Banding in obsidian from Big Glass Mountain (BGM), Medicine Lake volcano, California, and Mayor Island (MI), New Zealand, provides a record with a 1/wavenumber power-spectral density and multifractal characteristics. The samples are compositionally homogeneous, with banding defined by variable microlite content (BGM) or vesicularity (MI). In both samples, banding formation is well explained by ...

The flow of obsidian lava leads to crystal alignments that reflect both the accumulated strain and the type of flow across the surface. Microlite preferred orientations are used to investigate the emplacement dynamics, strain history, and structural evolution of Obsidian Dome, eastern California. Measurements of three-dimensional microlite trend and plunge in samples from the near-vent region, ...

Replenishment of mineral resources, especially gold and rare metals, is critical for progress in the mining metallurgical industry Eastern Kazakhstan. To substantiate scientific background exploration, we study microinclusions minerals from rare-metal fields, as well trace-element patterns ores their hosts that may mark mineralization. The revealed compositions gold-bearing sulfide a number typ...

Abstract The eruption of the Tambora volcano in 1815 was initiated by two precursory Plinian falls and formed generations pyroclastic density current (PDC) deposits. In this study, we found slight changes phenocrysts (modal mineralogy, content, size), bulk-rock feldspar microlite chemical compositions, bubble number densities through stratigraphic position. fall units are characterized a lower ...

Abstract Arc magmas typically contain phenocrysts with complex zoning and diverse growth histories. Microlites highlight the same level of intracrystalline variations but require nanoscale resolution which is globally less available. The southern Taupo Volcanic Zone (TVZ), New Zealand, has produced a wide range explosive eruptions yielding glassy microlite-bearing tephras. Major oxide analyses ...