Field and Petrographic Relationships between the Charnockitic and Associated Granitic Rock, Akure Area, Southwestern Nigeria
The charnockitic and associated granitic rocks of Akure area were studied for their field and petrographic relationship's. The outcrops locations were plotted in Surfer 8. The granitic rock exhibits a porphyritic texture and outcrops in the north-eastern side of the study area while the charnockitics outcrop in the central/western part. An essentially dark coloured and fine grained intrusive exhibiting xenoliths and xenocrysts (plagioclase phenocrysts) of the granite outcrops between the granitic and charnockitic rocks. Mineralogically, the central rock combines the content of the other two indicating that it is most likely a product of their hybridization. The charnockitic magma is believed to have intruded and assimilated the granite substantially thereby contaminating itself and consequently emplacing the hybrid. The presented model of emplacement elucidates the hybridization proposal. Conclusively, the charnockitics are believed to be (a) younger than the granite, (b) of Pan-African age and (c) of igneous origin.
[1] J.A. Kilpatrick, and D.J. Ellis, "C-type magmas: igneous charnockites
and their extrusive equivalents". Proc. 2nd Hutton Symposium on the
Origin of Granites and Related Rocks. Brown, P. E. and Chappell, B.
W., (editors), Trans. Roy. Soc. Edinburgh, Earth Sciences, 83 parts 1-2,
507, pp. 155-164, 1992.
[2] M. O. Oyawoye, "The petrology of the district around Bauchi, Northern
Nigeria". Journ. Geology 70, 1962, pp. 604-615.
[3] M. O. Oyawoye, "The contact relationship of charnockite and biotite
gneiss at Bauchi, Northern Nigeria". Geol. Mag. 10, No. 2, 1964, pp
138-144.
[4] V.O. Olarewaju, "Petrology and geochemistry of the charnockitic and
associated granitic rocks of Ado-Ekiti, Akure, S.W. Nigeria". In:
Precam. Geol. Nig. Pp 231-239. Geological Survey of Nigeria
Publication, 1988.
[5] M. A. Rahaman, T. R. Ajayi, I. O. Oshin, and F. O. I. Asubiojo, "Trace
element geochemistry and geotechnic setting of Ife-Ilesha schist belt".
In: Oluyide, P.O., Mbonu, W.C., Ogezi, A.E., Egbuniwe, I.G., Ajibade,
A.C., Umeji, A.C (Eds.) Precambrian Geology of Nigeria. Geological
Survey of Nigeria, Publication, pp 241-256, 1988.
[6] S.S. Dada, J.R. Lancelot, and Briqueu, "Age and origin of the annular
charnockitic complex at Toro, Northern Nigeria: U-Pb and Rb-Sr
evidence". Journal of African Earth Sciences, Vol. 9, Issue 2, 1989, pp
227-234.
[7] V. O. Olarewaju, "The charnockitic intrusive of Nigeria". In: Oshin, O.
(Ed.), The Basement Complex of Nigeria and its Mineral Resources.
Akin Jinad & co, Ibadan, Nigeria, 2006, Pp 45-70.
[8] J.A. Adekoya, O.O. Kehinde-Phillips, and A.M. Odukoya, "Geological
distribution of mineral resources in southwest Nigeria". In: A. A. Elueze
(Ed.) Prospects for investment in mineral resources of southwestern
Nigeria, 2003, pp 1-13.
[9] M. A. Rahaman, "A review of the basement geology of southwestern
Nigeria". In: Kogbe, C. A., (Ed.), Geology of Nigeria. Lagos:
Elizabethan Publ. Co., 1976, pp 4-58.
[10] V.O. Olarewaju, "Charnockite-Granite Association in S.W. Nigeria:
Rapakivi granite type and charnockitic plutonism in Nigeria". J. Afri.
Earth Sci., 6, No. 1, 1987, pp 67-77.
[11] F.H. Hubbard, "Precambrian crustal development in Western Nigeria:
Indication from the Iwo region". Geol. Soc. Amer. Bull., vol. 86, 1975,
pp. 548-554.
