Geochemistry of metasedimentary rocks of Uwet area, Oban Massif, southeastern Nigeria

Ekwueme, Barth N.; Onyeagocha, A.C.

doi:10.1007/bf01820620

Cited by 28 publications

(21 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…4 B). This trend of distribution is consistent with the report of Ekwueme and Onyeagocha (1986) in the metasedimentary schists of Oban area of Southeastern Nigeria. The schists of Northwest Obudu area are metasediments possibly derived from clays and shales which could have been contaminated by other crustal rocks.…”

Section: Discussionsupporting

confidence: 92%

“…Mineralogical, textural and structural properties of schists mapped in Northwest Obudu Plateau show that they share similar characteristics with pelitic metasedimentary rocks reported by Ekwueme and Onyeagocha (1986) Table 2), which has Si0 2 content of 68.36 wt %, possibly indicating quartz-rich specimen from the leucocratic portion of the migmatitic QMS (Table 2). …”

Section: Discussionsupporting

confidence: 64%

“…% in the BMS at Vandeikya to 66.58 wt % in the QMS at Dura River, with average of 64.56 wt % (Table 2). Hence, reflecting the pelitic characteristics of the protoliths of the schists which could be shales and clays (Ekwueme and Onyeagocha 1986;Ekwueme, 1993). The Ti0 2 concentration shows narrow variation from 0.45 wt % in the (HBS) to 0.96 wt % in the MS at Mbakeum (Table 2).…”

Section: Resultsmentioning

confidence: 99%

“…The average composition of the analysed schists (Table 2), when plotted in the ACF diagram (Fig. 4 B), more than 62.5 % of the analyzed samples plot in the field 2b (between arrows) of Winkler (1967) and Ekwueme and Onyeagocha (1986), indicating shales and clays containing about 30 % carbonates; 25 % plot in the field 3 (Wyoming greywackes), while only one sample plots in the field 2 (carbonate free mud rocks) (Fig. 4 B).…”

Section: Discussionmentioning

confidence: 99%

See 3 more Smart Citations

Geochemistry of Schists of Northwest Obudu Plateau, Southeastern Nigeria

Obioha¹,

Ekwueme²

2013

Glo Jnl Geo Sci

View full text Add to dashboard Cite

Precambrian, highly foliated, fine -medium grained schists, which comprise migmatitic schist (MS), quartz mica schist (QMS), biotite mica schist (BMS) and hornblende biotite schist (HBS) constitute important lithological unit in Northwest Obudu Plateau. The schists are associated with gneisses, amphibolites and metaquartzites, and variously intruded by granites, pegmatites and quartzo-feldspathic veins. Sedimentary rocks, which are mostly Cretaceous sandstones, flank the western margin of the study area. Modal analysis shows that all the schists are enriched in quartz, plagioclase (An 32 ), biotite and garnet, except the HBS which is relatively depleted in quartz but highly enriched in biotite (25 vol. %) and hornblende (55 vol. %). Sillimanite and epidote occur in accessory amounts. The co-existence of quartz-plagioclase (An 32 )-garnet-biotite-muscovite-sillimanite in the MS assemblage indicates that the Schists are derivatives of metamorphism of pelitic and mafic rocks, which had attained the uppermost amphibolite facies grade. Geochemically, the schists are enriched in Si0 2 , which ranges from 60.11 wt % in the HBS, rising to 62.94 wt % in the BMS and 66.58 wt % in the QMS, with average of 64.56 wt %. The high SiO 2 content points to a probable effect of an intruding granitic magma on the Pan -African schists. The Al 2 O 3 , Fe 2 O 3 , MgO, CaO and alkalies are relatively moderate to high. The samples are quartz normative, have high molecular value of Al 2 O 3 > {CaO + Na 2 O + K 2 O}. Plots in chemical discrimination diagrams confirm the peraluminous characteristics of the schist and suggest pelitic rock protolith except for the HBS.

