Estimations of Depth to Magnetic Contacts and Dykes of Extended Areas in a Typical Southwestern Basement Terrain Using Aeromagnetic Data

Aeromagnetic data of an extensive area covering sheets 243 and 244 (Ilesa-Ado-Ekiti) from the Nigerian Geological Survey Agency (NGSA) were subjected to data enhancement filters and thereafter profiled into eleven (11)  lines and interpreted quantitatively using forward modeling method to estimate depths to magnetic dykes and contacts of all lines. The profile depths solution revealed depths to dykes ranged from 209 – 494 m and depths to contact ranges from 35 – 498 m. Also, Euler De-convolution solution of structural index one (1) used to model dykes revealed depths ranging from 177-4389.8 m while Euler De-convolution of structural index 0.5 used to model contacts revealed depths ranging from 162-3262.8 m. Lastly, the Local Wave Number (LWN) result showed that depths to the magnetic contacts ranges from 277.2-4529.7m and which resolved best for deepest seated contact. The results obtained from this work are vital information for recognition of geological features such as contacts and dykes

Experimental modelling of hydraulic parameters for fluid flow in stratified porous media

AbstractFrom works in in-situ seepage through dams and laboratory experiments using Layered Heterogeneous Porous Media (LHPM), it has been noted that a refraction-like phenomenon, such as that experienced in light, affects fluids’ flowlines when crossing the contact interface of layers characterised by different porosity viz-a-viz permeability. This concept has many applications in fluid dynamics, such as the dispersion process in stratified media. Currently, no study exists that models and analyses the relationship between the porosities of two layers in contact and the resulting flowline refraction using validated LHPM data. Hence, this work aims to establish a relationship between the porosity ratio [Formula: see text] of stratified media made up of two layers and the refraction angle [Formula: see text] of the maximum volume flux [Formula: see text]. Volume flux data from the flow of a single-phase fluid through five LHPMs with [Formula: see text] ranging from 0.8325 to 0.9524 were used in the modelling. The flow was oriented from the lower to the higher porosity vis-à-vis permeability layer. It was found that [Formula: see text] which is also the refraction angle of the peak solute plume flux, refracts away from the normal as [Formula: see text] reduces. This indicates an increase in the dilution rate vis-à-vis spread of plumes with the reduction in homogeneity between the two layers. Also, [Formula: see text] does not correlate with the stratification inclination [Formula: see text], but the [Formula: see text] which is also the peak solute plume flux correlates with [Formula: see text]. Furthermore, an efficient model, which is the best-unbiased estimator, with [Formula: see text] was derived. Findings from this work can help better understand solute plume dispersion and the general fluid flow dynamics in stratified media such as capillary barrier effect covers for pollution control and hydrocarbon reservoirs