New multi-dimensional diagrams for tectonic discrimination of siliciclastic sediments and their application to Precambrian basins

Relationships between organic matter and carbon contents of organic wastes

Geochemical discrimination of siliciclastic sediments from active and passive margin settings

The determination of soil organic matter by wet digestion techniques is a slow and laborious analysis. Loss‐on‐ignition (LOI) provides a simple alternative technique for the estimation of soil organic carbon in non‐calcareous A horizon soils of the Natal midlands and Zululand forestry regions. Using multiple regressional techniques, the relationships between loss‐on‐ignition, Walkley organic carbon and soil texture for 55 soils were determined over a range of ignition temperatures. The relationships hold best for soil samples with relatively low organic carbon contents (< 5%). The optimum temperature for ignition was found to occur at 450°C and resulted in the relationship: Soil organic carbon = 0.284∗LOI percent. No advantage is gained through ignition at higher temperatures due to the loss of clay mineral structural water, even if the soil texture is accurately known.

Loss-on-ignition as an estimator of soil organic carbon in A-horizon forestry soils.

A regional lithostratigraphic and hydraulic interpretation is presented for the upper 0–300 m of the Benin Formation where groundwater is abstracted in the Rivers State, Nigeria. The aquifers are predominantly sand beds with minor clays, lignite, and conglomerate intercalations. The sands are very fine to coarse grained, subangular to subrounded, poor to fairly well sorted and mostly lithic arenites. A maximum thickness greater than 50 m is developed in places and vertical stacking is common. Most of the conglomerate beds have a matrix support fabric and appear restricted to the east as the lignite beds. An east-west trending belt, about central to the state, seems to contain more clay interbeds. The transmissivity values for the aquifers range from 1.05 × 10−2 to 11.3 × 10−2 m2/sec, while the coefficient of storage varies between 1.07 × 10−4 and 3.53 × 10−4 and specific capacity values lie between 19.01 and 139.8 m3/h/m drawdown. These values suggest that the aquifers have very good capacity to transmit groundwater. The static water level map shows a north-to-south regional groundwater flow pattern except in the northeast (Imo River catchment area) where the flow is northeast to southwest. The groundwater quality is very good and compares favorably with WHO standards for drinking water. However, relatively high iron and chloride values are localized in time and space. Deposition of the aquifer materials is thought to have occurred in alluvial fan, fluvial channel, tidal channel, intertidal flat, beach, and related microenvironments.

Aquifers in the benin formation (miocene—recent), eastern Niger delta, Nigeria: Lithostratigraphy, hydraulics, and water quality

Zonal mineralogical/geochemical characteristics of soils ofMidwestern Nigeria

Mineralogical and physico-chemical properties of Niger Delta soils in relation with geotechnical problems

Clay diagenesis as a function of marine and nonmarine water flow, Niger Delta, Nigeria

Factors influencing the geochemistry of surface sediments in the supratidal Niger Delta

Environmental and diagenetic implications for the rare earth element geochemistry of sediments of the Niger Delta

B.N. Olorunfemi

Papers

Zonal mineralogical/geochemical characteristics of soils ofMidwestern Nigeria

Mineralogical and physico-chemical properties of Niger Delta soils in relation with geotechnical problems

Clay diagenesis as a function of marine and nonmarine water flow, Niger Delta, Nigeria

Factors influencing the geochemistry of surface sediments in the supratidal Niger Delta

Environmental and diagenetic implications for the rare earth element geochemistry of sediments of the Niger Delta