scholarly journals Retrogression of Orthopyroxene-bearing Gneiss of Iboropa Akoko, Southwestern Nigeria

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
E.J. Oziegbe ◽  
V.O. Olarewaju ◽  
O.O. Ocan ◽  
G. Costin
Keyword(s):  
Granulite Facies ◽  
Mineral Chemistry ◽  
Accessory Mineral ◽  
High Concentration ◽  
Southwestern Nigeria ◽  
Eu Anomaly ◽  
Mineral Assemblages ◽  
The Relationship ◽  
Rehydration Process ◽  
Alkali Feldspars

AbstractIn this article, we report the mineral chemistry and petrographic features of charnockitic exposure of Iboropa within Precambrian Basement Complex of Nigeria. The mineral assemblages are pyroxene, plagioclase, biotite, hornblende, alkali feldspars, microperthite, quartz and ilmenite, with apatite occurring as accessory mineral. Apatite occurs in abundance as euhedral crystals. Orthopyroxene observed is strongly pleochroic and has numerous microfractures, and it is hypersthene (En45Fs54Wo1) with low TiO2 and MnO, having extremely low percentage of CaO. Hypersthene is mantled by a complex corona of amphibole, and the amphibole is hornblende with a chemical formula: (K,Na)(Ca,Fe)2 (Fe,Mg,Al,Ti)5(Al,Si)8O22(OH)2. Plagioclase occurs as inclusions in both pyroxene and biotite. Biotite has high concentration of TiO2 and extremely low CaO. The opaque mineral observed is ilmenite and it is concentrated around hypersthene and amphibole. Rare earth element (REE) displays negative Eu anomaly with enrichment of light REE over heavy REE. Amphiboles surrounding orthopyroxene are evidences of retrograde reactions and are formed at the expense of orthopyroxene reacting with plagioclase and quartz in the presence of fluid. The relationship between the mineral assemblages suggests the retrogression of the gneiss that might be as a result of rehydration process, and it is a transition from granulite facies to amphibolite facies during a retrogressive form of metamorphism.

scholarly journals MINERAL CHEMISTRY AND GEOCHEMISTRY OF HYPERSTHENE-BEARING DIORITE FROM ERUSU AKOKO, SOUTHWESTERN NIGERIA

2020 ◽  
Vol 4 (1) ◽  
pp. 13-18
Author(s):  
E. J. Oziegbe ◽  
V. O. Olarewaju ◽  
O. O. Ocan
Keyword(s):  
Chemical Composition ◽  
Chemical Properties ◽  
Mineral Chemistry ◽  
Accessory Mineral ◽  
Southwestern Nigeria ◽  
Hydrous Minerals ◽  
Icp Ms ◽  
Composition Of Minerals ◽  
Textural Relationship ◽  
Opaque Minerals

Samples of mafic intrusive rock were analyzed for their mineralogical and chemical properties. The textural relationship was studied using the petrographic microscope, elemental composition of minerals was determined using the Electron Microprobe and the whole rock chemical analysis was done using the XRF and ICP-MS. The following minerals were observed in order of abundance; pyroxene, amphibole, plagioclase, biotite, opaque minerals, quartz and chlorite, with apatite and zircon occurring as accessory mineral. Two types of pyroxenes were observed; orthopyroxene (hypersthene) and clinopyroxene. Texturally, amphiboles have inclusions of plagioclase and pyroxene. The plagioclase has undergone sericitization. The chemical composition of the pyroxene is En51.95Fs44.53Wo3.52, biotite has Fe/(Fe+Mg):0.42, Mg/(Fe+Mg):0.59, and plagioclase is Ab63.5An34.55Or1.95. Whole rock chemistry shows a chemical composition; SiO2: 45.15 %, Al2O3: 14.04 %, Fe2O3: 16.01 %, MgO: 5.65 %, CaO: 7.58 % and TiO2: 3.59 %. There is an enrichment of LREE and a depletion of HREE. Based on the minerals, mineral chemistry and the geochemistry of the studied rock, the rock is mafic and hydrous minerals formed by hydration recrystallization of pyroxene. The rock has extensively retrogressed but has not been affected by any form of deformation.

