by Ominigbo O. E., Ukwang E. E., Okumoko J. P. and Ukpai U. J.
Original Research
The basement rocks around Irruan in southern Obudu Plateau, southeastern Nigeria were studied using field mapping and geochemical data. Both igneous (granodiorite and biotite granite) and metamorphic rocks (granite gneiss, banded gneiss and migmatite gneiss) were mapped in the area. The rocks are generally quartzofeldspathic and range from alkali-calcic to calc-alkali. Fairly strong negative correlation exists between Al2O3 and Na2O with SiO2 as well as between Al2O3 and Fe2O3. The magma source for the Irruan granitoids is continental as indicated by the high SiO2 content (≥70.11 wt.% except the biotite granite that records 61.10 wt.% of SiO2) and discriminant plots for the area. A sedimentary protholith has been interpreted for the gneissic rocks. Magmatism in the area commenced during the later stages of the Pan-African orogeny and continued much into the post-orogenic period, leaving behind, imprints of syn-collosional and post-orgenic tectonic settings.
Journal of Geosciences and Geomatics. 2020, 8(1), 35-44. DOI: 10.12691/jgg-8-1-5
Pub. Date: April 13, 2020
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by D. M. J. Fubara, Lawrence Hart and Golden Ibinabo Otasanya
Original Research
Bonny River is arguably the most important river in Rivers State because it registers per season high volume of vessel traffic compared to other rivers in the state and also has infrastructures, major cities, companies and institutions along its banks. This high vessel traffic on the channel comes with mishaps that can render a once navigable channel unsafe which can lead to loss of property, resources, life and cause environmental pollution. This research sought to provide analysis of navigational hazards on about 15Km of the study area using a positioning device and some acoustic sensors. It yielded the following findings. The upstream end of the research area had a depth range of 1.5m to 15.1m and its navigable channel with depth range of 3.2m to 15.1m while the Port Harcourt Wharf axes about 12Km farther downstream had a range of 0.1m to 18.7m and its navigable channel with depth range of 10.1m to 18.7m. The maximum depth being downstream was 18.7m. The upstream area was noticed to have the presence of all wrecks (visible and submerged) in the study area. The percentage space occupied by the wrecks (partly submerged and completely submerged) in relation to the entire research space was less than one percent. Although the magnetometer detected several isolated ferrous presence, the side scan sonar representation of the riverbed suggest the ferrous presence are all buried debris. These findings upstream suggests the need for maintenance of the section.
Journal of Geosciences and Geomatics. 2020, 8(1), 25-34. DOI: 10.12691/jgg-8-1-4
Pub. Date: March 25, 2020
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by Robinson Tchatchueng, Habib Dadjo Djamo, Timoléon Ngnotué, Evine Laure Tanko Njiosseu, Mamadou Traoré, Cyriel Moudioh, Hervé Wabo, Cédric Djeutchou and Jean Paul Nzenti
Original Research
The Endengue iron formations (IFs) belong to the Archaen Ntem greenstones belt at the NW edge of Congo craton and comprise magnetite-bearing gneiss associated with biotite-pyroxene gneiss and intruded by biotite granite and charnockite. The studied IFs are fine-grained; weak foliated rocks, composed of quartz-pyroxene-magnetite-plagioclase mineral assemblages, suggesting high-grade metamorphism. Whole-rock geochemical composition reveals that iron and silica are the main chemical components of the studied IFs with an average TFe2O3 + SiO2 of 93.06 wt-%, suggesting the purity of the chemical precipitation. In addition, the high average Si/Al (38.69); Fe/Ti (766.83) and Fe/Al (56.36) ratios and the Fe/Ti vs Al/(Al+Fe+Mn) plot suggest that the major components (> 80%) of the Endengue IFs are predominantly hydrothermal in origin. However, the slightly high Al2O3+TiO2 content (average of 2.14 wt-%) suggested a detrital input during their deposition. The studied IF samples with an average Total Fe content of 39.40 wt-%, low gangue (34.68 wt-% SiO2 and 1.05 wt-% Al2O3) and deleterious (P2O5: 0.07 wt-%) elements contents, correspond to accepted commercial low grade siliceous ore by global standards. The Edengue IFs shared chemical similarities with other Precambrian IFs worldwide.
Journal of Geosciences and Geomatics. 2020, 8(1), 15-23. DOI: 10.12691/jgg-8-1-3
Pub. Date: March 03, 2020
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by Kenneth S. Boling, Robert D. Hatcher Jr, Peter J. Lemiszki and Gary G. Bible
Original Research
Several episodes of uplift have occurred along the Cincinnati arch. These periods of uplift are likely a result of several orogenic events although the exact timing of the uplift in relation to these orogenic events is not fully understood. One reason for this has been the lack of accessible structural data over this region. The southern end of the Cincinnati arch and the Nashville and Jessamine domes occur along the arch in Kentucky, Tennessee, and northern Alabama. These states have very different levels of data availability, but potentially enough to identify more subtle, second- and third-order folds and faults along and on the flanks of the arch. These structures may be the key to unraveling the pre-Devonian tectonic history of the two domes, and can be identified in structure contour maps with sufficient data. The goal of this study was to perform a preliminary assessment of the viability of constructing a complete series of structure contour maps of several geologic units across the region, using publicly available data. Thirty-two geologic quadrangle maps selected across the southern end of the Nashville dome in Tennessee were manually digitized utilizing ArcGIS™. The results from this initial study were then compared to the results produced using a less labor intensive method using basic GIS functions to generate data points. The results of this initial investigation seem promising, but methods of cross-verification to remove erroneous data points, the incorporation of subsurface data, and the incorporation of data sets from other states will be required to expand the coverage area. Automation of this process will need to be developed to allow further research to be performed.
Journal of Geosciences and Geomatics. 2020, 8(1), 9-14. DOI: 10.12691/jgg-8-1-2
Pub. Date: February 23, 2020
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by Bidjo Emvoutou Gery Christian, Ndzie Mvondo Justin, Ngo Bidjeck Louise Marie, Ipan Antoinnette, Ntomb Yvan Demonstel and Ndong Bidzang Francois
Original Research
The meteoric weathering of Precambrian ferriferous quartzites from Meyomessi in southern Cameroon has led, in a humid tropical climate, to the formation of secondary oxidized ores. The weathering profile of the ferriferous quartzites shows from the base to the summit: the bedrock, the saprolites, the gravel horizon and a surface sandy clayey aggregate, ferriferous quartzite is a finely banded rock showing alternating quartz beds and iron oxide beds. The main features of the Meyomessi quartzite geochemistry show that the ferruginous facies are remarkably poor in any element other than Fe and Si. The alteration of the materials shows high Fe, Si, Al, Cr, Zr, Ba, Ga, Nb and Th. Rare earth elements levels are generally low compared to Ce, La and Nd, which are concentrated in upper gravel and sandy-clay levels. The rare earth elements spectrum indicates a positive anomaly in Ce and a negative anomaly in Eu. The results obtained from the calculated balances show a very high enrichment in Al, Ti and K in all the altered materials, low in Si and P in the higher levels and weak in iron in the weathered fragments and in the sandy clay loam level. The losses are total and moderate for all the trace elements, while the rare earths elements are enriched in the soft materials of the whole profile. The iron content in the bedrock (64.9%) versus 68% in the weathered rock fragments (ore), shows that the climatic alteration improves the quality of the ore in the ferruginous fragments by dissolution of the silica and relative concentration iron.
Journal of Geosciences and Geomatics. 2020, 8(1), 1-8. DOI: 10.12691/jgg-8-1-1
Pub. Date: January 19, 2020
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