Open Access Original Research Article

Preliminary Structural and Petrographic Studies of Oke Ogun Rocks, Southwestern Nigeria

Olusola Ayoade Adeagbo, Lukuman Abudulawal, Sikiru Adetona Amidu

Journal of Geography, Environment and Earth Science International, Page 1-16
DOI: 10.9734/JGEESI/2018/40010

This study attempts to analyze structural elements and mineralogical compositions that are present in rocks in parts of Oke Ogun and relates their occurrences to the geology of the area. The main objectives are to better understand the structural history of the rocks and the deformational episodes that pervaded them. Geological field mapping was undertaken to identify and study field occurrences and structural relationships of rock types. Strike and dip directions were measured with compass-clinometer, whereas coordinates of sampling points and locations were taken using Global Positioning System (GPS). In addition, rock samples were collected and thin sections prepared for petrographic analysis. The main lithologic units found in the area are syenite, migmatite-gneiss and porphyroblastic gneiss, mica schist, banded gneiss and biotite hornblende granite. Geologic features such as faults, joints, fractures, foliations, quartz veins, folds, and xenoliths were also observed on the outcrops. The result of petrographic studies shows that most samples have highest concentrations of plagioclase, which range from 29.4% to 26.5%, followed by quartz (24.6% to 24.4%). Few locations recorded highest concentrations of microcline ranging from 41.5% to 19.6%. Biotite values range from 17.5% to 6.7%, whereas hornblende and opaque mineral values range from 7.4% to 5.5% and from 2.0% to 0.9%, respectively. Deformation-induced elongations of minerals were also observed in thin sections. The resultant orientations of macro-structural veins based on structural measurements show a NE-SW and NW-SE trends,                  whereas joints trend N-S and E-W. These structural trends have been interpreted to be analogous to directions of tectonic events responsible for metamorphism and/or fracturing of rocks in the region.

Open Access Original Research Article

Delineation of Channel Migration Zone and Its Change in Post Farakka Barrage, a Case in Kalindri River of Eastern India

Somen Das

Journal of Geography, Environment and Earth Science International, Page 1-10
DOI: 10.9734/JGEESI/2018/40154

Migration of river channel is a natural process but sometimes it can create problems such as land ownership conflict, land loss and loss of infrastructure. Present study deals with the river Kalindri of Malda district which is considered as a branch of Pullahar. The principle objective of this work is to delineate channel migration corridor of the river Kalindri. For the demarcation of channel migration zone (CMZ), construction of historical migration zone (HMZ), erosion buffer (EB), avulsion potential zone (APZ) etc. is performed. The results clearly display that the river has a historical channel migration zone of 218.24 km2 with average lateral width of 3.37 km in between 1924 to 2015. After Farakka Barrage project (1973), volume of water and river energy is reduced significantly and it causes squeezing of wide channel migration zone (1.63 km). Total 74 number of villages fall under present channel migration zone and out of them 27% villages are prone to high frequency channel migration problem.

Open Access Original Research Article

Pebble Size in Matrix of Palaeoplacer Conglomerate Correlated with Gold Grade

H. D. Braimah

Journal of Geography, Environment and Earth Science International, Page 1-14
DOI: 10.9734/JGEESI/2018/40428

This study aimed at finding a complementary field guide to recognize the relative gold ‘grade’ of the palaeoplacer banket conglomerate of the Tarkwaian Group in southwestern Ghana, West Africa. The study was conducted on a drill core from the Ajopa pit near Tarkwa, which, intercepted a palaeoplacer conglomerate from a depth of 5 m to 105 m. The conglomerate forms part of the Tarkwaian gold-bearing unit, deposited from 3132 Ma to 2095 Ma. The pebbles in the rock are mainly made up of oligomictic quartz of milky or vitreous whitish grey and coarse-grained. The size ranges from 8.50 mm to 30.50 mm, rounded, well to moderately sorted, and closely packed. Gold occurs in the matrix of the pebbles, composed of fine to medium-grained quartz, and associated with chlorite, and sericite, with heavy minerals mainly comprised of magnetite and hematite. The Tarkwaian Group sediments were sourced from the Birimian Supergroup which is a hydrothermal gold-bearing terrain of about 2.2 billion years (b.y.) old. The results of the study confirm that gold grade increases with increase in pebble sizes in the conglomerate. The study also found out that there is a relationship between bigger grain sizes in the matrix to gold grades. Also, the medium-grained fragments in the matrix which range in size from 0.60 mm to 4.35 mm show a positive correlation with gold grade (0.01 g/t to 3.67 g/t). These findings apply to higher and lower gold grades.

Open Access Original Research Article

Identifying Land Use Change Trends Using Multi-temporal Remote Sensing Data for the New Damietta City, Egypt

S. M. Arafat, K. Abutaleb, E. Farg, M. Nabil, M. Ahmed

Journal of Geography, Environment and Earth Science International, Page 1-12
DOI: 10.9734/JGEESI/2018/40132

The current study aims to utilize the use of multi-remote sensing data for land use land cover changes and trend analysis for the New Damietta city in Damietta governorate. Three different sensors were used in this study in different dates (SPOT-4 2007, SPOT-5 2011, and Kanopus-V1 2016). The FAO classification system (FAO-LCCS) was used to identify the different land use/cover classes in the study area. Results showed 13 main land use/land cover classes exist in the study area. The land use/land cover maps are produced for 2007, 2011 and 2016 with overall accuracies of 0.91, 0.92, 0.91 and kappa statistics of 0.88, 0.86 and 0.89 respectively. Results revealed that four different classes had a significant change over the study period. These classes are urban areas, cultivated lands, fish farms and bare areas. Trend analysis revealed that urban areas had the highest increase rate (+2.76 km2/year short term & +2.73 km2/year long-term) while cultivated land and bare areas suffer from the highest decrease rates (-1 km2/year short and long-term, -1.54 km2/year short-term and -1.59 km2/year long term respectively).

Open Access Original Research Article

Biodiversity and Oil Activities in the Niger Delta Region of Nigeria

Oke A. Emuedo, Crosdel O. Emuedo

Journal of Geography, Environment and Earth Science International, Page 1-8
DOI: 10.9734/JGEESI/2018/35770

The variation among living organisms, encompassing species, genetic and ecosystem diversity is known as Biodiversity. It includes all species of plants, animals, and microorganisms, the ecosystems and ecological processes of which they are part, covering all forms of life on earth. Oil activities have for over fifty years, been carried out in the Niger Delta, without recourse to the environment resulting in detrimental impacts on the environment with concomitant effects of biodiversity. This study investigates the impact of oil activities on biodiversity in the Niger Delta, deploying an eclectic approach in which, structured questionnaire schedule and focus group discussion were used to obtain relevant data. It concludes that the adverse effects of oil activities on the environment have had concomitant negative impacts on biodiversity in the Niger Delta.