Repository:	University of Hawaii at Manoa Contact the Curator
Ship:	Moana Wave
Cruise:	MW8805
Sample:	MW8805 STA58 RD58
Device:	dredge, rock
Latitude:	13.91
Longitude:	163.062
Water Depth(m):	0
Date:	19880517
IGSN:	IEUHM006H
Storage:	room temperature, dry

Central Pacific Ocean, Marshall Islands. Chain bag dredge. Field description: basalt
1 :
Lithology/Mineralogy:	igneous (extrusive/volcanic), basalt
Comments:	1/2 bucket: RD58-1 - three pieces basalt/ash (?) agglomerate or hyaloclastite. Each piece is about 10-15 cm diam. Two are similar rocks recovered at several earlier dredges: clasts of vesicular basalt and glassy ash or pumice welded together. There is no apparent limestone matrix. The third piece was believed to be basalt until cut open. The edges are green and the rock is well cemented with calcite (?). Apart from the cement, the texture is similar to the other two samples. A few clasts in this piece look scoriaceus. RD58-2 - one 25x25x15 cm piece of extremely hard Bahamian oolitic limestone. Rock is densly packed with ooids and micrite envelopes from dissolbed fossil debris. Several large shells are completely dissolved and replaced by sparry calcite. The rock is covered with a thin sandy layer containing more ooids and clasts of volcanic origin. Mn coating is 1-2 mm.