[12] K.A. Shitta, "Lithostratigraphy of Nigeria: An overview". Proceedings
of 32nd Workshop on Geothermal Reservoir Engineering, Stanford
University, Stanford, California, pp: 18-23, Jan. 22-24, 2007.
[13] A. O. Oyinloye, and R. Obasi, "Geology, geochemistry and geotectonic
setting of the Pan-African granites and charnockites around Ado-Ekiti,
Southwestern Nigeria". Pakistan Journal of Scientific and Industrial
Research, vol. 49, no.5, 2006, pp. 299-308.
[14] O.A. Ademeso, "Deformation traits in the charnockitic rocks of Akure
area, Southwestern Nigeria". Asian Journal of Earth Sciences 2(4),
2009, pp 113-120.
[15] ImageJ, "Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
California 95054, U.S.A.", known as "ImageJ" version 1.40c, 2008.
[16] V.O. Olarewaju, "Fluid inclusion studies of coarse-grained charnockitic
and the hybrid rocks in Ukpilla area, southwestern Nigeria". Journ. Min.
Geol., 35(1), 1999, pp1-7.
[17] I.B. Odeyemi, "A review of the orogenic events in the Precambrian
basement of Nigeria, West Africa". Geologische Rundschau Vol. 70
No.3, 1981, Pp 897-909.
[18] I.B. Odeyemi, "Lithostratigraphy and structural relationship of the
Upper Precambrian metasediments in Igarra area, South-Western
Nigeria". Precambrian Geology of Nigeria, Geological Survey of
Nigeria. Kaduna, Nigeria, 1988, pp111-125.
[19] I.A. Tubosun, J.R. Lancelot, M.A. Rahaman, and O.O. Ocan, "U-Pb
Pan-African ages of two charnockite-granite". Contrib. Mineral Petrol,
88, 1984, pp188-195.
[1] J.A. Kilpatrick, and D.J. Ellis, "C-type magmas: igneous charnockites
and their extrusive equivalents". Proc. 2nd Hutton Symposium on the
Origin of Granites and Related Rocks. Brown, P. E. and Chappell, B.
W., (editors), Trans. Roy. Soc. Edinburgh, Earth Sciences, 83 parts 1-2,
507, pp. 155-164, 1992.
[2] M. O. Oyawoye, "The petrology of the district around Bauchi, Northern
Nigeria". Journ. Geology 70, 1962, pp. 604-615.
[3] M. O. Oyawoye, "The contact relationship of charnockite and biotite
gneiss at Bauchi, Northern Nigeria". Geol. Mag. 10, No. 2, 1964, pp
138-144.
[4] V.O. Olarewaju, "Petrology and geochemistry of the charnockitic and
associated granitic rocks of Ado-Ekiti, Akure, S.W. Nigeria". In:
Precam. Geol. Nig. Pp 231-239. Geological Survey of Nigeria
Publication, 1988.
[5] M. A. Rahaman, T. R. Ajayi, I. O. Oshin, and F. O. I. Asubiojo, "Trace
element geochemistry and geotechnic setting of Ife-Ilesha schist belt".
In: Oluyide, P.O., Mbonu, W.C., Ogezi, A.E., Egbuniwe, I.G., Ajibade,
A.C., Umeji, A.C (Eds.) Precambrian Geology of Nigeria. Geological
Survey of Nigeria, Publication, pp 241-256, 1988.
[6] S.S. Dada, J.R. Lancelot, and Briqueu, "Age and origin of the annular
charnockitic complex at Toro, Northern Nigeria: U-Pb and Rb-Sr
evidence". Journal of African Earth Sciences, Vol. 9, Issue 2, 1989, pp
227-234.
[7] V. O. Olarewaju, "The charnockitic intrusive of Nigeria". In: Oshin, O.
(Ed.), The Basement Complex of Nigeria and its Mineral Resources.
Akin Jinad & co, Ibadan, Nigeria, 2006, Pp 45-70.
