scholarly journals Reconnaissance geochemical and geophysical exploration for gold at Iri gold field, north central Nigeria

2020 ◽  
Vol 18 (2) ◽  
pp. 19-31
Author(s):  
Ahmed Sidi Aliyu ◽  
Nuhu Musa Waziri ◽  
Hadiza Liman Mohammad ◽  
Mohammed Abubakar Mohammed ◽  
Apeh Aromeh Gideon

Reconnaissance geochemical and geophysical exploration for gold was carried out at IRI Gold field. Geological mapping was conducted and rocks, soils and sediments samples were collected. The outcome revealed rocks of the basement complex of Nigeria made up of mainly, Migmatite Gneiss, Older Granite and the Schist. The major lithology in the area is silicified sheared rocks and large quartz vein. Isolated occurrence of undifferentiated schist was found as parent material on which quartzite intruded possibly during a major geological activity. Shattering of the rocks left boulders and rubbles of quartzite all around two major ridges within the study area. The rocks have shown weak geochemical anomaly except in two locations were positive anomalies were observed and identified as target for further exploration. Gold veins are prominent in the area suggesting potential gold mineralization. Interpretation of the aeromagnetic data give the orientations of the structural features, the major structural trend in the area is NE-SW. The lineaments extracted from the magnetic data range in length from 46.43m to about 1251.66m. Most of the lineaments extracted from the area are subsurface within the quartz-mica and migmatites while some of them have surface expressions even though not clearly defined. These magnetic lineaments could be the contacts between two rock types of contrasting magnetic   susceptibility   or   edges   of   structures   that   could   be faults or intrusive bodies. Interpreted satellite data show several subsurface structures which could be hosts to gold mineralization in the area. Results of the geochemical analysis of rocks, soils and sediments were super imposed on the interpreted aeromagnetic data and similar geochemical and geophysical signatures were established.   Index Terms: Gold mineralization, aeromagnetic data, geochemical data, schist belt, Nigeria

2015 ◽  
Vol 12 (6) ◽  
pp. 563-576
Author(s):  
Tharwat H. Abdel Hafeez

The study area is regionally covered by rock exposures ranging in age from the Precambrian to Quaternary. The aeromagnetic survey is a useful tool that help in geological mapping, providing information at a reasonable proportion of the cost of ground mapping. The reduced to the northern magnetic pole (RTP) map was separated into regional and residual magnetic component maps by the computed power spectrum of the magnetic data. The estimated mean depths of both regional and residual magnetic sources were found to be 2510 m and 383 m respectively. Also, two advanced techniques were used to analyze the depth magnetic data. These methods are analytical signal (AS) and source parameter imaging (SPI). The results of average depth estimates both methods (–950 m). These depth values were helped -to great extent- for define the direction of throw for the interpreted faults in the basement tectonic map. The statistical analysis shows that, most of the welldeveloped structural features are oriented mostly in the N-S, NNE-SSW, NW-SE and NNWSSE trending faults are considered the main trends affecting the distribution of the radioactive minerals.


2020 ◽  
Author(s):  
Voltaire Souga Kassia ◽  
Theophile Ndougsa-Mbarga ◽  
Arsène Meying ◽  
Jean Daniel Ngoh ◽  
Steve Ngoa Embeng

Abstract. In the Pitoa-Figuil area (Northern Cameroon), an interpretation of aeromagnetic data was conducted. The aim of this investigation was first to emphasize lineaments hidden under geological formations and secondly to propose two 2.75D models of the subsurface structures. Different magnetic data processing techniques were used, notably horizontal gradient magnitude, analytic signal, and Euler deconvolution. These techniques in combination with the 2.75D modelling to the aeromagnetic anomaly reduced to the equator permit to understand the stratification of the deep and near surface structures, which are sources of the observed anomalies. We managed to put in evidence and characterize 18 faults and some intrusive bodies. According to Euler's solutions, anomaly sources go up to a depth of 5.3 km.


2020 ◽  
Vol 59 (3) ◽  
pp. 19-26
Author(s):  
Musab Awad Ahmed HASSAN ◽  
◽  
Aleksandr Evgen’yevich KOTEL’NIKOV ◽  

Relevance and purpose of the work. The study area is located in Gedarif state in Sudan. The ongoing work is aimed at solving fundamental problems of the geological structure of the Qala En Nahal-Um Saqata Ophiolitic Complex and applied tasks of mineral exploration. Detailed studies are being conducted for the first time in this area. The purpose of the investigation is to study the geological and structural features of the region, as well as to obtain information about the localization of gold mineralization. Methods of research. Within the study area, a geological mapping of the ophiolitic complex was carried out. It’s included an analysis of structural elements for investigation of the structural evolution and the phases of deformation. Chemical analysis of the mineralized quartz veins to determine the gold was carried out by Atomic Absorption Spectrometry (AAS) technique at the ALS Laboratory in Saudi Arabia. Results of the work. The investigation of the structural evolution revealed at least three phases of deformation. The gold mineralization occurs in auriferous quartz veins, which are hosted in metavocano-sedimentary, sheared synorogenic granites and listvenites. The auriferous quartz veins are structurally controlled by dominantly NE main shear directions. Conclusions. The gold mineralization in the area can be classified shear zone related mineralization, which is formed during the final event accomplished by crustal cooling, and formation of auriferous quartz vein along shear zones. Gold concentration were recorded in both quartz veins and associates alteration rocks. The area is promising for the presence of a gold deposit.


