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Heterogeneous Granitic Pluton of Central Toumodi-Fettekro Sillon (Central Côte d'Ivoire): Petrographic and Geochemical Characterization
Aka Wilfried Glwadys Ghislain,
Ouattara Gbele,
Kouassi Brice Roland
Issue:
Volume 11, Issue 4, August 2022
Pages:
142-149
Received:
21 May 2022
Accepted:
27 June 2022
Published:
5 July 2022
DOI:
10.11648/j.earth.20221104.11
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Abstract: The petrographic and geochemical data of the granitoids of the central part of the Toumodi-Fettekro sillon (or belt) have allowed to characterize a complex set whose main terms can be summarized as follows: biotite granites, granodiorites, leucogranites and aplitic bodies. These rocks are composed of quartz, plagioclase, biotite, potassium feldspar, with variable hues (leucocrate to mesocrat), structures (medium to coarse grained) and mineralogical proportions (depending on abundance). The geochemical interpretation is based on the systematic search for genetic links between the various terms of this assemblage. Thus, geochemistry has enabled us to distinguish three facies (biotite granites, leucogranite and aplitic granite) that are weakly altered and peraluminous in character (A/CNK > 1) and a fourth (granodiorite) that tends to be metaluminous (A/CNK < 1). The strongly aluminous character of these three facies and the presence of minerals such as muscovite, garnet and tourmaline, as well as the presence of numerous pegmatite veins, suggest a sedimentary origin (S-type granite). The granodiorite, on the other hand, seems to have genetic links with TTG-type protoliths through a partial fusion process.
Abstract: The petrographic and geochemical data of the granitoids of the central part of the Toumodi-Fettekro sillon (or belt) have allowed to characterize a complex set whose main terms can be summarized as follows: biotite granites, granodiorites, leucogranites and aplitic bodies. These rocks are composed of quartz, plagioclase, biotite, potassium feldspar...
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Stratigraphic Order and Age of the Bang Ca Formation in Bang Ca Area, Ha Lang District, Cao Bang Province
Nguyen Huu Hung,
Doan Dinh Hung,
Nguyen Ba Hung
Issue:
Volume 11, Issue 4, August 2022
Pages:
150-157
Received:
11 May 2022
Accepted:
29 June 2022
Published:
12 July 2022
DOI:
10.11648/j.earth.20221104.12
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Abstract: Stratigraphic division also age of the sequence of cherty shale (the Bang Ca Formation) in Bang Ca Townlet, Ly Quoc Commune, Ha Lang District, Cao Bang Province, North Vietnam presently is still a subject for debate: Bourret R. 1922 (Late Devonian), Vasilevskaya A. D. 1965 (Eifelian-Givetian), Pham Dinh Long 1973 (Givetian), Duong Xuan Hao et al. 1973, 1980 (Frasnian); Pham Huy Thong, Nguyen The Dan 1984 (Famennian); Doan Nhat Truong, Ta Hoa Phuong 1999 (Middle-Upper Devonian); Doan Nhat Truong, Ta Hoa Phuong 1999 (Frasnian-Famennian); Tong Dzuy Thanh 2011 (Middle-Upper Devonian). Studying stratigraphic order of Devonian sequence exposed in the Ban Thung-Bang Ca-Lung Thoang section, also based on macro-fossils newly collected from the cherty shale, the Bang Ca Formation is recognized as a lithostratigraphic unit, overlying the Na Quan Formation (D1-2 nq), and underlying the Toc Ta Formation (D3-C1 tt) with total thickness about 200 m. The Frasnian age of the Bang Ca Formation is based on macrofossil asemblages Atrypa (Desquamatia) cf. zonataeformis, Spinatrypa sp., Monelasmina sp. (Brachiopoda); Glyptohallicardia cf. ferruginea (Bivalvia), Manticoceras sp. (Ammonoidea); Homoctenus sp., Viriatellina sp., Striatostyliolina sp., Styliolina sp. and conodont Ozarkodina sp.
Abstract: Stratigraphic division also age of the sequence of cherty shale (the Bang Ca Formation) in Bang Ca Townlet, Ly Quoc Commune, Ha Lang District, Cao Bang Province, North Vietnam presently is still a subject for debate: Bourret R. 1922 (Late Devonian), Vasilevskaya A. D. 1965 (Eifelian-Givetian), Pham Dinh Long 1973 (Givetian), Duong Xuan Hao et al. 1...