Mineral chemistry of gahnite from the Lalor metamorphosed VHMS deposit, Snow Lake, Manitoba

2020 ◽  
Vol 58 (4) ◽  
pp. 511-532
Author(s):  
Elliot A. Wehrle ◽  
Andrew M. McDonald ◽  
Douglas K. Tinkham
Keyword(s):  
Trace Element ◽  
Major Element ◽  
Mineral Chemistry ◽  
Accessory Mineral ◽  
Major Element Composition ◽  
Trace Element Chemistry ◽  
Element Chemistry ◽  
Mineral Assemblages ◽  
Partitioning Coefficients ◽  
Vhms Deposit

ABSTRACT Gahnite (ZnAl2O4) is a common accessory mineral at the Lalor auriferous Zn-Cu metamorphosed VHMS deposit (Snow Lake, Manitoba). To evaluate factors influencing its crystal chemistry, gahnite representing a range of textures, host mineral assemblages, and whole-rock compositions were analyzed for major, minor, and trace elements. The analyzed grains span the range of Ghn63-75Her15-22Spl10-18 and are un-zoned with respect to Zn, Fe, and Mg. A moderate positive correlation exists between Mg in gahnite and whole-rock MgO (R2 = 0.66). The minor- and trace-element chemistry of the Lalor gahnite is dominated by Mn (400–2600 ppm), Si (<25–250 ppm), and V (<25–2300 ppm). Based on the limited variability in gahnite major-element composition, as well as similar partitioning coefficients of Zn and Fe between sphalerite-gahnite pairs (indicating comparable metamorphic conditions of crystallization for the analyzed gahnite), metamorphic grade is interpreted to have had the strongest influence on gahnite major-element chemistry. Most sphalerite occurs with pyrite and pyrrhotite, an assemblage that would have buffered fS2 and fixed the Zn:Fe ratio in sphalerite, which also could have contributed to the narrow compositional range observed in gahnite. Magnesium was not an essential component of the sphalerite-consuming, gahnite-producing reactions, so its concentration in gahnite was more readily affected by whole-rock Mg. A small proportion of gahnite grains may have formed from the destabilization of silicates (staurolite and biotite), rather than sphalerite. These possible gahnite-forming reactions (sphalerite- versus biotite- or staurolite-consuming) appear to have had the strongest control on gahnite minor- and trace-element chemistry, as gahnite formed from sphalerite desulfidation reactions shows a range in Mn (450–2600 ppm) and restricted V/Mn values (<0.5), while gahnite interpreted to have formed from the dehydration of biotite and staurolite shows restricted Mn (<430 ppm) and a range of V/Mn values (0.75–5.5). Further work is recommended to investigate the possibility of using gahnite trace-element signatures (such as with Mn and V) to discriminate between gahnite that crystallized in sphalerite-rich and sphalerite-barren environments, as this concept has potential for application to exploration using detrital gahnite.

Application Of Electron Probe Analyses Of Minerals In Discussing The Relationship Between Ductile Deformation And Metamorphism

1990 ◽  
Vol 48 (2) ◽  
pp. 250-251
Author(s):  
Fan Guochuan ◽  
Sun Zhongshi
Keyword(s):  
Chemical Composition ◽  
Shear Deformation ◽  
Electron Probe ◽  
General Rule ◽  
Granulite Facies ◽  
Ductile Deformation ◽  
Higher Temperature ◽  
Ductile Shear ◽  
The Relationship ◽  
Ductile Shear Deformation

Under influence of ductile shear deformation, granulite facies mineral paragenesis underwent metamorphism and changes in chemical composition. The present paper discusses some changes in chemical composition of garnet in hypers thene_absent felsic gnesiss and of hypersthene in rock in early and late granulite facies undergone increasing ductile shear deformation .In garnet fetsic geniss, band structures were formed because of partial melting and resulted in zoning from massive⟶transitional⟶melanocrate zones in increasing deformed sequence. The electron-probe analyses for garnet in these zones are listed in table 1 . The Table shows that Mno, Cao contents in garnet decrease swiftly from slightly to intensely deformed zones.In slightly and moderately deformed zones, Mgo contents keep unchanged and Feo is slightly lower. In intensely deformed zone, Mgo contents increase, indicating a higher temperature. This is in accord with the general rule that Mgo contents in garnet increase with rising temperature.

