Leg 174B Scientific Report
The main objective of Leg 174B was to reenter Hole 395A (Fig. 1), to run a selected suite of downhole logs followed by installation of an instrumented borehole seal or CORK (Circulation Obviation Retrofit Kit; Davis et al., 1992). The purpose of the logs and CORK experiment were (1) to document the in situ physical properties and hydrogeology at this young crustal reference site and (2) to test a hydrological model developed from observations obtained during three earlier reentries since the hole was drilled over 21 years ago in 1975-1976. The observations from Hole 395A generally support a model of lateral flow of seawater in the upper basement beneath the sediment pond in which the site is located. The logs and CORK experiment will provide essential information about the formation pressure and permeability structure, which are keys to understanding the crustal hydrogeology at the site.
To 174B Table of Contents