Delineation of Potential Mineral Zones from Aeromagnetic Data Over Eastern Part of Zamfara

Delineation of Potential Mineral… Savanna Journal of Basic and Applied Sciences

Available online at http://www.sjbas.com.ng Savanna Journal of Basic and Applied Sciences (June, 2021), 3(1): 60 - 66

P:ISSN 2695-2335 | E:ISSN 2705-3164

Delineation of Potential Mineral Zones from Aeromagnetic Data over Eastern Part of Zamfara

Augie, A.I. and Ridwan, M.M.

Applied Geophysics Department, Federal University Birnin Kebbi, Nigeria

ABSTRACT

In this study, acquired aeromagnetic data was used to delineate structures that may host minerals over the eastern part of Zamfara State. The acquired aeromagnetic data were analysed, processed and interpreted using the following techniques; IGRF/DGRF computation, reduction to magnetic equator (RTE), geologic contact (GC), centre for exploration targeting (CET) and source parameter imaging (SPI). The result from these techniques revealed the presence of granite, migmatite, biotite, gneiss, diorite, medium coarse grained quartz-mica schist and biotite- homblende granite as compared with geology of the area. Magnetic anomalous zones identified in these area were associated with the Fe-bearing mineral and sediments with widest variation in Fe- content that form various silicate and oxide mineral species which may probably formed during the formation of both intrusive and extrusive igneous rocks. These regions also have revealed the lineaments that were trending in South-East of the study area within the Birnin Magaji/Kiyawa, eastern part of Bungudu, southern part of Gusau, NE part of Tsafe and western part of Faskari. These structures were associated with hydrothermal solutions of the host rocks that may form mineral and the types of rocks/or structures within the zones play an important role in solid minerals exploration. The structures highlighted within the area have agree well with the results found in geologic contact as well as geological setting of the study area. Estimated depth of shear/faults/structural trends associated with the study area were found to be; 100 m to 185 m and 185.1 m to 250 m.

Keywords: Solid Mineral, Exploration, Geologic Contact, CET and SPI.

INTRODUCTION mineral price increases that followed the oil price rises and Minerals are naturally occurring and crystalline the specific these brought about extensive exploration programs for chemical composition, structural arrangement of many mineral resources (Danbatta et al., 2008). These component atoms, and physical properties (Olalekan et al., brought to awareness of the importance of mineral 2016). The economic mineral resources are commonly resources led to more rational use, to more widespread used to denote all solid, liquid, or gaseous earth materials recycling of metals, and to the development of new plastic, exploitable for use (Tawey et al., 2020). In economic ceramic and glass materials which substitute for some of practice, mineral resources are generally classified as; the traditional mineral resources (Clark, 2010). building materials, industrial minerals, metallic minerals, and energy resources, all of which could be used for The formation of exploitable mineral deposits is closely construction, industry, agriculture, housing, or transport tied to the overall evolution of the earth's crust and to (Olalekan et al., 2016). geophysical processes down to local geologic processes. The main task of the exploration and mining is to Nigeria as a country have been blessed with many solid understand the ore-forming mineral, and to recognize the mineral resources, but none of these resources have been environments which are favourable to the formation of fully exploited which would enable them to become major mineral deposits (Saleh et al., 2020). contributors to the economy (Ejepu et al., 2018). Much reason is that, the greater attention has been paid to its oil For this study, geophysical technique that is aeromagnetic and gas sector because Nigeria is Africa’s largest oil method was employed in mapping the structures associated producer and crude oil exports (Augie & Sani, 2020). With with the study area. These were achieved by mapping out the vast solid mineral resources existed within the country, major structural trends and geologic contact that controls mining in Nigeria can contribute significantly to our mineralisation potential and also determined the depth to economy (Adetona et al., 2018). These can therefore lead the basement and other intrusive bodies were estimated to numerous employment opportunities and will ultimately within the area. The method measures the variation in the improve long-term community development (Ramadan and magnetic field of the earth materials below the curie depth Abdel Fattah, 2010). that usually produced as the results of remnant and induced For the past 40 years profound changes have taken place in magnetisation compared with the mineralised bodies and world mineral markets, the full extent and effects of which the host rock (Augie and Ologe, 2020). It is capable of can only now be assessed (Danjumma et al., 2019). The delineating/or mapping the crustal deformation that could

