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Event details
Voyage: | IN2019_V04 [details] |
When: | 2019-08-25 21:06:00 UTC |
Log: | Geology_Rocks_in2019_v04 |
Equipment: | Not specified |
Position: | Latitude: -13.3674 Longitude: 159.0017 Position from underway logging |
Sample number: | in2019_v04_D41-009 |
Dredge: | D41 |
Sample Number Assigned: | Yes |
Sample photographed (include scale and sample number): | Yes |
Number of photos: | 4 |
Sample sawn: | Yes |
Sticker: | yes |
Colour: | black | brown | yellow | green |
Composition: | sedimentary |
Alteration: | Mn crust | altered |
Phenocryst abundance (%): | 0 |
Groundmass: | microcrystaline |
Features: | volcanic brecciated |
Vesicle abundance: | 30-50% |
Vesicle Filling (%): | 80 |
Vesicle fill: | calcite, clay, zeolite |
Grain size: | silt | sand (<2 mm) | pebble (2-64 mm) | cobble (>64 mm) |
Grain shape: | angular |
Sorting: | poor |
Components: | volcanic vesicular | carbonate/shell | other |
Cement: | calcite | other |
Sample bagged: | yes |
Bucket number: | 75 |
Rock name: | Highly altered, vesicular basalt clast, polymictic breccia |
Comments: | Lots of large (4-7mm) black crystals (probably pyroxene but subhedral crystals - difficult to tell shape) Lots of lath-like yellow/orange crystals (1-2 mm)- presumed plag - now quite altered Lots of while mica also (1-3 mm) - took picture with microscope Small slither of carbonate/clay breccia on sie of gabbro Possibly dolerite with coarser pyroxene phenocrysts |
Comments: | - Highly altered basalt - purple/pink in colour and very fine grained - Full of vesicles (1-12 mm) -Now infilled by clear calcite, green zeolite, and purple and brown clay - Some fractures and veining - Other, smaller volcanic and clay clasts around the edge of the larger clast |