Results 1 to 10 of about 4,197 (167)
High Mg# of the continental crust explained by calc-alkaline differentiation. [PDF]
Natl Sci Rev, 2023 ABSTRACTWe used compiled geochemical data to investigate the mechanisms that control Mg# (molar ratio of Mg/(Mg + FeT)) in andesitic arc lavas. We find that andesites from mature continental arcs with crustal thickness of >45 km have systematically higher Mg# than those from oceanic arcs with crustal thickness of <30 km.
Tang M, Liu X, Chen K.
europepmc +3 more sources
Radiological risk assessment and geochemical signatures of calc-alkaline bostonite dikes [PDF]
Scientific ReportsThe bostonite dikes in the studied area of Egypt are one of the most radioactive felsic intrusions found in the South Eastern Desert due to their elevated levels of natural occurring radionuclides and the radiological hazards associated with them.
Ahmed E. Abdel Gawad +2 more
doaj +2 more sources
Magmatic sulfides in high-potassium calc-alkaline to shoshonitic and alkaline rocks [PDF]
Solid Earth, 2020 We investigate the occurrence and chemistry of magmatic sulfides and their chalcophile metal cargo behaviour during the evolution of compositionally different magmas from diverse geodynamic settings both in mineralised and barren systems.
A. A. Georgatou, M. Chiaradia
doaj +1 more source
Petrography, geochemistry and petrogenesis of high-silica Adakitic rocks from Bayram Abad area in the northwest Neyshabour (Northeast of Iran) [PDF]
پترولوژی, 2021 The volcanic rocks of Bayram Abad area, located 12 km northwest of Neyshabour, are dominated by the Paleogene units composing of dacite and andesite rocks.
mohammad ebrahim fazel valipour
doaj +1 more source
Lithosphere, 2022 In Pagondas and Kimi areas, central Evia Island, Greece, variably serpentinized ultramafic rocks of an ophiolitic origin are crosscut by rodingite dikes.
Christos Karkalis +4 more
doaj +1 more source
Geochemistry, Geophysics, Geosystems, 2023 In the Mississippian Matachel small volcanic field of the Ossa‐Morena Zone (southern Iberian Massif) outpoured basic‐intermediate lavas exhibit geochemical characteristics of Low‐Ti continental tholeiites and calc‐alkaline lavas.
F. Sarrionandia +5 more
doaj +1 more source
Geology, petrography, alteration, and geochemistry of the Shahrab igneous rock, Central Iran
Geology, Ecology, and Landscapes, 2021 Eocene to Quaternary calc-alkaline volcanic and intrusive rocks are exposed in Shahrab area in the Urumieh-Dokhtar magmatic belt in the Central Iran structural zone.
Kaveh Pazand +2 more
doaj +1 more source
Bulletin of the Mineral Research and Exploration, 2020 Volcanism that has been active since the early Miocene along a N-S trending line from Eskişehir to Isparta displays calc-alkaline and alkaline character and is closely associated with slab tearing processes.
Selin Bi̇lgi̇ç Gençer +2 more
doaj +1 more source
Study of origin and petrogenesis of granitoid bodies of Soursat complex (Northwest of Takab): Whole- rock geochemical and Sr-Nd isotopic evidences [PDF]
پترولوژی, 2019 The plutonic bodies in the Soursat complex are parts of the widespread plutonic bodies in the Sanandaj- Sirjan zone. Based on field observations and microscopic studies, the study area is dominated by hornblende gabbro, quartz diorite, monzodiorite ...
Soraya Dadfar +3 more
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The unique speciation of iron in calc-alkaline obsidians
Chemical Geology, 2021 Abstract Obsidians found in silicic domes and rhyolitic tuffs are an ideal system to understand the formation conditions of calc-alkaline felsic magmas. The Optical Absorption and Electron Paramagnetic Resonance (EPR) spectroscopic data presented in this study demonstrate that Fe-speciation in obsidians is different from that observed in other ...
Galoisy, Laurence, Calas, Georges
openaire +2 more sources