The influence of fibres on the structure of thermally dried sludge product

1996 ◽  
Vol 34 (3-4) ◽  
pp. 469-473
Author(s):  
Paul Lowe ◽  
Michael Brown ◽  
Kathleen Hudson
Keyword(s):  
Bulk Density ◽  
Fibre Content ◽  
High Concentration ◽  
Secondary Sludge ◽  
Limited Experience ◽  
Apparent Reason ◽  
Drying Technology ◽  
Dried Sludge ◽  
Lower Bulk Density ◽  
The Relationship

There appears to be a limited experience world-wide in the application of thermal drying technology to processing raw undigested sludge. This limited experience has shown that the products from raw sludge processing have a much lower bulk density than those from digested sludge. The apparent reason for this phenomenon demonstrated by this work, is the high concentration of fibres in the raw undigested sludge. Different sludges show varying degrees of fibre concentration with a decrease in fibre content as the proportion of secondary sludge increases. The relationship between the bulk density of the product and the fibre content are given and this shows that as the fibre content increases the bulk density of the product will fall. It is recommended that a compaction/pelletisation stage is included in the process stream for high fibre sludges.

scholarly journals Morphology of lateral line canals in Neotropical freshwater stingrays (Chondrichthyes: Potamotrygonidae) from Negro River, Brazilian Amazon

2010 ◽  
Vol 8 (4) ◽  
pp. 867-876 ◽  
Author(s):  
Akemi Shibuya ◽  
Jansen Zuanon ◽  
Maria Lúcia G. de Araújo ◽  
Sho Tanaka
Keyword(s):  
Lateral Line ◽  
The Body ◽  
Mechanical Stimuli ◽  
High Concentration ◽  
Ventral Region ◽  
Negro River ◽  
Accurate Localization ◽  
Posterior Lateral Line ◽  
The Family ◽  
The Relationship

The relationship between the distribution of the lateral line canals and their functionality has not been well examined in elasmobranchs, especially among Neotropical freshwater stingrays of the family Potamotrygonidae. The spatial distribution of the canals and their tubules and the quantification of the neuromasts were analyzed in preserved specimens of Potamotrygon motoro, P. orbignyi, Potamotrygon sp. "cururu", and Paratrygon aiereba from the middle Negro River, Amazonas, Brazil. The hyomandibular, infraorbital, posterior lateral line, mandibular, nasal and supraorbital canals were characterized and their pores and neuromasts quantified. The ventral canals are known to facilitate the accurate localization of prey items under the body, and our results indicate that the dorsal canals may be employed in identifying the presence of predators or potential prey positioned above the stingray's body. The presence of non-pored canals in the ventral region may be compensated by the high concentration of neuromasts found in the same area, which possibly allow the accurate detection of mechanical stimuli. The concentration of non-pored canals near the mouth indicates their importance in locating and capturing prey buried in the bottom substrate, possibly aided by the presence of vesicles of Savi.

scholarly journals Geochemical Characteristics and Tectonic Setting of Amphibolites in Ifewara Area, Ife-Ilesha Schist Belt, Southwestern Nigeria

2016 ◽  
Vol 6 (1) ◽  
pp. 43 ◽  
Author(s):  
Anthony Temidayo Bolarinwa ◽  
Adebimpe Atinuke Adepoju
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Major Element ◽  
Tectonic Setting ◽  
Crustal Contamination ◽  
Geochemical Evolution ◽  
Schist Belt ◽  
Southwestern Nigeria ◽  
Eu Anomaly ◽  
Ree Patterns

