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Open Journal of Geology, 2018, 8, 1043-1055 http://www.scirp.org/journal/ojg
ISSN Online: 2161-7589 ISSN Print: 2161-7570
The Uranium Prospects in Mika Region, Northeastern Nigeria
Hinyuen Tsang1, Shamim Akhtar1,2*, Saif-ur-Rehman2, Qifan Wu3, Insung Lee4, Nosheen Sahir5, Xiaoyong Yang1
1School of Earth and Space Sciences, University of Science and Technology of China, Hefei, China 2Department of Earth Sciences, University of Sargodha, Sargodha, Pakistan 3Department of Engineering Physics of Tsinghua University, Beijing 4School of Earth and Environmental Sciences, Seoul National University, Seoul, Korea 5Department of Earth and environment Sciences, Bahria University, Islamabad, Pakistan
Abstract Uranium exploration especially in currently non-producing countries like Nigeria possesses high economic prospect. This study investigates a new ura- nium prospect in Mika, Northeastern Nigeria. The Mika uranium mineraliza- tion is located in Mika, Taraba State. Two lodes were identified and addition- al nine (9) trenches were added. The main lode in the west extends about 10 m, ore vein strikes 348˚, inclination 42˚ and the strike of the lode 306˚ with average uranium content of 18%. The eastern trench is about 8 × 4 × 6 m which exposes a veinlet of pitchblende. From the petrography, one can de- duce that the granitic host rock has suffered deformation resulting in crush- ing of quartz crystals and stretching of plagioclase. The uraninite and chalce- dony in the late phase filled up the fractures along the crystal grain bounda- ries as veinlets. The laboratory gamma ray analysis of the samples showed that the secondary uranium content is 0.1%, while the primary uranium ore grade is 1.5%. Radiometric in situ measurements showed that Th and K ranges from 47.3 - 3654 ppm and 4.26% - 6.26% respectively. From the survey, a strong radiometric zone extends 800 × 35 m in a NW-SE direction and has highest radiation content of 1200 cpm against the background count rate of 30 cpm. Generally, the uranium concentrations in the ores in Mika area range from 0.03% - 0.12%. Since only the surface occurrences have been explored, the study area is a good prospect for future development when properly ex- plored. The North-eastern Nigeria has been roughly explored by Nigeria Ura- nium Mining Company (NUMCO) in 1980, but no formal exploration had been followed after that, especially near the site of this article. The company
How to cite this paper: Tsang, H., Akhtar, S., Saif-ur-Rehman, Wu, Q.F., Lee, I., Sahir, N. and Yang, X.Y. (2018) The Uranium Prospects in Mika Region, Northeastern Nigeria. Open Journal of Geology, 8, 1043-1055. https://doi.org/10.4236/ojg.2018.811063 Received: September 11, 2018 Accepted: October 7, 2018 Published: October 10, 2018 Copyright © 2018 by authors and Scientific Research Publishing Inc. This work is licensed under the Creative Commons Attribution International License (CC BY 4.0). http://creativecommons.org/licenses/by/4.0/
DOI: 10.4236/ojg.2018.811063 Oct. 10, 2018 1043 Open Journal of Geology
http://www.scirp.org/journal/ojg https://doi.org/10.4236/ojg.2018.811063 http://www.scirp.org https://doi.org/10.4236/ojg.2018.811063 http://creativecommons.org/licenses/by/4.0/
H. Tsang et al.
(ACE Mines, Ltd) of the first author was among the few uranium mining companies approved in the list of Nigerian Geological Survey agency of Abuja in Nigeria. The authors determined the coordinates of the site in their first survey which formed the prospect area in the licence.
Keywords Uranium Exploration, Uranium Mineralization, Radiometric Zone Mika Area, Nigeria
Uranium has become a prominent energy resource in many countries as the principal fuel for nuclear power plants . It has been projected that the cumu- lative aggregate world uranium requirements far outweigh production capacity from the existing and planned centers. To balance such demand on a worldwide basis; enormous additional mining centers are needed. In the long term, new occurrences must be prospected and explored for production. This forecast should lead to a renewed interest in uranium exploration especially in currently non-producing countries like Nigeria with high future energy demand.