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Delineation of Potential Mineral… Savanna Journal of Basic and Applied Sciences

be; alteration/shear zone, fractures and faults system of the within the low latitudes/inclination of magnetic equatorial basement rocks that controls the mineralisation of a zones, where the North to South bodies have undetectable particular area (Adewuni and Salako, 2018). Most near induced magnetic anomaly at zero geomagnetic inclination. surface/subsurface mineralised bodies are associated with These area lies between latitudes 11°30′0″N and these deformation activities, the interpretation of 12°30′0″N, and longitudes 6°30′0″E and 7°0′0″E. These aeromagnetic maps can aid the visualisation of the areas cover; Gusau, Bungudu, Tsafe, southern parts of subsurface geological features which are covered by Kaura Namoda and Birin Magaji/Kiyaw local government overburden that serves as the search of conduits for areas of Zamafara state, and western part of Faskari local of mineralised bodies (Sani et al, 2019). government area of Katsina state (see Fig. 1). This research would contribute significantly in delineating Geologically, the study area falls under Basement complex the zones harbouring mineralisation potential within the of Nigeria which underlain by; granite, migmatite, biotite, study area which could lead to numerous employment gneiss, diorite, medium coarse grained, quartz-mica schist opportunities for teaming population. The study area falls and biotite- homblende granite (see Fig. 2).

Figure 1: Location of the Study Area METHODOLOGY Kaura Namoda and Birin Magaji/Kiyaw. The method The surveys were carried out by Fugro airborne surveys measures the combination of the earth’s main field between 2005 and 2010 sponsored by Federal Government originates the core, and the induced field due to magnetized of Nigeria and the obtained data were then handed to susceptible rocks that usually occurs in the earth’s crust Nigeria Geological Survey Agency (NGSA). The data were combine with the remanent magnetism of the earth acquired under the following high-resolution survey materials. These data were further corrected by removing conditions; Flight direction is NW-SE, Flight line spacing geomagnetic gradient using the International Geomagnetic (500 m), Tie line spacing (2000 m), Terrain clearance (80 Reference Field (IGRF). m) and the Tie line direction is NE-SW. The acquired grid data of Gusau-54 and Tsafe-77 were The acquired aeromagnetic datasets have covered the assembled in order to generate the composite Total following areas Gusau, Bungudu, Tsafe, southern parts of Magnetic Intensity (TMI) map of the study area. These grid

Delineation of Potential Mineral… Savanna Journal of Basic and Applied Sciences

data was further converted in digitized form which nano Tesla). The acquired corrected aeromagnetic dataset comprises of; X (longitude measured in metre), Y (latitude was subjected to the bi-directional gridding method in order measured in metre) and Z (magnetic intensity measured in to produce the combined TMI map of the study area.

Figure 2: Geological Setting of the Study Area (Olugbenga and Augie, 2020).

DATA PROCESSING AND INTERPRETATION regional magnetic field were align horizontally due to most In this study, different processing techniques were adopted of the source magnetizations are horizontal and these has such as; reduction to magnetic equator (RTE), centre for indicated different magnetization of earth’s materials that exploration target (CET), geologic contact and source measure magnetic susceptibility (Fig. 3B). parameter imaging (SPI) in order to processed, enhanced, and interpreted acquired magnetic data. The TMI grid data Having look at the map (Fig. 3B) closely, high and low obtained from NGSA was converted in database and that magnetic zones were characterized in different rock the data was short-up by 33,000 nT which was initially formations that lead to differences in the magnetic remove for convenience of contouring or imaging. susceptibility of the rocks within the area and usually the Therefore, the value (33,000 nT) was added back to give susceptible rocks occur at depths shallower than the curie the TMI grids for the area. The generated core fields points isotherm. The high magnetic zones were associated (DGRF for the epoch period) are subtracted from the grid with the Fe that form various silicates and oxide mineral values of TMI which give rise to the magnetic anomaly as species which may form during the formation of both shown in Fig. 3A. intrusive and extrusive igneous rocks. The regions were For this, the TMI map were subjected to magnetic equator corresponded to; Bungudu, northern and southern parts of in order to produce anomalies of magnetized body that Gusau and Tsafe, and western part of Faskari. The mafic usually depend on the inclination, declination, local earth’s and ultramafic rocks of these zones contain more of Fe- field and orientation of the body with respect to the bearing minerals. magnetic north. The produced RTE magnetic anomaly of

Delineation of Potential Mineral… Savanna Journal of Basic and Applied Sciences

However, Low magnetic zones were associated with of Kaura-Namoda and Birnin Magaji/Kiyaw. And these sediments showing the widest variation in Fe-content regions are of more diamagnetic minerals. within the regions of; central part of Tsafe, southern parts

