Costa Rica Rift hole deepened and logged

During Leg 111 of the Ocean Drilling Program, scientists on the drilling vessel JOIDES Resolution studied crustal structure and hydrothermal processes in the eastern equatorial Pacific. Leg 111 spent 43 days on its primary objective, deepening and logging Hole 5048, a deep reference hole in 5.9-million-year-old crust 200 km south of the spreading axis of the Costa Rica Rift. Even before Leg 111 , Hole 5048 was the deepest hole drilled into the oceanic crust, penetrating 274.5 m of sediments and 1,075.5 m of pillow lavas and sheeted dikes to a total depth of 1,350 m below sea floor (mbsf). Leg 111 deepened the hole by 212.3 m to a total depth of 1,562.3 mbsf (1,287.8 m into basement), and completed a highly successful suite of geophysical logs and experiments, including sampling of borehole waters

Absorption of iron by platinum capsules in high pressure rock melting experiments

Samples of hornblende eclogite (olivine basanite composition), containing 0.38 wt percent H_2O bound in amphibole, were sealed in Pt capsules, held above the liquidus at 1250°C, 10 kbar, in 1/2-inch piston-cylinder apparatus for various time periods, and then sectioned for microprobe analyses. The resultant liquids lost about half of their initial 14 wt percent FeO (total Fe as FeO) to the Pt capsule during an experiment of only thirty minutes duration, and lost 97 percent during a run lasting four hours. This rate is significantly greater than rates of iron loss reported previously, and can affect significantly the interpretation of experimental results in high temperature studies of basaltic and periodotitic compositions