Trace and Rare Earth Elements (REEs) data are used to constrain the geochemical evolution of the amphibolites from Ifewara in the Ife-Ilesha schist belt of southwestern Nigeria. The amphibolites can be grouped into banded and sheared amphibolites. Major element data show SiO2 (48.34%), Fe2O3 (11.03-17.88%), MgO (5.76-9.90%), CaO (7.76-18.6%) and TiO2 (0.44-1.77%) contents which are similar to amphibolites in other schist belts in Nigeria. The Al2O3 (2.85-15.55%) content is varied, with the higher values suggesting alkali basalt protolith. Trace and rare earth elements composition reveal Sr (160-1077ppm), Rb (0.5-22.9ppm), Ni (4.7-10.2ppm), Co (12.2-50.9 ppm) and Cr (2-7ppm). Chondrite-normalized REE patterns show that the banded amphibolites have HREE depletion and both negative and positive Eu anomalies while the sheared variety showed slight LREE enrichment with no apparent Eu anomaly. The study amphibolites plot in the Mid Oceanic Ridge Basalts (MORB) and within plate basalt fields on the Zr/Y vs Zr discriminatory diagrams. They are further classified as volcanic arc basalt and E-type MORB on the Th- Hf/3- Ta and the Zr-Nb-Y diagrams. The amphibolites precursor is considered a tholeiitic suite that suffered crustal contamination, during emplacement in a rifted crust.

Experimental Study on Adsorption of Gasoline Vapor on Activated Carbon at High Concentration

2013 ◽  
Vol 807-809 ◽  
pp. 549-552 ◽  
Author(s):  
Chen Lu Zhao ◽  
Wei Qiu Huang ◽  
Ying Xia Wang ◽  
Li Shi
Keyword(s):  
Temperature Rise ◽  
Activated Carbons ◽  
Thermodynamic Characteristics ◽  
High Concentration ◽  
Vapor Adsorption ◽  
Gasoline Vapor ◽  
Adsorption Capacities ◽  
Bed Temperature ◽  
Relationship Of ◽  
The Relationship

Dynamic and thermodynamic characteristics of gasoline vapor adsorption at 0.3 mol/mol on different activated carbons (ACs) were investigated. The adsorption capacities of AC1 and AC3 were 0.295 g/g and 0.189 g/g at 20 oC, and 0.284 g/g and 0.165 g/g at 30 °C, respectively. Bed temperature rise was up to 50°C to 60°C in the adsorption of gasoline vapor at 0.3 mol/mol.The heat effect formula for high concentration vapor adsorption was deduced to evaluate the relationship of the adsorption capacity of the activated carbons, the mole fraction of the inlet gasoline vapor, the recovery efficiency of the gasoline vapor with the temperature rise.

scholarly journals Petrogenetic and Compositional Features of Rare Metal Pan-African Post-Collisional Pegmatites of Southwestern Nigeria; A Status Review

2018 ◽  
Vol 7 (2) ◽  
pp. 166-187
Author(s):  
Abiola Oyebamiji ◽  
Adeniyi JohnPaul Adewumi ◽  
Tehseen Zafar ◽  
Adegbola Odebunmi ◽  
Philips Falae ◽  
...  
Keyword(s):  
Mineral Chemistry ◽  
Rare Metal ◽  
Border Zone ◽  
Chemical Compositions ◽  
Molten Material ◽  
Southwestern Nigeria ◽  
Pan African ◽  
Opening And Closing ◽  
High Degree ◽  
Rare Metal Pegmatite

Abstract This research reviews the geology, petrogenesis, compositional trends and geochronology of the rare-metal pegmatite of southwestern Nigeria. The source of these pegmatites is still presently debated which have been explained as either product of highly fractionated molten material or anatexis of the local crust. However, published works of past authors have been compiled to give a detailed understanding of the formation of the mineral deposits. The basement complex of southwestern Nigeria comprises of Precambrian rocks of amphibolite, the hornblende gneiss and the granite gneisses which were formed as a result of the opening and closing of the ensialic basin with significant, extensive subduction during the Pan-African orogeny. The pegmatites in this region have shown internal zoning and a high degree of evolution from the border zone to the core zone during the crystallization and solidification of the felsic granite to pegmatite melt. The rare-metal pegmatites have distinct chemical compositions and mineralogy, containing quartz, biotite, muscovite, microcline, garnet with localized tourmaline, tantalite and columbite. These pegmatites vary significantly by their bulk-rock and mineral chemistry which indicates a more peraluminous attribute and enrichments of lithophile elements of Rb, Cs, Ta and Ba. Previous K/Ar isotopic ages (502.8±13.0 Ma and 514.5±13.2 Ma) suggest that the pegmatites are related to the post-collisional phase of intensive metasomatism. Adopted from previous studies, a five-stage conceptual model of evolution which is widely accepted have been proposed for the origin of the pegmatites.