Figure 3: (A) TMI and (B) RTE Maps of the Study Geologic Contact Centre for Exploration Target (CET) and Source Geologic contact technique was also applied to RTE grid Parameter Imaging (SPI) data anomaly for structural features and boundaries within CET and SPI techniques were also applied to RTE grid data the study area of basement complex and this also help in anomaly for structural features and estimate depth to the detecting the position of the outcrops and intrusive bodies position causative bodies associate with mineralisation in the area. potential. Having a look at Figure 5A closely, the regions Fig. 4A has generates a heat map called geologic contact having lineament (linear structures) were trending South- map that highlights the structural contacts combined with East of the study area. These zones were corresponding to; junctions and intersections of different structures and Birnin Magaji/Kiyaw, eastern part of Bungudu, southern locations where structures have significant orientation part of Gusau, NE part of Tsafe and western part of changes. These locations were agreeing well with the Faskari. rock’s formation from geological setting of the area (Fig. The linear structures found within these areas are 4B) and were corresponds to; Gusau, Bungudu, Tsafe, associated with hydrothermal solutions of the host rocks southern parts of Kaura Namoda and Birin Magaji/Kiyaw that probably form mineral. These types of rocks/structures and western part of Faskari. The kind of rocks forming minerals there are; granite, migmatite, biotite, gneiss, naturally play an important role in solid minerals diorite, medium coarse grained, quartz-mica schist and exploration (Danbatta, 2005). The regions of these biotite- homblende granite. lineaments also highlighted high density of structural contacts combined with junctions and intersections of different structures. And these locations were agreeing well

Delineation of Potential Mineral… Savanna Journal of Basic and Applied Sciences

the results found in Fig. 4A as well as geology of the study zones may extended to deep depths which can allow the area. The kind of structures existed within area are hydrothermal solutions to pass through hosts rocks forming associated with metallic minerals which may include; mineral. The depth at shear/or fractures/ or faults along the quartz, pyrite, diamond, precious metals, gold, iron and the hydrothermal alteration zones consociated with solid steel, alloys, manganese, chromium, vanadium, minerals were delineated as shown in Fig. 6B. These molybdenum, tungsten, nickel, the light metals aluminum, categorized the depth into five; 100 m to 155 m, 156 m to magnesium, titanium etc. 185 m, 185.1 m to 189 m, 198.5 m to 250 m and 251.1 m to However, SPI technique has helped in specifying the depth 475.5 m respectively. The zones between 100 m to 185 m of the boundaries of causative bodies associated with and 185.1 m to 250 m depth corresponds to the regions of minerals. The result from Figure 5B has shown that most of shear/faults/structural trends associated with solid mineral the mineralisation potentials were found below curie which were identified in Birnin Magaji/Kiyaw, eastern part magnetic depth along Birnin Magaji/Kiyaw, eastern part of of Bungudu, southern part of Gusau, NE part of Tsafe and Bungudu, southern part of Gusau, NE part of Tsafe and western part of Faskari of the study area western part of Faskari. The structures existed within the .

Figure 4: (A) Geologic Contact and (B) Geological Setting Maps of the Study Area

RESULTS AND DISCUSSION techniques; IGRF/DGRF computation, RTE, CET, geologic The results obtained from this study were shown in Figures contact and SPI. These techniques have helped the 3, 4 and 5 with the help of the following adopted researcher to identified the regions of different magnetic

Delineation of Potential Mineral… Savanna Journal of Basic and Applied Sciences

zones associated with the Fe-bearing mineral or sediments structures were associated with hydrothermal solutions of with widest variation in Fe-content that form various the host rocks that probably form mineral and the types of silicate and oxide mineral species which may formed rocks/or structures within the zones play an important role during the formation of both intrusive and extrusive in solid minerals exploration. The lineament also igneous rocks. The zones of magnetic anomalous revealed highlighted the structural contacts combined with junctions the presence of granite, migmatite, biotite, gneiss, diorite, and intersections of different structures and have agreeing medium coarse grained, quartz-mica schist and biotite- well the results found in geologic contact as well as homblende granite as compared with geology of the area. geological setting of the study area. The depth of These identified zones of mineralisation were corresponded shear/faults/structural trends associated with solid mineral to Birnin Magaji/Kiyaw, eastern part of Bungudu, southern were found to be; 100 m to 185 m and 185.1 m to 250 m. part of Gusau, NE part of Tsafe and western part of The regions were occupied with granite, migmatite, biotite, Faskari. gneiss, diorite, medium coarse grained, quartz-mica schist The regions having lineament were trending South-East of and biotite- homblende granite (Fig. 2). These rocks type the study area which also corresponding to; Birnin usually allowed the alteration fluids within the regions to Magaji/Kiyaw, eastern part of Bungudu, southern part of effect on the magnetic anomaly. Gusau, NE part of Tsafe and western part of Faskari. These

Figure 5: (A) Lineament and (B) SPI Maps of the Study Area CONCLUSION also revealed the alteration zones (faults, fractures/ or The magnetic technique adopted in this study has revealed shears zones) that usually consociated with vein of bearing the regions that might host mineralisation potential as a mineralization which plays an important role in determine shown in Figures 3 to 5. These zones of mineralisation many minerals. SPI depth map has aided the study in potential were corresponded to the Birnin Magaji/Kiyaw, specified the depth of the boundaries of causative bodies eastern part of Bungudu, a southern part of Gusau, NE part associated with the mineralisation potential to be ranges of Tsafe and a western part of Faskari. These areas have from 100 m to 185 m and 185.1 m to 250 m.

