scholarly journals Petrochemistry and petrogenesis of the Precambrian Basement Complex rocks around Akungba-Akoko, southwestern Nigeria

2020 ◽  
Vol 66 (3) ◽  
pp. 173-183 ◽  
Author(s):  
Abimbola Chris Ogunyele ◽  
Oladotun Afolabi Oluwajana ◽  
Iyanuoluwa Queen Ehinola ◽  
Blessing Ene Ameh ◽  
Toheeb Akande Salaudeen
Keyword(s):  
Granite Gneiss ◽  
Biotite Granite ◽  
Geological Mapping ◽  
Precambrian Basement ◽  
Biotite Gneiss ◽  
Basement Complex ◽  
Southwestern Nigeria ◽  
Anhydrous Mineral ◽  
Geochemical Analyses ◽  
Igneous Protoliths

AbstractField, mineralogical and petrochemical studies of the Precambrian Basement Complex rocks around Akungba-Akoko were carried out with the aim of determining their petrology, petrochemical characteristics and petrogenesis. The petrology of Akungba-Akoko area comprises migmatite, granite gneiss and biotite gneiss intruded by biotite granite, charnockite and minor felsic and basic rocks. Seventeen representative samples of the granite gneiss, biotite gneiss, biotite granite and charnockite were collected during field geological mapping of the area for petrographic and geochemical analyses. Modal mineralogy revealed that the granite gneiss, biotite gneiss and granite have assemblages of quartz + feldspar + mica + hornblende + opaques and are granitic in composition. The charnockite is characterized by anhydrous mineral assemblage of quartz + feldspar + biotite + hornblende + pyroxene + opaques. Petrochemical data of the rocks revealed that they are moderately to highly enrich in SiO2, sub-alkaline, peraluminous, magnesian to ferroan and calcic and have K/Rb < 283. The geochemical characteristics and discrimination of the rocks indicated that the granite gneiss and biotite gneiss are orthogneisses formed by metamorphism of igneous protoliths of granitic composition and the biotite granite and charnockite are of igneous/magmatic origin. The biotite granite, charnockite and the igneous protoliths of the biotite gneiss are I-type granitoids formed from crustal igneous-sourced melt(s), while the igneous protoliths of the granite gneiss is a S-type granitoid probably derived from shallow crustal or sedimentary-sourced melt(s). Tectonic discrimination of the rocks indicated that they were formed during a phase of magmatic activity related to collision and subduction.

scholarly journals Mineralogy and Geochemistry of Residual Clay Occurrences in Idi-Ayunre and Akure Areas, Southwestern Nigeria

2015 ◽  
Vol 7 (4) ◽  
pp. 23 ◽  
Author(s):  
Adewole J. Adeola
Keyword(s):  
Raw Materials ◽  
Thermal Characteristic ◽  
Granite Gneiss ◽  
Industrial Applications ◽  
Precambrian Basement ◽  
X Ray Diffraction ◽  
Basement Complex ◽  
Southwestern Nigeria ◽  
X Ray ◽  
Porphyritic Granite

<p class="zhengwen">Three residual clay occurrences in Idi-Ayunre, and Akure areas which belong to the Precambrian basement complex of southwestern Nigeria were investigated for their mineralogical, chemical and industrial properties. The investigation was to evaluate their industrial applications and economic importance. The clay within the weathered profiles above banded gneiss at Idi-Ayunre is whitish with red spots, whereas the clays derived from profiles above porphyritic granite and granite gneiss in Akure are grayish and brown in color respectively.</p><p class="zhengwen">The X-ray diffraction studies show that kaolinite is the dominant clay mineral, goethite, microcline, quartz, albite are the major non clay minerals in the samples. Chemical data showed that the average values of SiO<sub>2</sub>, Al<sub>2</sub>O<sub>3</sub>, and Fe<sub>2</sub>O<sub>3</sub> were 52.3. 30.29 and 3.54 wt% respectively constituting 86.13% of the bulk compositions.</p>Evaluation of the clay thermal characteristic, firing colour, water absorption capacities and shrinkage values show that the brownish Idi-Ayunre clay, gray and brown Akure kaolinitic clays could serve as raw materials for ceramics, building bricks, and other structural wares

scholarly journals Rare Earth Elements Assessment in the Granitoids of Part of Southwestern Nigeria

2020 ◽  
Vol 1 (5) ◽  
Author(s):  
Victoria B. Omotunde ◽  
Akinade S. Olatunji ◽  
Maryam O. Abdus-Salam
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Inductively Coupled Plasma ◽  
Granite Gneiss ◽  
Biotite Granite ◽  
Geochemical Data ◽  
Southwestern Nigeria ◽  
Lithological Mapping ◽  
Inductively Coupled ◽  
Gneiss Granite

The Rare Earth Elements (REE) composition of granitoids in and around Ila-Orangun area Southwestern Nigeria was assessed in order to ascertain their potential for possible exploitation. Detailed lithological mapping of the area was undertaken followed by whole rock geochemical analysis of representative samples of the granitoids using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) technique. Petrographic study of the samples was carried out as well as the interpretation of the geochemical data using diverse geochemical discrimination plots. The rock units mapped were biotite granite gneiss, granite gneiss and hornblende biotite granite. Biotite hornblende gneiss, quartzite, talc-chlorite-tremolite-schist, mica schist and pegmatites were the surrounding country rocks. The REE concentrations (in ppm) revealed higher concentrations of the light REEs compared to the heavy REEs. The fractionation ratio, (La/Yb)N ranged from 4.35-15.04 (granite gneiss) and 13.78-18.48 (hornblende biotite granite) indicating enrichment in LREEs over the HREEs. The spider plot for the REEs also showed that the granitoids are LREE-enriched and HREE-depleted suggesting fractional crystallisation and a distinct negative Eu anomaly indicating plagioclase fractionation. Enrichment plot also revealed that the REEs in the granitoids are significantly enriched. Comparison with other areas showed that the granitoids of the study area especially the hornblende biotite granite has higher concentrations of REEs and may be a possible pointer of REE mineralisation.

