World Data Service for Geophysics

Index to Marine and Lacustrine Geological Samples (IMLGS)
an international partnership

doi:10.7289/V5H41PB8


Repository: SOEST [Contact the Curator]
Ship: Kana Keoki
Cruise: KK820316
Sample: KK820316 STA55 RD31
Device: dredge, rock
Latitude: -8.21283
Longitude: 156.46467
Water Depth(m): 2045 to 1635
Date: 19820602
IGSN: UHMHAP1QL
Storage: room temperature, dry

Ridge just NW of Simbo. Four buckets of samples available each individually labeled 1-3
1 :   
Comments: 150 kg of pebble to boulder size rock fragments, all fresh and angular surfaces. 1) ~60% is vesicular basalt: of this ~ 40% is ol and/or cpx-rich with large euhedral phenocrysts of cpx and/or ol. A few of the samples are picritic 30% of these also contain plagioclase as a phenocryst together with cpx and olivine; however plagioclase contents are generally <5%. Spinel is a minor constituent in livines ~ 5% of the basalts are plag-pyroxene phyric with ~ 20% plag and 10-15% cpx. these may be transitional to the andesites. 2) ~ 30% andesite to Rhyodacite - one large boulder ~20 kg is holocrystalline Rhyodacite, the andesite contains plag (15%), cpx (10%) and possibly hornblende as phenocrysts in plag-rich groundmass; vesicles < 5%. Rhyodacite are holocrystalline with plag, K-spar, hornblende, qtz and aegirine cpx? less than <10 vesicles, some fragments have a glassy texture. 3) Sedimentary rocks: ~ 10% Epiclastic volcanic sandstones with various igneous clasts visible; pebbly mudstone and gravel; also a silty sand with foram. 1 bag described and 1 undescribed to HIG and Sol Is - also 1 bag with Rhyodacite boulder to HIG.
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