In Islamabad (Pakistan), surface water and groundwater extract water from shallow alluvial sediments are the sources of water supply. The direct research on hydrogeological conditions in Islamabad, carried out in 2020, included chosen hydrogeological field studies, physicochemical analyses of groundwater, surface water, precipitation and the investigation of and sediments permeability. The purpose of the hydrogeological research was to join the discussion on groundwater hazards and to recommend actions to overcome problems related to water supply. The study results indicate lithological heterogeneity of shallow aquifer, vertically and spatially variable, good chemical status of groundwater and groundwater recharge constituting 10 to 20% of annual precipitation. The groundwater is characterized by a high groundwater footprint, from 5747.8 to 11495.6 km2 depending on recharge variant, documenting the threat to the water. The research results made possible to present recommendations to protect groundwater and water management in Islamabad.
A combination of Shuttle Radar Topographic Mission (SRTM) Digital Elevation Model (DEM) and electrical resistivity were applied in parts of Minna, Sheet 164 SW, North-Central Nigeria to delineate favourable sites for drilling boreholes. Lineaments were extracted from derivative map of SRTM DEM datasets. Selected thematic layers which included lineaments, geologic structure and parametric maps derived from Vertical Electrical Sounding (VES) data were integrated and modelled using ArcGIS to generate a groundwater potential map of the area. Seventy VES were conducted using the Schlumberger array with a maximum AB/2 distance of 100 m and 500 m spacing between each VES sounding stations, to study the variation of resistivity of the ground at variable depths. Geologic mapping results revealed granite as the major lithology with schist occurring in the east. Principal joint directions and automated lineaments map of the combined four relief images trend in the NE - SW direction indicating weathering and probable high groundwater potentials along this direction. VES results revealed up to six geoelectric layers with different resistivities and depths. Six different geoelectric curves were generated from the analysis namely: HA, AA, HK, AK, KH and QH portraying various aquifers within the region. VES results also revealed that the area has undergone slight weathering (less than 6 metres in most parts) and is fractured from place to place. The fractures were found to be convergent to the middle portion of the study area indicating more groundwater accumulation towards that direction. Drill depths in this area should target a minimum of 100 m to ensure sufficient and sustainable supplies to drilled wells.
The Wadi Masilah Basin is part of the larger Say’un-Masilah Basin, a Mesozoic sedimentary basin located in the southeastern Yemen. It consists of a sedimentary sequence hosting polymetallic barite, lead, zinc, iron, manganese, and vanadium mineralisations. The area is strongly faulted as a result of extensional and transtensional tectonics connected to the opening of the Gulf of Aden-Red Sea rift system. Quaternary volcanic activity is associated to the post-rift phase. The present paper deals with the Fe-Mn oxide mineralisation hosted by Cretaceous and Eocenic shallow marine carbonates. The mineralogical assemblage consists of hematite, limonite, goethite, hollandite, romanechite, cryptomelane, pyrolusite, and rodochrosite. Mineralisation may be stockwork, vein-like, and disseminated in carbonate rocks. Iron orebodies made up of massive hematite contain ~80-74% Fe2O3. Mineralised veins have tenors of Fe2O3 variable from ~ 52% to ~11%. Pb, Cr, and Zn contents can be high in some samples. Manganese orebodies have mostly high MnO tenors (~65-52%) and are characterised by very high Ba, Pb, and Zn contents. The disseminated carbonate rocks have Fe2O3 contents up to ~13%, and MnO contents up to ~5%. Their Pb and Zn contents can locally be very high. Samples coming from 12 drillcores, mostly limestones and dolomitic limestones are low-grade in both Fe2O3 (~6-0.4%) and MnO (~0.8-0.1%). As for the source of the mineralising fluids, discriminative diagrams based on Fe/Mn and transition metals support a hydrothermal origin with possible contribution from diagenetic processes. The distribution of Zn and HFSE suggests that hydrothermal mineralising fluids are related to the magmatic-hydrothermal systems affiliated to the neighbouring Quaternary volcanic fields. Widespread positive Ce spikes in the trace element patterns suggest the Fe-Mn ore deposition occurred in a relatively shallow, oxidizing environment.
Detailed down-dip, bed-by-bed sedimentary logging of outcrops of the Ameki Group in the Awka-Onitsha area of south-eastern Nigeria, was performed to identify and characterize components of the Group in the area. Thirteen exposures were measured and analyzed for lithological changes, composition, sedimentary structures, trace fossils, and stratigraphic surfaces. Stratigraphic analysis shows that the Ameki Group in the study area consists of two stratigraphic components- a basal sandstone component (> 200m) and an overlying mud rock component (>20m). Facies analysis reveals that the sandstone component consists of two facies associations: (i) a tidally-influenced channel facies association comprising strongly ferruginized, pebbly- to medium grained, fining-upwards sandstone that is inter-bedded with kaolinitic claystone and ironstone of variable thickness and(ii) sand-rich heterolithic facies association that reflects sand flat sedimentation. The mud rock component of the Ameki Group also contains two facies associations: (i) clay-rich heterolithic facies association that reflects deposition in mixed flats and (ii) carbonaceous claystone-lignite facies association that reflects mudflats and swamp sedimentation. Field relations and facies analysis confirm that the contact between the channelized, basal sandy component of the Ameki Group and the underlying Imo Formation is defined by the upward transition from dark-coloured, fine grained marine facies, to coarse grained fluvial channel sandstone. Similarly, the contact between the of the muddy component of the Ameki Group and the overlying Ogwashi Asaba Formation is defined by the transition from dark coloured mud flats/swamp facies to light coloured pebbly-coarse grained coastal plain sandstone and lignite. These new information should serve as a major contribution toward the resolution of the problems of the stratigraphy and contact relations of the Ameki Group in this part of southern Nigeria.
Tanzania has abundant natural resources potential to provide means for inclusive and sustainable private sector development. This paper assesses levels of risks and impact of Covid-19 on the private sector production systems, employment and commodity prices in the extractive sectors. The assessment is founded on the small and open macro-economic production model that assumes production systems, employment and product prices are main policy targets, well behaved and endogenous variables; determined simultaneously in the complex domestic and global social economic systems. Both secondary and primary data and information are used for the empirical risk analysis. Data and policy analysis use visual data discovery, prescriptive and predictive analytics detect patterns or structures in data sets that seem at first sight impenetrable.
The primary data analysis suggests that there is a high health risk and negative effects of the covid-19 pandemic on the private sector production systems, employment and commodity prices in the extractive sectors. Secondary data reveals that there have been significant risks and negative effects on the gold production and petroleum importation patterns during first and second Covid-19 pandemic in 2020/2021. There are also high level of risks and negative effects in the use of human resources. The domestic gold mining product price patterns were somehow stable since the domestic product prices were determined competitively by global extractive product prices with given domestic extractive production techniques. The levels of risks and effects on the domestic prices of the oil and gas sector have been high and unstable. The patterns and rate of change of domestic gold production quantities and prices in percentage before and during the Covid-19 were observed to be similar and stable throughout the sample period.
The paper recommends that in order to minimize the risks and negative effects of Covid-19, Tanzania should particularly aim at maximizing private sector productions, effective use of workers; and ensuring that domestic extractive sector products and commodity price systems are efficient and stable. The specific objectives are; ensuring stable and increasing gold production activities; maintaining optimal petroleum importation and supplies; optimal uses of human resource, employment and labour productivity; stable domestic gold mining product and price patterns; stable, fair and competitive domestic prices of oil and gas sector and to ensure continuous price and quantity stabilities.