scholarly journals Pedogenic Forms of Iron in Soils Developed from Four Parent Materials

2020 ◽  
Vol 25 (1) ◽  
pp. 47
Author(s):  
Ayodele Owonubi
Keyword(s):  
Iron Oxides ◽  
Ammonium Oxalate ◽  
Granite Gneiss ◽  
Field Work ◽  
Biotite Granite ◽  
Total Iron ◽  
Basement Complex ◽  
Parent Materials ◽  
Basaltic Rocks ◽  
Forms Of Iron

Information on the distribution of various forms of iron in soils are valuable in the study of soil genesis. The objective of this study was to to evaluate the pedogenic forms of iron in soils developed over basement complex and basaltic parent materials of the study area. Geologic units considered in the basement complex area were granite gneiss, biotite granite and migmatite. Stratified random sampling formed the basis for field work. Soil sampling was carried out by digging at least two soil profile pits in each geologic unit. Organically bound, amourphous and total iron oxides were estimated using 0.1 M sodium pyrophosphate, acidified (pH 3) ammonium oxalate, and dithionite-citrate-bicarbonate method, respectively. The total Fe in the soil samples were determined after a mixed acid digestion. In general, total iron fractions were statistically similar among the soils of basement complex geologic units but significantly lower than those of soils derived from basaltic rocks. However, the distribution of iron oxide fractions was similar among the basement and basaltic geologic units. Furthermore, there were significant differences in the distribution of iron oxides in the B horizons of basement complex derived soils. Consequently, the quantity of iron oxides in the B horizon was in the order migmatite > biotite granite > granite gneiss. About 70% of total iron oxides in the soils over granite gneiss, biotite granite and basaltic rocks was amorphous in nature. Furthermore, total iron oxides constitute less than 20% of total clay both in the basement complex and basaltic soils.

U–Th–Pb and Rb–Sr ages in granite reference sample from southwestern Saskatchewan

1970 ◽  
Vol 7 (1) ◽  
pp. 184-187 ◽  
Author(s):  
J. N. Rosholt ◽  
Z. E. Peterman ◽  
A. J. Bartel
Keyword(s):  
Reference Sample ◽  
Biotite Granite ◽  
Drill Core ◽  
Precambrian Basement ◽  
Basement Complex

Concordant total rock 206Pb–238U, 207Pb–235U, 207Pb–206Pb, 208Pb–232Th and 87Sr–87Rb ages of 1805 ± 40, 1815 ± 55, 1820 ± 110, 1790 ± 60, and 1810 ± 50, in millions of years, respectively, were obtained on the reference sample of biotite granite. The sample is a piece of drill core from a depth of 7300 ft (~2225 m), about 80 ft (~24.4 m) below the top of the Precambrian basement complex, in southwestern Saskatchewan.

scholarly journals EDX-SEM-XRF data from selected Precambrian Basement Complex rock samples in part of Southwestern Nigeria

Data in Brief ◽  
2018 ◽  
Vol 20 ◽  
pp. 1525-1531 ◽  
Author(s):  
J.S. Kayode ◽  
Y. Yusup ◽  
M.N.M. Nawawi ◽  
K.S. Ariffin ◽  
A.E. Kalil ◽  
...  
Keyword(s):  
Precambrian Basement ◽  
Basement Complex ◽  
Southwestern Nigeria ◽  
Rock Samples

scholarly journals Petrography of Allanite-bearing Tonalite from Iwo Region, Osun State, Nigeria

2020 ◽  
Vol 67 (2) ◽  
pp. 79-89
Author(s):  
E.J. Oziegbe ◽  
O.O. Ocan ◽  
A.O. Buraimoh
Keyword(s):  
Alkali Feldspar ◽  
Precambrian Basement ◽  
Basement Complex ◽  
Southwestern Nigeria ◽  
Compositional Zoning ◽  
Thin Sections ◽  
Accessory Minerals ◽  
Secondary Minerals ◽  
Mineral Assemblages ◽  
Opaque Minerals

AbstractPrimary, secondary and accessory minerals in tonalitic rocks from Iwo region of the Precambrian Basement Complex of Southwestern Nigeria were identified and analysed with the aim of determining the various processes involved during the crystallisation of magma. Thin sections of tonalite were prepared and studied with the aid of a petrographic microscope. The mineral assemblages observed are biotite, plagioclase, alkali-feldspar, amphiboles, pyroxene, quartz, muscovite and chlorite. Allanite, titanite, apatite and zircon occur as accessory minerals. Muscovite and chlorite are found to be secondary minerals. The mineral allanite has a characteristic form of zoning and shows evidence of metamictisation, and is surrounded by dark-coloured biotite having radioactive haloes. Titanite is anhedral to subhedral crystals and forms reaction rim round opaque minerals. Plagioclase shows evidence of compositional zoning as well as plastic deformation of the twin lamellae. The allanite observed is primary in nature and has undergone radioactive disintegration; chlorite and muscovite are formed by secondary processes of chloritization and sericitisation, respectively. The tonalite is formed as a result of rapid cooling of magma close to the Earth's surface.

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