Geochemistry of basement granitic rocks from northcentral Nigeria

Onyeagocha, A.C.

doi:10.1016/0899-5362(86)90032-1

Cited by 10 publications

(10 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The granitic rocks show high degree of fractionation with steep patterns, especially the Light Rare-Earth Elements (LREE) (La to Sm) fractionation relative to Heavy Rare-Earth Elements (HREE) (Gd to Lu) which exhibit varying degree of depletion in the area. [19,21]. The abundances and distribution patterns of the Rare-Earth Elements (REE) of the granitic rocks of the study area compare very closely with the fine-grained granite and granite gneiss of Ado-Ekiti-Akure region, southwestern Nigeria [22] which is typical of the crust and also of calc-alkaline rocks.…”

Section: Rare Earth Elements Geochemistrymentioning

confidence: 90%

Petrogenesis and Geotectonic Settings of the Granitic Rocks of Idofin-osi-eruku Area, Southwestern Nigeria using Trace Element and Rare Earth Element Geochemistry

Odewumi¹,

Olarewaju²

2013

J Geol Geosci

View full text Add to dashboard Cite

The Idofin-Osi-Eruku area occurs in the southeastern margin of the southwestern sector of the Nigerian Basement Complex. Granitic rocks and early gneiss samples were studied geologically and geochemically using ICP-MS. The study focuses on the trace elements and rare earth elements geochemistry in determining the geochemical characteristics and geotectonic processes of formation of the granitic rocks. Geologically, Idofin-Osi-Eruku area is underlain by early gneiss, quartzite and marble which have been intruded by granite gneiss, porphyritic granite and fine to medium-grained granite of probable Pan-African (ca. 600Ma) age. Geochemical data indicate that the granitic rocks are Fe-rich potassic granites. The varying ratios of the incompatible elements of Rb/Sr ratios (0.664-1.388) in porphyritic granite, (0.338-2.390) in the fine to medium-grained granite and (0.593-1.509) in granite gneiss are higher than Rb/Sr ratio (0.029) in the early gneiss. Also, Ba/Sr ratios (2.815-5.424) in porphyritic granite, (3.463-4.636) in fine to-medium grained granite and (2.132-4.734) in granite gneiss are higher than Ba/Sr ratio (0.912) in the early gneiss. And Ba/Rb ratios (2.486-6.192) in porphyritic granite, (1.473-1.520) in the fine to-medium grained granite and (3.183-3.595) in the granite gneiss are lower than Ba/Rb ratio (31.02) in the early gneiss. Higher ratios of Rb/Sr and Ba/Sr, and lower ratio of Ba/Rb in the granitic rocks than the early gneiss indicate high fractionation associated with magmatic differentiation. The granite rocks have fractionated Rare-Earth Elements (REE) patterns characterized by enrichment in the Light Rare-Earth Elements (LREE) which is confirmed by high values of the normalized ratios of La/Yb, Ce/Yb and La/Sm, with negative europium anomalies and varying degrees of Heavy Rare-Earth Elements (HREE) depletion which is typical of the crust and also of calc-alkaline rocks. Based on the overall abundances of Rare-Earth Elements (REE), the similarities in the Rare-Earth Elements (REE) patterns of the granitic rocks suggest the same origin. Geotectonically, the granite gneiss, fine to medium-grained granite and porphyritic granite plot as syncollisional and volcanic arc granites. The granitic rocks are products of volcanic arc magmatism emplaced in the late phase of the Pan-African Orogeny.

show abstract

Section: Rare Earth Elements Geochemistrymentioning

confidence: 90%

Petrogenesis and Geotectonic Settings of the Granitic Rocks of Idofin-osi-eruku Area, Southwestern Nigeria using Trace Element and Rare Earth Element Geochemistry

