Study of Baghalbid iron mineralization using geological, mineralogical and geochemical evidences, Sangan-e-Khaf area, north-eastern Iran

Baghalbid iron mineralization is one of the eastern anomalies of Sangan iron mines. This area is geologically located in the north-eastern part of Lut block. In this area, Paleozoic and Mesozoic units such as schist, phyllite and sandstone are in contact with Tertiary igneous units and Neogene sedimentary rocks. The iron mineralization occurs as hematite in the upper part of a brecciated volcanic layer with a length of more than 1 km. The footwall rocks contain breccia, tuff and sandstone and hanging wall rocks contain subvolcanic granodioritic dikes. The hematite occurs as open space filling in breccia, indicating that the iron mineralization is classified as epigenetic type. Barite, calcite, and quartz were also formed in fractures and open spaces of iron-bearing horizon. In addition to the iron, copper mineralization occurs as quartz veins containing chalcopyrite and malachite in footwall rocks. The iron oxide contents vary from 8 to 55 wt. % in the iron-bearing horizon. In mineralized rocks, the amount of chromium, vanadium and phosphorus is relatively low, while those of barium, arsenic, silver and antimony are relatively high, and LREE and LILE show enrichment relative to HREE and HFSE, respectively. According to geological, mineralogical and geochemical characteristics, ore texture and structure, REE pattern, the Baghalbid iron mineralization is classified as hydrothermal type. The iron was probably leached from pyroclastic rocks by hydrothermal fluids and was re-concentrated in the upper permeable breccia and conglomerates.