Delineation of Potential Mineral… Savanna Journal of Basic and Applied Sciences

REFERENCES Danbatta, U. A. (2005). Precambrian Crustal Development Adetona, A. A. Salako, K. A. and Rafiu, A. A. (2018). of The Northwestern Part of Zuru Schist Belt, Delineating the Lineaments Within the Major NW Nigeria. A paper presented at the 41st Structures around Eastern Part of lower Benue Annual Conference of Nigerian Mining, and Trough from 2009 Aeromagnetic Data, FUW Geos. Soc. (NMGS). Trends in Science & Technology Journal, 3(1): Ejepu J. S. Unuevho, C. I. Ako, T. A. and Abdullahi S. 175–179 e-ISSN: 24085162; p-ISSN: 20485170. (2018). Integrated Geosciences Prospecting for Adewumi, T. and Salako, K.A. (2018). Delineation of Gold Mineralization in Kwakuti, North-Central Mineral Potential Zone using High Resolution Nigeria, Journal of Geology and Mining, Vol. Aeromagnetic Data over Part of Nasarawa State, 10(7), pp. 81-94, DOI: 10.5897/JGMR2018.0296. North Central, Nigeria, Egyptian Journal of Olalekan, O., Afees, O. and Ayodele, S. (2016). An Petroleum, Empirical Analysis of the Contribution of Mining https://doi.org/10.1016/j.ejpe.2017.11.002 Sector to Economic Development in Nigeria. Augie, A.I. and Ologe, O. (2020). Analysis of Khazar Journal of Humanities and Social Aeromagnetic Data for Coal Deposit Potential Sciences, 19(1), 88–106. over Birnin Kebbi and its Environs Northwestern Olugbenga, T. T. and Augie, A. I. (2020). Estimation of Nigeria, Nigerian Journal of Science and Crustal Thickness within the Sokoto Basin North- Environment, 18 (1): 145 – 153. Western Nigeria Using Bouguer Gravity Augie, A.I. and Sani A.A. (2020). Interpretation of Anomaly Data, WASET, International Journal of Aeromagnetic Data for Gold Mineralisation Geological and Environmental Engineering, Potential over Kabo and its Environs NW 14(9): 247–252. Nigeria, Savanna Journal of Basic and Applied Ramadan, T. M. and Abdel Fattah, M. F. (2010). Sciences, 2 (2): 116-123. Characterization of Gold Mineralization in Garin Clark, D. (2010). Magnetic Petrophysics and Magnetic Hawal area, Kebbi State, NW Nigeria, using Petrology; Aids to Geologic Interpretation of Remote Sensing. Egyptian Journal of Remote Magnetic Surveys, Australia Geological Survey Sensing and Space Science, 13(2): 153–163. Organization, Journal of Austrian Geology & https://doi.org/10.1016/j.ejrs.2009.08.001 Geophysics, 36(2):120–137 Saleh, A. Qudus, B. Magawata, U.Z. and Augie, A.I. Danjumma, S. G. Bonde, D.S. Mohammed, A. Lawali, S. (2020). Delineation of Structural Features and Amina, M. B. T. (2019). Identification of Mineral Depth to the Magnetic Sources over Allawa and Deposits in Garin Awwal Mining Site, Kebbi its Environs, Northcentral Nigeria, International State, North-Western Nigeria, Journal of Journal of Advances in Engineering and Multidisciplinary Engineering Science and Management (IJAEM), 2(6): 545-553, ISSN: Technology (JMEST), Vol. 6, Issue 6, pp. 10276- 2395-5252. 10280, ISSN: 2458-9403 Sani, A.A. Augie, A.I. and Aku, M.O. (2019): Analysis of Danbatta, U.A. Abubakar, Y. I. and Ibrahim A. A. (2008). Gold Mineral Potentials in Anka Schist Belt Geochemistry of Gold Deposits in Anka Schist North Western Nigeria using Aeromagnetic Data Belt, Northwestern, Nigeria, Nigerian Journal of Interpretation, Journal of the Nigerian Chemical Research, .13: 19-29. Association of Mathematical Physics, 52: 291- 298. Tawey, M. D. Alhassan, D. U. Adetona, A. A. Salako, K. A. Rafiu, A. A. and Udensi, E. E. (2020). Application of Aeromagnetic Data to Assess the Structures and Solid Mineral Potentials in Part of North Central Nigeria, Journal of Geography, Environment and Earth Science International, 24(5): 11-29, ISSN: 2454-7352.