2019 ◽  
Vol 122 (4) ◽  
pp. 455-488 ◽  
Author(s):  
C.A. Smit ◽  
D.D. Van Reenen ◽  
S. McCourt ◽  
J.M. Huizenga ◽  
G. Belyanin ◽  
...  

Abstract The paper reviews published and unpublished geological data pertaining to the structural and metamorphic controls, rock types, characteristic features, source, and timing of hypozonal orogenic gold mineralization in the Giyani Goldfield. The Giyani Goldfield includes the NW domain of the >3.0 Ga Giyani greenstone belt (GGB) at the northern edge of the Kaapvaal Craton and the southern retrograde hydrated domain of the juxtaposed Southern Marginal Zone (SMZ) of the ca. 2.72 Ga Limpopo Complex (LC). Mineralization at all gold mines and gold prospects of the Giyani Goldfield is structurally controlled and closely associated with the Hout River shear zone (HRSZ) and associated smaller shear zones suggesting a specific tectonic setting. This tectonic setting is the direct consequence of thrusting the SMZ of the LC against and over the adjacent GGB at the position of the steeply north-dipping (south verging) HRSZ during the exhumation stage of the ca. 2.72 to 2.69 Ga Limpopo orogeny followed by regional retrograde hydration of the southern part of the SMZ at ca. 2.68 to 2.62 Ga. This tectonic setting offers an explanation for a deep-seated crustal source for gold and for the concentration of orogenic gold mineralization within specific structural features located within the Giyani Goldfield. This tectonic setting also explains the lithological, structural and metamorphic complexity, metasomatic alteration and post-peak metamorphic timing of gold mineralization. Finally, it provides important clues with regards to a crustal source for gold mineralizing fluids and the identification of new potential targets for gold exploration in the Giyani Goldfield.


2021 ◽  
Vol 258 ◽  
pp. 03009
Author(s):  
Mohammed Ibrahim ◽  
Alexander Kotelnikov ◽  
Pavel Podolko ◽  
Elena Kotelnikova

The mineral exploration has improved in the last decades, today there are different methods of remote exploration, that are applied in mining industry worldwide, helping to discover ore minerals deposits in zones that have not access to them. The study area of this article is located about 400 km from Khartoum, characterized by low reliefs covered by sand and gravely sand. The study wants to carry out the geological mapping and the prospective zones using remote sensing and GIS techniques. Sudan is characterized by geological formations over inaccessible areas, in that way the remote sensing technique has a great value in these conditions, saving time and money. The used methodology has been divided into three phases: Pre-field office work, field work and post-field work. The processing of the satellite images includes color band composites, in order to obtain the lithological and geological features, the different types of rocks were defined by a different color. Obtaining the following rock types: High-grade gneisses and migmatites described to comprise the basement complex, ophiolitic mafic-ultramafic rocks that appear in the northern and southern sides of the area, metasediments that cover most of the study area, syn-orogenic intrusions that cut the older mafic-ultramafic units and the metavolcanosedimentary sequences, post-orogenic intrusions and gold mineralization. Based on the image analysis results of Landsat 8 OLI, 32 ore samples were collected to analysis gold and pathfinder elements obtaining high anomalies results for Au, Ag, Cu, Zn, Pb and Fe.


2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Boris Sterligov ◽  
Sergei Cherkasov

The use of light and ultralight unmanned aerial vehicles (UAVs) for magnetic data acquisition can be efficient for resolving multiple geological and engineering tasks including geological mapping, ore deposits’ prospecting, and pipelines’ monitoring. The accuracy of the aeromagnetic data acquired using UAV depends mainly on deviation noise of electric devices (engine, servos, etc.). The goal of this research is to develop a nonmagnetic unmanned aerial platform (NUAP) for high-quality magnetic surveys. Considering parameters of regional and local magnetic survey, a fixed-wing UAV suits geological tasks better for plain area and copter type for hills and mountains. Analysis of the experimental magnetic anomalies produced by a serial light fixed-wing UAV and subsequent magnetic and aerodynamic modeling demonstrates a capacity of NUAP with internal combustion engine carrying an atomic magnetic sensor mounted on the UAV wings to facilitate a high-quality magnetic survey.


