فهرست مطالب sayed reza mosavi harami

The present study has been performed to evaluate the prospective effects of activity mining on the mineralogy of sediments in the Dar-e-Allo copper mine, south of Kerman. Sediments affected by Dar-e-Allo mine are divided into six sedimentary groups including: natural background sediments, sediments of waterways leading to the mine, sediments of the Sarmashk River, sediments under the waste rock dump, sediments containing secondary phases, Fe-Mg oxy-hydroxide sediments, and evaporative sediments. Mineralogical studies of sediments as an indicator to evaluate the environmental effects of mining are classified into five main groups including primary and unaltered, carbonate, clay, sulfate and oxide minerals. Sediments in the operational area of the Dar-e-Allo copper mine are associated with extreme mineralogical diversity. The sulphide minerals are the most important source of acid mine drainage and secondary minerals such as gypsum, starkeyite, copiapite, magnesiocopiapite and natrojarosite are the most important temporary reserves of potentially toxic elements (PTEs) and H+ ions. The dissolution of the mentioned minerals, especially during the initial flushing events in the wet season, cause a sharp increase in the acidity and concentration of PTEs in the surface runoff.

Tufa is the non- marine carbonates that formed from cold to low temperature freshwater at low depth and low energy flow conditions. Abgarm’s tufa is a typical kind of these deposits. Field and microscopic studies led to recognize of seven allochthonous and autochthonous lithofacies. The presence of dense plant covering river margins, increasing use of dissolve CO2 in water and providing chemical conditions due to turbulence are factors that are important in the formation of tufa. Based on concentrations of dissolved ions, the type of Abgarm water is Ca- Mg- HCO3. Based on ions ratio, the water with primary meteoric origin is affected by passing through dolomitic limestone and evaporite of the Mozduran and Shurijeh formations. The high concentrations of these ions caused the carbonate to be trapped between algae filamentous and formed a kind of active tufa. The presence of gastropod species show a dominance wet climatic conditions when these deposits formed. At the next step, decreasing rainfall and increasing temperature and evaporation, caused the death of two gastropods species (Melanopsis praemorsa and Galba truncatula) in the studied area. Isotopic analysis of oxygen and carbon show the effects of meteoric waters and Mozduran aquifer limestone formation in isotopic compositions of tufa in Abgarm area.

In order to understand the impact of salt plug on facies, depositional environment and diagenesis of the Sarvak Formation in the Kourdeh Anticline, three sections close to the salt plug measured and studied. The thickness of Sarvak Formation in three sections are 25 (close the salt plug), 90 and 185m (away from the salt plug) and is composed of limestone. Based on facies analysis and petrography, 11 microfacies identified. Microfacies analysis, high dip of sediments, differences in thickness, reducing of interbedded shale and shallowing environment toward the salt plug show that the Sarvak Formation deposited in three facies belts including outer, middle and inter shelf. Approaching to the salt plug, facies are shallower so that tidal flat facies have been in the margin of salt plug and deeper facies formed away from the salt plug. Digenetic processes affected this formation include micritization, neomorphism, dissolution, compaction, fracture, replacement (silicification, dolomitization, hematitization and pyritization) and cementation (equant, darusy, blocky, overgrowth and isopachous). The salt plug caused changes such as fracture and dolomitization of the bioclasts, reduction of dissolution, increases compaction and silicification that are operated in three Eogenetic, mesogenesis and telogenetic stages