عنوان مقاله :
Geologic and geochemical investigation on the Mn veins in Jonub-E Sehchangi, SW Birjand, Southern Khorasan province (east Iran
پديد آورندگان :
Behnaz، Barghi Department of Earth Sciences - Faculty of Natural Sciences - University of Tabriz , Ali Asghar ،Calagari Department of Earth Sciences - Faculty of Natural Sciences - University of Tabriz , Mohammad Hossein، Zarrinkoub Department of Geology - University of Birjand , Vartan، Simmonds Research Institute for Fundamental Sciences - University of Tabriz
كليدواژه :
Mn vein , Jonub-E Sehchangi , Andesite , Pyrolusite , Psilomelane , Argillic alteration
چكيده لاتين :
Mn-bearing veins of Jonub -E Sehchangi are located 200 km southwest of Birjand, Southern
Khorasan province (east of Iran). These veins are hosted by andesitic rocks of Eocene to
Oligocene ages. Ore minerals identified by XRD method and mineralographic studies and
are pyrolusite, cryptomelane, psilomelane, hollandite, hematite and goethite, displaying
colloform and open-space filling textures. Gypsum, halite, barite, carbonate and silica are the
gangue minerals. Alteration zones, specifically argillic alteration zone, are developed along
the vein within the andesitic wall rocks. Based on the mineralogical and geochemical data,
the primary manganese minerals were Mn oxides and hydroxides, which have gradually been
converted to psilomelane and hollandite, and finally to pyrolusite. The average grade of Mn
within the veins is 38.61%. Considering the average Mn/Fe ratio (about 48.55) in the Mnbearing
veins, as well as the positive correlation of Sr, U and Ba with Mn, mineralization in
this area show hydrothermal origin.