Uranium occurrences in Nigeria are found in sedimentary sequences and de- formed granitic basement rocks. Although most of these occurrences are small and scattered, the major occurrences are the Ghumchi, Kanawa and Mika pros- pects in granitic rocks; and the Zona and Dali occurrences in the Bima Sand- stone. These prospects are restricted to northeastern Nigeria and were all dis- covered by Nigeria Uranium Mining Company (NUMCO). Prior to their dis- covery, efforts in uranium exploration in Nigeria were concentrated towards the Younger Granite Province in the North Central Nigeria. These include the Ri- ruwai ring complex and Kigom hills where pyrochlore disseminations were re- ported but where no significant prospect was discovered .
This article is a summary of several investigations conducted by the survey teams organized by “AlanCrawley Enterprises, Ltd” which later on formed a lo- cal subsidiary company (ACE Mines, Ltd) and owned the exploration rights of the target site in the Mika area.
2. Regional Geology
The oldest rocks in the region comprise migmatites and pre- to synkinematic- granitoids (Table 1) with emplacement ages ranging from 680 to 620 Ma. This basement was intruded by orogenic granites , post kinematic granitoids with emplacement ages ranging from 620 to 590 Ma.
Mesozoic magmatism has been described by  giving ages of 147 ± 7 Ma and 103 ± 5 Ma respectively. The initial magmatic activity was bimodal in nature, consisting of alkaline rhyolites (Burashika) and transitional alkaline basalts (Shani). The second involved transitional alkaline basalts and tholeiitic basalts.
DOI: 10.4236/ojg.2018.811063 1044 Open Journal of Geology
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Table 1. Summary of the regional geology of NE Nigeria.
Pleistocene Deposition of Chad Formation
Late Tertiary to Quartenary
Basalt (Biu and Longuda Plateux), trachyte and phonolite
Paleocene Uncomformable deposition of Keri Keri Formation
Maastrichtian Deposition of Dukul, Pindiga, Jessu
Lower Turonian to Campanian
Gongila Formation (marine beds of clays, shales limestone)
Albian Yolde Formation ( with calcareous units) Bima Sandstone deposition
Mesozoic 147 ± 7 Ma
(103 ± 5 Ma) Alkaline rhyolites (Burashika) and transitional alkaline basalts (Shani)
620 - 590 Ma Post-kinematic emplacement of granitoids (biotite, biotite-muscovite granites and pegmatites)
680 - 620 Ma Migmatite and ante to synkinematicgranitoids (granite gneiss)
Deposition of sedimentary succession
The host rock of the region is part of the Pan-African basement complex and consists mainly of medium grained granite which is, in places, intruded by rhyo- lites and siliceous veins. Regional Geology of NE Nigeria is also summarized in Table 1.
There is no record of sedimentation in the long interval between Precambrian and late Mesozoic times. The oldest sedimentary rocks are thick and widespread series of continental grits, sandstones and clays of the Bima Sandstone. The Bi- ma Sandstone is subdivided into three main siliciclastic members, the lower, middle and upper members . Transgression of the sea in Middle Cenomanian led to deposition of the Yolde Formation . A widespread, shallow marine transgression occurred during Lower Turonian times, as evidenced by marine beds of clays, shales and limestones of the Dukul, Pindiga, Jessu and Gongila Formations. Marine conditions persisted until the Maastrichtian and were ac- companied in the south by localized volcanic activity  . Over the northern and central areas marine conditions gave way to deltaic and estuarine environ- ments in which the Gombe Sandstone was deposited. This was followed by a pe- riod of folding which resulted in the development of major anticlinal structures affecting the whole sedimentary succession . A younger sequence of conti- nental deposits, the Keri-Keri Formation was laid down in the Paleocene  . The continental sedimentation was followed by a period of extensive laterite formation overlying the Keri Keri Formation. During the late Tertiary and Qua- ternary, widespread volcanic activity occurred in the southern and central areas giving rise to Biu and Longuda Plateaux and small volcanic plugs were intruded over the area in the age range from 7 Ma to 1 Ma .
The regional structural patterns are dominated by a series of large NE-SW trending faults and folds, parallel to the Benue Trough. Folding and strike slip
DOI: 10.4236/ojg.2018.811063 1045 Open Journal of Geology
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faulting results from a horizontal regional compression acting in a N160˚E mean direction which is related to Late Cretaceous compressive tectonic phase by  . The basement rocks display many joints, fractures and faults. The most do- minants are the faulted boundary between the Basement and the Early Creta- ceous sedimentary basins which follow N110˚ - N120˚ (Chad) trend and N60˚ - N70˚ (Benue) trend . There is the NS dominant structural trend of both folia- tion and joint directions and its extensi