Odewumi¹,

Olarewaju²

2013

J Geol Geosci

View full text Add to dashboard Cite

show abstract

“…The gneisses of the Obudu area have a high SiO 2 content (53-66 wt.%), similar to gneisses in the Oban Massif located south of Obudu (Ekwere and Ekwueme, 1991). The CaO content of some gneisses is higher than values of 1.48-2.08 wt.% as reported for the Akwanga granite gneisses in northcentral Nigeria (Onyeagocha, 1986) but similar to gneisses in the Oban Massif and those in Ilesha, southwestern Nigeria (Elueze, 1982). Al 2 O 3 ranges from 14 to 18 wt.%, and the occurrence of sillimanite in the garnet-sillimanite gneiss is a reflection of the peraluminous nature of the protolith.…”

Section: Geochemistrymentioning

confidence: 57%

Single zircon ages of migmatitic gneisses and granulites in the Obudu Plateau: Timing of granulite-facies metamorphism in southeastern Nigeria

Ekwueme

Kröner

2006

Journal of African Earth Sciences

View full text Add to dashboard Cite

“…5a-i). Computations and plots of the same variables proposed by Frost et al (2001) using the data on granitic rocks from the other parts of the Precambrian basement complex of Nigeria obtained from published work (Egbuniwe et al, 1985;Onyeagocha, 1986;Olarewaju, 1987;Rahman et al, 1988) show that the rocks are also generally magnesian. Unlike the rocks in this study, they are mostly alkali-calcic and metaluminous; it is only the granitoids in the work of Rahman et.…”

Section: Resultsmentioning

confidence: 95%

“…1), and may have culminated in a collision between this active margin and the passive continental margin of the West African craton, at about 600 Ma. It is a popular view by most workers in the Precambrian basement complex in Nigeria that the basement granitic rocks are products of anatectic melting of the highest grades of amphibolite facies regional metamorphism of the surrounding schists and gneisses (Onyeagocha, 1984(Onyeagocha, , 1986Rahman et al, 1988). The rocks later suffered K-metasomatism which led to the widespread occurrence of large porphyroblasts of K-feldspars in the granitic rocks (Rahaman, 1976b;Rahman et al, 1988).…”

Section: Discussionmentioning

confidence: 96%

Petrology and geochemical characteristics of Precambrian granitic basement complex rocks in the southernmost part of North-Central Nigeria

Obiora

Ukaegbu

2009

Chin. J. Geochem.

View full text Add to dashboard Cite

The Precambrian basement complex in the southernmost part of North-Central Nigeria is underlain by migmatitic banded gneisses, granitic intrusions and dykes of dolerite, rhyolite porphyry and pegmatite. The rocks are generally felsic, containing modal and normative hypersthene, as well as normative corundum. The basement complex has experienced high-grade regional metamorphism as indicated by the presence of hypersthene and plagioclase of andesine composition. Anatectic melting is suggested by the occurrence of ptygmatic folds, folded gneissose foliation, numerous quartzo-feldspathic veins and lenses of dark-colured, micaceous schistose rocks. Geochemically, the rocks have magnesian, calc-alkalic and strongly peraluminous characteristics. Their overall characteristics suggest derivation from progressive (fractional) partial melting of pelitic rocks during high-grade regional metamorphism, possibly associated with intense hydrothermal activities. The magnesian characteristics reflect close affinity to relatively hydrous, oxidizing melts and source regions in settings broadly related to subduction.

show abstract

Geochemistry of basement granitic rocks from northcentral Nigeria

Cited by 10 publications

References 7 publications

Petrogenesis and Geotectonic Settings of the Granitic Rocks of Idofin-osi-eruku Area, Southwestern Nigeria using Trace Element and Rare Earth Element Geochemistry

Petrogenesis and Geotectonic Settings of the Granitic Rocks of Idofin-osi-eruku Area, Southwestern Nigeria using Trace Element and Rare Earth Element Geochemistry

Single zircon ages of migmatitic gneisses and granulites in the Obudu Plateau: Timing of granulite-facies metamorphism in southeastern Nigeria

Petrology and geochemical characteristics of Precambrian granitic basement complex rocks in the southernmost part of North-Central Nigeria

Contact Info

Product

Resources

About