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1 - Diagenesis, microfacies and determination of original carbonate mineralogy of the Asmari Formation in the southern flank of Rig anticline
Kakemem hamid mirmohammadsadeghi

The aim of this study is to recognize diagenetic processes, microfacies and geochemical evidence for original carbonate mineralogy of Oligocene- Miocene Asmari limestone deposited in the Rig anticline at Rig mountain oil field. In this area, the Asmari Formation with a More

The aim of this study is to recognize diagenetic processes, microfacies and geochemical evidence for original carbonate mineralogy of Oligocene- Miocene Asmari limestone deposited in the Rig anticline at Rig mountain oil field. In this area, the Asmari Formation with a thickness of 364 m have been exposed as a sequence of thin, medium, thick, and massive carbonate rocks. Twelve microfacies types have been distinguished on the basis of depositional textures, petrographic analysis and fauna. These carbonate microfacies belong to four major sub-environments including tidal flat, lagoon, bar/ shoal, and open marine. Absence of turbidite deposits, reefal belt and gradual changes in facies indicated that the Asmari Formation was deposited in a homoclinal carbonate ramp environment. The main diagenetic processes includes: dolomitization, cementation, micritization, dissolution, and compaction. Petrographic evidence and variation of major and minor element and compare this information with modern aragonite warm water and calcitic cool to cold temperate carbonate and originally aragonite mineralogy of Ordovician sub-tropical carbonate, the calcite mineralogy of Permian sub-polar cold water of Tasmania, the Upper Jurassic aragonite Mozduran limestone, the Ilam carbonate formation, and the Fahliyan Formation indicate that original carbonate mineralogy was aragonite in the Asmari Formation. High Sr/Na ratio suggests original aragonite mineralogy. Variation of Sr and Na values versus Mn confirm replacement of aragonite by calcite during the two stages of diagenetic stabilization. The bivariate plot of Sr/Ca versus Mn shows that Asmari limestone have been influenced by meteoric diagenesis in a closed to semi-closed diagenetic system. Manuscript profile
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2 - Mineral chemistry and P-T estimation of formation of garnetschist Mount Argon (west of Angoran Mine)
Moazzen Izadyar

The Mount Argon garnet schists contain mineral assemblages of quartz, feldspar, mica and garnet. The chemical composition of, plagioclase, biotite, muscovite and garnet in the studied sample shows that plagioclases are albite-rich, white mica flakes are rich in muscovit More

The Mount Argon garnet schists contain mineral assemblages of quartz, feldspar, mica and garnet. The chemical composition of, plagioclase, biotite, muscovite and garnet in the studied sample shows that plagioclases are albite-rich, white mica flakes are rich in muscovite end-member, phlogopite-annite is the dominant constituent in biotite and chemical composition of the analysed garnets shows that they are almandine and spessartine-rich. Maximum and minimum pressure and temperature of the studied rocks were estimated by using common calculation methods. The minimum and maximum temperature of metamorphism was calculated using Mg-Fe exchange between garnet and biotite. Considering a nominal pressure of 4 kbar, the highest calculated temperature was 615C and the lowest temperature was 380C. These were 644C and 392C for pressure of 8 kbar respectively. Also using multi-equilibria calculations, temperature of 800C and pressure of 9kbar were obtained for the peak of the metamorphism and temperature of 450C and pressure of 7kbar was calculated for the lower part of the metamorphism. . Two phases of metamorphism and deformation affected these rocks. The second deformation was associated with the peak of metamorphism. A decrease in temperature about 351°C with reduced pressure of about 2 Kbars is observed in the metapelitic rocks. Manuscript profile
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3 - Occurrence of copper mineralization of Abgareh deposit based on geology, mineralogy and geochemical evidences, south of Damghan
Raziyeh Mahabady Mohammad Hassanpour sedghi

The Torud-Chah Shirin volcanic-sedimentary arc, in the south of Kavir-e-Chah Jam depression (SE of Damghan), hosted many Pb, Zn, Cu, Ag and Au occurrences and deposits. Abgareh copper deposit is located in the northeastern part. Field and petrographic studies indicate t More

The Torud-Chah Shirin volcanic-sedimentary arc, in the south of Kavir-e-Chah Jam depression (SE of Damghan), hosted many Pb, Zn, Cu, Ag and Au occurrences and deposits. Abgareh copper deposit is located in the northeastern part. Field and petrographic studies indicate that deposit area consist of andesite, basaltic andesite and basalt rocks and to a lesser extent crystal tuffs with a middle–upper Eocene age. The rocks are of high-K, calc-alkaline to shoshonitic in nature, and are formed in a magmatic arc setting in a subduction zone. According to the field observations and mineralogical studies, the mineralization in the region occurred in two stages: hypogene and supergene and weathering. Hypogen zone minerals are generally pyrite, chalcopyrite and bornite, while chalcocite, covellite, malachite and chrysocolla are considered as the main minerals in the supergene zone. Fractures resulting from faults in the rocks of the region created a favorable location for the influence of hydrothermal solution and it is considered as the main controller of mineralization. Most of the textures observed in the mineralization include vein-veinlets, open space filling, radial, replacement and disseminated forms. Geochemical studies indicate that copper has the most relative correlation with silver. Since silver has not been found as an independent crystalline phase, therefore copper was replaced by silver in chalcopyrite and chalcocite. Compared with chondrite and primitive mantle normalizing diagrams, the studied rocks show significant enrichment with respect to LREE and LILE and depletion in HREE and HFSE and negative anomalies in Ti and Nb elements. Based on the relevant diagrams, differential crystallization of mantle rocks had the essential role in the evolution of the studied rocks which were probably derived from enriched mantle. Based on petrography, structural control of mineralization, alteration type and its extention and simple mineralogy, it can be concluded that mineralization at Abgareh district has characteristics of an individual mineralization system. This system is related to evolution of hydrothermal fluid mineralization resulted in vein-type Cu mineralization. Manuscript profile

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