Journal of Geosciences and Geomatics

Support Vector Machine (SVM) optimization technique is rapidly gaining attractiveness in the area of geophysics, mining and geomechanics. This paper discusses the importance of SVM for prediction of longitudinal pressure-wave velocity and its advantages over other conventional methods of computing. Pressure-wave measurement, an indicator of peak particle velocity (PPV) during blasting in a mine is an important parameter to be determined to minimize the damage caused by ground vibrations. A number of previous researchers have tried to use different empirical methods to predict pressure-wave. But these empirical methods are less versatile in their applications. The fracture propagation is not only influenced by the physico-mechanical parameters of rock, but they are also affected by the dynamic wave velocity of rock (e.g. compressional wave velocity). Wave velocity measurements have wide applications in the different fields of geophysics. A Support Vector Machine (SVM) model is designed to predict the pressure wave velocity of different rocks. To avoid the blindness in man-made choices of parameters of SVM, we use the chaos optimization algorithm to find the optimal parameters which can help the model to enhance the learning efficiency and capability of prediction. The fracture roughness coefficient and physico-mechanical properties are taken as input parameters and pressure wave velocity as output parameters. The mean absolute percentage error for the pressure wave velocity (PrV) predicted value has been found to be the least (0.258%) as compared to values obtained by Multivariate Regression Analysis (MVRA), Artificial Neural Network (ANN) and Adaptive Neuro Fuzzy Inference System (ANFIS) and generalization capability of the SVM model is found to be very useful for such type of geophysical problems.

Journal of Geosciences and Geomatics. 2014, 2(3), 130-138. DOI: 10.12691/jgg-2-3-9
Pub. Date: June 24, 2014

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Review of Gully Erosion in Nigeria: Causes, Impacts and Possible Solutions

by I. A. Abdulfatai, I. A. Okunlola, W. G. Akande, L. O. Momoh and K. O. Ibrahim

Review Article

Gully erosion, the most impressive and striking erosion type, has been recognized as one of the major global environmental problems. Many States in Nigeria are currently under the threats of this phenomenal process, south-eastern part of the country being the most affected. It has numerous causes; and these causes can be both naturally and artificially-induced, but the underlying geology and the severity of accompany surface processes play a key role. Observations have shown clearly that gully erosion is more prevalent in sedimentary terrain than in the basement complex of Nigeria. This erosion activity at various scales has resulted in the loss of lives and properties almost on a yearly basis. Solutions that have been proffered include public awareness campaign, improved farming techniques, cultural method of gully control, enactment of laws against any activities that favour gully growth, and thorough implementation of suggested solutions.

Journal of Geosciences and Geomatics. 2014, 2(3), 125-129. DOI: 10.12691/jgg-2-3-8
Pub. Date: June 23, 2014

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Stratigraphy of Vali-Abad Section (Central Alborz– North Iran) Based on Corals

by Kaveh Khaksar, Fatemh Rezvannia and M. R. Kebriaei-Zadeh

Original Research

The Mobarak Formation in the Vali-Abad section (Central Alborz-South of Chalus) was studied at the central Alborz. The stratigraphical section show regressive sequences from Tournaisian to Namurian?. Three main environments containing rugosa and tabulate corals were identified: open shelf, oolitic shoals and lagoon. Up to 25 species of rugosa and tabulate corals belonging to 16 genera have been identified: Zaphrentites parallela, Zaphrentites delanouei, Ampelexizaphrentis iraniense, Ampelexizaphrentis sp., Siphonophyllia cylindrica cylindrica, Siphonophyllia iranica, Siphonophyllia cf. dorlodoti, Kueichophyllum alborsense minor, Kueichophyllum alborsense major, Caninia aff. irinae, Dibonophyllum bipartitum, Quinghaiphyllum pygmaeum, Aullophyllidae sp. Kailingophyllum sp., Marzanophyllum chalusense, Marzanophyllum crassiseptum, Hapsiphyllum sp.1, Hapsiphyllum sp.2, Zaphrentoides sp.A, Zaphrentoides sp. B, Ufimia sp., Hapsiphyllidae indet., Syringopora sp., Michelinia sp. and Favosittidae indet. Coral assemblages allow us to distinguish three biozones, with local value. Lowermost assemblage is composed of small, solitary, undissepimented corals and it is typical open and deep platform. Corals at assemblage II are must diverse and abundant. This assemblage developed at shallow areas of the open shelf. Assemblage III proceed from lagoon and it is composed of small, solitary, undissepimented corals. Iranian Lower Carboniferous corals belong to shallow areas of open shelf-lagoon of unique oceans. Tournaisian- Namurian? platform are well-developed in the Alborz, Central Alborz and Baluchestan and rich in fossil corals. They are extended from southeast to northwest in the area of Lower Carboniferous deposition.

