THE BAFQ MINING DISTRICT IN CENTRAL IRAN - A HIGHLY MINERALIZED INFRACAMBRIAN VOLCANIC FIELD

The paper describes for the first time the Bafq mining district and it s deposits of magnetite, apatite, manganese, and base metals. It is ba sed on two decades of field work and the re-evaluation of more than 50 ,000 m of drill cores. Central Iran is a fragment of Gondwana with a P recambrian basement. Within a Pan-African rift zone a huge Infracambri an volcanic field was formed on top of a silicic diapir, with ignimbri tic cauldrons, ring fracture intrusions, and resurgent granites. The v olcanic field was partly covered by a shallow sea (shales, dolomitized reefs, salt, and gypsum beds). Along the ring fractures, phreatomagma tic explosions led to the formation of diatremes. They are filled with tuffs, which include basement xenoliths and fragments of rocks which had covered the basement during diatreme formation but which have been eroded together with the uppermost part of the diatreme (eroded xenol iths), welded agglutinates, intrusive breccias, and multiple intrusion s of aplosyenite (anorthoclase, scapolite), hornblendite (diopside, ma gnesio-hornblende), and magnetitite (magnetite, REE-rich fluorapatite) . The magmatic material is considered to be the product of differentia tion and liquid immiscibility of a melanephelinitic melt. Magnetitite also occurs as lava flows, sills, dikes, and pyroclastic ores. The exp lored diatremes of Choghart (mined since 1971), Chador Malu (stripping commenced in 1992), Se Chahun; and Chah Gaz contain 750 Mt of iron or es. Esfordi, a funnel filled with 50 Mt of magnetite-pyroxene-apatite, is being explored. Anomaly XX is a large magnetite prospect associate d with uranothorianite mineralization at Duzakh Darreh. Narigan is a m anganiferous jaspilite deposit situated in the former moat. Kushk is a subaqueous-hydrothermal massive lead-zinc deposit intercalated in Inf racambrian (informal designation in Iran for Upper Riphean-Vendian; 75 0-570 Ma) volcanics. It is being mined and has 4 Mt of reserves.