Type I beds have a cream, pink, or gray color; they contain less than 20% phenocrysts and have bubblewall shards, pumice with large vesicles, glass spheres, and, typically, small amounts of dark brown glass shards. Major minerals are feldspar, orthopyroxene, and clinopyroxene with minor or trace amounts of green and red amphibole, titanomagnetite, ilmenite, apatite, zircon, and biotite. The composition reported here is the average of five samples: UT822, UT869, UT870, UT872, UT895
Tephrochronology of late Cenozoic loess at Fairbanks, central Alaska
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