by Mero Yannah, Juliana Amboh Tifang, Eric Martial Fozing, Yaya Fodoué, Armand Dongmo Kagou and Samuel Ndonyui Ayonghe
Original Research
Somie-Ntem area within the Tikar plain form part of the Western Cameroon Domain (WCD) that belong to the Central African Pan-African Fold Belt (CAPFB). Petrography and whole rock geochemistry characterize the granitoids of this area into granites (Gr), granodiorites (GD) and tonalite (Tn) forming group I granitoids. These rocks displaying high-calc-alkaline to shoshonite affinity and strongly metaluminous I-type. They also show strong enrichment in Ba-Sr and no pronounced Euanomaly, belongs to syn-to post collisional tectonic setting. Group II rocks consist of AGr show strange characteristics with high K-calc-alkaline affinity, metaluminous and peraluminous of I-type, and also very poor in Ba-Sr, strong negative Eu anomaly typical of post orogenic. Both groups depleted in Nb, Th, Ti with Pb and Dy enrichment. However, the Al2O3/TiO2vs TiO2Harker plot show that the group I granitoids originated from a common melt and got differentiated through fractional crystallization during syn-to-post tectonic regime at subduction environment induced by a crustal thickening tectonic regime. Group II granitoids are post orogenic, emplaced following tectonic extension at subduction leading to the injection of strongly evolved magma from partial melting of new material at the lower crust.
Journal of Geosciences and Geomatics. 2019, 7(5), 221-236. DOI: 10.12691/jgg-7-5-2
Pub. Date: November 24, 2019
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by Alick R Mwanza, Edwin Nyirenda and Wilma Nchito
Original Research
The Lukanga Swamp is a major wetland situated in the Central Province of Zambia. It is Zambia’s fifth largest wetland whose flood boundary fluctuates with rainfall. Despite one of their many uses being that of flood control, they are no exceptions to this natural phenomenon - flooding. Hence, this study aimed at determining the most probable flood boundary of Lukanga swamps using Landsat images and rainfall data. Seasonal rainfall amounts received over the study area for the period 1972 – 2002, as well as the water level data of the swamp was used to determine wettest years as a means of selecting Landsat imagery which depicted flooding. Rainfall was determined by interpolating rainfall from adjacent meteorological stations as there is no such station in the study area. The selected Landsat imagery was used for delineation of the swamp’s likely maximum flood extent using Remote Sensing and GIS software. The most likely maximum flood extent was found to be 11,891 km2 at peak flooding.
Journal of Geosciences and Geomatics. 2019, 7(5), 237-244. DOI: 10.12691/jgg-7-5-3
Pub. Date: December 08, 2019
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by Sowmya D R, P Deepa Shenoy and Venugopal K R
Original Research
In this paper, we have generated a 5m Digital Elevation Model (DEM) from GeoEye-1 along-track stero pair satellite imagery. The Rational Polynomial Coefficients (RPCs) provided by vendors are biased using the Rational Function Model (RFM) to improve the geo-positional accuracy. The texture features and edge features are extracted to efficiently identify the conjugate points. Epipolar resampling is performed and Normalized Correlation Coefficient (NCC) is used as a template matching technique. The patch transformation using the slope and aspect analysis is performed to match the conjugate points and whose success rate is more than without using patch transformation. The points which satisfy the defined correlation factor are accepted for DEM construction. The RMSE at five different random points of generated DEM are calculated using Google earth data and found better than LPS eATE algorithm.
Journal of Geosciences and Geomatics. 2019, 7(5), 212-220. DOI: 10.12691/jgg-7-5-1
Pub. Date: October 17, 2019
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