International Science Community Association International Research Journal of Earth Sciences 6 10 2018 10 25 Geochemical evaluation of groundwater origin using source rock deduction and hydrochemical facies at Umuoghara Mining Area, Lower Benue Trough, SE Nigeria 1 11 EN Eyankware M.O. 1 Department of Geology, Faculty of Science Ebonyi State University, Abakaliki, Nigeria Ogwah C. 2 Department of Geology, Faculty of Science Ebonyi State University, Abakaliki, Nigeria Okeke G.C. 3 UZGIB Integrated Services, Lagos Nigeria > Research Paper 2018 7 3 2018 10 25 The research is aimed at geochemical evaluation of the origin of groundwater at Umuoghara area. The parameters listed below were analyzed following APHA, 2012 standard: pH, EC, TDS. Cations; (magnesium) Mg2+, potassium (K+), calcium (Ca2+) while anions; bicarbonate (HCO3-), chloride (Cl-) and sulphate (SO42-). Twelve groundwater samples were collected within the study, with the aim to get baseline information regarding source of groundwater origin. This was done using source rock deduction proposed by Hounslaw, 1995 and hydrochemical facies (Gibbs, Piper, Durov, Schoeller plots and Slotan classification). From source rock deduction approach it was observed that weathering played a major role in groundwater chemistry. Gibbs plot showed that rock water interaction is has greater influence on groundwater chemistry, from Piper plot the dominant ions are; Ca2+, Cl- and SO42- , dominant ions in Durov are; Ca2+, Cl- and SO42-, from Schoeller diagram water trend of Ca2+>Mg2+>Cl->SO42->Na++K+>HCO3-. From Piper, Durov and Schoeller. From detailed interpretation, it was observed that groundwater origin is of different source. Soltan classification, it was observed that groundwater source is of deep meteoric. Copyright@ International Science Community Association