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Construction and Application of Traditional Chinese Medicine Minerals Database
Shanna Xue,
Mingyue He,
Mei Yang,
Zhiyuan Wu
Issue:
Volume 11, Issue 4, August 2022
Pages:
158-170
Received:
18 June 2022
Accepted:
1 July 2022
Published:
18 July 2022
DOI:
10.11648/j.earth.20221104.13
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Abstract: Mineral drugs are rich in resources in China and have distinct curative effects, and are an irreplaceable component of traditional Chinese medicine (TCM). So, this makes minerals drugs become a research hotspot in the medical and geological fields, and a large number of related literatures have emerged. However, there are still some problems in mineral medicine research, mainly reflected in the qualitative and quantitative detection method is not mature, ignoring the importance of mineral properties for the study of pharmacological effects, and the studies on mineral drugs from the perspective of mineralogy are few at present. Chemical constituents of mineral drugs are the main source for the study of Pharmacological action. Therefore, it is meaningful to study mineral drugs by combining mineralogy with pharmacology. In this paper, a comprehensive classification system of mineral drugs is summarized, and the modern detection techniques (Infrared and Raman spectroscopy) for studying qualitative and quantitative analysis of mineral drugs are discussed. In addition, the design and application of TCM minerals database is also described. Here, we hope that this will provide a useful reference for the classification and analysis of mineral drugs from the perspective of mineralogy, and the digitization construction and application of Traditional Chinese Medicine minerals database.
Abstract: Mineral drugs are rich in resources in China and have distinct curative effects, and are an irreplaceable component of traditional Chinese medicine (TCM). So, this makes minerals drugs become a research hotspot in the medical and geological fields, and a large number of related literatures have emerged. However, there are still some problems in min...
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Pedo-geochemistry of Vertisols Under Tropical Seasonally Contrasted Climate, Northern Cameroon: Implications for Vertisolization
Gouban Hamadjida,
Lionelle Estelle Bitom-Mamdem,
Jean Pierre Temga,
Elisé Sababa,
Primus Tamfuh Azinwi,
Simon Djakba Basga,
Elisabeth Yaboki,
Jean Pierre Nguetnkam,
Dieudonné Lucien Bitom
Issue:
Volume 11, Issue 4, August 2022
Pages:
171-193
Received:
7 June 2022
Accepted:
29 June 2022
Published:
22 July 2022
DOI:
10.11648/j.earth.20221104.14
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Abstract: Fourthy one representative profile of Northern Cameroon Vertisols on lowland and upland areas under tropical seasonally contrasted climate were investigated to assess the genesis of smectite and vertisolization processes on their geochemistry relation. Macro-micromorphological, physico-chemical, mineralogical and geochemical properties were determined for 137 soil samples. Statistical analysis was used to interpret the dataset and identify affinity groups of samples and properties. Dark gray color, slickensides, cracks and micro relief gilgaï are major characteristics of the soils within the abundance of the major mineral constituents: smectite, kaolinite and quartz. Silicon, Al and Fe were the most abundant elements in Vertisols. Vertisols developed upland and lowland under tropical seasonally contrasted climate showed the following orders for REE concentrations: Ce > Nd > La > Pr > Sm > Gd > Dy > Yb > Er > Eu > Ho > Tb > Lu > Tm and Ce > La > Nd > Pr > Sm > Gd > Dy > Yb > Er > Eu > Ho > Tb > Lu > Tm, respectively. The grouping of properties into affinity groups is mostly weak with properties showing a diffuse distribution with no very distinct affinity groups. In the upland Vertisols, genesis of the smestites is made from the feldspars present in the parent rock; meanwhile, high smectite content was related to the low landscape positions, a strongly contrasted climate and the presence of a clay-rich alluvial parent material in lowland Vertisols. Climates with contrasting seasons, there is intense weathering during the wet season. The released ions are concentrated in the dry season and give smectite. This concentration can take place on site on basic or acid crystal rocks, or in the low points of the landscape.
Abstract: Fourthy one representative profile of Northern Cameroon Vertisols on lowland and upland areas under tropical seasonally contrasted climate were investigated to assess the genesis of smectite and vertisolization processes on their geochemistry relation. Macro-micromorphological, physico-chemical, mineralogical and geochemical properties were determi...
