This study reports the first detailed geochemical characterization of Kolumbo submarine volcano in order to investigate the role of source heterogeneity in controlling geochemical variability within the Santorini volcanic field in the central Aegean arc. Kolumbo, situated 15 km to the northeast of Santorini, last erupted in 1650 AD and is thus closely associated with the Santorini volcanic syst...

The San Miguel de Allende graben, Guanajuato, Mexico, contains numerous rhyolitic volcanic ash beds. Electron microprobe and x-ray fluorescence analyses of glass shards from 14 localities, combined with mineralogic, stratigraphic, radiometric, and paleomagnetic data, allow us to correlate the ash beds (and the intervening sedimentary strata and fossils), understand the timing of volcanism, date...

Concentrations of water molecules and hydroxyl groups have been measured in rhyolitic glasses with 0.5% to 5.0% H2Ot using infrared spectroscopy at room temperature. The glasses were cooled at ;10 C/s after having been held at 400 to 600C, for sufficient time for the equilibrium distribution of species to have been reached. The speciation of water in samples with greater than 2.5 wt.% total dis...

Geochemical modeling using the basalt composition analyzed at the Vega 2 landing site indicates that intermediate to silicic liquids can be generated by fractional crystallization and equilibrium partial melting. Fractional crystallization modeling using variable pressures (0.01 GPa to 0.5 GPa) and relative oxidation states (FMQ 0 and FMQ -1) of either a wet (H2O = 0.5 wt%) or dry (H2O = 0 wt%)...

Spherulitic structures are classically defined as concentrically zoned crystal clusters that form in igneous systems (especially alkaline rocks), and usually occur different mineral layers or shells.
 The volcano-sedimentary series observed the Kırka region, south of Eskişehir, within Kırka-Afyon-Isparta Volcanic Province, Western Anatolia, consists predominantly Lower Miocene volcanic pyr...

The weathering of volcanic rocks contributes significantly to the global silicate weathering budget, effecting carbon dioxide drawdown and long-term climate control. The rate of chemical weathering is influenced by the composition of the rock. Rock-dwelling micro-organisms are known to play a role in changing the rate of weathering reactions; however, the influence of rock composition on bio-we...

Magma ascending in the Earth’s crust can undergo oscillations pressure, from ultra-low frequency changes associated with tectonics, to relatively higher seismicity. Seismic waves travelling through shallow magma bodies lead a range of unrest phenomena and potentially trigger volcanic eruptions. The mechanisms by which pressure induce or eruption remain debated. Here, we experimentally impose on...