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Basic Petrological and Structural Analysis in the Zimbi Gold Area (East Cameroon)
Ntomb Yvan Demonstel,
Ndzie Mvondo Justin,
Ndong Bidzang Francois
Issue:
Volume 9, Issue 2, April 2020
Pages:
52-60
Received:
26 December 2019
Accepted:
13 January 2020
Published:
20 February 2020
Abstract: The plutono-metamorphic series of the locality of Zimbi, extends over a narrow strip of 135 km2 on the eastern edge of the gold district of Baden-Colomine in East Cameroon. The work carried out in this locality is based on a cartographic approach (processing of maps and Landsat-7 ETM + images), combined with a geological and mining survey on the ground using conventional tools. On the morphostructural level, we observe NE-SW oriented penetrative lineaments. The trajectories of these are deviated or not in contact with other less dense lineaments, organized in networks of directions N-S, NE-SW, ENE-WSW, E-W, NW-SE. Parallel to the main Cameroon Center Shear (N070E), the ENE-WSW network which induces a significant reversal of foliation on contact, defines a structuring dexter shear zone accompanied by NE-SW and EW satellite shear zones with dexter kinematics and NW-SE and NS of senestrial kinematics. The lithological diversity allows the facies of calc-alkaline granite to predominate. Zimbi's range of structural elements highlights a magmatic fluidity substituted in foliation. The foliation directed NE-SW, of dip (40-90 °) either towards the NW, or towards the SE; carries a linearization of stretch subméridienne. The folding that affects it is induced by two directions of compression perpendicular N-S to NE-SW and E-W to NW-SE, which define the voltage slots favorable to mineral concentrations by circulation of mineralizing fluids. The shear zones and the quartz-feldspathic veins, structures favorable to mineralization such as gold, secondarily affect this complex. These geomorphological, lithological and structural geology data make the plutono-metamorphic procession of Zimbi a privileged area for mining research, in the gold district of Baden-Colomine.
Abstract: The plutono-metamorphic series of the locality of Zimbi, extends over a narrow strip of 135 km2 on the eastern edge of the gold district of Baden-Colomine in East Cameroon. The work carried out in this locality is based on a cartographic approach (processing of maps and Landsat-7 ETM + images), combined with a geological and mining survey on the gr...
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Research Methods of Different Levels of Reservoirs Based on Seismic Data
Issue:
Volume 9, Issue 2, April 2020
Pages:
61-64
Received:
14 November 2019
Accepted:
7 January 2020
Published:
6 March 2020
Abstract: The lack of drilling data is a difficult problem in the study of reservoir configuration under the condition of sparse well pattern. In this paper, the seismic data are fully excavated, and the methods of frequency RGB fusion, small scale river sand attribute fusion and horizontal well data combination are used to study the river level, the level point bar level, and the internal configuration of point bar. The frequency division RGB fusion method has a good effect on the characterization of large-scale channel reservoirs, especially the channel stacking period and channel boundary response. The integrated attributes of river channel and sand body distribution method has a good effect on depicting the small-scale end river channel and abandoned river channel, and on this basis, the research on point bar sand body is consistent with the actual drilling. The high-precision edge detection section and RGB fusion section are superimposed to display the development of lateral volume, and verify with the actual horizontal well. River facies reservoirs of different scales have been verified by drilling with targeted research techniques. The results show that under the condition of sparse well pattern, well-seismic combination is the key to the division of small-scale sedimentary units, multi-attribute fusion under high-resolution seismic data is an important means to identify and depict point bar and abandoned river channels, and the application of horizontal well data is a supplementary means to test results and depict lateral accumulation. The research results have achieved good application results in guiding the actual production of oil field.
Abstract: The lack of drilling data is a difficult problem in the study of reservoir configuration under the condition of sparse well pattern. In this paper, the seismic data are fully excavated, and the methods of frequency RGB fusion, small scale river sand attribute fusion and horizontal well data combination are used to study the river level, the level p...
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Hydro-climatology Characterization of Degraded Lwamunda Forest Catchment Based on Probability Distributions
Ausi Abubakar Ssentongo,
Nsubuga Francis Waswa,
Daniel Darkey
Issue:
Volume 9, Issue 2, April 2020
Pages:
65-75
Received:
21 November 2019
Accepted:
27 January 2020
Published:
17 March 2020
Abstract: Hydroclimatology assessment is conventionally based on area data for identification of change patterns and trends. In this paper, monthly averages, maximum seasonal and maximum annual hydro- climatology data series from Lwamunda forest catchment area in central Uganda have been analyzed in order to determine the appropriate probability distribution models for the underlying climatology (i.e. rainfall, soil moisture content, evapotranspiration and temperature). A total of 7 probability distributions were considered and three goodnessof- fit tests were used to evaluate the best-fit probability distribution model for each hydro-climatology data series. They were Lilliefors (D), Anderson-Darling (AD), and Cramer-Von Mises (W2). A ranking metric based on the test statistic from the three GoF tests was used to select the most appropriate probability distribution model capable of reproducing the statistics of the hydroclimatological data series. The best fit probability distribution was selected based on the minimum sum of the three test statistic. Results showed that different best fit probability distribution models were identified for the different data series depending on location and on temporal scales which corroborate with those reported in literature. With the exception of soil moisture content for annual and seasonal maximum series who have the same best fit model. The same applied to evapotranspiration seasonal maximum and near surface temperature seasonal maximum as well as monthly near surface temperatures have the same best fit model. The soil moisture content data series was best fit by the Weibull probability distribution, rainfall series was best fit by Chi square and Gamma probability distributions. The evapotranspiration data series was best fit by Logistic and Extreme value maximum (Gumbel) probability distributions. Finally for near surface temperature it was best fitted by Logistic and Gumbel probability distributions. The contribution of this study lies in the use of hydroclimatological data series including soil moisture content from the area that had forest cover change to analyzeits impact on water resources patterns. The contribution is important for agricultural planning and forest managers’ simulation of forest degradation impacts.
