Early Cambrian volcanic rocks of the Posht-e Badam tectonic block in Central Iran which is hydrothermally altered to green color rocks, hosts the Kiruna-type Iron Oxide-Apatite (IOA) mineralization in Anomaly 10 of Sechahun deposit. Geochemically, these volcanic rocks are classified as high-potassium calc-alkaline and mainly consist of rhyolite and trachyandesite. These rocks are important for ...

Abstract Alkaline-peralkaline igneous systems are promising sources of Rare Earth Elements (REE). Preservation bias has resulted in a gap the geological record for alkaline-peralkaline magmatic systems, with hypabyssal plumbing system linking magma chambers to extrusive volcanic rocks poorly represented. Large plutonic varieties these often proposed have fed (now eroded) volcanoes, and current ...

New Zealand’s newest and most active volcano, Mt. Ngauruhoe in the Taupo Volcanic Zone, produced andesite fl ows in 1949 and 1954, and avalanche deposits in 1975. Potassium-argon “dating” of fi ve of these fl ows and deposits yielded K-Ar model “ages” from <0.27 Ma to 3.5±0.2 Ma. “Dates” could not be reproduced, even from splits of the same samples from the same fl ow, the explanation being var...

We used thermochemical equilibrium calculations in the O–S– Na–K–Cl–H system to model the speciation of volcanic gases emitted from high-temperature (1000–2000 K) silicate magmas on Io. The effects of temperature, pressure, and bulk composition of the gases are explored. The bulk compositions are based on atomic ratios observed in Io’s plasma torus and extended atmosphere, and from chondritic a...

in the centeral iranian volcanic belt (civb), north-west of shahre-babak, in area of javazm, dehaj and khabr, about 20 plutonic porphyritic tonalitic to granodioritic masses (1-50 km2) are intruded into a varity of rock sequences from eocene to early miocene in age. tonalitic and granodioritic rocks are some part of dehaj-sardoieh belt and having early miocene age. the civb contains intrusive a...

The Euganean Hills (NE Italy) magmatic district represents the final volcanic activity of Veneto Volcanic Province. Alkaline to subalkaline suite dominated by intermediate felsic rocks characterises latest Hills. Magmatic (intrusive and volcanic) enclaves are common in trachytes. We used ability clinopyroxene record variations P, T, fO2 reconstruct geological history trachytic host. Despite sim...

Introduction: Throughout the history of Mars, aqueous solutions should have existed at some depths below the surface. On early Mars, high geothermal gradients and intensive volcanic activity would have favored near-surface existence of aqueous solutions and sapping of ground water (e.g., [1]). During later epochs, solutions could have been stable deep below the surface, usually below ice-bearin...