We investigate the ability to refine pyroxene composition and modal abundance from laboratory and remotely acquired spectra. Laboratory data including the martian meteorites, Shergotty, Zagami, MIL03346, and ALH84001 as well as additional pyroxene-rich spectra obtained from the OMEGA (Observatoire pour la Minéralogie, l’Eau, les Glaces, et l’Activité) spectrometer for Mars are characterized usi...

The Aurora volcanic field, located along the northeastern margin of Mono Lake in the Western Great Basin, has erupted a diverse suite of high-K and shoshonitic lava types, with 48 to 76 wt% SiO2, over the last 3.6 million years. There is no correlation between the age and composition of the lavas. Three-quarters of the volcanic field consists of evolved (,4 wt% MgO) basaltic andesite and andesi...

Streck et al. (2007) state that primitive andesite lavas (Mg# > 0.6; 53–63 wt% SiO 2 ) from Mt. Shasta are not primary melts, but instead are mixtures of evolved, high-Sr/Y, low-Mg# dacite with primary, low-Sr/Y, high-Mg# basalt. They propose that this mixing forms primitive andesites worldwide, and they dismiss the idea that primitive andesite is an end member in arc magmatism. Magma mixing is...

Abstract Petrological analysis of the 2020–21 La Soufrière lava dome reveals ubiquitous oxidation textures. Comparison natural rock to subsequent explosive scoria phases highlights lack any features in latter, indicating that processes affected only dome-forming magma, either during pre-eruptive storage or upon emplacement. To investigate causes we present a series one-atmosphere experiments, u...

The Mars Global Surveyor mission carries a remote-sensing gizmo called the Thermal Emission Spectrometer (TES). TES detects heat waves flowing from the surface of the Red Planet. The TES team, led by Phil Christensen (Arizona State University), identified two large regions on Mars that have distinctive spectral properties. Using mathematical mixing calculations based on the thermal emission spe...

Ruapehu (150 km3 cone, 150 ring-plain) and Tongariro (90 60 are iconic stratovolcanoes, formed since ∼230 ∼350 ka, respectively, in the southern Taupo Volcanic Zone Rift. These volcanoes rest on Mesozoic metasedimentary basement with local intervening Miocene sediments. Both have complex growth histories, closely linked to presence or absence of glacial ice that controlled distribution preserva...

The origin of silicic rocks in the Michoacán-Guanajuato volcanic field (MGVF) has been understudied since attracted attention researchers. Using geochemical, petrological and structural data from literature, here we propose a model for magmas. We found that all known to date MGVF can be divided 40 % andesite, 33 basaltic 15 basalt, 2 trachybasalt trachyandesite, 10 dacite-rhyolite. systems defo...