[8] J.A. Adekoya, O.O. Kehinde-Phillips, and A.M. Odukoya, "Geological
distribution of mineral resources in southwest Nigeria". In: A. A. Elueze
(Ed.) Prospects for investment in mineral resources of southwestern
Nigeria, 2003, pp 1-13.
[9] M. A. Rahaman, "A review of the basement geology of southwestern
Nigeria". In: Kogbe, C. A., (Ed.), Geology of Nigeria. Lagos:
Elizabethan Publ. Co., 1976, pp 4-58.
[10] V.O. Olarewaju, "Charnockite-Granite Association in S.W. Nigeria:
Rapakivi granite type and charnockitic plutonism in Nigeria". J. Afri.
Earth Sci., 6, No. 1, 1987, pp 67-77.
[11] F.H. Hubbard, "Precambrian crustal development in Western Nigeria:
Indication from the Iwo region". Geol. Soc. Amer. Bull., vol. 86, 1975,
pp. 548-554.
[12] K.A. Shitta, "Lithostratigraphy of Nigeria: An overview". Proceedings
of 32nd Workshop on Geothermal Reservoir Engineering, Stanford
University, Stanford, California, pp: 18-23, Jan. 22-24, 2007.
[13] A. O. Oyinloye, and R. Obasi, "Geology, geochemistry and geotectonic
setting of the Pan-African granites and charnockites around Ado-Ekiti,
Southwestern Nigeria". Pakistan Journal of Scientific and Industrial
Research, vol. 49, no.5, 2006, pp. 299-308.
[14] O.A. Ademeso, "Deformation traits in the charnockitic rocks of Akure
area, Southwestern Nigeria". Asian Journal of Earth Sciences 2(4),
2009, pp 113-120.
[15] ImageJ, "Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
California 95054, U.S.A.", known as "ImageJ" version 1.40c, 2008.
[16] V.O. Olarewaju, "Fluid inclusion studies of coarse-grained charnockitic
and the hybrid rocks in Ukpilla area, southwestern Nigeria". Journ. Min.
Geol., 35(1), 1999, pp1-7.
[17] I.B. Odeyemi, "A review of the orogenic events in the Precambrian
basement of Nigeria, West Africa". Geologische Rundschau Vol. 70
No.3, 1981, Pp 897-909.
[18] I.B. Odeyemi, "Lithostratigraphy and structural relationship of the
Upper Precambrian metasediments in Igarra area, South-Western
Nigeria". Precambrian Geology of Nigeria, Geological Survey of
Nigeria. Kaduna, Nigeria, 1988, pp111-125.
[19] I.A. Tubosun, J.R. Lancelot, M.A. Rahaman, and O.O. Ocan, "U-Pb
Pan-African ages of two charnockite-granite". Contrib. Mineral Petrol,
88, 1984, pp188-195.
@article{"International Journal of Earth, Energy and Environmental Sciences:61088", author = "Ademeso and Odunyemi Anthony", title = "Field and Petrographic Relationships between the Charnockitic and Associated Granitic Rock, Akure Area, Southwestern Nigeria", abstract = "The charnockitic and associated granitic rocks of Akure area were studied for their field and petrographic relationship's. The outcrops locations were plotted in Surfer 8. The granitic rock exhibits a porphyritic texture and outcrops in the north-eastern side of the study area while the charnockitics outcrop in the central/western part. An essentially dark coloured and fine grained intrusive exhibiting xenoliths and xenocrysts (plagioclase phenocrysts) of the granite outcrops between the granitic and charnockitic rocks. Mineralogically, the central rock combines the content of the other two indicating that it is most likely a product of their hybridization. The charnockitic magma is believed to have intruded and assimilated the granite substantially thereby contaminating itself and consequently emplacing the hybrid. The presented model of emplacement elucidates the hybridization proposal. Conclusively, the charnockitics are believed to be (a) younger than the granite, (b) of Pan-African age and (c) of igneous origin.
", keywords = "Charnockitic rock, Hybrid rock, ImageJ, Xenocryst", volume = "4", number = "11", pages = "602-5", }
