Fine Tuff
Field Collector: Esper Signius Larsen Jr.
Place Collected:Part of the Santiago Peak Volcanics near Corona, Southern California
Object number: Cor 38-70
DescriptionLight tan-brown pyroclastic igneous rock consisting almost entirely of ash particles < 1/16 mm. In thin section minor amounts of phenocrystic feldspar crystals are apparently replaced by too-small to identify micro-crystals. There are minor amounts of opaques that are probably magnetite and hematite and some patchy calcite.