements, and a "point" susceptibility meter. This system was not used very much during this leg and was packed up to be sent back to ODP for extensive modification. A new core box on the catwalk was built as a prototype using PVC for the top. The catwalk hatch has a new locking-type mechanism when it is raised. This will make it easier to lock the hatch in place and eliminate the search for bolts. The last of the "new" style core boxes were used up, and we are back to our original style.


The primary objective of Leg 170 was to gain a better understanding of fluid-flow patterns and structural deformation associated with the Costa Rica margin accretionary wedge. Most of the sample requests received for this leg focused on detailed pore-water analyses, consolidation and trivial testing, microstructural analyses, and geochemical/geotechnical analyses of gas hydrate and its associated host sediments. Detailed paleoceanographic studies focused on the one pelagic reference site, Site 1039, drilled at the start of the leg.

Great emphasis was placed on pore-water analysis and consolidation/triaxial testing to determine fluid flow/dewatering characteristics of the accretionary prism. Since most of the sediments recovered were obviously consolidated, large volume whole rounds were required to obtain enough water for shipboard analyses. Sample volume was determined by Information Handling Panel (IHP) policy as mandated by Patty Fryer: no more than 10% of the core was to be taken for IW, and any whole round greater than 25 cm required co-chief approval. Structural geologists were also present on the catwalk to ensure that critical intervals were not squeezed into oblivion. Catwalk sampling went very smoothly and the amount of sediment taken for squeezing as related to the total recovery is a little over 3%.

The scientists and technicians tried out the JANUS sample application for the first time. Although double entry was necessary in the JANUS sample application and the old MUDLOG, everyone agreed that the new sampling program will be much easier to use and decrease mistakes.

Downhole Lab

In situ temperature measurements were taken repeatedly to measure the anomalously low heat flow values that may suggest widespread refrigeration of the crust by vigorous fluid flow at depth. Most of the temperature measurements were with the new Davis-Villinger Temperature Probe. Water samples were also taken both above the seafloor and in the sediment.

Electronic Service

The lab equipment acted satisfactorily for the most part during the leg. The two lower NGR detectors on the multisensor (MST) track were corroded due to water leaking on them. One detector was dead, but the other could be tuned. New detectors are on order. The library Xerox copier's document belt ripped. This is temporarily working and spares are on order. The centrifuges in the Paleo lab also required a lot of maintenance.


During the initial seismic survey, the 80" water gun was deployed but suffered a blown air line just before the start of the line. The 200" water gun was deployed and used for the entire survey. The six-channel digital streamer and the single-channel analog streamer were both used for the survey to compare the two systems. The six-channel streamer developed a cracked depth transducer and was shipped back to shore for replacement.


The Marine Emergency Technical Squad (METS) volunteers continue to train with ODL on a limited basis. We report to each drill, but unless we are the initial response team to the area, we standby on the catwalk.


The microscopes were used heavily in the core lab. The photographer was busy instructing and maintaining the microscopes. An inventory was done on all the microscopes.

Paleomagnetics Lab

Paleomagnetics lab activities for Leg 170 included further testing/evaluation of the new Labview cryomagnetometer software and the new count buffer chips that arrived at port call. The usual suite of pass-through measurements were made and interesting results were obtained from high resolution runs. The new cryomagnetometer impressed everyone with its ability to run many discrete samples in very short order. Other equipment in the lab (spinner, K-bridge, etc.) was not used.

Special Projects:

Photography Lab

The photo lab ran smoothly during the leg. There were no problems associated with equipment for the core photos, color transparencies, or close ups.

Physical Properties Lab

This lab was heavily used by four scientists. A new Moisture and Density (MAD) program was used for the Index Properties. This program was designed to collect the weight of the sample from the balance; collect the reading from the pycnometer, and download the results to the JANUS database. There were problems with the program and the scientists preferred using Excel spreadsheets.

Data from the MST was downloaded to the JANUS database. This is still in the testing phases, and there were many problems associated with this. The National Gamma Radiation (NGR) detector experienced problems due to water dripping onto two of the sensors and corroding them. The system was cleaned and new sensors ordered. The new TK04 thermal conductivity system was used for the half space measurements, but the scientists finished the leg using the old Woods Hole System for the full space measurements. Vane, shear, and resistivity measurements were also collected.

Thin Section Lab

This lab was not heavily used. Twenty-seven thin sections were produced. Most of them were basalts with some sediment requests and a pyrite. Some of the instruments needed a lot of maintenance.

UnderWay Geophysics Lab

Navigation, bathymetry, and seismic data were collected during Leg 170. The site locations were well surveyed with 3D geophysics from previous expeditions. All beacons were dropped on predetermined coordinates. A short seismic survey was done during the approach to the first site. Hole positions were determined by averaging GPS fixes taken for each hole at one-minute intervals over a period of many hours. A new version of the navigation program, WinFrog, was installed during the port call. Additional memory was also added to the primary WinFrog PC.

X-ray Lab

During Leg 170, 213 samples were analyzed by X-ray diffraction. Most of the samples submitted were a split of the "trimmings" from IW samples. This procedure conserved sample material, and significantly improved the turnaround time for X-ray diffraction (XRD) analyses, because the sample was taken almost immediately after the core was recovered. Results of the XRD analyses were often available to the scientists within 24 hr.

The X-ray fluorescence (XRF) was used extensively this cruise to analyze samples from a wide range of lithologies. A total of 94 samples for major element analysis and 118 samples for trace element analysis were submitted. Sample lithologies include basalt, glass, and siliciclastic and carbonate sediment. The sediment samples were generally splits of IW squeezecakes, or samples of ash layers taken from the core.

The XRF performed flawlessly throughout the cruise, producing a large dataset of accurate and precise results. Basalt sample beads for major element analysis were made with the new flux (Flux VII) using the NT-2100 bead sampler throughout the cruise, and the bead sampler was used to make all the sample beads at the last few sites. High quality beads can now be safely produced without the requirement of having a technician present. This results in a significant time savings for the technician and will increase lab productivity. A new ashing furnace was installed to replace the old "original equipment" ashing furnace.


Many long-line fishing lines drifted towards the ship and had to be cut. The ship's new water maker produces water at 130°. Because of the warm surface water (89°F), it was difficult cooling the water low enough to send to the hotels and labs. We also had problems with pressure and flow of drill water to the core lab. New drain lines with plastic lining will be installed under the labs during the port call.

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