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.
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.
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.
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.
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.
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.
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
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
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.
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