In Situ Trace Element and Fe-O Isotope Studies on Magnetite of the Iron-Oxide Ores from the Takab Region, North Western Iran: Implications for Ore Genesis

The early Cambrian Takab iron ore deposit is situated in the northern part of Sanandaj-Sirjan zone, western Iran. It consists banded, nodular and disseminated magnetite hosted folded micaschists. Trace element Fe O isotopic experiments reveal various hydrothermal precipitation environments under reduced to slightly oxidizing conditions. Disseminated has high Ti (945–1940 ppm) positively correlated with Mg + Al Si, heavy (+0.76 +1.86‰) (+1.0 +4.07‰) compositions that support a magmatic/high-T origin. Banded low (15−200 ppm), V (≤100 Si (mostly ≤300 variable Al. ∂56Fe values vary from −0.2‰ +1.12‰ but most also However, ∂18O (−2.52 +1.22‰) provide evidence re-equilibration lower-T fluid at ~200–300 °C. Nodular shows Mn (≤1%), mostly negative (average, −0.3‰) indicative an isotopically light fluid. Re-equilibration carbonated rocks/fluids likely results Ce anomaly higher +6.30‰). has, thus, experienced complex history.