Faculty of Physical Sciences http://repository.unizik.edu.ng/handle/123456789/83 2026-04-04T02:52:04Z 2026-04-04T02:52:04Z *Onuigbo, Evangeline ,N. Okoro, Anthony U Obiadi, Ignatus, I. Akpunonu, Eliseus O Okeke, Harold C. Maduewesi, Victor U. http://repository.unizik.edu.ng/handle/123456789/1153 2025-07-21T10:59:06Z 2016-01-01T00:00:00Z

Title: Tide-generated Sedimentary Structures, Lithofacies and Particle Size Distribution: Proxies to the depositional setting of the Ajali Sandstone in the Anambra Basin, Southeastern Nigeria. Authors: *Onuigbo, Evangeline ,N.; Okoro, Anthony U; Obiadi, Ignatus, I.; Akpunonu, Eliseus O; Okeke, Harold C.; Maduewesi, Victor U. Abstract: Herringbone cross stratification, mud draped foresets, reactivation surfaces, tidal bundles, flaser beddings, ripple and horizontal laminations were identified on the Ajali Sandstone studied. The biogenic structures occur as dominantly vertical to sub-vertical and u -tubed burrows of the Skolithos ichnofacies commonly Skolithos verticalis and Ophiomorpha nodosa. Occasional Thalassinoides and Teichichnus isp burrows of the Cruziana Ichnofacies also occur. Three lithofacies were identified and these include; the medium to coarse grained cross bedded sandstone lithofacies, Fine grained cross bedded sandstone lithofacies and the mudstone lithofacies. The paleocurrent pattern from cross bed azimuths shows a bimodal – bipolar pattern indicative of tidal process. The grain size frequency histograms indicate both unimodal and bimodal asymmetrical patterns with shifting modes. The cumulative frequency curves suggest traction, saltation and suspension as the mechanisms of the sediment transport. The bivariate plots of the discriminant functions (Y1, Y2 and Y3) for the sands suggest deposition in a shallow agitated marine environment. Intertidal to subtidal shallow marine depositional setting is proposed for the Ajali Sandstone. Description: Scholary work

2016-01-01T00:00:00Z OBIADI, I. I. OBIADI, C. M. AJAEGWU, N. E. ANAKWUBA1, E. K. ONUIGBO, N. E. MADUEWESI1, U. V. OKOLO, C. M. EZIM, O. E. http://repository.unizik.edu.ng/handle/123456789/1152 2025-07-21T10:52:52Z 2015-01-01T00:00:00Z

Title: STRUCTURAL EVIDENCE FOR PAN-AFRICAN EVENT IN THE SW BASEMENT BLOCK OF NIGERIA: THE IGARRA EXAMPLE Authors: OBIADI, I. I.; OBIADI, C. M.; AJAEGWU, N. E.; ANAKWUBA1, E. K.; ONUIGBO, N. E.; MADUEWESI1, U. V.; OKOLO, C. M.; EZIM, O. E. Abstract: Fractures and folds are common evidences for post-formational deformation in rocks. They result from the action of stress on the rocks and as such bear imprints of the nature and magnitude of the deformative force. The style and orientation of the recorded strain reflect the interaction between the applied force (stress) and the pre existing rock body. Force is a vector quantity, having both magnitude and direction. The stress acting normal against a surface can be resolved into three mutually perpendicular principal axes of maximum stress σ1, intermediate stress σ2 and minimum stress σ3; while the resultant strain can also be resolved into three mutually perpendicular principal strain axes. There exist some relationship between the applied stress and the resultant strain (structures). This relationship shows correspondence between the principal stress axes and the principal strain axes. Structural analysis using the stress and strain relationship technique was carried out at Igarra. Fractures and folds characterized in the crystalline basement rocks at Igarra shows that the orientation of the strike of the fractures and the fold axes of the folds are dominantly in the N-S direction. Assuming pure shear, and that the strain on a large scale is essentially homogeneous statistically, reflecting both the orientation and size of the bulk finite strain; the orientation, style and intensity of the mapped structures suggest a dominantly E W directional compressional stress. This generally agrees with the tectonic location and orientation, geologic and lithologic relationships of the Pan-African suites and indicates that the Pan-African event played a major role in the structural evolution of the Schist Belt. Description: Scholarly work