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Elastic Impedance Inversion with GRU-CNN Hybrid Deep Learning: Visualizing the Black Box
Xiujuan Liu,
Lifeng Liang,
Zhiming Kang,
Qiang Guo
Issue:
Volume 11, Issue 4, August 2022
Pages:
194-203
Received:
22 June 2022
Accepted:
13 July 2022
Published:
22 July 2022
DOI:
10.11648/j.earth.20221104.15
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Abstract: The process of hybrid deep learning is highly integrated with the seismic inversion, leading to the black box phenomena, which hampers the understanding of deep-learning inversion process. In this paper, a numerical example is presented to visualize the process of deep learning from the perspective of elastic inversion. Synthetic seismic data is generated by forward modeling on a wedge model, after which the GRU-CNN hybrid deep learning algorithm is applied to obtain the inverted impedance method. In specific, the extraction of local seismic features by CNN, the extraction of low-frequency seismic features by GRU, activation layer, Adam and learning rate schedules, initialization model, loss function, and training process are detailed illustrated and visualized, all of which reveal the internal operating mechanism of the black box. The results show that: 1) after required epoch iterations, the features extracted by CNN becomes close to the real impedance, while the features extracted by GRU is close to the low-frequency information involved in conventional seismic inversion (which is consistent with the cognition from commercial software, e.g., Jason, Geoview, etc.), 2) The learning rate is a very critical parameter in the optimization process. Comparing with the constant learning rate, the cosine learning rate converges faster with better performance, and 3) the initial impedance model in hybrid deep learning is to initialize the weights of all neurons, which is essentially different from those of conventional seismic inversion scheme, e.g., constrained sparse pulse inversion.
Abstract: The process of hybrid deep learning is highly integrated with the seismic inversion, leading to the black box phenomena, which hampers the understanding of deep-learning inversion process. In this paper, a numerical example is presented to visualize the process of deep learning from the perspective of elastic inversion. Synthetic seismic data is ge...
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Seismic Risk Analysis for Large Dams in West Africa Region
Stephen Ayanfe Irinyemi,
Domenico Lombardi,
Syed Mohammed Ahmad
Issue:
Volume 11, Issue 4, August 2022
Pages:
204-213
Received:
24 September 2021
Accepted:
27 October 2021
Published:
26 July 2022
DOI:
10.11648/j.earth.20221104.16
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Abstract: Dams are critical infrastructures, the failure of which would cause a catastrophic effect on a regional scale. West Africa has more than 150 large dams across the region, constructed in strategic locations which pose a potential risk for people and properties at the downstream paths. A method of seismic risk analysis for large dams within the West Africa region is discussed to evaluate the seismic hazard rating at the dam sites and the risk rating of its appurtenant structures. Although the study region is considered as a stable continental, two major earthquakes with casualty figures have been reported in Ghana and Guinea areas of the study basins in 1939 and 1983, respectively. This paper summarizes the procedures for analyses seismic risk and explain the seismic hazards of seventeen large dams selected within the study basins based mostly on the significance of each dam and location of earthquakes in and around the dam sites. The results show the values of peak ground acceleration (PGA) at dam sites ranges from 0.02 g to 0.45 g. A hazard map of PGA indicating preliminary analysis of dam structures was developed for the study basins. Based on the results of this analyses, 59% of the analysed dams identified as high-risk dams while the rest dams fall within the moderate-risk class. These dams require further analyses for their safety to protect the populace and the built environments along the downstream paths.
Abstract: Dams are critical infrastructures, the failure of which would cause a catastrophic effect on a regional scale. West Africa has more than 150 large dams across the region, constructed in strategic locations which pose a potential risk for people and properties at the downstream paths. A method of seismic risk analysis for large dams within the West ...
