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SAMPLE INFO : unnamed1
Sample ID:unnamed1
Station ID:unnamed1
Latitude:62.00572
Longitude:-144.01935
Datum:NAD83
Date Sampled:1902-01-01
Sample Type 1:Lava
 Text Description:
From Nadina River Glacier, flowing out of the heart of Mount Drum, an abundantly but not coarsely porphyritic lava was collected, which is gray in color, with prominent white feldspar phenocrysts and less numerous brown biotite and glossy black amphibole crystals in a gray groundmass. The short, thick feldspar prisms seldom exceed 5 mm in cross section, while the much less abundant biotite plates are occasionally 1 cm in diameter. The amphibole needles are smaller, being usually only about 1 mm in length. Under the microscope the broad prisms of plagioclase, usually twinned and frequently zoned, varying in size up to about 5 mm, are seen to make up 40 or 50 per cent of the rock mass. Tested optically, the majority of them prove to be labradorite, but the zoned species give the extinctions for andesine in their more acid bands. The most abundant mineral, except the plagioclase, is a greenish-brown hornblende, with a low extinction angle, which occurs in large and small phenocrysts. A red-brown biotite is less abundant, and there are numbers of small phenocrysts of hypersthene. Magnetite, apatite, and zircon are accessories. The base is a gray glass, which, under a high power, exhibits abundant microlitic forms. There is practically a complete gradation in size between the phenocrysts and the minute crystals of this groundmass.

References:
Geology of the central Copper River region, Alaska

GEOCHEM DATA
StationIDLatitudeLongitudeGeologistDateVisitedAge InfoVolcanoEruptionLocation DescriptionText DescriptionSample IDSample Type 1Sample Type 2Geologic 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
unnamed162.00572-144.01935Mendenhall, W. C.1902-01-01 WrangellFrom Nadina River Glacier, flowing out of the heart of Mount Drum, an abundantly but not coarsely porphyritic lava was collected.From Nadina River Glacier, flowing out of the heart of Mount Drum, an abundantly but not coarsely porphyritic lava was collected, which is gray in color, with prominent white feldspar phenocrysts and less numerous brown biotite and glossy black amphibole crystals in a gray groundmass. The short, thick feldspar prisms seldom exceed 5 mm in cross section, while the much less abundant biotite plates are occasionally 1 cm in diameter. The amphibole needles are smaller, being usually only about 1 mm in length. Under the microscope the broad prisms of plagioclase, usually twinned and frequently zoned, varying in size up to about 5 mm, are seen to make up 40 or 50 per cent of the rock mass. Tested optically, the majority of them prove to be labradorite, but the zoned species give the extinctions for andesine in their more acid bands. The most abundant mineral, except the plagioclase, is a greenish-brown hornblende, with a low extinction angle, which occurs in large and small phenocrysts. A red-brown biotite is less abundant, and there are numbers of small phenocrysts of hypersthene. Magnetite, apatite, and zircon are accessories. The base is a gray glass, which, under a high power, exhibits abundant microlitic forms. There is practically a complete gradation in size between the phenocrysts and the minute crystals of this groundmass.unnamed1LavaWhole-rock 62.66 0.48 16.62 4.09 0.11 3.08 5.56 4.24 1.67 0.15Total not given in table. 100.351993NN3.251.17H2O=0.23; H2OP=1.01; CO2=0NN 1993

SAMPLE LOCATION

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