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: Melville
Cruise: BMRG06MV
Sample: BMRG06MV STA31 RD49
Device: dredge, rock
Latitude: -39.8225
Longitude: 78.59833
Water Depth(m): 2350 to 2535
Date: 19960312
PI: Kevin Johnson
Storage: room temperature, dry
Province: rise or ridge, aseismic ocean

Southeast Indian Ridge; Sampling locale: pseudofault scarp on older seafloor, northeast side of segment J2.
1 :   
Comments: Sample Type: Ol-plg phyric lava. Mineralogy: Plagioclase, olivine. Weathering: Fe- Mn Oxides, Moderate to Heavy Weathering. Glass condition: Some palagonitized glass and Mn/Fe oxide. 1 bucket. DG and KJ subsampled bulk glass. DG also subsampled 49-1 glass. KN subsampled whole rock. Remainder of glass placed in 49-1 glass bag.Lava with abundant (~30%) plagioclase phenocrysts, some megacrysts and glomerocrysts; some olivine phenocrysts. Glass rind is plagioclase phyric withheavy weathering. Type 1 of this dredge.
2 :   
Weathering/Metamorphism: weathering - moderate
Comments: Sample Type: Plg-cpx phyric basalt. Mineralogy: Plagioclase, clinopyroxene. Weathering: Moderate. Glass condition: Notable Mn/Fe oxide coatings; no glass. 1 bucket. No glass available. KN sampled whole rock.Plagioclase - clinopyroxene phyric lava - plagioclase phencrysts are smaller and fewer than type 1. Small tabular phenocrysts of clinopyroxene (&/or olivine) are present, and in glomerophyres withplagioclase in one case. Type 2 of this dredge.
3 :   
Comments: Sample Type: Ol-plg-cpx basalt. Mineralogy: Plagioclase, clinopyroxene, olivine. Weathering: Moderate to Heavy. Glass condition: Some fresh glass and Mn/Fe oxide coatings. 1 bucket. DG and KJ subsampled crummy glass. KN sampled whole rock. Plagioclase phyric lava - plagioclase is smaller and fewer than Types 1 and 2. Small amounts of clinopyroxene and olivine also present. Type 3 of this dredge.
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