Journal of Geosciences and Geomatics. 2014, 2(3), 120-124. DOI: 10.12691/jgg-2-3-7
Pub. Date: June 22, 2014

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Impact of Gas-Flaring on the Quality of Rain Water, Groundwater and Surface Water in Parts of Eastern Niger Delta, Nigeria

by Amadi and Akobundu N.

Original Research

The environmental and health impact associated with over 50 years of oil exploration and exploitation in Eastern Niger Delta region of Nigeria is of great concern. Flaring is the controlled burning of the natural gas associated with oil production. This study has clearly shown that gas-flaring constitutes a major source of water pollution in the oil producing region of Eastern Niger Delta. The results of the laboratory analysis of the water samples revealed that the water sources in the area have been negatively impacted acid-rain and NO₂, SO₂ and CO₂ from the burning gas. The sulphate, bicarbonate and nitrate content of rain water samples within the radius of 20 km from the gas-flaring station are high but the concentration decreases away from the gas-flaring stations. It was ascertained that the acidity and hence the nitrate, sulphate and bicarbonate content of rain water is a function of the frequency and duration of the rainfall as well as the direction of the prevailing wind prior to the rainfall and it gives rise to the formation of acid-rain. Corrosion of buildings, the dominance of respiratory problems and skin diseases are some of the signatures of gas flaring on the host communities. However, there may be a serious long term effect on the water resources in region in terms of quality if gas-flaring in the area does not stop.

Journal of Geosciences and Geomatics. 2014, 2(3), 114-119. DOI: 10.12691/jgg-2-3-6
Pub. Date: June 22, 2014

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Using Low Cost DeskTop Publishing (DTP) Scanners for Aerial Photogrammetry

by Khalid L. A. El-Ashmawy

Opinion Paper

This paper emphasizes on investigating the suitability of using low cost DeskTop Publishing (DTP) scanners for aerial photogrammetric applications. The paper involves calibrating the scanner geometric errors. Mathematical and actual photogrammetric data were used during this investigation. The mathematical data shows that calibration of DTP scanners improves the root mean square error (RMSE) values of the photogrammetric solution by about 81% and 83% in horizontal and vertical directions respectively. The actual data proofs that the use of low cost DTP scanner as opposed to the use of Leica BC2 analytical plotter increases the horizontal and vertical RMSE values of about 35% and 43% respectively. The obtained accuracies allow the generation of planimetric maps at a scale of 1:500 or smaller and topographic maps with a contour interval of around 1 m or larger. This methodology is of great interest to small engineering firms for the generation of local area maps.

