D Dehnavi; S.R Moussavi-Harami; M.H Mahmudy Gharaie; F Ghaemi; F Ghaemi
Abstract
For understanding parent rocks, tectonics setting, paleoweathering condition and classification of Binalood’s Oligocene deposits, the petrography analysis was done, on samples from Damanjan and Baghshan-Gach sections, north of Neyshabour. 14 sandstones and 6 shale samples from both sections were ...
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For understanding parent rocks, tectonics setting, paleoweathering condition and classification of Binalood’s Oligocene deposits, the petrography analysis was done, on samples from Damanjan and Baghshan-Gach sections, north of Neyshabour. 14 sandstones and 6 shale samples from both sections were analyzed for major elements. Petrographic studies and geochemical data show that these sandstones are Litharenite to lithic arkose and have been deposited in tectonics setting including active continental margin for Damanjan section and continental island arc for Baghshan-Gach section with felsic to intermediate source. Based on elemental analysis, paleoweathering condition was relatively weak at the time of deposition in both sections; however, paleoweathering was stronger in Damanjan than Baghshan –Ghch sections. Also, using petrographic and elemental data, it can be concluded that the paleoclimate was semi-humid to semi-arid at the time of deposition.
Soroush Modabberi; Y. Rahimsouri; A. Yaghubpur; S. Alipour
Abstract
Black shales of the abandoned antimony mine of Aq-Darreh Bala Village in northwest of Takab city, northwest Iran, contain high concentrations of toxic elements, especially As (4403–11883 ppm), Sb (405–1022 ppm) and Hg (30–58 ppm). Enrichment factor calculations revealed that some ...
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Black shales of the abandoned antimony mine of Aq-Darreh Bala Village in northwest of Takab city, northwest Iran, contain high concentrations of toxic elements, especially As (4403–11883 ppm), Sb (405–1022 ppm) and Hg (30–58 ppm). Enrichment factor calculations revealed that some trace elements including As, Sb, Hg, Zn, U, Sr, Ni, V, Co, Cu, Mo, Ni, and Zr have been depleted, while, Pb, Th, Ga, Rb, and Ta are enriched during weathering. Mass balance calculation results show the highest release percents (% loss) belongs to Cd, Zn, U, Sr, Ni, V, Cu, As, Mo, Tl, Zr, Hg and Sb respectively. The highest weight amount of released elements belongs to As, Sb, Sr, Zn, Ni, V, Zr, Cu, U, and Hg respectively. As a result, it can be concluded that the black shale outcrops in the Aq-Darreh Bala abandoned antimony mine area have a main role as a geogenic source in environmental contamination of downstream environments.
S. H. Hejazi; M. H. Adabi; S. R. Moussavi Harami
Abstract
The Givetian-Frasnian sandstones in the Kuh-e-Tizi section (25 km NE Kerman), unconformably overlie the Upper Cambrian Kuhbanan and underlie the Lower Carboniferous Hutk Formations respectively, in southeastern Central Iran. Petrographical data show that these sandstones are well-sorted, sub-angular ...
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The Givetian-Frasnian sandstones in the Kuh-e-Tizi section (25 km NE Kerman), unconformably overlie the Upper Cambrian Kuhbanan and underlie the Lower Carboniferous Hutk Formations respectively, in southeastern Central Iran. Petrographical data show that these sandstones are well-sorted, sub-angular to rounded quartzarenite. Diagenetic features include physical and chemical compactions (straight, concavo-convex, sutured grain contacts and pressure solution of quartz grain), reduction of the pore space through rearrangements and cementation (mostly silica, as quartz overgrowth). The provenance and tectonic setting of these sandstones have been interpreted using integrated petrographic and geochemical data. Petrographic analysis using standard methods revealed that mono and poly-crystalline quartz grains have been derived from plutonic rocks of an interior cratonic setting. Trace element analyses and their ratios used for provenance studies (Th/Sc and La/Sc) are similar to sediments derived from weathering of mostly felsic rocks. Values representing chemical index of alteration (CIA) and the plagioclase index of alteration (PIA) range from 44.24 to 83.43, with an average of 69.96, and from 42.98 to 92.56, with an average of 75.8, respectively. However, most samples have values greater than 60, suggesting moderate to high weathering in the source area or during transportation prior to find deposition. Major and trace element concentrations indicated a depositional setting in a passive continental margin.