Abstract: Hydroclimatology assessment is conventionally based on area data for identification of change patterns and trends. In this paper, monthly averages, maximum seasonal and maximum annual hydro- climatology data series from Lwamunda forest catchment area in central Uganda have been analyzed in order to determine the appropriate probability distribution...
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New Data Obtained with CT Scanning on Platypeltoides cuervoae (Corbacho & López-Soriano, 2012) Nileidae from the Lower Ordovician; Western Anti-Atlas, Morocco
Joan Corbacho,
Francisco Javier López-Soriano,
Scott Morrison,
Keith Hammond
Issue:
Volume 9, Issue 2, April 2020
Pages:
76-81
Received:
4 March 2020
Accepted:
18 March 2020
Published:
7 April 2020
Abstract: The present study illustrates for the first time the ventral aspect and the hypostome of Platypeltoides cuervoae (Corbacho and López-Soriano, 2012) of the Upper part of the Lower Fezouata Formation (Lower Ordovician: Tremadocian) of the Guelmim area; Western Anti-Atlas, Morocco. Computed tomography of the holotype and paratype kept at the Natural History Museum in London (United Kingdom) for the conduct of a study on computed tomography and radiography as expert legal evidence in paleontology has revealed the hypotheses of the two previously cited specimens (Corbacho and López-Soriano, 2012) and another disarticulated specimen below, which was discovered during the computed tomography process. All CT Scanning images in this article have been obtained from a CT Scanned at the Natural History Museum, London, UK. By describing the ventral aspect and the hypostomes of the specimens studied in this article, any possible uncertainty and affiliation to Nileidae is stated and dissipated as suggested by Gutiérrez Marco, Sá, García Bellido and Chacaltana as belonging to Asaphidae, incorrectly suggesting that It is the species: Asaphellus stubssi Fortey, 2009. Consequently, membership in the Nileidae family is reaffirmed and Asaphidae is ruled out. The genus Platypeltoides is also reaffirmed and Asaphellus is discarded. Being the correct species Platypeltoides cuervoae (Corbacho & López-Soriano, 2012).
Abstract: The present study illustrates for the first time the ventral aspect and the hypostome of Platypeltoides cuervoae (Corbacho and López-Soriano, 2012) of the Upper part of the Lower Fezouata Formation (Lower Ordovician: Tremadocian) of the Guelmim area; Western Anti-Atlas, Morocco. Computed tomography of the holotype and paratype kept at the Natural H...
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A Study of Human Response in the Blind Zone of Earthquake Early Warning
Kunsung Liu,
Hsiangchi Huang
Issue:
Volume 9, Issue 2, April 2020
Pages:
82-88
Received:
12 April 2020
Accepted:
29 April 2020
Published:
14 May 2020
Abstract: The potential for seismic hazard in Taiwan is quite high. In addition to the comprehensive reinforcement of the earthquake resistance of old construction, a short period of time can be immediately is the implementation of earthquake prevention and rescue education. Because of the blind zone of the existing strong earthquake real-time alarm system, the response time is limited, so the application of the message will have better efficiency in an automated way. As regards the emergency response of schoolchildren and the population in the blind zone of strong earthquake early warning, it is suggested that people should be using methods in line with local circumstances. In order to understand and make good use of the vibration characteristics of seismic waves, this study analyzes and illustrates them with several practical examples, including (1) 20100304 Jiasian earthquake with local magnitude (ML) of 6.4,(2) 20130327 Nantou earthquake with local magnitude (ML) of 6.2, as well as (3) 19990921 Chi-Chi earthquake with moment magnitude (Mw) of 7.6. The results of this study show that the human body's feelings are one of the most direct, real-time strong earthquake warning messages, especially in the blind zone of earthquake early warning where it is too late to provide seismic information. Judging by the obvious vibrations up and down by the P wave, it is advisable for the people on the first floor of the old low earthquake-resistant premises to seize the opportunity and suggest a time take an immediate approach to outdoor escape response. While fear and panic may be an obstacle to escape, reflex movements can overcome fear, and reflex movements can be developed through regular drills. Accordingly, people will make a correct seismic response immediately within the earthquake, in a short period of time without panic of the emergency evacuation to reach a safe location.
Abstract: The potential for seismic hazard in Taiwan is quite high. In addition to the comprehensive reinforcement of the earthquake resistance of old construction, a short period of time can be immediately is the implementation of earthquake prevention and rescue education. Because of the blind zone of the existing strong earthquake real-time alarm system, ...
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