scholarly journals UPLC-MS/MS Determination of Linezolid and Heme in Plasma of Infected Patients and Correlation Analysis

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Yingying Wang ◽  
Xuemei Ye ◽  
Qin Lan ◽  
Xiaofang Ke ◽  
Lufeng Hu ◽  
...  
Keyword(s):  
Correlation Analysis ◽  
Healthy Subjects ◽  
Haematological Toxicity ◽  
Diagnostic Value ◽  
High Concentration ◽  
High Positive Correlation ◽  
Positive Correlation ◽  
Early Diagnose ◽  
The Relationship

Linezolid can cause serious haematological toxicity, such as thrombocytopenia and aneamia. Heme, composed of iron and porphyrin, is an important component of hemoglobin. In order to investigate the relationship between the concentration of linezolid and heme in the plasma of infected patients, a UPLC-MS/MS method that can determine the concentrations of linezolid and heme simultaneously was developed and validated. A total of 96 healthy subjects and 81 infected patients, who received blood routine blood tests, were included and determined by the UPLC-MS/MS method. The results showed that the concentration of linezolid was 5.08 ± 3.46   μ g / mL in infected patients who were treated with linezolid. The heme in healthy subjects was 7.05 ± 8.68   μ g / mL , and it was significantly decreased to 0.88 ± 0.79   μ g / mL in infected patients ( P < 0.01 ). Spearman correlation analysis showed that linezolid had a high negative correlation with platelet (PLT) ( R = − 0.309 ). Heme had a high positive correlation with hemoglobin (Hb) ( R = 0.249 ) in healthy subjects and infected patients. The ROC analysis showed that heme had diagnostic value to distinguish low Hb (110 g/L). In conclusion, there was a positive correlation between heme and Hb, and this correlation was also observed in infected patients. A high concentration of linezolid was inclined to decrease PLT. Monitoring of heme and linezolid helps in the early diagnose of low Hb and PLT.

scholarly journals Effects of Bacterial Cell-Free Supernatant on Nutritional Parameters of Apis Mellifera and Their Toxicity Against Varroa Destructor

2020 ◽  
Vol 64 (1) ◽  
pp. 55-66
Author(s):  
Fiorella G. De Piano ◽  
Matias D. Maggi ◽  
Facundo R. Meroi Arceitto ◽  
Marcela C. Audisio ◽  
Martín Eguaras ◽  
...  
Keyword(s):  
Apis Mellifera ◽  
Varroa Destructor ◽  
High Concentration ◽  
Colony Losses ◽  
Nutritional Parameters ◽  
Low Concentrations ◽  
Bee Health ◽  
Contact Exposure ◽  
Fat Bodies ◽  
The Relationship

AbstractApis mellifera L. is an essential pollinator that is currently being affected by several stressors that disturb their ecological function and produce colony losses. Colonies are being seriously affected by the ectoparasitic mite Varroa destructor. The relationship between stressors and bee symbionts is being studied in order to enhance bee health. The goal of this study was to evaluate the effect of cell-free supernatants (CFSs) produced by Lactobacillus johnsonii AJ5, Enterococcus faecium SM21 and Bacillus subtilis subsp. subtilis Mori2 on A. mellifera nutritional parameters and their toxicity against V. destructor. Toxicity and survival bioassays were conducted on adult bees with different concentrations of CFSs. Nutritional parameters such as soluble proteins and fat bodies in abdomens were measured. Varroa destructor toxicity was analyzed by a contact exposure method and via bee hemolymph. At low concentrations, two of CFSs tends to enhance bee survival. Remarkably fat bodies maintained their levels with all CFS concentrations in the abdomens, and soluble protein increased at a high concentration of two CFSs. Toxicity against V. destructor was observed only via hemolymph, and results were in agreement with the treatment that produced an increase in bee proteins. Finally, CFS produced by L. johnsonii AJ5 could be a promising natural alternative for strengthening bee health.

Sign in / Sign up

Export Citation Format

Share Document