نتایج جستجو برای: rhyolite
تعداد نتایج: 435 فیلتر نتایج به سال:
The rare earth elements (REE) are increasingly important in a variety of science and economic fields, including (bio)geosciences, paleoecology, astrobiology, and mining. However, REE distribution in early rock-microbe-plant systems has remained elusive. We tested the hypothesis that REE mass-partitioning during incipient weathering of basalt, rhyolite, granite and schist depends on the activity...
We report the first experimental study of the diffusion of H2O in dacitic melts. Dehydration experiments were conducted at 551–637 8C and 1–1450 bars for samples with ~0.8 to ~2.5 wt.% total dissolved H2O. The H2O diffusivity is proportional to total H2O contents at V0.8 wt.%, but increases exponentially with total H2O at higher H2O contents. The diffusivity of the total dissolved H2O (in Am /s...
Thermoluminescence characteristics of natural rhyolite have been studied. Dose response at a wide dose range 0.5–2000 Gy has determined. Minimum detectable and thermal fading rate are evaluated. Glow curve deconvolution is conducted after determining the best read-out conditions. The repeated initial rise (RIR) method used to detect overlapping peaks, glow procedure extract thermoluminescence p...
The production of small volume silicic rocks in areas of oceanic crust is understood with less certainty than the production of silicic rocks in a continental setting. While the anatexis of silicic continental crust produces rhyolites within a continent, it is unlikely to occur in Iceland, an island composed of basaltic oceanic crust. After analyzing rhyolitic samples I collected from multiple ...
Porous asphalt (PA) pavements are widely employed in areas with wet climates. As particle enhancement inclusions mastic, mineral fillers play essential roles improving the performance of PA pavements. This study developed a coupled multiscale finite element (FE) model, involving mesostructure mixture and pavement. Four types mastic properties were four (Granodiorite, Limestone, Dolomite, Rhyoli...
The Gacun deposit is a typical Volcanic Hosted Massive Sulfide (VHMS) associated with Late Triassic seafloor calc-alkaline felsic volcanics. Studies of zircon ages, petrology, major and trace element geochemistry, Sr-Nd-Hf isotope geochemistry volcanic rocks from the Northern Yidun arc were undertaken in this paper. We reshaped magmatic system activity time, defined origin magma evolution, prop...
The study area is located at 130 km northwest of Nehbandan in South of Khorasan and is a part of the rectangular Chahvak (Dehsalm). Dacite, rhiodacite, andesite, rhyolite, tuff and lithic tuff with Eocene age are recognized in the study area. According to mineralogy, mentioned rocks include plagioclase, quartz, pyroxene, amphibole, biotite and alkaline feldspar. Plagioclase consists of zonal st...
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