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Text Description: Porphyritic specimen. Examination in thin section reveals that the specimen is made up largely of the outer shells of fresh-looking phenocrystic and lathlike feldspars, with interiors replaced by isotropic glass. A little quartz and one or two small crystals of an altered ferromagnesian mineral, probably biotite, are also present. The feldspathic shells are thin, but each is fairly continuous, and both twinning and zoning are plainly visible. The appearance suggests an andesite or a fine-grained diorite as the original rock. References: ![]() |
StationID | Latitude | Longitude | Geologist | DateVisited | Age Info | Volcano | Eruption | Location Description | Text Description | Sample ID | Sample Type 1 | Sample Type 2 | Final Unit | Material | SiO2 | TiO2 | Al2O3 | FeOT | MnO | MgO | CaO | Na2O | K2O | P2O5 | Total-majors | REF majors | METH majors | Fe2O3/Fe203T orig | FeO/FeOT orig | Volatiles csv | METH volatiles | Cs | Rb | Ba | Sr | La | Ce | Pr | Nd | Sm | Eu | Gd | Tb | Dy | Ho | Er | Tm | Yb | Lu | Y | Zr | Nb | Hf | Ta | Pb | Th | U | Sc | V | Cr | Fe | Co | Ni | Cu | Zn | Ga | Mo | As | Na | K | Ref trace1 | METH trace1 | Rb | Ba | Sr | La | Ce | Nd | Sm | Eu | Gd | Dy | Er | Yb | Lu | Y | Zr | Nb | Pb | Th | U | Sc | Ti | V | Cr | Ni | Cu | Zn | Ga | Ref trace2 | METH trace2 | Light csv | Halogen csv | other major csv | other lile csv | other ree csv | other hfse csv | other hpe csv | other tm csv | other misc csv | |
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415 | 58.2654 | -155.1591 | Fenner, C. N. | Novarupta | Porphyritic specimen. Examination in thin section reveals that the specimen is made up largely of the outer shells of fresh-looking phenocrystic and lathlike feldspars, with interiors replaced by isotropic glass. A little quartz and one or two small crystals of an altered ferromagnesian mineral, probably biotite, are also present. The feldspathic shells are thin, but each is fairly continuous, and both twinning and zoning are plainly visible. The appearance suggests an andesite or a fine-grained diorite as the original rock. | 415 | Whole-rock | 85.03 | 0.94 | 7.83 | 0.01 | 0.37 | 2.33 | 2.27 | 0.61 | 0.1 | 99.9 | 1176 | NN | 0.27 | 0.34 | H2OP=2.35; H2OM=4.9; Cl=0.77 | NN | 1176 |
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