نتایج جستجو برای: igneous petrology
تعداد نتایج: 4399 فیلتر نتایج به سال:
The Nikuyeh district is located south of the Tarom-Hashtjin metallogenic province in Western Alborz. Oligo-Miocene subvolcanic intrusion and Mid-Eocene volcanic rocks with composition of dacite to andesite are main igneous settings associated with Nikuyeh polymetallic epithermal ore mineralization. Igneous phase in the Nikuyeh district are porphyritic granodiorite, monzodiorite, quartz monsonit...
Extensive work has been carried out by the U.S. Department of Energy (DOE) in the development of a proposed geologic repository at Yucca Mountain (YM), Nevada, for the disposal of high-level radioactive waste. In support of this development and an associated license application to the U.S. Nuclear Regulatory Commission (NRC), the DOE completed an extensive performance assessment (PA) for the pr...
[1] We present a new quantitative framework to understand the process of mantle melting based on the velocity structure of igneous crust. Our approach focuses on the lower crustal section, which is expected to be least affected by porosity and seawater alteration, especially for thick igneous crust. Our methodology is thus best for constraining the origin of large igneous provinces. First, a qu...
introduction the study area is located in the shurab area that is about 50 km southeast of qom. volcanic rocks of the shurab area have basaltic composition that is associated with salt and marl units. igneous rocks of the shurab area have not been comprehensively studied thus far. clinopyroxene composition of volcanic rocks, and especially the phenocrysts show magma chemistry and can help to id...
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...
The extrusive component of the Karoo Large Igneous Province, Drakensberg Continental Flood basalts South Africa and Lesotho, is mainly composed altered tholeiitic without uraniferous mineral phases that are suitable for high-precision dating (e.g. baddeleyite or zircon), thus restricted to 40Ar/39Ar groundmass plagioclase. Previous dates plagioclase span from 178.9 ± 4.2 Ma 189.2 3.3 Ma, while ...
The rare earth elements (REE) are composed of the Lanthanide Series of 15 elements with atomic numbers (57) through (71) and yttrium (39). Because of their geochemical behavior, REE rarely form their own minerals and more commonly are found incorporated within the structure of other minerals. There is growing concern over the economical availability of REE because of their diverse and expanding...
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