2015-01-01T00:00:00Z Oghuma, A .A Obiadi, I. I Obiadi, C. M http://repository.unizik.edu.ng/handle/123456789/1151 2025-07-21T10:47:28Z 2015-01-01T00:00:00Z

Title: 2-D Spectral Analysis of Aeromagnetic Anomalies over Parts of Monguno and Environs, Northeastern Nigeria Authors: Oghuma, A .A; Obiadi, I. I; Obiadi, C. M Abstract: 2-D Spectral Analysis of aeromagnetic anomalies over parts of Monguno and environs, northeastern Nigeria was carried out to determine the depth to basement, establish the basement topography and determine the temperature at depths in the area. Data enhancement was carried out to delineate residual features and the more intense anomalies relative to the strong regional gradients. Typical techniques applied were computations of reduction to pole, trend surface analysis, and a number of filtering processes. Results of the 2-D spectral analysis of the aeromagnetic data revealed a two depth source model. The depth to the deeper magnetic source bodies ranges from 1.22 to 3.14 km, with an average depth of 2.341 km. This layer may be attributed to magnetic rocks of the basement, lateral variations in basement susceptibilities and intra- basement features like faults and fractures. The shallower magnetic sources range in depth from 0.12 to 0.93 km, with an average depth of 0.572 km and could be attributed to near surface magnetic sources, which are magnetic rocks that intruded into the sedimentary formations. Based on the computed average sediment thickness obtained in this study together with the temperature at depths in the area, some parts of the study area have been demarcated for detail hydrocarbon exploration in-line with the renewed interest in hydrocarbon exploration in the basin Description: Scholarly work

2015-01-01T00:00:00Z Adione, Nnamdi Markben Onyeka, Ifeanyi Peter Abba, Chika Christiana Okoye, Nkeoma Nkasi Eze, Peter Maduabuchi Umeokoli, Blessing Ogechukwu Anyanwu, OgechI Ozioma Okoye, Festus Basden Chiedu http://repository.unizik.edu.ng/handle/123456789/1141 2025-07-16T14:19:25Z 2022-08-01T00:00:00Z

Title: Antimicrobial Activities of the Endophytic Fungus, Fusarium equiseti, Isolated from The leaves of Ocimum gratissimum Authors: Adione, Nnamdi Markben; Onyeka, Ifeanyi Peter; Abba, Chika Christiana; Okoye, Nkeoma Nkasi; Eze, Peter Maduabuchi; Umeokoli, Blessing Ogechukwu; Anyanwu, OgechI Ozioma; Okoye, Festus Basden Chiedu Abstract: Introduction: Fungal endophytes of medicinal plants origin are gaining increasing interest as sources of novel bioactive agents with therapeutic capacity. This study was designed to identify and evaluate secondary metabolites isolated from Fusarium equiseti; an endophytic fungus isolated from leaves of Ocimum gratissimum for their antimicrobial potentials. Methods: The isolation and molecular identification of the endophytic fungus, as well as fermentation, and extraction of secondary metabolites were carried out following standard laboratory procedures. The crude extract was partially purified by partitioning into different fractions using column chromatographic techniques and the fractions were tested for antimicrobial activity. The phytoconstituents in the bioactive fractions were detected by dereplication using High-Performance Liquid Chromatography linked with Diode Array Detection (HPLC-DAD).Results: Our findings showed that fraction 4 (DCM/ Methanol fraction 95:5) exhibited moderate to strong inhibition against the test micro-organisms namely, Bacillus subtilis, Staphylococcus aureus,Escherichia coli, and Candida albicans with MIC values in the range of 0.03 to 1 mg/mL but had no inhibition against Aspergillus niger and Salmonella typhi. The compounds detected in the HPLCassay include Phomoxanthone A, Scalarolide, equisetin, epi-equisetin an episomer of equisetin, Naamine A, Carbonarone A, destruxin B, cytosporin G, and WLIP (β-hydroxydecanoyl-Leu1-D Glu-De-Thr-Dval-DLeu3 DSer-Leu-Dser-Ile). These compounds have been reported to possess antimicrobial activity. Conclusion: The detection of these metabolites further confirms the potential of the endophytic fungus, Fusarium equiseti isolated from leaves of Ocimum gratissimum as a potential source of bioactive molecules for treatment of infectious diseases. Description: scholarly work

2022-08-01T00:00:00Z