Petrography and physicomechanical properties of alkali granites, alkali quartz syenite, and nepheline syenite from Ambela, NW Pakistan, have been investigated. Whereas the alkali quartz syenite and most of the alkali granites are megaporphyritic, the nepheline syenite and some of the alkali granites are microporphyritic. Their phenocryst shape and size and abundance of groundmass are also diffe...

Feldspathic materials are used in the glass and ceramic industries as a source of alkalis, alumina and silica. These elements affect the rate and temperature of melting. fluidity of the melt and physical properties of the finished product. Silica, sodium, potassium and alumina ratios in the feldspar product vary for each industrial user, however, iron must be limited to less than 0. I per cent ...

The Monte Santo Alkaline Intrusive Suite (MSAIS) is an association syenite foid, nepheline syenite and syenite. The MSAIS rocks are intruded in metapelites of the Rio do Coco meta-volcanic-sedimentary Sequence and are abundant pegmathoid veins cutting all of them. The mineral paragenesis is represented by aegirina, arfvedsonite, albite and nepheline, crystallized during the initial phase of cry...

The isotopic thermochronological study included the U–Pb (SHRIMP) and fission-track dating of zircon and fission-track and (U–Th)–He dating of apatite from syenite intrusions cropping out in the eastern slope of the Sredinnyi Range of Kamchatka. The emplacement time of the intrusion was determined, and its exhumation velocity was evaluated. According to U–Pb (SHRIMP) zircon dating, the age of s...

Rare earth abundances were determined by neutron activation in twenty Hawaiian lavas and one diabase of known chemical and mineralogical compositions. These results demonstrate a systematic relationship between the absolute or relative rare earth abundances and the petroehemistry of these rocks. Three distinct lava groups are recognized. These correspond to: (1) tholeiites, (2) alkali series, (...

The area of Esfordi-Zarigan in Central Iran is located in Bafq metallogenic province where most the rock units belong to Precambrian, Infracambrian and Cambrian periods. Although the sedimentary and volcanic rocks are widely distributed, this research is mainly focused on petrogenesis of plutonic rocks. From stratigraphic point of view sedimentary and volcanic rocks can be classified in five ma...

The effects of particulate matter (PM) from diesel and leaded gasoline motor vehicles exhaust emissions on sulfation of granites, syenite and gabbro stones have been experimentally studied. Abundant gypsum crystals and corrosion features developed on stones covered with diesel PM (DPM) following 72 h exposure to 100 ppm SO2 at a relative humidity of 100%. In contrast, very small amounts of gyps...