scholarly journals Petrological characteristics of some cretaceous igneous rocks, in Southwest of Gboko, Southern Benue Trough, Nigeria

2020 ◽  
Vol 12 (2) ◽  
pp. 35-44
Author(s):  
Chigozie Ani Emmanuel ◽  
Andrew Oha Ifeanyi
Keyword(s):  
Author(s):  
Josephine N. Onwualu-John ◽  
J. I. Nwosu

Some part of the Southern Benue Trough (Afikpo and Anambra Basins) has been mapped to determine the areas of occurrence of industrial minerals and to determine their lateral extent. The result shows that Southern Benue Trough is enriched with mostly industrial minerals of sedimentary and magmatic origin. The magmatism that occurred in the study area and its evolutionary processes led to mineralization of the study area. Interaction of the magma with host rocks gave rise to mineral genesis. The contamination and assimilation processes that occurred in the magmatic stage resulted to enrichment of minerals in the study area. The contact relationship of the magma with the host rock created a contact aureole though the resultant minerals (metamorphic minerals) of the contact aureole are not significant and exposed. The repetitive transgressive-regressive sedimentary cycle that occurred in the Southern Benue Trough probably resulted to the massive deposition of industrial minerals of sedimentary origin. The dominant and significant industrial minerals in Afikpo and Anambra Basins are sandstones (ferruginized sandstone, calcareous sandstones and carbonaceous sandstones), clay mineral (kaolinite), pebbles, igneous rocks of diverse levels of emplacement (intrusive/ extrusive), olivine , hematite, Feldspar, mica and quartz.


Author(s):  
I. Nwachukwu ◽  
V. U. Ukaebgu ◽  
N. Egesi

Some health implications of structurally-controlled igneous intrusions in Ishiagu area of southern Benue Trough were studied using the field investigations, trace element geochemistry and geostatistical studies of some of the igneous rocks, the surrounding water and edible vegetables. Results of the study revealed that the average concentrations of these trace metals in the igneous rocks decreased from Mn to Mg as follows: Mn (1431 ppm), Sr (419.5 ppm), Ba (58.11 ppm), Cu (45.63 ppm), Pb (5.48 ppm), As (1.20 ppm), Mo (3.270 ppm), Cd (0.960 ppm) and Mg (0.940 ppm); in water decreased from Mg to Cd as follows: Mg (5.840 mg/l), Sr (1.270 mg/l), Fe (0.3 mg/l), Mo (.013 mg/l), Mn (0.002 mg/l), Ni (0.001 mg/l), As (0.0004 mg/l), Ni (0.001 mg/l), Co (0.0001 mg/l), and Cd (0.0001 mg/l), while in the edible vegetables trace elements decreased from Fe-Ni as follows: Fe (8540 mg/kg), Mg (4085 mg/kg), Al (2352.1 mg/kg), Pb (360.76 mg/kg), Sr (182 mg/kg), Zn (53.38 mg/kg), Ba (46.3 mg/kg) Cu (21.75 mg/kg), Mo (8.97 mg/kg) and Ni (4.92 mg/kg). Geostatistical analysis of the edible vegetables indicates that the bioaccumulation factor of the vegetation with respect to the rock decreased from Pb to Ni as follows: Pb> Mo >Cd >As> Fe > Cr > Cu > Zn>Sr>Mg>Ni. The concentrations of Fe, Ni, Cu, Cr, Mn, Cd, Pb and Zn in water and edible vegetables are higher than the permissible levels recommended by World Health Organization. Thus, the inhabitants of the study area are at risk of myocardial infarction, insulin alteration, anemia, neurodegenerative conditions in humans, renal dysfunction, metal fumes fever, hair and skin discoloration, respiratory tract diseases, carcinogenic diseases, kidney disease, fanconi syndrome, lipid peroxidation of the heart, liver and spleen, hypertension, anemia, colic, headache, brain damage and central nervous system disorder, kidney disease, neurotoxin, lipid peroxidation in the heart, liver and spleen, fanconi syndrome, oesteomalacia, renal dysfunction, learning disabilities and hyperactivity, loss of vision, heart and liver failures, skin irritation, hazardous effects on lungs and brains. The outcome of this study has provided a data base for intervention endeavors for health practitioners to comprehensively monitor and control health issues arising from geologic and mining processes in Ishiagu area of Ebonyi State. The area is in dire need of standard medical facilities, which will, among other things, offer medical aids, document such health matters and keep surveillance so as to detect impact of the trace metals on  the health of the inhabitants of the study area.


2020 ◽  
Vol 22 ◽  
pp. 25-28
Author(s):  
Prakash Luitel ◽  
Suman Panthee

The section between Tal to Talekhu of Manang District lacks the detailed geological study. The geological mapping in the scale of 1:50,000 followed by the preparation of geological cross-section and lithostratigraphic column has been done in the present study. The studied area lies partially in the Higher Himalayan Crystalline and the Tibetan Tethys Sequence. The units of the Higher Himalayan Group from Tal to Talekhu consists mainly of vigorous to faintly calcareous gneiss, migmatitic gneiss, quartzite, granite, etc. They are named as the Calc. Silicate Gneiss and Paragneiss and the Orthogneiss and Granite units. The lowermost part of the Tibetan Tethys consisted of metamorphosed calcareous rocks containing silicates and feldspar, so this unit is termed as the Marble and Calc. Gneiss. The section is about 9 km in thickness and is highly deformed with presence of igneous rocks at many places.


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