نتایج جستجو برای: plutonic rock
تعداد نتایج: 39311 فیلتر نتایج به سال:
sangan magnetite skarn mine is located 300 km southeast of mashhad, along the eastern part of khaf-drouneh volcanic-plutonic belt. granitoids from three areas within the sangan mine a, c-north and dardvay were studied. within the study area, three intrusive rocks including biotite-hornblende monzonite porphyry, biotite syenite and syenogranite were recognized. based on field cross cutting, abse...
The Contrast between Extrusive and Plutonic Rocks, and the Problem of the Ultra-Basic Rock Formation
introduction the generation and evolution of granitic magmas has been a hot debated subject among petrologists. the diversity of their origin has led different authors to propose that these rocks are not simple in their origin and might be generated in more ways than one. in the past several decades, many petrologists used a variety characteristics to subdivide the granitoid rocks. such proposa...
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Introduction: Crystallization ages of lunar impact melt rocks provide the primary evidence for a spike in the impact flux at ~3.9 Ga. Here we report U-Pb isotopic ages of accessory phases (apatite, zirconalite) in lunar melt breccia 67955 that confirm a crystallization age of ~4.2 Ga and reveal a younger overprint possibly related to entrainment of the breccia by one or more younger basins such...
Abstract Amphibole-dominated dehydration melting of gabbro is the primary process responsible for genesis adakites, low-K tonalites, modern trondhjemites, and plagiogranites as well Archean tonalite-trondhjemite-granodiorite suites that represent earliest examples continental crust. Previous literature has mostly focused on role Al-rich amphibole during anatexis a mafic source many these studie...
Introduction: Shocked rocks are known from various planetary bodies of the solar system including Earth, Moon, Mars, and several types of asteroids. It was first recognized on Earth that stages of progressive shock metamorphism can be defined [1,2,3,4] and this concept was later on confirmed for lunar rocks [5] and meteorites [6,7,8]. Initiated by the IUGS “Subcommission on the Classification o...
the arghash area is located 45 km to southwest of neyshabour. the subvolcanic rocks in the area consist of biotite hornblende quartz monzodiorite porphyry, hornblende biotite quartz monzodiorite porphyry, hornblende monzonite porphyry, biotite hornblende monzonite porphyry, monzodiorite porphyry and biotite quartz monzodiorite porphyry units. the volcanic rocks consist of hornblende biotite dac...
Babolsar eastern coastal dunes have been developed along the southern coast of the Caspian Sea. The studied area is coordinated in N36°43' to N36°44' latitude and E52°44' to E52°52' longitude. The objectives of this research were to: Study mineralogy and geochemistry of sand dunes, to obtain chemical alteration index (CIA) and its relationship to climate and mineralogy, to de...
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