List of Articles Thermogene

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  1 - An investigation on sedimentary facies and hydrochemistry characteristics of carbonate deposits in the Ab-e Ask region, Southeast of Damavand volcano
  S.  Rahmani Javanmard Mohsen Ranjbaran V. Amiri
  Calcareous springs of Ab-e Ask are located 85 km northeast of Tehran, in the southern range of the Damavand volcano. Microscopic studies represent the existence of four abiotic and two microbialite facies in the Ab-e Ask travertines. The travertines are the main deposit More

  Calcareous springs of Ab-e Ask are located 85 km northeast of Tehran, in the southern range of the Damavand volcano. Microscopic studies represent the existence of four abiotic and two microbialite facies in the Ab-e Ask travertines. The travertines are the main deposit types of these springs. Based on sedimentation sequence and lithofacies these travertines are categorized as first type (vent and channel), second type (pound, dam, and cascade), and third type (laminated) travertines. On a δ18O versus δ13C plot (VPDB), these travertines are plotted in the oncoid and crystalline crust lithofacies fields. These facies show the character of hydrothermal spring and set the spring in the thermogenic group. Positive values of the Langelier Saturation Index (LSI) for Pashnak, Nadaali, and Zagh springs indicate that these water samples are supersaturated with respect to calcium carbonate, which leads to considerable sedimentation around the springs. In contrast, a negative LSI value at the Sare Pole spring indicates the water is undersaturated with respect to calcium carbonate. Therefore, this spring has a lesser role in travertine deposition compared to the other springs. Also, the position of the samples on the modified Gibbs and Van Wirdum diagrams, suggests that the interaction of water with carbonate and to some extent silicate rocks is considered as the most important source of Ca and Na. Manuscript profile
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  2 - Carbon and oxygen stable isotope study of the Majdar travertine deposits, southeast of Ardabil
  َAli Lotfi Bakhsh
  Freshwater carbonates differ from each other according to isotopic geochemical properties. The study of carbon and oxygen stable isotopes is one of the most important study tools for carbonates, including travertine deposits. In Majdar area, which is located in the west More

  Freshwater carbonates differ from each other according to isotopic geochemical properties. The study of carbon and oxygen stable isotopes is one of the most important study tools for carbonates, including travertine deposits. In Majdar area, which is located in the western Alborz-Azerbaijan tectonic zone, Quaternary travertine deposits are located in the Eocene porphyry andesite volcanic units. Based on mineralogical studies, travertines are mainly composed of aragonite. The mean values of δ13C and δ18O isotopes of travertines in the study area are + 6.47 and -8.77, respectively, which indicates the thermogenic origin of travertines. Also, the mean value of δ13C (CO2) is -2.73, which suggests an inorganic and endogenic origin for CO2. It is thought that CO2-rich hydrothermal fluids have provided the calcium bicarbonate ions needed to form travertine after circulation within the calcareous unit in the area and reacting with it. Then, these fluids ascended through the fault systems and deposited travertine on the surface. Manuscript profile