The chemical composition of gases emitted by active volcanoes reflects both magma degassing and shallower processes, such as fluid-rock hydrothermal interaction mixing with atmospheric-derived fluids. Untangling the magmatic fluid endmember within surface gas emission is therefore challenging, even use well-known tracers noble gases. Here, we investigate deep at Nisyros caldera (Aegean Arc, Gre...

Owing to advances in microanalytical techniques over the last 15 years, there is a growing database on the volatile contents of subduction-related magmas as recorded in melt (glass) inclusions trapped in phenocrysts in volcanic rocks. Basaltic magmas from subduction zones show a wide range of water contents, ranging from as high as 6–8 to b0.5 wt.% H2O. Variations are related in some places to ...

he Boddington Au-Cu mine is located in the southwestern corner of the Yilgarn craton in the Western Gneiss terrane in Western Australia. The mineralization is hosted in the northern part of the Saddleback greenstone belt which includes an early sequence of basaltic to dacitic volcanic rocks and associated shallow level porphyry intrusions emplaced between ~2714-2696 Ma. After two periods of def...

Oxygen isotope data are reported for clinopyroxene phenocrysts from volcanic rock samples from Filicudi island, Italy, with the aim of investigating mechanisms of magma evolution and mantle source characteristics in a continental arc volcano. Filicudi rocks range from calc-alkaline basalt to high-K andesite and dacite. Mafic rocks have MgO 6-7 wt%, Mg# 60, Ni < 50 ppm and Cr < 200 ppm, suggesti...

a r t i c l e i n f o Crust extracted from the mantle in arcs is refined into continental crust in subduction zones. During sediment subduction, subduction erosion, arc subduction, and continent subduction, mafic rocks become eclogite and may sink into the mantle, whereas more silica-rich rocks are transformed into felsic gneisses that are less dense than peridotite but more dense than the uppe...

Western Turkey has been dominated by N–S extension since the Early Miocene. The timing and cause of this N–S extension and related basin formation have been the subject of much debate, but new data from the Bigadiç borate basin provide insights that may solve this controversy. The basin is located in the Bornova Flysch Zone, which is thought to have formed as a major NEtrending transform zone d...

MARTIAN LITHOLOGIES. M.E. Minitti, V.E. Hamilton and M.B. Wyatt, Center for Meteorite Studies, Arizona State University, Tempe, AZ 85287-1404 ([email protected]), Hawai'i Institute of Geophysics and Planetology, University of Hawai'i, Honolulu, HI 96822, Department of Geological Sciences, Arizona State University, Tempe, AZ 85287-1404. Introduction: Mineralogical and spectral data from multiple s...

Uranium-series isotopes provide important constraints on the timescale of magma differentiation and this can be used to identify where in the crust and silicic magmas acquire their geochemical characteristics. Timescales of differentiation can be inferred from the observed co-variations of U-series disequilibria with differentiation indexes. When crustal assimilation of secular equilibrium mate...

The Sierra Nevada Volcanic Range (SNVR), which includes Popocatépetl, Iztaccíhuatl and Tláloc-Telapón volcanoes, has been the source of multiple large explosive eruptions that have dispersed tephra across central México. Several since 40 ka previously described, particularly from southernmost volcano range. However, longer-term eruption history SNVR is poorly understood, due to challenges with ...