Volcanic ash is fragments of magma, and consists of minerals and volcanic glass. These materials in the ash can provide important information on the nature of the magma, because chemical compositions of magma usually show distinct features in each volcano, and because assemblages and compositions of minerals reflect their host melt. Using assemblages and chemical compositions of minerals and gl...

The Yellowstone supervolcano is one of the largest active continental silicic volcanic fields in the world. An understanding of its properties is key to enhancing our knowledge of volcanic mechanisms and corresponding risk. Using a joint local and teleseismic earthquake P-wave seismic inversion, we revealed a basaltic lower-crustal magma body that provides a magmatic link between the Yellowston...

Plagioclase crystal fragments and a block of anorthosite occur in small basaltic dykes on the Jos Plateau. The anorthosite is unusual, for the feldspar is labradoritic, but the interstitial mineralogy is granitic rather than basic, displaying granophyric intergrowths in places. The anorthosite is probably not an intermediate stage in fractionation from a basic parent magma towards granite, sinc...

This study reassesses the development of compositional layering during the growth of granitic plutons, with emphasis on fractional crystallization and its interaction with both injection and inflationrelated deformation. The Dolbel batholith (SW Niger) consists of 14, kilometre-sized plutons emplaced by pulsed magma inputs. Each pluton has a coarse-grained core and a peripheral layered series. ...

Introduction: Recent work on chronology seem to point to older ages for eucrites: which favor a magma ocean model for Vesta. [1] indicate a Pb-Pb age for the eucrite Asuka 881394 of 4.566 + 0.3 Ga. Whole rock isochrons of eucrites based on Hf-W, Al-Mg and Mn-Cr [2-4] indicate somewhat younger ages at around 4.564 Ga (or about 3.5 Myrs after CAI formation). From the perspective of thermal modeli...

A left order on a magma (e.g., semigroup) is a total order of its elements that is left invariant under the magma operation. A natural topology can be introduced on the set of all left orders of an arbitrary magma. We prove that this topological space is compact. Interesting examples of nonassociative magmas, whose spaces of right orders we analyze, come from knot theory and are called quandles...

After 11 5 ka of quiescence (24 5–13 ka), the Nevado de Toluca volcano started a 2500 year period of activity. This period was characterized by a dome destruction event at 13 ka, a small Plinian event at 12 1 ka, and a large Plinian eruption at 10 5 ka. About 10 km of magma was erupted that was homogeneous in composition (63 3–65 7 SiO2 wt % whole-rock) and in mineralogy. Pumice consists of pla...

changes that cannot be reversed. Short residence times also imply A technique is described for determining the cooling history of olivine that large unzoned cores of high-Fo phenocrysts cannot reflect diffusive phenocrysts. The technique is based on the analysis of the diffusive re-equilibration of originally zoned phenocrysts. The unzoned cores re-equilibration of melt inclusions trapped by ol...

Campi Flegrei is a large volcanic complex located west of the city of Naples, Italy. The area has been the site of volcanic activity for more than 60 ka and represents a potential volcanic hazard owing to the large local population. In this study, the geochemistry of the magma associated with two different eruptions at Campi Flegrei has been characterized, with the aim to identify geochemical t...

introduction the investigated area is situated in the south west of the khorasan razavi province along the north west of the lut block. different types of metal ore bodies along with non-metal deposits have already been documented in the lut block (karimpour et al., 2008). most of the study area is covered with granitoid rocks. metamorphic rocks with unknown age are present in the north of the ...