ABSTRACT

of the electrical resistivity technique, which red to the seismic technique in fault seal . .. ., ....... . . . , The Agu Abor fault is a prominent growth fault that provides insights on the processes of clay smearing at the fault zone. The properties of the sheared zone in the Cretaceous Enugu Shale were investigated to evaluate the dimensions of the fault, by the use is a cheaper method when compa study. The methodology used for evaruaang tnese possltmtles Involves tne resistivity mapping and concepts of tension and extension created at the shear zone. By theses combinations, details of the fault geometry were developed. Eight Vertical Electrical Soundings (VES) were carried out at stations 1- 8; along a NE-SW strike direction, covering a land mass of about 250m2. The sounding curves interpretations indicated mostly three-five layer geoelectric sections. Interbedded shales, siltstones, and sandstone zones, were delineated. Shaly beds were inferred as low resistivity zones (~30 ohmlm), while siltstone lay (30-80 ohmlm), Sandstones ucw "I I LI IC ULI ICI IWIU WCIC II ILCI~ICLGU Q3 zones of high resistivity (>80 ohmlm). The resistivity contour map of the area shows the fault-zone, as a gouge with a determined shale gouge ratio (SGR) of 59-71%. A plot of bed thickness (T) against shale smear thickness (t) reveals a linear dependency, invariably implying that shale smear thickness increases the capacity of a fault to seal. Inferences drawn from these results indicate that the fault possess the ability to trap hydrocarbon