OBJECTIVES To review the published literature on respirable quartz exposure and associated disease in agricultural related settings systematically and to describe personal respirable dust and quartz measurements collected on a sandy soil farm in the Free State province of South Africa. METHODS The published studies on exposure to respirable silica and quartz in agriculture and related setting...

Introduction: Quartz is one of the most abundant minerals in terrestrial crustal rocks. Viewed in planepolarized light with a petrographic microscope, quartz is clear (i.e., transparent). In cross-polarized light, quartz typically displays gray to white interference colors. Quartz (and other minerals) is deformed and transformed when subjected to strong shock waves, as a consequence of impact e...

arghash – ghasem-abad area in ne iran is located in the rim of the sabzevar structural zone. tertiary outcrops include granite and quartz monzodiorite porphyry associated with dacite and andesite volcanic rocks. in the study area, quartz gabbro and quartz monzodiorite dykes intruded the older rocks. granite and volcanic rocks host au-sb-bearing quartz-calcite veins. mineralized veins are mainly...

The grade of a quartz ore is not a measure of its chemical reactivity. A high grade quartz sample (B) showed low reactivity in sodium silicate production. Structural imperfection usually occurs due to lattice defects in the quartz tetrahedron as a result of several substitutions that happen during mineralization. The random distortion of the quartz tetrahedron that could be affected by various ...

qaleh-zari is a fe-oxide cu-ag-au vein type deposit located 180 km south of birjand, in eastern iran. host rocks are mainly tertiary calc-alkaline to k-rich calc-alkaline with transition to shoshonitic andesite and andesitic basalts, but in the central part shale and sandstone of jurassic age. andesitic rocks from the western region of qaleh-zari were dated to 40.5 ± 2 ma. four trends of faults...

We describe the Jebel Aja igneous intrusion (JAII), which sits at farthest northeastern edge of exposed Arabian Shield in Saudi Arabia. The JAII consists late Neoproterozoic post-collisional A-type granites, and was emplaced during tectonic extension. It is a composite pluton consisting granitic core (monzogranite, syenogranite alkali feldspar granite) surrounded by later phase alkaline peralka...

the base (cu–pb–zn) and precious metals (ag±au) mineralization at the no. 4 anomaly of golojeh deposit occurred in volcanic and sub–volcanic eocene–oligocene host rocks, in the central part of the tarom–hashtjin zone. basic to intermediate volcanic, volcaniclastic and sub–volcanic rocks are dominated in the area and include andesite, basaltic andesite, trachy-andesite, dacite and tuff with affi...