Journal of Geosciences and Geomatics. 2014, 2(3), 107-113. DOI: 10.12691/jgg-2-3-5
Pub. Date: June 16, 2014

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A Review of Jurassic Oceanic Anoxic Events as Recorded in the Northern Margin of Africa, Tunisia

by Mohamed Soua

Review Article

During these last years, considerable attention has been given to Jurassic oil and gas shale in the middle and high latitudes of the northern hemisphere such as the west Europe and Russian platform where the most attractive Jurassic basins are located (e.g. Cleaveland basin, UK; Boulonnais, northern France; Pechora Basin, Moscow Basin, etc). In most petroleum systems which characterize these basins, the Jurassic (mainly the early Toarcian) played the major role in hydrocarbon generation which constitutes 25% of the global reserve of hydrocarbon. Tunisian basins represented by the northern Tunisian trough, the Dorsale and the North South Axis (NOSA) belong to the southern Tethyan margin where northern and central area have recorded the early Toarcian oceanic anoxic event (T-OAE). This short lived (c. 2 Ma) period of anoxia ranges within the whole Harpoceras serpentinum Zone which corresponds to deep water environments marked by black shale accumulation. Interestingly, towards the south, the dysaerobic conditions in the Chott basin appear to have begun largely later where the oxygen depletion is assumed to have prevailed during the Callovian, whereas it was limited to the early Toarcian in the Central and Northern Tunisia only a few hundreds of kilometers away. In addition, biostratigraphic and complete geochemical review has been undertaken from published papers and unpublished internal reports to better assess these important source intervals.

Journal of Geosciences and Geomatics. 2014, 2(3), 94-106. DOI: 10.12691/jgg-2-3-4
Pub. Date: June 09, 2014

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Foraminiferal Stratigraphy and Paleoecological Interpretation of Sediments Penetrated by Kolmani River -1 Well, Gongola Basin, Nigeria

by C. N. NWOJIJI, P. OSTERLOFF, A. U. OKORO and G. NDULUE

Original Research

Foraminiferal investigation of the Kolmani River -1 well yielded a total of forty two (42) species. The foraminiferal assemblages comprise 86% arenaceous benthonics, 4% calcareous benthonics and 8% planktonic foraminifera. Few ostracod and gastropods shells were recovered and they make up the remaining 2% of the assemblages. Quantitative and qualitative analyses of the recovered foraminifers were used to interpret the age, paleoecology, paleobathymetry and paleoenvironment of the sediments penetrated by the well. Three foramineferal assemblage zones consisting of Agathamina sp.2, Haplophragmoides bauchensis and Heterohelix moremani-Haplophragmoides talokensis Assemblage Zones were identified in the drilled interval of Kolmani River -1 Well. These zones are dated Campanian-early Santonian, early Coniacian-early Turonian and early Turonian-late Cenomanian respectively. The paleobathymetry ranges from Inner to Outer neritic suggesting water depths of less than 200 m. The overall depositional environments varies between coastal plain/estuarine to open marine setting. The dominance of agglutinated foraminiferal species such as Ammobaculites sp, Haplophragmoides sp, Miliammina sp and Trochamina sp suggest restricted, low oxygen bottom water conditions for most of the paleoenvironments.

Journal of Geosciences and Geomatics. 2014, 2(3), 85-93. DOI: 10.12691/jgg-2-3-3
Pub. Date: May 27, 2014

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Chemistry of Maiganga Coal Deposit, Upper Benue Trough, North Eastern Nigeria

by Usman Shehu Onoduku

Original Research

Chemical studies have been carried out on coal samples from Maiganga coal mine, Gombe formation, Upper Benue Trough of Nigeria with a view to determine theirchemical characteristics and possible utilization as coking coal or otherwise. The coal samples used for the analyses were sourced from the Maiganga coal mine. Various conventional coal analytical methods were adopted according to the relevant ASTMs. Chemical analysis of the coal samples indicated that, on average, they contain4.8% moisture, 49% ash, 31.11% volatile matter, 0.92% sulphur, 15.64% organic carbon, 0.02% phosphorus, 2283Kj/kg calorific value and 0(zero) Free Swelling Index(FSI). The above analytical results show that the coals show an appreciable property of coking and thus can be employed in the generation of substantial heat for the working of blast furnace.

Journal of Geosciences and Geomatics. 2014, 2(3), 80-84. DOI: 10.12691/jgg-2-3-2
Pub. Date: May 15, 2014

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21494 Views6978 Downloads33 Likes6 Citations