Pb-Zn-Ba deposits in the Nigerian Benue Trough: A synthesis on deposits classification and genetic model

• DOI: 10.1016/j.oregeorev.2024.105947
• Publication Date: 2024-02-20T02:40:55Z
• Authors: Saleh Ibrahim Bute; Jia-Xi Zhou; Kai Luo; Musa Bala Girei; Raymond Tabale Peter
• Keywords: Trough (economics); genetic model

The Benue Trough stretching about 800–1000 km with a width ranging between 100 and 150 km, is megarift structure whose origin was related to the opening of south Atlantic during early Cretaceous. This mega rift contains economically significant Pb-Zn-Ba-F deposits that form well-defined metallogenic belt 600 long in Nigeria. In Southern (SBT), are localized four districts namely Abakaliki, Ishiagu, Wanikande Gabu-Oshina hosted by carbonaceous shale; Central (CBT) deposit silicified limestone arkosic sandstone Arufu, Akwana Azara districts; while Northern (NBT) ores occur arenaceous sediments Yolo, Gombe Gulani districts. Previously published sulfur (S) isotopic data sulfides suggest ore-forming S sourced from marine sulfates reduction sulfate mainly thermochemical process CBT NBT. Whereas SBT, bacterial dominant. compiled C-O compositions slightly metamorphosed sedimentary rocks supplied materials hydrothermal systems through water/rock interaction. available bulk Pb for ore minerals, host crystalline comprising basement as well basaltic which composed detrital feldspars eroded Precambrian could be likely source metals. Our model proposed fluids were hot connate-brine expelled compaction development deep basins. Mesozoic magmatic events distributed throughout basin provided initial thermal flow elevated geothermal gradient. brines have leached metals syn-rift continental formations. tensional fractures serve conduit migrated, abundant sulphate precipitated their contents transcurrent fault system sulfides, barite associated polymetallic ores. geological, mineralogical, geochemical characteristics Nigerian Pb-Zn consistent Mississippi Valley-type (MVT) North Africa typical MVT worldwide.