Observers: Ken Macdonald (transcript) and Ken Rubin (transcript)
Pilot: Stephen Faluotico
Launch: 18° 34.80' S, 113° 23.85' W
Dive Summary: Macdonald and Rubin landed on the east side of the OSC basin on age 1.5 pillow lavas. We traversed the axis several times heading generally south, encountering a contact between age 1 sheet flows/lobate flows(the "Animal Farm" flow?)and age 1.5 pillow lavas. Near the OSC tip, the outcrop is all age 1.5 pillows; we climbed up several pillow mounds and ridges which were several tens of meters high and sampled them. These were seen clearly in the DSL 120 side scan sonar records. To the south, we encountered age 1 sheets and lobates often in lava channels. We explored 3 lava channels up to ~100-150m wide. We followed them uphill to their source regions which were eruptive fissures 2-3 m wide and collapsed lava lakes. The tops of the lava channel levees were usually lobate flows of age 1, the edges of the floors were often jumbled sheet flows grading to folded sheet flows and finally to flat, striated sheet flows toward the centers of the lava channels. We traversed back and forth across the boundary between age 1 sheets/lobates and age 1.5 pillows many times; the older pillow lavas reappeared near the end of the dive downslope from the summit. We collected 12 rock samples from both sides of the age 1/1.5 contact. No hydrothermal activity was observed, but we saw some yellowish sediment which may have had a hydrothermal component. We stopped a few hundred m short of animal farm.