Economic Geology
Kourosh Shabani; Nima Nezafati; Morteza Momenzadeh; Mohammad Hashem Emami; Seyed Jamal Shaykhzakaryaii
Abstract
The Tareek Darreh gold Gold & Copper deposit is located 40km north of Torbat- e Jam in the Khorasan-Razavi province,NE-Iran. The study area is mainly comprised of slightly metamorphosed, sedimentary rocks of Jurassic age including alternation of shale, siltstone, and sandstone. These rocks have been ...
Read More
The Tareek Darreh gold Gold & Copper deposit is located 40km north of Torbat- e Jam in the Khorasan-Razavi province,NE-Iran. The study area is mainly comprised of slightly metamorphosed, sedimentary rocks of Jurassic age including alternation of shale, siltstone, and sandstone. These rocks have been intruded by plutonic rocks such as gabbronorite, diorite, quartz-diorite, and rhyodacite. The ore bodies are exposed by trenching and pitting. The alteration minerals quartz, chlorite, albite, and sericite which are observed mostly on the top or margin of the stocks. Alteration is more intensive at the contacts of the stocks where vein type mineralization has occurred. The veins are mainly composed of silica type and calcite type, arsenopyrite, chalcopyrite, and pyrite main ore minerals. Probably more than 2-stages telescopic mineralization occurred in these zones and the conditions of temperature and pressure, as seen below. Appears to be a continuation of tectonic activity in the same place as intrusive and a little later the main cause of this phenomenon. According to our studies, The Tareek Darreh gold deposit is considered to be similar to the "intrusion-related gold "type.
H Mosaddegh; M Hadi; M Parandavar
Abstract
The Eocene marine deposits in the Chenarbu section in Torbat-e-Jam region (eastern part of Central Iran Zone) have been biostratigraphically studied based on large benthic foraminifera coincide with Shallow Benthic Zones (SBZ) and Calcareous Nannofossils, according to standard worldwide zones (NP). This ...
Read More
The Eocene marine deposits in the Chenarbu section in Torbat-e-Jam region (eastern part of Central Iran Zone) have been biostratigraphically studied based on large benthic foraminifera coincide with Shallow Benthic Zones (SBZ) and Calcareous Nannofossils, according to standard worldwide zones (NP). This investigation has been conducted on carbonate sediments with a focus on large benthic foraminifera assemblage such as Eorupertia magna (La Calvaz), Fabiania cassis (Oppenheim), Eoannulariaeoconica (Cole ve Bermudez), Gypsina sp., Textularia sp., Nummulites perforatus (De Montfort) Nummulites sp., Discocyclina sp., Rotalia sp., Acervulina sp., and calcareous nannofossils such as Cribrocentrum reticulatum, Sphenolithus obtusus, Sphenolithus spiniger, Sphenolithus editus, Helicosphaera compacta, Coccolithus pelagicus, Coccolithus eopelagicus, Reticulofenestra sp., Discoaster sp., Discoaster siapanensis, Discoaster barbadiensis. Therefore, based on the determined index species, the SBZ15?- 17 biozones of large benthic foraminifera and the NP16 biozone of calcareous nannofossils in the studied section have been detected which both assign the Late Lutetian- Early Bartonian (Middle Eocene) age for the section.Also, the Lutetian- Bartonian boundary according to index calcareous nannofossil species was separated carefully, and the first appearance of the foraminifera species of N. perforatus (de Montfort) in the middle part of the deposited sequence was recorded during geological time of the Bartonian stage. Therefore, this fact points that in Iran alike western parts of the Tethys basin, the first appearance of N. perforatus (de Montfort) occurred in Early Barthonian (SBZ17). Systematic of Nummulites perforatus (de Montfort) was described based on typological and biometrical characterization.
