Iranian Journal of Earth Sciences
Volume:5 Issue: 2, Oct 2013

The geochemical composition of surface soils and potential bedrocks in Davarzan area has been investigated to determine soil origin and evaluate environmental aspects. Davarzan plain is composed of soils and deposits derived by weathering and transportation of different bedrocks from northern mountains. The bedrocks consist of Eocene (andesitic to basaltic lavas and volcano-sedimentary rocks composed of alternating beds of marl, sandstone and tuffaceous lime stone) and ophiolitic (peridotites and serpentinites) units. Davarzan soils have high concentration of Mg (22000-28000 ppm), Cr (693-1353ppm), Co (31-51ppm) and Ni (486-1105 ppm) and low Al (28000-51000 ppm), K (3000-10000 ppm), Na (1700-7900 ppm), Ce (10-22 ppm), Li (9-16 ppm) and Zn (19-30 ppm). These characteristics are very similar to composition of serpentinite and peridotite rocks and completely different from other lithologies. It could be inferred that these rocks are the major parental materials for Davarzan soils. The strong correlation between major and trace elements of soil samples indicates identical geogenic origin for their production. Anthropological processes do not have significant effect on the soil composition so that all samples (include natural, agricultural and residential) show the same geochemical particulars. The content of Ni, Cr and Co is higher than maximal permissible concentration for environmental issues and could be regarded as potential risk in related topics

This paper presents results of an assessment of dominant hydro-geochemical processes controlling groundwater chemical composition, using an integrated application of cluster analysis and factor analysis. The area is located in south of saline playa and in Arak city. Cluster analysis classified samples into two main clusters according to their dominant chemical composition: cluster A (dominant composition: Ca, Cl and SO4) and cluster B (dominant composition: Ca–HCO3). These clusters were in turn described by factor analysis. Results of factor analysis and geochemical interpretation suggest that spatial variation of groundwater quality in the area is influenced by different processes: Analyses revealed three major sources of variation in groundwater composition: carbonat and silicate mineral weathering, saltwater intrusion and anthropogenic contamination. Factor 1 shows processes of dissolution of C and SO4 evaporative salts (for samples close to Arak playa). Factor 2 exhibits strong positive correlation in Zn and Cu and show anthropogenic or industrial sources. Factor 3 exhibits HCO3 and NO3 and is resulted from weathering of carbonate and silicat minerals by percolating water and disposal of domestic wastes.

In this research, totally 610.4 meters of the Asmari Formation are studied in two stratigraphic sections on Bavan Mountain an Sarvestan section in Fars province, Iran. The indexed microfacies are carefully determined through studying of 230 thin sections.This research shows that the indexed microfacies are mudstone, wackestone, packstone, prainstone and the amount of microfacies elements such as bioclasts, pellets, extraclasts and intraclasts. They are varied in different parts of the studied sections and the total amount of bioclasts in the section is more than other elements. The abundance of benthic bioclasts represents the regression of the basin from the open sea into the sub tidal and intertidal zone.

In this research, biostratigraphy related to the carbonate succession of the Shahbazan Formation at the southeastern flank of Chenar anticline, Lurestan Basin, is discussed. A study of large benthic foraminifera from the 294 mthick Shahbazan Formation led to the identification of two Middle Eocene biozones: Somalina sp. Zone, Nummulites-Alveolina Assemblage Zone. The age of the Shahbazan Formation in the study area is determined as Middle Eocene. The Shahbazn Formation overlies the Pabdeh Formation and underlies Asmari Formation in the studied stratigraphic section. The lower part of Asmari Formation is characterized by thick – bedded of limestone, with Nerpherolepidina sp., which reflects deposition during Chattian age. In this study, we introduced a paraconformity between Shabazan and Asmari Formations which is attributed to the PriabonianChattian.

The nomenclature. development of the Phanerozoic rock units mentioned in the stratigraphic lexicon of Yemen is revised. Forms violating the nomenclature rules are corrected in accordance with the nternational rules of the stratigraphic nomenclature. The concerned forms are categorized as: informally introduced, dropped, named or re-named units, all of these categories are discussed in detail.

The aim of this study is separation of Fe2O3, TiO2 and V2O5 anomalies in Esfordi 1:100,000 sheet which is located in Bafq district, Central Iran. The analyzed elements of stream sediment samples taken in the area can be classified into 5 groups (factors) by factor analysis. The Concentration–Number (C-N) fractal model was used for delineation of the Fe2O3, TiO2 and V2O5 thresholds. According to the thresholds, the distribution of elemental concentration for Fe2O3 and TiO2 were divided to four lassifications and V2O5 has five geochemical populations in the area. Based on correlation between obtained results with geological and remote sensing data, the results show that the major anomalies of Fe2O3, TiO2 and V2O5 and related factor are mostly situated around granitic/rhyolitic rocks, iron alterations and along faults.

20 soil samples collected from the vicinity of the Khash Cement plant, Iran, were analyzed for As, Cd, Co, Cr, Cu, Mn, Mo, Ni, Pb and Zn using ICP-OES. The results revealed that the metal distribution were in a fluctuating manner considering various distances and direction from the cement facility. However, it was observed that the mean concentration of the soil samples has no special trend with respect to distance and direction from the facility for most metals. However, the cement plant is a major source responsible for metal distribution, but it seems that uniformity in topography and vegetation is major factor to control this kind of distribution pattern. According to the index of geoaccumulation, the soils of the study area are considered to uncontaminated with respect to As,Co, Cr, Cu, Mn, Mo, Pb and Zn. Cd and Ni shows uncontaminated to moderated contaminated characteristics. The result of enrichment factor show that, with the exception of Cd and Ni enrichment, all the metals were deficiency to minimal enriched in all the distances and directions considered for the study. The results of the metal analysis indicated that the environment under study is not at risk seriously..