Timescales of magma transfer and differentiation processes can be estimated when the mechanism is known. When conventional major trace element analyses fail to distinguish between various differentiation, isotope compositions useful. Lower Th ratios in silicic relative basaltic magmas at a given volcano could result from storage over period several tens thousands years, or if process was fracti...

Magmas with matrix glass compositions ranging from basalt to dacite erupted a series of 24 fissures in the first 2 weeks 2018 Lower East Rift Zone (LERZ) eruption K?lauea Volcano. Eruption styles ranged low spattering and fountaining strombolian activity. Major element trajectories glasses melt inclusions hosted by olivine, pyroxene plagioclase are consistent variable amounts fractional crystal...

Abstract Late Mesozoic volcanic rocks comprising mainly basalt and basaltic-andesite to dacite occur in south-central Vietnam (Dalat zone) a lesser extent southwestern (Bay Nui area). Mineral whole-rock chemistry indicate calc-alkaline affinity for samples the Dalat zone high-K shoshonitic Bay area. characteristics variation diagrams of selected elements suggest that fractional crystallization ...

    Introduction Epithermal deposits are usually found in association with near-surface magmatic-hydrothermal environments with volcanic rocks. According to studies, their formation depth is less than 1.5 km and the temperature for their formation is less than 300 ° C. Epithermal deposits are usually rich in gold to gold-silver and rich in silver and include low sulfide, medium sulfide and hig...

Magmatic products of the Karoo Large Igneous Province can be divided into a volumetrically dominant, compositionally uniform low-Ti tholeiitic suite, and subordinate, geographically restricted, diverse, incompatible-rich high-Ti suite. High-Ti picrites contain up to 2,400 ppm Sr, 1,900 Ba, 550 Zr, which seems unusual for olivine-enriched rocks. We studied six determine phase(s) in Sr resides. S...

neyshabour turquoise mine is located in northwest of neyshabour, southern quchan volcanic belt. eocene andesite and dacite forming as lava and pyroclastic rocks cover most of the area. subvolcanic diorite to syenite porphyry (granitoids of magnetite series) intruded the volcanic rocks. both volcanic and subvolcanic rocks are highly altered. four types of alteration are recognized including: sil...

Abstract New trace-element, radiogenic Sr-Nd-Pb isotopic and geochronological data from Middle-Late Cretaceous Zagros ophiolites of Iran give new insights into the tectono-magmatic history these supra-subduction zone (SSZ)-type ophiolites. The distribution SSZ-type in comprises two parallel belts: (1) outer ophiolitic belt (2) inner belt. These were generated by seafloor spreading what became f...