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Just Accepted Manuscripts

  • Ali Amiri. 2017. Mineralogical evolutions of carbonate-hosted Zn-Pb-(F-Mo) deposits in Kuhbanan-Bahabad area, Central Iran: metal source approach. Journal of Tethys, Vol. 5, No. 1, 001-032.

Abstract: Over forty nonsulfide dominated Zn (-Pb) deposits with the same character are situated at the Kuhbanan-Bahabad area (KBA), Central Iran. The host rock of these deposits is the Upper Permian (-Lower Triassic) carbonate rocks. Mineralogical studies showed that three dependent mineralization have been occurred in the area. Firstly, a unique and less common disseminated sulfide (sphalerite, galena and pyrite) have formed during the diagenesis stages in the Upper Permian carbonate rocks as a syndiagenetic mineralization. Secondly, because of the later tectonic squeezing of the sulfide bearing strata of Upper Permian, the economic vein-type sulfide mineralization has formed hydrothermally and is present in a few deposits of the area (Tajkuh and Tarz deposits). Sphalerite, galena and pyrite are the main sulfide minerals and a lesser amounts of chalcopyrite and arsenopyrite is accompanied the ore. Sulfur stable isotope studies on the main sulfide minerals showed that the mineralization is comparable with the MVT deposits and the mixing model is the best model for sulfide precipitation. Finally, the third mineralization evolution is outcropping the vein-type sulfide mineralization and exposing to the oxidation conditions and so, formation of the nonsulfide Zn (-Pb) ore has occurred. Smithsonite, hydrozincite and hemimorphite are the most abundant nonsulfide minerals and some minor to accessory minerals such as cerussite, anglesite, willemite and wulfenite are present in some cases.  Carbon and oxygen stable isotope studies showed that combination of meteoric, ground and entrapped connate waters are the fluids responsible for transformation of sulfide to nonsulfide minerals. It seems that the Upper Permian carbonate rocks have played two separate important roles, source and host rock for the mineralization in the KBA.

Keywords: Nonsulfide Zinc Deposits; Mineralogy; MVT; Mixing Model; Supergene; Kuhbanan-Bahabad.

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  • Younes Hamed, Belgacem Redhaounia, Amina Ben Sâad, Rihab Hadji, Farid Zahri, Karim Zighmi. 2017. Hydrothermal waters from karst aquifer: Case study of the Trozza basin (Central Tunisia). Journal of Tethys, Vol. 5, No. 1, 033-044.

Abstract: Tunisia is rich in geothermal resources from ancient civilizations. Hydrothermal activity in Tunisia has been related to three main stages: magmatic and tectonic activities, eustatisme (Atlantic and Mediterranean coupling) and climate change. The principal factor and the responsable of this phenomenon is the meteoric water by piston flow processes. It constitue the catalyst of volcanism. The Trozza basin, well known since the Roman period for the importance of its thermo-mineral waters, is characterized by a large occurrence of thermal fluid discharges whose main thermal aquifer. Hydrochemical pattern is mainly controlled by the dissolution of evaporitic sediments (halite, gypsum and/or anhydrite) as well as by the incongruent dissolution of carbonate minerals. This reservoir represents the only vapor hydrothermal system in Tunisia. It is constitute the deepest formation cropping out in the study area. The Triassic deposits and the filonic of Pb-Zn/S caused the contamination of the Continental Intercalaire thermal water in this reservoir. The upwelling of the deep groundwater to the shallow level and discharging also in karst caves of the carbonates minerals. This carbonate reservoir of thermal water (≈ 50 °C), consist of emissions of hot air and vapors and represent a unique case gas hydrothermal karst in Tunisia. It plays a role in the attraction for local population and tourists. But the use of geothermal energy is still in its juvenile stage. Presently, the thermal waters are a resort for wellness, fitness and therapeutic purposes. Kairouan basin, in particular, has numerous thermo-mineral springs, the majority of which are used for public baths, swimming pools, and for medical treatments provided by thermal establishments. Previous studies have shown that location and chemical composition of these thermal manifestations are strongly influenced by the regional geology, the tectonic and the climate impact.

Keywords: Thermal water, Karst aquifer, Trozza basin, Tunisia.

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