4-5. South of Oahu (PC-14 and PC-15) 　　　　　　　　　　

Objectives
PC14 and PC15 are 150 km SSW and 180 km SW of Oahu, respectively. Waianae landslide covers the southwest flank of Oahu, but two other landslide deposits, with more substantial aprons of avalanche debris, are actually closer to the two piston core sites, as mapped by Moore et al. (1989): the toe of the South Kauai slide is roughly 50 km north of PC15, and the western lobe of Clark landslide from Lanai is ~70 km east of PC14. In addition, Alika 2, from the west side of Hawaii island, is a debris avalanche that may have reached the site of PC14.

PC14 is 150 km Oahu-ward of ODP site 842, which was drilled in 1992. Garcia and Hull (1994) attribute volcanic sand layers in the 842 core to turbidity currents generated during Hawaiian landslides, but do not identify individual sources. PC14 and PC15 will help constrain the sources of sand layers in the region.

Lithology
PC14: The lithology of Sec 2-4 is distinguished by interbeds of several volcaniclastic layers. The lithology of Sec 5-9 is massive moderate brown clay. Sec 10 is mottled with volcanic sand.

PC15: The lithology of Sec 2-3 is distinguished by interbeds of several volcaniclastic layers. The lithology of Sec 5-9 is massive moderate brown clay. Sec 8 mottle with volcanic sand.

Overall, PCs 14 and 15 contained the fewest volcanic sand layers of all the cores recovered this year. Their lithologies correlate well with one another, and also resemble the core recovered from ODP site 842. Both contain several small sand layers in the top 3 m, underlain by 6+ m of massive brown clay.

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