AVO Logo
Site Map | FAQ |
Alaska Volcano Observatory
 
You are here: Home > Samples > 54-Sn-284B

SAMPLE INFO : 54-Sn-284B
Sample ID:54-Sn-284B
Station ID:54-Sn-284B
Latitude:53.88707
Longitude:-166.93202
Datum:NAD83
Date Sampled:1954-01-01
Sample Type 1:Countryrock
Sample Type 2:Plutonic
Field Lithology:Granitic
 Text Description:
Granite, the matrix of a "plum pudding" rock, from a beach boulder near the head of the north arm of Skan Bay. The texture is hypidiomorphic-granular; the original rock contains many inclusions but this analysis is of matrix only. Felsic minerals compose 93-97 percent of the rock: 10-20 percent quartz, 50-70 percent alkalic feldspar heavily altered to kaolin (10-20 percent), and 15-25 percent plagioclase partly altered to epidote (0.1-0.5 percent), sericite (0.1-1 percent), and kaolin (lumped with above). The plagioclase composition, by extinction angle, is A18 [mean of 5 crystals, standard deviation is 9 percent An, average amount of zoning per individual plagioclase crystal is 0 Percent An per crystal]. Mafic minerals compose 3-7 percent: 2-3 percent hornblende and 0.1-0.5 percent is biotite both partly altered to epidote (0.1-1 percent) and penninite (0.1-0.3 percent), 1-1.5 percent is magnetite, 0.1-1 percent is sphene slightly altered to lucoxene, 0.1-0.5 percent is rutile occurring as stubby yellow rods in sphene, and 0.1-0.3 percent is penninite (interstitial). Comparison of the mode and norm for this rock indicates that the alkalic feldspar contains large quantities of both orthoclase and albite.

References:
Geology of Unalaska Island and adjacent insular shelf, 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
54-Sn-284B53.88707-166.93202Snyder, G. L.1954-01-01 MakushinGranodiorite and related rocks from 1 mi N of 3600 Mtn. From a beach boulder near the head of the north arm of Skan Bay.Granite, the matrix of a "plum pudding" rock, from a beach boulder near the head of the north arm of Skan Bay. The texture is hypidiomorphic-granular; the original rock contains many inclusions but this analysis is of matrix only. Felsic minerals compose 93-97 percent of the rock: 10-20 percent quartz, 50-70 percent alkalic feldspar heavily altered to kaolin (10-20 percent), and 15-25 percent plagioclase partly altered to epidote (0.1-0.5 percent), sericite (0.1-1 percent), and kaolin (lumped with above). The plagioclase composition, by extinction angle, is A18 [mean of 5 crystals, standard deviation is 9 percent An, average amount of zoning per individual plagioclase crystal is 0 Percent An per crystal]. Mafic minerals compose 3-7 percent: 2-3 percent hornblende and 0.1-0.5 percent is biotite both partly altered to epidote (0.1-1 percent) and penninite (0.1-0.3 percent), 1-1.5 percent is magnetite, 0.1-1 percent is sphene slightly altered to lucoxene, 0.1-0.5 percent is rutile occurring as stubby yellow rods in sphene, and 0.1-0.3 percent is penninite (interstitial). Comparison of the mode and norm for this rock indicates that the alkalic feldspar contains large quantities of both orthoclase and albite.54-Sn-284BCountryrockEnclave/InclusionWhole-rock 66 0.73 15.8 3.1 0.06 1.1 2.1 4.7 5.4 0.17Total not given in table. 100.74315RAPIDA1.71.6H2OM=0.05; H2OP=0.61; CO2=0.05; Cl=0.13; F=0.09RAPIDA

SAMPLE LOCATION

Contact AVO Privacy Accessibility Information Quality FOIA
URL: www.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.