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Goldschmidt2018 gsa2018 2018 Ocean Sciences Meeting (OSM) egu2018

Just Accepted Manuscripts

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  • Naser Amini Zadkovich, Morteza Tabaei, Ahmad Reza Mokhtari, Mohsen Soleimani. 2017. Exploration of hidden Pb-Zn deposit through geomicrobiological studies at Irankuh area, Iran. Journal of Tethys, Vol. 5, No. 4, 327-336.
Abstract: Different methods have been developed for mineral exploration so far, amongst which biological-based methods known as geomicrobiological studies are of the most recent ones. Geomicrobiology as an interdisciplinary approach has achieved great progresses during the past two decades and involves the study of microbes in a number of fundamental geological processes, both in the past and present. The primary purpose of this study was to survey the possible relationship between soil bacterial populations with mineral deposit occurrence underground in order to find biogeochemical anomalies in mineral exploration. Irankuh Pb-Zn mining area located in central Iran was selected as the sampling site in order to evaluate the efficiency of geomicrobiology for exploration of blind deposits. Totally 32 soil samples were collected from 10-30 cm depth and then they are characterized by enumeration of total bacteria and microbial respiration, pH and electrical conductivity (EC) measurements. Furthermore, the isolated bacteria were identified using morphological characteristic tests and 16S rRNA technique. The results showed that while there was no significant relationship between most of soil characteristics (e.g. total bacterial count, pH, EC) and the hidden Pb-Zn mineralization, a class of bacterial colonies (identified as Arthrobacter agilis) was corresponded to the position of mineralization in the depth. Therefore, an effective biogeochemical exploration technique may be developed through targeting the concentration of Arthrobacter agilis counts in exploration of Pb-Zn mineralization for further detailed exploration activities.

Keywords: Blind mineralization; Geomicrobiology; Arthrobacter agilis; Irankuh.

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  • Milad Kurdi, Saeed Soltani-Mohammadi, Taymour Eslamkish, Natalia Larina. 2017. Evaluating the performance of concentration-number (C-N) fractal model for separation of soil horizon regarding vertical distribution and 3D models. Journal of Tethys, Vol. 5, No. 4, 337-349.

Abstract: This study aims to evaluate the efficiency of the concentration-number (C-N) fractal model for discrimination of soil horizon regarding the depth distribution profile. In this regard, soil parameters such as pH, organic carbon content, calcareous mineral content, electrical conductivity and available phosphorus of Ziarat forestland in Golestan Province, north of Iran, has been investigated. The C–N model of all parameters except EC reveals three distinct horizons, while EC indicates 4 horizons. Results of the distribution profile based on fractal thresholds for pH and available phosphorus accurately classified horizons in most of the samples. The result of vertical distribution of EC regarding the fractal method identified horizons correctly except for Z4 and Z7. In addition, horizons of Z1, Z3, Z6, and Z8 have been classified distinctly by using fractal thresholds of organic carbon content in this area. However, vertical distribution of the calcareous mineral content of the study area according to the fractal method was not applicable and soil horizons were not obtainable. In conclusion, based on the combination of results driven by fractal and vertical distribution, the closest model to soil horizons have been created by EC and pH distribution. The 3D model of soil horizon based on thresholds of fractal method shows a SE to NW trend in pH variation from acidic to basic.
Keywords: Concentration-number (C-N); Fractal model; Soil parameter; Vertical distribution profile; Ziarat Forestland.

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  • Seyed Naser Mazhari, Fateme Hadavi, Ahmad Reza Khazaei . 2017. Biostratigraphy and paleoecology of Paleogen rocks based on calcareous nannofossil in Kafaz section, east Iran. Journal of Tethys, Vol. 5, No. 4, 350-366.

Abstract: In this study, the assemblage of calcareous nannofossils has been investigated in long and continuous deposits from a Kafaz section in Eastern Iran. A systematic study of calcareous nannofossils has indicated 39 nannofossils species. In order to the age determination of Kafaz's deposits, a revised zonation for the Eocene is used. Based on it, the Early-Middle Eocene deposits of Kafaz section is divided into 6 zones (NP11-NP16). Eventually, the Paleoecological applications of Eocene nannofossils are considered in this section. Three key factors which are mentioned as the main agents in controlling species distribution include surface water temperature, productivity and fertility. On the basis of three abundant species (Zhgrhablithus bijugatus, Coccolithus plagicus and Sphenolithus moriformis), Early-Middle Eocene sediments of Kafaz section were deposited in an environment with high temperature, lower productivity and lower depth.

Keywords: Biostratigraphy; Paleoecology; Eocene; Calcareous nannofossil; Kafaz; Iran.

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  • Morteza Tabaei, Mahin Mansouri Esfahani, Pezhman Rasekh, Ali Esna-ashari. 2017. Mineral prospectivity mapping in GIS using fuzzy logic integration in Khondab area, western Markazi province, Iran. Journal of Tethys, Vol. 5, No. 4, 367-379.

Abstract: Khondab area is located in western Markazi province, within the Sanandaj-Sirjan Zone. The zone has been previously known to be associated with Pb, Zn, Cu, Fe, Ba and Si elements. The current study is carried out to identify new promising targets for regional exploration. Multiple data sources (e.g., magnetic surveys, faults, geological and satellite data) are processed and then integrated by using Fuzzy Logic modelling to produce a final prospectivity map for regional exploration of MVT deposits in the Khondab area. Finally, resulted prospectivity map is validated by analyzing field derived samples collected over revealed promising zones of the study area and ore-microscopic studies of the collected samples also confirmed MVT mineralization.Validation process indicates that Cretaceous limestone units are in high correlation with MVT mineralization in this area. Based on priority rating of exploration targets, the eastern and the south-eastern parts of the study area are the most promising parts for further exploration of MVT deposits.

Keywords: Fuzzy Logic modelling; Khondab area; MVT; Sanandaj-Sirjan Zone.

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