Evolution of saline waters and brines in the Benue-Trough, Nigeria Editorial handling by W.M. Edmunds

• Published in: Applied geochemistry Vol. 19; no. 9; pp. 1355 - 1365
• Main Author: Tijani, M N
• Format: Journal Article
• Language: English
• Published: 01-09-2004
• ISSN: 0883-2927
• DOI: 10.1016/j.apgeochem.2004.01.020

Hydrogeochemical assessment of 40 saline waters and brines from 20 locations within the lower (southern) and middle regions of the Benue-Trough, Nigeria are presented and discussed in terms of genesis of the primary salinity and subsequent hydrochemical evolution. The total dissolved ions range from 5263 to 88, 800 mg/L and 5148 to 47, 145 mg/L in the lower and middle region, respectively. The saline waters and brines are characteristically Na-Cl type enriched in Ca and Sr on the one hand and depleted in Mg and SO sub(4) on the other, relative to the seawater evaporation trend. Ionic ratios, Na-Cl-Br systematic and divalent cations suggest two likely sources of primary salinity: a fossil seawater source and dissolution of halite. However, water-rock interaction involving Mg uptake by clay minerals and possibly dolomitization during diagenesis appear to be responsible for further modification of the primary chemistry. A conceptualized hydrogeological/flow model for the brines is presented.