show abstract

Section: Discussionsupporting

confidence: 92%

Section: Discussionsupporting

confidence: 64%

Section: Resultsmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

See 2 more Smart Citations

Geochemistry of Schists of Northwest Obudu Plateau, Southeastern Nigeria

Obioha¹,

Ekwueme²

2013

Glo Jnl Geo Sci

View full text Add to dashboard Cite

show abstract

“…It has not been as extensively studied as other parts of the Precambrian Basement. Geological workers such as Orajaka (1973), Olade (1980), Ekwueme and Onyeagocha (1985a, b), Ekwueme and Caen-Vachette (1992), Ekwueme and Kroner (1998), Rahaman et al (1981Rahaman et al ( , 1988, Ekwueme et al (1988Ekwueme et al ( , 1991 have studied different aspects of the geology of Oban. Most of these studies were field oriented with bulk-rock chemical analyses of some rock samples.…”

Section: Introductionmentioning

confidence: 98%

Mineralization of pegmatites in parts of the Oban Massif, Southeastern Nigeria: A preliminary analysis

Ero

Ekwueme

2009

Chin. J. Geochem.

View full text Add to dashboard Cite

The Oban Basement Massif of southeastern Nigeria is composed of metamorphosed rocks including phyllites, schists, gneisses and amphibolites cut by pegmatitic dykes of varying length and thickness, which intruded the metamorphic rocks. Preliminary geochemical study and analysis of these pegmatites from western Oban Massif at Uyanga, Akwa Ibami, Iwuru I, Iwuru II and Igbofia showed that the pegmatites are highly albitized. This is inconsistent with earlier postulations that the pegmatites in this part of Nigeria are barren. Indices of fractionation such as Ba/Rb, K/Rb, Na/K, K/Cs, K/Ba reveal that the pegmatites are mineralized and different discrimination plots show that they are enriched in Li, Be, Sn, Ba, Ta, Ni, Cs, Sn and Zn. Rare metal indicative elements such as Ta, Nb, Rb, Cs, and Sn are enriched in the pegmatites, confirming that the pegmatites are mineralized.

show abstract

Integration of Landsat 8, gravity, and field data for exploration of gold mineralization in Gamba District, Northern Cameroon

et al. 2021

View full text Add to dashboard Cite

Remote sensing is a robust and useful tool for providing high‐resolution image data and enabling reliable geological mapping during the initial stage of mineral exploration. One of its main applications is the extraction of lineaments and to locate alteration areas to target gold exploration. It has been long used in the Pan‐African belt of Cameroon to identify a hydrothermal alteration and a great number of lineaments associated with mineralizations. The study area located in the Pan‐African belt hosts numerous alluvial gold deposits where the primary mineralization was still largely poorly unknown until now, due to deep weathering. Therefore, remote sensing combined with field data is useful for targeting potential zones of primary gold resources involved in the hydrothermal and lineament systems. In this study, remote sensing data from Landsat 8 imagery were selected to map the distribution of hydrothermal minerals, and gravity data were interpreted for highlighting structural patterns related to the control of high‐potential zone for gold mineralization, generating a mineral prospect map. The lineaments network shows directions ranging from ENE‐WSW to E‐W, with main direction N45° and a secondary striking N275°. Image enhancement/processing techniques included the application of band ratio and principal component analysis that were helpful to demarcate potential alteration zones marked by iron oxide/hydroxides in which haematite and pyrite are used as proximal alterations and hydroxyl‐bearing minerals in which sericite (muscovite) is used as a marker of proximal alteration, while chlorite, epidote, biotite, quartz, and calcite are used as distal alteration zone, as described by field and petrographic data. The identified alteration zones display a high consistency with the known locations of gold occurrences (mining sites) and closely concordant with large‐scale gold mineralization in the study area. This study presents an integrated approach of Landsat 8 imagery with gravity data and field data for discovering primary mineral resources in a deep weathering area.

show abstract

Geochemistry of metasedimentary rocks of Uwet area, Oban Massif, southeastern Nigeria

Cited by 28 publications

References 9 publications

Geochemistry of Schists of Northwest Obudu Plateau, Southeastern Nigeria

Geochemistry of Schists of Northwest Obudu Plateau, Southeastern Nigeria

Mineralization of pegmatites in parts of the Oban Massif, Southeastern Nigeria: A preliminary analysis

Integration of Landsat 8, gravity, and field data for exploration of gold mineralization in Gamba District, Northern Cameroon

Contact Info

Product

Resources

About