Depth‐based correlation analysis between the density of lineaments in the crystalline basement's weathered zones and groundwater occurrences within the Voltaian basin, Ghana

Abstract

Geological structures have been shown by studies to have influence on the occurrence, storage and transportation of groundwater. Understanding the structural network of an area unearths a deep insight into the groundwater dynamics of the area. A geological structural analysis was carried out to reveal the geological structural network of Ghana's Voltaian basin. Using aeromagnetic data, structural density models were generated using the Center for Exploration Targeting grid analysis technique for two depth ranges (that is up to 100 m and 300 m) over the Voltaian basin. The total length of geological structures (lineaments) delineated at depths up to 100 m and 300 m were more than 5000 km and more than 8000 km, respectively. Given this, the study area was observed to be structurally dense at each of the aforementioned depths. The structural density models were discretized into five classes (very low, low, moderate, moderately high and very high regions), each of which was evaluated to determine their spatial association with known locations of groundwater occurrences within the study area using the frequency ratio technique. Frequency ratio results for both structural density models derived at 100 m and 300 m depths show the existence of a strong correlation between high structural density model classes and the known groundwater occurrences. The structural density models were further evaluated using the receiver operating characteristics curve. The area under the receiver operating characteristics curve scores indicates that, although both structural density models showed very good performance (with receiver operating characteristics scores greater than 0.7), the 300‐m depth structural density model performed better than the structural density model generated at a depth of 100 m (with their receiver operating characteristics scores being 0.721 and 0.715, respectively). The obtained results corroborate with literature assertion that groundwater occurrence within the Voltaian basin is mainly associated with structural features. It is expected that the outputs of this study would guide future groundwater exploration programmes within the study area.

Application of a hybrid BWM-TOPSIS approach for mineral potential mapping

“…5 (b)) could be associated with sulphide-associated indicator minerals such as pyrite, arsenopyrite as well as magnetite. Also, from the magnetic data, the lineament density factor was generated by employing the CET (Centre for Exploration Targeting) grid analysis technique [ 9 , [47] , [48] , [49] ]. Lineaments such as faults, fractures, etc., depict low pressure zones and consequently act as conduits for hosting various mineralised fluids.…”

“…This type of data-integration technique is dependent on adequate availability of known occurrence locations of the targeted mineral resource (known as brown fields). Examples of the empirically-based data integration techniques are frequency ratio [ [9] , [10] ], Shannon entropy [ 11 ], multi-index overlay [ 12 ], evidence belief functions [ 13 ] and machine learning methods [ [14] , [15] , [16] ]. In the case of the conceptually-based data integration techniques, the weight of the mineral predictors to be synthesised are determined using expert judgment.…”

Prediction of gold mineralization zones using spatial techniques and geophysical data: A case study of the Josephine prospecting licence, NW Ghana

“…The Center for Exploration Targeting (CET)-based lineament density thematic layer (shown in Fig. 4 (a)) characterizes various regions with varying intensities of structural occurrences within the study area [ 13 ]. Thus, it concerns a particular region’s structural endowment potential due to the occurrence of various geological structures or features.…”