2020 ◽  
Vol 57 (4) ◽  
pp. 375-388
Author(s):  
Ryan Bessen ◽  
Jennifer Gifford ◽  
Zack Ledbetter ◽  
Sean McGuire ◽  
Kyle True ◽  
...  

This project involved the construction of a detailed geologic map of the Park Reservoir, Wyoming 7.5-Minute Quadrangle (Scale 1:24,000). The Quadrangle occurs entirely in the Bighorn National Forest, which is a popular recreation site for thousands of people each year. This research advances the scientific understanding of the geology of the Bighorn Mountains and the Archean geology of the Wyoming Province. Traditional geologic mapping techniques were used in concert with isotopic age determinations. Our goal was to further subdivide the various phases of the 2.8–3.0 Ga Archean rocks based on their rock types, age, and structural features. This research supports the broader efforts of the Wyoming State Geological Survey to complete 1:24,000 scale geologic maps of the state. The northern part of the Bighorn Mountains is composed of the Bighorn batholith, a composite complex of intrusive bodies that were emplaced between 2.96–2.87 Ga. Our mapping of the Park Reservoir Quadrangle has revealed the presence of five different Archean quartzofeldspathic units, two sets of amphibolite and diabase dikes, a small occurrence of the Cambrian Flathead Sandstone, two Quaternary tills, and Quaternary alluvium. The Archean rock units range in age from ca. 2.96–2.75 Ga, the oldest of which are the most ancient rocks yet reported in the Bighorn batholith. All the Archean rocks have subtle but apparent planar fabric elements, which are variable in orientation and are interpreted to represent magmatic flow during emplacement. The Granite Ridge tear fault, which is the northern boundary of the Piney Creek thrust block, is mapped into the Archean core as a mylonite zone. This relationship indicates that the bounding faults of the Piney Creek thrust block were controlled by weak zones within the Precambrian basement rocks.


2018 ◽  
Vol 14 (2) ◽  
pp. 15-28
Author(s):  
A A ALABI ◽  
O OLOWOFELA

Airborne magnetic data covering geographical latitudes of 7000‟N to 7030‟N and longitudes of 3 30′E to 4 00′E within Ibadan area were obtained from Nigeria Geology Survey Agency. The data were ana-lyzed to map the sub surface structure and the source parameters were deduced from the quantitative and qualitative interpretation of magnetic data. The upward continuation technique was used to de-emphasize short – wavelength anomaly while the depth to magnetic sources in the area was deter-mined using local wavenumber technique, the analytic signal was also employed to obtain the depths of the magnetic basement. Analysis involving the local wavenumber, upward continuation and appar-ent magnetic susceptibility techniques significantly improves the interpretation of magnetic data in terms of delineating the geological structure, source parameter and magnetic susceptibility within Iba-dan area.. These depth ranges from 0.607km to 2.48km. The apparent susceptibility map at the cut-off wavelength of 50 m ranges from -0.00012 to 0.00079 which agree with the susceptibility value of some rock types; granite gneiss, migmatite biotite gneiss, biotite muscovite granite, hornblende granite, quartz and schists. The result of the local wavenumber suggests variation along the profiles in the surface of magnetic basement across the study area.


2021 ◽  
Author(s):  
Benoit Deffontaines ◽  
Kuo-Jen Chang ◽  
Samuel Magalhaes ◽  
Gérardo Fortunato

<p>Volcanic areas in the World are often difficult to map especially in a structural point of view as (1) fault planes are generally covered and filled by more recent lava flows and (2) volcanic rocks have very few tectonic striations. Kuei-Shan Tao (11km from Ilan Plain – NE Taiwan) is a volcanic island, located at the soutwestern tip of the South Okinawa trough (SWOT). Two incompatible geological maps had been already published both lacking faults and structural features (Hsu, 1963 and Chiu et al., 2010). We propose herein not only to up-date the Kuei-Shan Tao geological map with our high resolution dataset, but also to create the Kuei-Shan Tao structural scheme in order to better understand its geological and tectonic history.</p><p>Consequently, we first acquired aerial photographs from our UAS survey and get our new UAS high resolution DTM (HR UAS-DTM hereafter) with a ground resolution <10cm processed through classical photogrammetric methods. Taking into account common sense geomorphic and structural interpretation and reasoning deduced form our HR UAS-DTM, and the outcropping lithologies situated all along the shoreline, we have up-dated the Kuei-Shan Tao geological mapping and its major structures. To conclude, the lithologies (andesitic lava flows and pyroclastic falls) and the new structural scheme lead us to propose a scenario for both the construction as well as the dismantling of Kuei-Shan Tao which are keys for both geology and geodynamics of the SWOT.</p>


Sign in / Sign up

Export Citation Format

Share Document