Understanding the mechanisms that control the start-up of volcanic unrest is crucial to improve the forecasting of eruptions at active volcanoes. Among the most active volcanoes in the world are the so-called persistently degassing ones (e.g., Etna, Italy; Merapi, Indonesia), which emit massive amounts of gas during quiescence (several kilotonnes per day) and erupt every few months or years. Th...

The Aligoodarz granitoid occurs in Sanandaj-Sirjan Zone (SSZ), Western Iran. Tonalite, granodiorite and granite are the main rock types cropping out in the area. Comparison of Aligoodarz granitoid with Dehno and Boroujerd granitoids reveals several similarities in their chemical characteristics. Thus, the above mentioned granitoids can be assigned as a co-genetic magmatic suite, in which pluton...

Pitchblende mineralization was studied in the younger granite samples collected from Gabal Gattar, north Eastern Desert, Egypt using electron scanning microscope (ESM) and electron probe microanalyses (EPMA). This study revealed that this pitchblende contains significant Zr content reaching up to (66.80% ZrO2), which suggests that volcanic rocks were probably the source of such a deposit. High ...

Introduction: Loki Patera is the largest volcanic thermal source on Io [1-10]. Previously, we have considered Loki Patera as a magma 'sea' nearly 200 km in diameter, so-called as this is larger than any previously observed lava lake, and smaller than a magma 'ocean' [10-12]. The process by which a solid crust forms on the sea, thickens, and eventually founders has been previously described [6, ...

nain ophiolite melange is located 140 km east of isfahan. based on the geological studies, this area belongs to mesozoic ophiolite of urumieh – dokhtar zone, west of central iran. country rocks are pridotite and serpentinized pridotite. the pridotite rocks are composed of harzburgite, lherzolite and replacement dunite which is belong to spinel pridotite facies.paragenesis of ore minerals are ch...

Introduction: Crystallization of the lunar magma ocean occurred ~4.4 Ga [e.g., 1-4] and produced three principal magma source regions [5-6]. These sources are characterized chemically by low titanium (Ti), high Ti, and high potassium, rare earth element, and phosphorous (KREEP) abundances. The KREEP component was produced after nearly complete solidification of the magma ocean and is highly enr...

Pichagchi pluton is situated in the northeastern part of the Soursat complex in Sanandaj-Sirjan metamorphic belt of Iran. The pluton with the age of 74.20 Ma is composed mainly granodiorite, diorite, and tonalite in which mafic minerals are biotite and amphibole. In this study, composition of minerals used to describe the nature of the granitic magma and estimate the pressure and temperature at...

[1] This paper presents major and trace element compositions of lavas from the entire 3098 m stratigraphic section sampled by phase-2 of the Hawaii Scientific Drilling Project. The upper 245 m are lavas from Mauna Loa volcano, and the lower 2853 m are lavas and volcanoclastic rocks from Mauna Kea volcano. These intervals are inferred to represent about 100 ka and 400 ka respectively of the erup...

By using recently determined experimental phase equilibria we show that the viscosity of granitic magmas emplaced atupper crustal levels is approximately constant a -• 104.5 Pa s, irrespective of their temperature and level of emplacement. Magmas crystallizing as granitic plutons are not water-poor and thus not more viscous than their extrusive equivalents. Instead, comparison between pre-erupt...

There is overwhelming and incontrovertible petrological and geophysical evidence for the significant role played by mantle-derived mafic magma in the generation and growth of continental crust. Likewise, intrusion of mafic magmas beneath or into continental crust is very likely the major source of enthalpy that drives intracrustal differentiation. A simple dynamical model has been constructed t...