About 39 m of basalt and basalt breccia were cored, but only 5% of that was recovered. The sample of interest for this study is from a breccia in Core 168-1026B-3R-1 (fig. 14A in Shipboard Scientific Party, 1997). Glass in the breccia of Sample 168-1026B-3R-1, 16-27 cm, was altered to clay along fractures (Fig. 2A) in a manner similar to alteration that has been attributed to microbial activity (Fisk et al., 1998; Furnes et al., 1996; Giovannoni et al., 1996; Torsvik et al., 1998). Dark zones between alteration products and glass are the locations within this rock that are likely to house microbes. Close examination by electron microscope of freshly exposed surfaces of clay in these samples shows that objects are present with many of the physical characteristics of microbes (Fig. 2B). These "cells" are about 1.5 µm long and 1 µm across; they are clustered into a small colony and have depressions that commonly occur in cells that are not carefully preserved (i.e., rocks were allowed to dry in air), and one pair of cells may have recently divided. These observations with optical and electron microscopy indicate that extant life is present in the basalts Hole 1026B.
The water sampling temperature and pressure tool (WSTP) was used to collect two water samples in situ from Hole 1026B. The tool (Barnes, 1988) collects water through a 1-µm filter that extends through the drill bit. The water passes through a stainless steel tube into a sample coil that is within a titanium overflow chamber. The coil in this case was copper tubing. The WSTP collected 10 mL of water in the copper tube and about 1000 mL in the overflow chamber. Water from the overflow chamber was filtered (100 mL at a time) through 0.45-µm sterile filters to remove particulate matter before the routine shipboard chemical analyses were conducted on the water (Davis, Fisher, Firth, et al., 1997). On the first run of the WSTP, three unopened filter cartridges were placed in 125-mL jars that contained 100% ethanol, and two filter cartridges were placed in a jar with sterile artificial sea water (SASW). The filtered water from the WSTP appeared to be 80% formation water and 20% sea water. Water from the second deployment of the WSTP was filtered as well. Four filters were placed in ethanol and four in SASW. The water from the second run appeared to be closer to the that of formation water. The filters were stored on board in the dark at 4°C and transported under refrigeration to Oregon State University.
Material on the filters from the first deployment of the WSTP was light brown, whereas that from the second was pale green. Most effort was expended in analyzing filters from the second water sample because initial analyses indicated that this sample contained less seawater than the first WSTP.
The second water sample collected by the WSTP appeared to contain little seawater, but there were several potential sources of microbial contamination in addition to sea water. These were the steel hole casing, drill pipe left in the hole, drilling mud, and the WSTP itself. The WSTP had a pair of filters to remove particles from the water that entered the sample coil. The smaller filter had an opening that was nominally 1 µm, but it was evident that many particles in the water sample were larger than 1 µm. This implies that the 1-µm filter over the entrance port to the WSTP was compromised.
The green particles on the filter we infer to be caused by Cu as indicated by several types of analyses. The Cu could be derived from fluids or from the WSTP. We attribute high levels of Cu in the second run to corrosion of the WSTP copper coil in the sample container between deployments of the tool or to contamination of the filter element at the tip of the WSTP with an antiseize compound that contains Cu and was used on threaded junctions of the tool.
The filters used to separate particles from the WSTP water were 0.45-µm Sterile Acrodiscs from Gelman Sciences. These have a polysulfone membrane that is covered with a wetting agent. The composition of the membrane and wetting agent are proprietary, but Gelman Sciences did reveal that the filter contained about 2 ppm of copper.