[1] Lava dome eruptions are commonly characterized by large fluctuations in discharge rate with cyclic behaviour on time-scales ranging from hours to decades. Examples include Bezymianny volcano (Russia), Merapi (Java), Santiaguito (Guatemala), Mt St Helens (USA), Mt Unzen (Japan), and Soufrière Hills volcano (Montserrat). Previous models have assumed simple cylindrical conduits for magma trans...

Deformation of the ground surface at active volcanoes provides information about magma movements at depth. Improved seafloor deformation measurements between 2011 and 2015 documented a fourfold increase in magma supply and confirmed that Axial Seamount's eruptive behavior is inflation-predictable, probably triggered by a critical level of magmatic pressure. A 2015 eruption was successfully fore...

Background/Overview: Most differentiated rocky worlds in our Solar System have mantles of olivine, pyroxene, spinel, and calcic plagioclase (or equivalent high-pressure phase assemblages). Earth’s mantle peridotite and similar rocks in other silicate planets and asteroids normally melt to form basaltic magma, komatiite, or other olivinenormative melts. Details of planetary mantle compositions a...

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...

Period 08/15/98-11/30/00, Title Active Seismic Imaging of Axial Volcano, PI's William Menke & Maya Tolstoy. The region of Axial Volcano, Juan de Fuca Ridge region provides an excellent opportunity to study the interplay between active "hot spot" and "mid-ocean ridge" magmatic systems. Important questions include how the two magma systems are fed; their magma and heat budgets; the degree of inte...

The granitic intrusives in southwest Saqqez are located in the northern Sanandaj Sirjan zone. These granites can be divided into mesocratic and leucocratic granites. The external morphology and internal structures of zircon from these granites have been investigated employing the classic Pupin method supplemented by electron microscope analysis. The zircon crystallization is a function of tempe...

Mard-abad calc-alkaline granite formed along the margin of active pull-apart or intra-continental plates, and it is post-collision granite type. Granophyric, perthitic and myrmekitic are main textures that could form from crystallization of hypersolvus source magma, which occurred under water vapor pressure of approximately 2 kb. During this study the temperature of formation of these granites ...

Large-volume caldera-forming eruptions of silicic magmas are an important feature of continental volcanism. The timescales and mechanisms of assembly of the magma reservoirs that feed such eruptions as well as the durations and physical conditions of upper-crustal storage remain highly debated topics in volcanology. Here we explore a comprehensive data set of isotopic (O, Hf) and chemical proxi...