Leg 174B Scientific Report
The Leg 174B program was designed (1) to acquire logging data to provide essential information about the in situ physical properties, permeability structure, and formation pressure, which are keys to understanding the crustal hydrogeology at Site 395, and (2) to install a CORK with a 595 m-long, 10-thermistor cable, a pressure sensor in the sealed section, and a reference pressure sensor at seafloor depth.
- 1. Acquisition of logging data to provide essential information about the in-situ physical properties, permeability structure, and formation pressure. Excellent quality logs were obtained with two temperature tools, the Schlumberger Formation MicroScanner, digital shear imager, azimuthal resistivity imager, density, and SP tools.
- 2. Installation of a CORK with a 595-m-long, 10-thermistor cable, a pressure sensor in the sealed section, and a reference pressure sensor at seafloor depth. The CORK was smoothly installed; first data will be recovered during a revisit tentatively scheduled for February of 1998, using the French submersible Nautile.
- 3. At contingency Site 1074, a 64-m-thick section of sediments was successfully cored. Downhole temperature measurements and pore-fluid chemistry indicate no significant pore-water advection through the sediments, supporting a model derived from observations at Hole 395A that significant lateral fluid flow occurs within basement beneath the sediment pond where both sites are located.
To 174B References
To 174B Table of Contents