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Bidzar Marble Tailing Characterization and Potential for Civil Engineering Works Northern Cameroon
David Ikome Lyonga,
Christopher Fuanya,
Frederic Mounsi,
Gazissou Zoulla Flaubert,
Aboubakar Abdoul,
Tchatchoua Fils Thomas Roger,
Setchokbe Hinfene Venceslas,
Ngalla Ndi,
Andrew Molonga Lyonga,
Sidney Tamasang Asangbeh,
Beri Sirnsai Fabian,
Jean Paul Sep Nlomngan
Issue:
Volume 11, Issue 4, August 2022
Pages:
214-219
Received:
30 June 2022
Accepted:
18 July 2022
Published:
26 July 2022
DOI:
10.11648/j.earth.20221104.17
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Abstract: Stockpiling of tailings is a common phenomenon in most mines around the world, though these tailings can be exploited for better usage, little is been done as this is concern. The Bidzar-Bataol area is known for high marble concentration within the sub region and the setting up of cement factories will see an increase in marble tailings stockpile. This study focuses on the characterization of tailings collected from the crushing of marble in Bidzar, North Region of Cameroon. A total of four samples were prepared from a grab sample collected at the mining site. The Bidzar marble tailings were tested on their geo-mechanical properties and compared to that of aggregates used in civil engineering works and other similar study. The investigated properties with their methods in this study are: grain size analysis (NF EN 933-1), specific gravity (NF P 94-054), Los Angelos (NF EN 1097-2), Micro Deval (NF EN 1097-1) and Flakiness Index (NF EN 933-3). The results obtained shows that the tailings are poor but uniformly graded with a Coefficient of Uniformity (Cu) 2.42 and Coefficient of Curvature (Cc) 1.02. Also, aggregate of granular class 10/14 shows average Los Angelos value of 20.18 % and average Micro Deval 16.9 %, making them good for constructions. Similarly, with average specific gravity of 2.71 g/cm3 and average Flakiness Index of 19.63 %, the tailings present good potentials for aggregate used in civil engineering. The tailings of granular class 10/14 mm present excellent results for specific gravity, and a satisfactory result were obtained on the Los Angelos and Micro Deval. It can therefore be concluded that Bidzar marble tailing can potentially serve as conventional aggregate and can be used in construction.
Abstract: Stockpiling of tailings is a common phenomenon in most mines around the world, though these tailings can be exploited for better usage, little is been done as this is concern. The Bidzar-Bataol area is known for high marble concentration within the sub region and the setting up of cement factories will see an increase in marble tailings stockpile. ...
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Seismic Hazard Microzonation of Tasikmalaya City, West Java Province, Indonesia
Asdani Soehaimi,
Sukahar Eka Adi Saputra,
Yayan Sopyan,
Rio Alcanadre Tanjung,
Rizky Komalasari,
Sandy Perdana Arief Setiawan
Issue:
Volume 11, Issue 4, August 2022
Pages:
220-231
Received:
6 July 2022
Accepted:
5 August 2022
Published:
29 August 2022
DOI:
10.11648/j.earth.20221104.18
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Abstract: Tasikmalaya, as the capital city of Tasikmalaya Prefecture in West Java Province, Indonesia, which has a high density population. More than 600.000 peoples are living in this city, many buildings, and some important infrastructures has been built. Base on probabilistic seismic hazard map of Indonesia by National Standardization Agency, shown the Tasikmalaya City located at the region of Peak Ground Acceleration (PGA)= 0.4 – 0.5 g and Pseudo Spectral Acceleration (PSA SS: 0.2 second and PSA S1: 1 second= 0.7 – 0.8g and 0.4 – 0.5g, for Soil Class SB, 2% probability in 50 years. In order to mitigate seismic risk, a potential seismic hazard micro-zonation map has been produced as guidance for urban city planning. We classify three potential seismic hazard micro-zonation based on the wave velocity of Vs30. The first class is High Potential Seismic Hazard Zones (Vs30 < 175 m/second and amplification 2), the second is Medium Potential Seismic Hazard Zonation (Vs30= 175 – 350 m/second and amplification 1.5), and the third is Low Potential Seismic Hazard Zonation (Vs30 = 350 – 750 m/second and amplification 1). The assessment of potential seismic hazard and risk refer to National Standardization Agency, the building and non-building has the risk categories I, II, III, and IV which are located in High, Medium and Low Potential Seismic Hazard Zonation’s. The risk category recommend to have building and non-building structures with seismic design categories D. However, the building and non-building that have been built do not follow the seismic design particularly design category D. Therefore, potential seismic risk and seismic design categories are recommended to be applied to spatial planning as an effort to mitigate earthquake risk in the city of Tasikmalaya. We defined 9 active faults and 5 potential active faults surrounding in the city. Most of them are threaten the settlement with a variety of maximum credible earthquake.
Abstract: Tasikmalaya, as the capital city of Tasikmalaya Prefecture in West Java Province, Indonesia, which has a high density population. More than 600.000 peoples are living in this city, many buildings, and some important infrastructures has been built. Base on probabilistic seismic hazard map of Indonesia by National Standardization Agency, shown the Ta...
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