Tectonic control on the distribution of onshore mud volcanoes in parts of the Upper Benue Trough, northeastern Nigeria.

Abstract

Onshore mud volcanoes are rare geological phenomena, which in Nigeria were reported for the first time few years ago in the Upper Benue Trough. In this study a detail geological mapping of the area of mud volcanoes occurrence was carried out, with the primary aim of defining their relationship, if any, to the structural geology there. The systematic field reconnaissance included field observations of the structural features, as well as analysis of the location and distribution of the onshore mud volcanoes, marking their locations on the topographic and geological maps, analysis of the aerial photographs and satellite images. The study area covered the central part of the Upper Benue Trough where the onshore mud volcanoes were found. The study area is the part of a sedimentary basin comprising Cretaceous clastic rocks that have been deformed intensively by a network of faults often embedded in the underlying Precambrian basement. This network of faults underwent a rejuvenation period from the Aptian to the Palaeocene. The most prominent tectonic structure in the study area is the NE -SW trending Kaltungo Fault Zone, however, there are other minor faults with N -S and NW -SE trends. This study shows that the mud volcanoes found in the study area are usually located near or within fault zones, within the outcropping Upper Cretaceous Yolde Formation and Upper Bima Sandstone, both of which were deformed by the Kaltungo faults, as well as by other minor faults.Worldwide, incidences of onshore mud volcano formation are usually attributed to areas of tectonic activity, rapid sedimentation or hydrocarbon occurrence. In this study, the interpretation of the field observations and mapping results, combined with information on the structural evolution of the study area and seismic pattern (very scarce), have led to the conclusion that the location of onshore mud volcanoes in the Upper Benue Trough, being located along the fault zones, is structurally controlled. The close relationship between mud volcano location and the structural framework of the area may be interpreted as one of several possible subsurface geological responses to present tectonic activity.

A spatial analysis for geothermal energy exploration using bivariate predictive modelling

“…Geological occurrence of hot springs and hydrothermal fluids in wells and boreholes are often considered as geothermal manifestations 5 , 6 , 15 , 32 . In the Awe area and mid Nigerian Benue trough, these occurrence have been previously reported 7 , 30 . Information on geothermal data was gathered from the open literature 30 , and from field studies.…”

“…A concise analysis of this plot suggests an augmented relationship exists between known geothermal points and spatial data related to lithological and structural intensity. Within the Nigerian Benue trough, evidence for lithological and structural control of geothermal occurrence have been reported by Musa et al 7 , and a substantial correlation of geothermal resources with lineament intensity may point to the possible presence of numerous closely spaced intersecting faults 70 . A positive correlation with land surface temperature obtained from thermally calibrated MODIS imagery may suggest a near surface manifestation for geothermal occurrence across the study location.…”

“…The exploration and exploitation of Nigeria’s geothermal resources is a viable task due to the widespread availability of enormous prospects that occur mostly within the Cretaceous sedimentary basins as well as certain parts of the basement complex terrains. Evidence from recent studies have suggested widespread geothermal prospects in the form of volcanic plugs, mud volcanoes and/or thermal springs 7 . More so, deduced geothermal gradient for most oil wells within the Niger Delta basin have revealed a significant geothermal potential 8 , 9 .…”

A Preliminary Geothermal Prospectivity Mapping Based on Integrated GIS, Remote-Sensing, and Geophysical Techniques around Northeastern Nigeria

“…All of the above-mentioned thematic (evidence) maps (structural-lineaments, geology, temperature gradients, heat flow, gravity data) and their associated sub-divisions (classes) that were earlier assigned a layer weight value were subsequently integrated into the geothermal prospectivity (favorability) map. The computed geothermal potential map was also validated by the field distributions of surface evidence of geothermal occurrences such as hot springs, basaltic plugs, and mud volcanoes reported in the work of [34].…”

“…Other studies that used geological information such as hot/warm springs, rock distributions, mud pods, and structural distributions that revealed geothermal indicators include [33][34][35], among others. An overview of the various studies carried out around this important terrain shows that the very effective multicriteria evaluation was never applied to partially integrate all the available geoscientific data that partially impact the geothermal occurrences in this area.…”