نتایج جستجو برای: basaltic composition
تعداد نتایج: 261472 فیلتر نتایج به سال:
he possibility to obtain sintered material from alkaline basaltic tuffs is demonstrated. The parent rock was milled for 10–15 min, the resulting owder was pressed at 100 MPa and the obtained samples were heat-treated in the range of 1000–1140 ◦C. The sintering behaviour and the phase ormation were studied by pycnometry, dilatometry, DTA, XRD and SEM. The final material was obtained by sintering...
Recent experiments conducted on natural rocks subjected to different mechanical loading conditions have shown energy emissions in the form of neutrons and anomalous chemical changes (“piezonuclear fission”). In the present study, we have used a numerical technique to simulate the anomalous nuclear products of piezonuclear fission. Specifically, the reactions were simulated by means of a nuclear...
The Mars Exploration Rover Opportunity has spent more than 2 years exploring Meridiani Planum, traveling approximately 8 kilometers and detecting features that reveal ancient environmental conditions. These include well-developed festoon (trough) cross-lamination formed in flowing liquid water, strata with smaller and more abundant hematite-rich concretions than those seen previously, possible ...
The +0.1‰ elevated 56Fe/54Fe ratio of terrestrial basalts relative to chondrites was proposed to be a fingerprint of core-mantle segregation. However, the extent of iron isotopic fractionation between molten metal and silicate under high pressure-temperature conditions is poorly known. Here we show that iron forms chemical bonds of similar strengths in basaltic glasses and iron-rich alloys, eve...
the study area is located at northwest of sarbisheh in south khorasan province and eastern border of lut block. in this area, tertiary (eocene-oligocene to pliocene) volcanic rocks consisting of basaltic andesite, dacite, rhyodacite, vitreous rhyolite (perlitic in some parts), tuff and ignimbrite are exposed. in the daghar mountain, a, b and c perlite layers with thicknesses of 102, 7 and 58 me...
The effect of chemical composition on the Raman spectra of a series of natural calcalkaline silicate glasses has been quantified by performing electron microprobe analyses and obtaining Raman spectra on glassy filaments (~450 µm) derived from a magma mingling experiment. The results provide a robust compositionally-dependent database for the Raman spectra of natural silicate glasses along the c...
Amygdaloidal, cavity- and fracture-filling zeolites in Eocene volcanic rocks from the Kuh-e-Aradeh of southern Kahrizak, in the northernmost part of Central Iran have been studied in some detail by optical, chemical analysis, SEM, and XRD techniques. The zeolites identified, in order of their relative time of formation from early to late, are tetranatrolite, analcime, natrolite, mesolite, stilb...
Plagioclase is the most abundant mineral in basaltic andesites in the north Gavkhouni. Olivine and pyroxene are the other rock forming mineral there. In their 3-dimensional shapes, they are unequal and varies between bladed to prolate. Plagioclase sometimes exhibit dusty texture, oscillatory zoning and sinusoid growth. Based on crystal size distribution data, the rate of crystal nucleation of p...
The possibility to obtain a cheap ceramic material based on 50 wt % basaltic tuffs and 50 wt % industrial clays was studied. The tuffs were characterized by optical microscopy, X-ray diffraction and differential thermal analysis. It was shown that this material is appropriate for the ceramic industry: it is easy for milling and is characterized by low liquidus temperature. The sintering behavio...
The orientation, petrography and geochemistry of numerous basaltic dykes between Kiama Gerroa were investigated in this study. Geochemical analysis shows that the range from sub-alkaline to alkaline composition. fit into three distinct geochemical groups, with most being transitional alkali basalts foidites, followed by lastly andesites/basaltic andesites. We suggest intrusive episodes occurred...
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