the dehbid magnetite deposit is located in northeastern part of fars province, in the southern border of sanandaj-sirjan metamorphic zone. the mineralization occurred as veins and lenses along nw-se faults. the ores are mainly hosted in silicified dolomite of early mesozoic (triassic). mineralogical studies show that the ores are dominated by magnetite and minor hematite with massive texture oc...

kuh- e -zar gold deposit located 35 km west of torbat-e-heydaryeh, (khorassan e- razavi province), east of iran. this deposit is a specularite-rich iron oxide type (iocg). this mine is situated within khaf-bardascan volcanic plutonic belt. based on recent exploration along this belt, several iocg type system plus kuh-e-zar deposit are discovered. in the study area, several type of tuff and lava...

This paper documents the exploration significance of Ag/Au, Au/Cu, Cu/Mo and (Ag×Au)/Cu×Mo) ratios of the supra-ore and sub-ore halos versus fluid inclusion evolution for 24 Cu, 6 Cu- Mo and 10 Cu-Au porphyry deposits worldwide. The ratios are based only on the economic and mineralized hypogene alteration zones. The results indicate that (Ag×Au)/(Cu×Mo), Au/Cu and Cu/Mo ratios increase with dec...

The partial pressure of oxygen in Earth's atmosphere has increased dramatically through time, and this increase is thought to have occurred in two rapid steps at both ends of the Proterozoic Eon (∼2.5-0.543 Ga). However, the trajectory and mechanisms of Earth's oxygenation are still poorly constrained, and little is known regarding attendant changes in ocean ventilation and seafloor redox. We h...

Zinc and lead are the two most widely used non-ferrous metals after aluminium and copper as vital materials in everyday life. They are mined and smelted in many countries in both the developed and developing world. Both pyrometallurgical as well as hydrometallurgical methods are used for production of lead zinc depending on the type of raw material used as a charge. In the pyrometallurgical pro...

In the relatively pristine ecosystem in Kejimkujik Park, Nova Scotia, methylmercury (MeHg) concentrations in loons, Gavia immer, are among the highest recorded anywhere in the world. This study investigated the influence of bedrock lithology on MeHg concentrations in wetlands. Twenty-five different wetland field sites were sampled over four different bedrock lithologies; Kejimkujik monzogranite...

In aquatic ecosystems, availabilities of Fe, Mo and Cu potentially limit rates of critical biological processes, including nitrogen fixation, nitrate assimilation and N2O decomposition. During long periods in Earth's history when large parts of the ocean were sulfidic, what prevented these elements' quantitative loss from marine habitats as insoluble sulfide phases? They must have been retained...