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پێشکەش کردنی سمینار بە شێوەی ئۆنلاین

دووشەممە ٢٠٢٢/٥/١٦، کاتژمێر (٨)ی شەو ، بەڕێز "د. نەمام محمد صالح" سێ سمینار بە شێوەی ئۆنلاین پێشکەش بە ئامادەبووابی بەڕێز کرا.  
سمیناری یەکەم:

" Formation of quartz veins within Serginil Phyllite Group‑Penjweenarea, Iraqi Kurdistan Region: insights from geochemical and fluid inclusion data"

This study investigates the field-relations, petrographical, and geochemical characteristics of the quartz veins, hosted within the Cretaceous-Paleogene Serginil phyllite group, occurring in the Mlay Lexaugira area — Penjween Town, Kurdistan Region northeast of Iraq. The aim is to present a genetic interpretation of the Serginil quartz veins. The studied quartz veins exhibit distinctly uniform mineral assemblages, consisting mainly of quartz, and usually having macroscopic deformation features, including folding and boudinage. Geochemical data show that all quartz samples have SiO2 content of 88.45–97.2 wt.%, and do not depict any marked correlation with the other contained oxides. TiO2 content of quartz in the veins is very low (and usually < 50 ppm), whereas the Fe2O3 concentration is high (average > 200 ppm), suggesting that these quartz veins were formed in a low temperature fluid. The chondrite normalized pattern of quartz veins shows variable smooth, HREEn enriched, and LREEn depleted with Eu positive anomaly and Ce negative anomaly and it is resembling to those of hydrothermal origin. Fluid inclusions data and more specific the calculated salinity suggest the circulation of hydrothermal-type fluid (possibly MVT) with homogenization temperature ranging between 140 and 219 °C. This high ToC could indicate a circulation of fluids under anchimetamorphic and epithermal conditions.

سمیناری دووەم:


Utilizing sophisticated tools in carbonate rocks is crucial to interpretating the origin and evolution of diagenetic fluids from the Upper Jurassic carbonate rocks along the Zagros thrust-fold Belt. The origin and evolution of the paleofluids utilizing in-situ strontium isotope ratios by high resolution laser ablation ICP-MS, integrated with stable isotopes, petrography and fieldwork are constrained. Due to the lack of information on the origin of the chemistry of the fluids, the cements that filled the Jurassic carbonate rocks were analysed from the fractures and pores. This allowed us to trace the origin of fluids along a diagenetic sequence, which is defined at the beginning from the sediment deposition (pristine facies). Based on petrography and geochemistry (oxygen-, carbonand strontium-isotope compositions) two major diagenetic stages involving the fluids were identified. The initial stage, characterized by negative 13CVPDB values (reaching 􀀀10.67‰), involved evaporated seawater deposited with the sediments, mixed with the input of freshwater. The second stage involved a mixture of meteoric water and hot fluids that precipitated as late diagenetic cements. The late diagenetic cements have higher depleted O–C isotope compositions compared to seawater. The diagenetic cements display a positive covariance and were associated with extra- 13CVPDB and 18OVPDB values (􀀀12.87‰ to 􀀀0.82‰ for 18OVPDB and 􀀀11.66‰ to 􀀀1.40‰ for 13CVPDB respectively). The distinction between seawater and the secondary fluids is also evident in the 87Sr/86Sr of the host limestone versus cements. The limestones have 87Sr/86Sr up to 0.72859, indicative of riverine input, while the cements have 87Sr/86Sr of (0.70772), indicative of hot fluid circulation interacting with meteoric water during late diagenesis.

سمیناری سێیەم:


The study is carried out on the Lower Cretaceous carbonate rocks along Zagros basin, NE-Iraq, allowing the recognition of syn-depositional and post-depositional microfacies. The paper recognized three mains microfa-cies: lime mudstone, fossiliferous wackestone, and orbitolinid wackestone/packstone microfacies. Orbitolinid wackestone/packstone comes in the base of the studied area, follows by argillaceous unit. Orbitolinid wack-estone/packstone contains orbitolinid foraminifera, indicates a shallow-water carbonates. lime mudstone micro-facies comes repeatedly at top of argillaceous unit, then followed by fossiliferous wackestone that contains Cu-neolina sp and miliolids. The repetition of fossiliferous wackestone, in between argillaceous unit with anhydrite grains mark a change of marine conditions and fluctuation of sea level that persisted through Early Cretaceous. Paragenetically, post-depositional products include: 1) replacive dolomite, 2) transparent, rhombohedral dolo-mite crystal, 3) saddle dolomites that postdate replacive and rhombohedral dolomites. Saddle formation suggest that late dolomitizing fluid is originated from hot circulating fluid during an intensive fracturing system and is associated with hydrocarbon migration. Zebra/breccia textures development are explained by focused fluid flow. Hydrothermal fluids in structure controlled by tectonic activity produced hydro-fractures that significantly filled by saddle dolomites during the hydrothermal dolomitization. The C isotope record shows two major positive excursions of δ13C (phase 1 & 3) precedes and predates the phase negative excursion of δ13C from argillaceous limest2