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چکیده
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This research investigates the geochemical characteristics of hydrothermal manganese deposits in the Su- laimani metallogenic district, Kurdistan Region of Iraq, to understand their formation processes, which may aid in the exploration of manganese resources in the region. These deposits are intimately associated with various units of Mesozoic Qulqula Formation, including jasparite, umber, radiolarian chert, siliceous shale, brown claystone, and basalt sequences of the Penjween ophiolite in the Mlakawa - Tapa sura area. In the Sulaimani district, two types of manganese deposits are found: strata-bound deposits with a thickness of around 200 meters, interbedded with late Cretaceous eip-ophilitic radiolarite chert of the Penjween ophiolite complex, and as exotic massive bodies within Eocene Merga Group, forming boulder placer deposits. The manganese deposits exhibit geochemical characteristics such as intermediate MnO content (up to 24 wt.%), low levels of transitional elements (Co + Ni + Cu < 0.01 wt.%), elevated concentrations of Ba (up to 4490 ppm), and low total rare earth elements. Geochemical analyses reveal negative Ce anomalies (-0.016 -1.024) and positive Y anomalies (3.4 22.3) in most samples, indicative of submarine hydrothermal processes within the Neotethys. However, some banded-type deposits show weak positive Ce anomalies (0.1), suggesting minor diagenetic influences. The presence of weak negative Eu anomalies (0.54 0.71) in all samples likely reflects the low Eu content in the ultramafic parent rocks and the influence of low-temperature hydrothermal serpentinization fluids. In summary, the geochemical signatures suggest that these manganese deposits, associated with regional radiolarite facies within the Neotethys, originate from mid-oceanic ridge proximal to distal hydrothermal sources.
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