Geochemical Characterization of Baryte Mineralization in the Gombe Inlier, Gongola Sub-basin, Northern Benue Trough, Nigeria: Insights into Its Origin and Physico-Chemical Conditions

Abstract

A detailed investigation was conducted on a baryte mineralization located in the Gombe Inlier within the Gongola Sub-basin of the Northern Benue Trough. The study aimed to determine the physico-chemical conditions of baryte crystallization and to gain insights into the ore genesis of the baryte mineralization in the Gombe Inlier through geochemical analysis. Using a Rigaku NEX DE X-ray fluorescence (EDXRF) spectrometer, we measured both the major and trace elements, as well as rare earth elements, present in the baryte ores. Geochemical investigations indicated that the baryte veins contain an average concentration of 72.86 wt.% BaO and 2.10 wt.% SrO. The mineralizing fluid is characterized as a strongly differentiated hydrothermal fluid, rich in Ba and Sr while being poor in high field strength elements (Hf, Zr, Ta, Nb, and rare earth elements), which precipitated earlier. Late-stage fluids typically concentrate incompatible elements like Ba and Sr, suggesting that the baryte deposits in the Gombe Inlier are part of the baryte end-member of the baryte-celestine solid solution series. The Ba-rich fluids are derived from magmatic hydrothermal fluids (juvenile water) and the leaching of oceanic or continental rocks, or a combination of both. The presence of Cu, Pb, Zn, and Fe oxides (in form of hematite), along with fluctuations in the Eu anomaly in both baryte fields, further supports the precipitation of baryte minerals by seawater-bearing hydrothermal fluids in fluctuating oxic-anoxic conditions within a low-temperature or near-surface environment. Variations in elevation from the Southern to the Northern Benue Trough contributed to changes in the redox conditions affecting baryte mineralization throughout the Benue Trough.