Matches in SemOpenAlex for { <https://semopenalex.org/work/W2074389230> ?p ?o ?g. }
Showing items 1 to 45 of
45
with 100 items per page.
- W2074389230 abstract "The basement complex, located at the south-eastern borders of Ogoja town in the south-eastern part of Nigeria, consists of two varieties of migmatitic gneisses, namely banded and augen gneisses, which, in some cases, are inter-layered with amphibolite. Many concordant to discordant quartzofeldspathic veins in these gneisses are related to granitoid rocks, namely porphyritic granites, coarse-grained leucogranite, aplitic granite, and granodiorite. The occurrence of plagioclase (An35-44), hornblende, almandine garnet and staurolite in the gneisses is an evidence of metamorphic conditions of the amphibolite facies grade. Mineral constituents and major element oxide data indicate that the gneisses are meta-sedimentary rocks derived from the metamorphism of pelites, whereas the amphibolite are meta-igneous rocks derived from a basic rock of subalkaline affinity. The banded gneisses possess NNW-SSE foliation trends, which are typical of pre-Pan-African deformation events, whereas the augen gneisses have NNE-SSW trends which are typical of Pan-African events. The granitoids are commonly foliated and lack clear magmatic contact with the gneisses. They are sub-alkaline, with alkali contents ranging from 6.87 to 9.65 per cent, and potash greater than soda. Their field, petrographic and geochemical features suggest that they were emplaced through remobilization, possibly accompanied by alkali-metasomatism during the Pan-African thermo-tectonic event. Discrimination of their tectonic environment agrees with an origin in a subduction environment of the continental type.ResumeLe complexe du sous-sol situe au sud-est et a l'est de frontieres de la ville d'Ogoja dans la zone au sud-est du Nigeria consiste en deux varietes de gneiss migmatitiques, a savoir: Les gneiss bandes et d'augen parfois avec l'amphibole entre les couches. Les veines quartzifeldspathiques concordantes et discordantes nombreuses dans ces gneiss sont liees aux roches granitoides, a savoir: les granits porphyriques, les leucogranits a gros grains, le granit d'aplite et la granodiorite. L'apparition de plagioclases (An 35-44), la hornblende, le garnet d'almandin et la staurolite entre les gneiss est une preuve de conditions metamorphiques de la qualite de facies amphibolique. Les constituants mineraux et les donnees d'oxyde d'element majeur indiquent que les gneiss sont metasediments, derives de metamorphisme de pelites alors que les amphiboles sont metaignees, derivees de roche basique de l'affinite subalcaline. Les gneiss bandes possedent les directions de la foliation NNW-SSE, qui sont typiques d'evenements de deformation prepanafricains, alors que les gneiss d'augen ont les directions NNE-SSW qui sont typiques d'evenements panafricains. Les roches granitoides sont generalement foliees manquant la relation de contact magmatique veritable et vive avec les gneiss. Elles sont subalcalines, ayant de hautes teneurs d'alcali, avec une potasse plus elevee que la soude. Leur gisement, les caracteristiques petrographiques et geochimiques suggerent qu'elles etaient emplacees par la remobilisation, peut-etre accompagnees par alcali-metasomatisme pendant l'evenement thermotectonique panafricain. Distinc-tion de leur environnement tectonique s'accorde avec une origine dans un environnement de subduction du type de l'arc continental. Ghana Journal of Science Vol. 46 2006: pp. 13-25" @default.
- W2074389230 created "2016-06-24" @default.
- W2074389230 creator A5071697804 @default.
- W2074389230 date "2008-02-22" @default.
- W2074389230 modified "2023-09-23" @default.
- W2074389230 title "Petrology and geotechnic setting of the basement comple rocks around Ogoja, South-Eastern Nigeria" @default.
- W2074389230 doi "https://doi.org/10.4314/gjs.v46i1.15912" @default.
- W2074389230 hasPublicationYear "2008" @default.
- W2074389230 type Work @default.
- W2074389230 sameAs 2074389230 @default.
- W2074389230 citedByCount "2" @default.
- W2074389230 countsByYear W20743892302023 @default.
- W2074389230 crossrefType "journal-article" @default.
- W2074389230 hasAuthorship W2074389230A5071697804 @default.
- W2074389230 hasConcept C127313418 @default.
- W2074389230 hasConcept C166957645 @default.
- W2074389230 hasConcept C17409809 @default.
- W2074389230 hasConcept C205649164 @default.
- W2074389230 hasConcept C2781297371 @default.
- W2074389230 hasConcept C5900021 @default.
- W2074389230 hasConceptScore W2074389230C127313418 @default.
- W2074389230 hasConceptScore W2074389230C166957645 @default.
- W2074389230 hasConceptScore W2074389230C17409809 @default.
- W2074389230 hasConceptScore W2074389230C205649164 @default.
- W2074389230 hasConceptScore W2074389230C2781297371 @default.
- W2074389230 hasConceptScore W2074389230C5900021 @default.
- W2074389230 hasIssue "1" @default.
- W2074389230 hasLocation W20743892301 @default.
- W2074389230 hasOpenAccess W2074389230 @default.
- W2074389230 hasPrimaryLocation W20743892301 @default.
- W2074389230 hasRelatedWork W2022142025 @default.
- W2074389230 hasRelatedWork W2029443844 @default.
- W2074389230 hasRelatedWork W2067421025 @default.
- W2074389230 hasRelatedWork W2091689277 @default.
- W2074389230 hasRelatedWork W2349947565 @default.
- W2074389230 hasRelatedWork W2358025071 @default.
- W2074389230 hasRelatedWork W2386365178 @default.
- W2074389230 hasRelatedWork W2387830747 @default.
- W2074389230 hasRelatedWork W2743550883 @default.
- W2074389230 hasRelatedWork W4307558643 @default.
- W2074389230 hasVolume "46" @default.
- W2074389230 isParatext "false" @default.
- W2074389230 isRetracted "false" @default.
- W2074389230 magId "2074389230" @default.
- W2074389230 workType "article" @default.