TRACT: The Cretaceous sediments in the Anambra Basin (SE Nigeria) consist of a cyclic succession of coals, carbonaceous shales, silty shales and siltstones  interpreted as deltaic deposits. The objective of this study is to compare the hydrocarbon generation potential of organic matter from shale sediments along Isugwuato-Okigwe axis in the Anambra Basin, Nigeria. Data obtained indicates the presence of Type III kerogen with Tmax values are between 424 and 441ºC indicating that the shales are thermally immature to marginally mature with respect to petroleum generation. Hydrogen Index (HI) values range from 14 to 388.9mgHC/gTOC while S1 + S2 yields values ranging from 0.2 to 1.0mgHC/g rock, suggesting that the shale have gas generating potential. The TOC values rangesfrom 1.3 to 3.0%, an indication of a good source rock of terrestrially derived organic matter. The high oxygen index (OI) (16.3 mgCO2g-1TOC), TS (1.35) and TOC/TS (1.5) suggest deposition in a shallow marine environment. Based on the kerogen type, shales from the studied area will equally generate oil and gas if its organic matter attained sufficient thermal temperature. Keywords: Shale, kerogen type, maturity, oil generation.

Gas geochemistry, an integral part of petroleum geosciences, has been used for evaluating source rocks potential for shale gas and in conventional exploration as a guide for determining potential productive formations. However, in contemporary times, new concepts of gas geochemistry have been applied in delineating the effectiveness of caprocks. Caprock is a vital element of a petroleum system, the volumes of rocks overlaying reservoirs are responsible for the configuration on which the accumulation sits and fosters essential preservation. In this study headspace gas served the purpose of delineating leakage and determining migration pathways, mechanism and discriminating gas types in the formations overlaying the reservoirs.

The objective of this research is to determine the actual source of organic matter in the Niger Delta Sea Shelf (NDSS). Organic carbon (OC) and n-alkanes were investigated in the suspended matter (SM) and surfcial sediments of the Niger and Imo Rivers and the opposite Niger Delta Sea Shelf. Organic nitrogen and carbon isotope (δ13C) values were determined as additional parameters in the sediments. OC and n-alkane concentrations were highly variable. This variability was interpreted as the result of sources of materials from the inland basins and a complex sedimentation pattern involving the discharges of these two rivers. Using the constant ratio of high molecular weight odd n-alkanes to OC in both rivers, the estimated value of more than 70% of the OC preserved in shelf sediments were terrestrially-derived. This result was substantiated by the overall dominance of land-derived n-alkanes. A second approach using δ13C values and assuming binary dilution of riverine and marine OC led to the determined source of organic matter. Keywords: Organic carbon; δ13C; n-Alkanes; Niger River; Imo River; Niger Delta Sea Shelf.

The present work deals with a study based on the geochemical techniques such as biomarkers, Rock-Eval pyrolysis, and detailed petrographic study to evaluate hydrocarbon generation potential of coal by collecting nine coal and carbonaceous shale samples from boreholes in Awgu Formation of Middle Benue Trough, Nigeria. The values vitrinite reflectance (0.94–1.15%VR) and Tmax (446–469°C) confirmed that samples are matured enough to generate liquid and gaseous hydrocarbon in coal. The coal samples also contain sufficient quantity of vitrinite and liptinite macerals varying from 70.28% to 74.10 wt%, which confirm the production of liquid hydrocarbon. The cross-plot between H/C and O/C atomic ratio indicates that samples were predominant in the bituminous rank and having kerogen Type III makes it suitable for hydrocarbon generation. Similar results were found in Rock-Eval pyrolysis analysis (Types II-III and Type III kerogen). The homohopane index (C35/C31 - C35) and homohopane ratio (C35αβS/C34αβS) range from 0.02 to 0.12 and 0.15 to 0.92 indicates oxic condition during organic matter deposition from Lafia-Obi samples. The Moretane/Hopane, Hopane/Hopane + Moretane, Ts/Ts + Tm, 22S/22S + 22RC32homohopane ratios range from 0.06 to 0.14; 0.88 to 0.94; 0.34 to 0.66; and 0.53 to 0.62 and 20S/20S+20R and αββ/αββ+ααα C29 ratios range from 0.43 to 0.58 and 0.42 to 0.55 indicate samples ar e within the late oil window/gas phase. Plots of 22S/22S+22R C32hopanes against C29αββ/αββ+ααα steranes show that Lafia-Obisamples are thermally mature.

The objective of this study has been carried out to assess the ground water quality of Ikwuano region southeastern Nigeria for drinking and irrigational purposes using standard method. Data obtained show that, the pH and levels of electrical conductivity, total hardness, alkalinity, calcium, magnesium, sodium, potassium, nitrate,orthophosphate, fluorides and SAR ranged from 7.50-8.00, 500-1000µS/cm, 150-400mg/l, 55-110mg/l, 130-250mg/l, 8.50-37.00mg/l, 5.00-52.00mg/l, 2.00-22.00mg/l, 20.00-120mg/l, 10-100µg/l, 0.40-2.00mg/l and 0.80-13.00meq/l respectively. Percentage Na values range between 5.00-48.00%. Sodium adsorption ratio (SAR) values showed a range of 0.80to13.00meq/L. The maximum concentration of SAR 13.00meq /L was recorded at Umugo and minimum concentration of 0.80meq /L was recorded at Ndoro. The calculated values of SAR integrated with the Electrical Conductivity indicated that the ground water in the study area can be utilized for irrigation purpose without any threat of imposition of any hazard (saline or alkaline hazard) to crop soils. Thus, the analytical data from the study area confirms that ground water present in the study area is suitable for domestic and irrigational purposes.