AVO Logo
Site Map | FAQ |
Alaska Volcano Observatory
 
You are here: Home > Samples > 52-Sn-37

SAMPLE INFO : 52-Sn-37
Sample ID:52-Sn-37
Station ID:52-Sn-37
Latitude:51.9242
Longitude:-177.1623
Datum:NAD83
Date Sampled:1952-01-01
Sample Type 1:Lava
Sample Type 2:Dike
Field Lithology:Dacite
Text Description:
Specimen 52-Sn-37 (Rittmann: dark rhyodacite) would be classified microscopically as vitrophyric labradorite dacite. This specimen is a dark-gray rock from the chill border of a small dike on northwest Kanaga. Its texture is porphyritic (~35 percent phenocrysts) with a hyalo-felty ground mass and strong flow structure. Phenocrystic plagioclase (<4 mm) is occasionally uniform, but usually shows either progressive or distinct oscillatory zoning. Composition ranges from An72-46, with most of the determinations about An54. A few of the crystals contain dusty zones of glassy inclusions. Augite (often as an overgrowth on hypersthene), hypersthene, opaque oxides, and rare ghost hornblende with a rim of granular pyroxene are also present as phenocrysts; small grains of cristohalite(?) are less conspicuous, and these are all set in a brown glass (n between 1.506 and 1.510) containing numerous plagioclase (An32-43) microlites. Potash, present in the analysis, is not expressed mineralogically and must be contained, along with occult quartz, in the low-index glass.

References:
Geology of the Delarof and westernmost Andreanof Islands, Aleutian Islands, Alaska

GEOCHEM DATA
StationIDLatitudeLongitudeGeologistDateVisitedAge InfoVolcanoEruptionLocation DescriptionText DescriptionSample IDSample Type 1Sample Type 2Final UnitMaterialSiO2TiO2Al2O3FeOTMnOMgOCaONa2OK2OP2O5Total-majorsREF majorsMETH majorsFe2O3/Fe203T origFeO/FeOT origVolatiles csvMETH volatilesCsRbBaSrLaCePrNdSmEuGdTbDyHoErTmYbLuYZrNbHfTaPbThUScVCrFeCoNiCuZnGaMoAsNaKRef trace1METH trace1RbBaSrLaCeNdSmEuGdDyErYbLuYZrNbPbThUScTiVCrNiCuZnGaRef trace2METH trace2Light csvHalogen csvother major csvother lile csvother ree csvother hfse csvother hpe csvother tm csvother misc csv
52-Sn-3751.9242-177.1623Snyder, G. L.1952-01-01 KanagaNW KanagaSpecimen 52-Sn-37 (Rittmann: dark rhyodacite) would be classified microscopically as vitrophyric labradorite dacite. This specimen is a dark-gray rock from the chill border of a small dike on northwest Kanaga. Its texture is porphyritic (~35 percent phenocrysts) with a hyalo-felty ground mass and strong flow structure. Phenocrystic plagioclase (<4 mm) is occasionally uniform, but usually shows either progressive or distinct oscillatory zoning. Composition ranges from An72-46, with most of the determinations about An54. A few of the crystals contain dusty zones of glassy inclusions. Augite (often as an overgrowth on hypersthene), hypersthene, opaque oxides, and rare ghost hornblende with a rim of granular pyroxene are also present as phenocrysts; small grains of cristohalite(?) are less conspicuous, and these are all set in a brown glass (n between 1.506 and 1.510) containing numerous plagioclase (An32-43) microlites. Potash, present in the analysis, is not expressed mineralogically and must be contained, along with occult quartz, in the low-index glass.52-Sn-37LavaWhole-rock 58.14 0.76 17.19 6.44 0.16 3.17 6.96 3.78 2.07 0.3 100.1355NN2.853.87H2OM=0.08; H2OP=0.74; CO2=0.03; Cl=0.13; F=0.04NN 51.5 444 13.1 units are percent 1.72745XRF: Rb, Sr, Ni; NN: K;
52-Sn-3751.9242-177.1623Snyder, G. L.1952-01-01 KanagaNW KanagaSpecimen 52-Sn-37 (Rittmann: dark rhyodacite) would be classified microscopically as vitrophyric labradorite dacite. This specimen is a dark-gray rock from the chill border of a small dike on northwest Kanaga. Its texture is porphyritic (~35 percent phenocrysts) with a hyalo-felty ground mass and strong flow structure. Phenocrystic plagioclase (<4 mm) is occasionally uniform, but usually shows either progressive or distinct oscillatory zoning. Composition ranges from An72-46, with most of the determinations about An54. A few of the crystals contain dusty zones of glassy inclusions. Augite (often as an overgrowth on hypersthene), hypersthene, opaque oxides, and rare ghost hornblende with a rim of granular pyroxene are also present as phenocrysts; small grains of cristohalite(?) are less conspicuous, and these are all set in a brown glass (n between 1.506 and 1.510) containing numerous plagioclase (An32-43) microlites. Potash, present in the analysis, is not expressed mineralogically and must be contained, along with occult quartz, in the low-index glass.52-Sn-37LavaWhole-rock H2OM=0.08; H2OP=0.74; CO2=0.03; Cl=0.13; F=0.04NN 355

SAMPLE LOCATION

Contact AVO Privacy Accessibility Information Quality FOIA
URL: avo.alaska.edu/samples/sample_info.php
Page modified: August 1, 2017 15:29
Contact Information: AVO Web Team

twitter @alaska_avo
facebook alaska.avo
email Receive volcano updates by email: USGS VNS

This website is supported by the U.S. Geological Survey under Cooperative Agreement Grant G19AC00060 and G19AC00171.

Mention of trade names or commercial products does not constitute their endorsement by the U.S. Geological Survey.