The physical properties of the bedrock influence widely the spatiotemporal evolution of the quarr... more The physical properties of the bedrock influence widely the spatiotemporal evolution of the quarry faces, the exploitation, the productivity of the quarry as well as the type of the ultimate rehabilitation. In this study, we propose a new method based on the statistical study of the fracture karstification couple of the bedrock, to initiate a harmonious exploitation which simultaneously gathers the investor, the natural environment and the local community. It does not only avoid the zones affected by fracture and karstification phenomena, but also adapts a long-term planning policy in order to benefit from the natural bedrock state, minimize the cost of extraction and the risk of eventual loss of high-quality materials. Furthermore, the environmental works should be managed at the rate of the exploitation in order to reduce the consecutive harmful effects of the excavation and to better integrate the site in its local socio-economic context.
At Zaghouan locality, north eastern Tunisia, significant sedimentary ores took place (e.g. sand, ... more At Zaghouan locality, north eastern Tunisia, significant sedimentary ores took place (e.g. sand, clay, limestone…). This sedimentary ores were largely extended and covered partially by quaternary deposits. In this paper, multidiscipline approaches with petrographic, mineralogical, chemical and geotechnical analyses were involved to valorize these materials in various industrial uses. The carbonates of the Lower Jurassic (Oust Formation) present good criteria and higher quality to be use in engineering application moreover huge reserves. The gray carbonates of the Lower Jurassic (Oust Formation) are constituted by limestones with packstone or grainstone texture, with relatively abundant lithoclasts which are well coated by a micritic matrix. Mineralogical studies reveal the presence of calcite with a small content of quartz and dolomite. The major element compositions of this limestone show higher content in CaO, ranging from 53% to 55%, and from 94.65% and 98.21% expressed as CaCO3. The limestone of Oust Formation display low amount of Al2O3, SiO2 and Fe2O3 which ranging from 2% to 5%. Other minor elements (Na2O and K2O) are also detected. Geotechnical tests (e.g. Los Angles, Humid Micro Deval, Density Index) conducted on the Lower Jurassic limestone at studied area show dense materials (2,55 to 2,81 g/cm3) and well resistant to the fragmentation. Depending on the provenance of the limestone rock of the Oust Formation, different employments can be proposed. The Bent SaNdane and Bou Garnine Mountains can be used to produce the aggregates while Rouas Mountains for marble manufactures. Either this applications, Lower Jurassic limestone from studied area can be used in the manufacture of Portland cement when mixed with Lower Cretaceous clay from the Zaghouan locality.
Des glauconies du Paléogëne de Tunisie ont été datées par la méthode K-Ar après une étude sédimen... more Des glauconies du Paléogëne de Tunisie ont été datées par la méthode K-Ar après une étude sédimentologique. Dans l'une des formations a été notée la présence de quartz automorphes bipyramidés dont certains renferment des minéraux verts. La contemporanéité des quartz et des grains verts, leur possible remaniement, sont les problèmes initialement posés. Les âges apparents calculés s'étagent de 40 à 65 Ma. On conclut que les grains verts ne sont pas repris de formations anté-crétacées. La signification de ces résultats est discutée en tenant compte de l'altération météorique et de l'évolution incomplète des grains verts qui font de ces glauconies des chronomètres imparfaits.
AbstractAlunite mineral was recently identified at the upper Eocene clay deposits associated with... more AbstractAlunite mineral was recently identified at the upper Eocene clay deposits associated with laminated primary gypsum and iron oxide in Central Tunisia, particularly at El Gnater site. The alunite characterization has been performed by several analytical techniques [atomic absorption spectroscopy (AAS), X- ray diffraction (XRD), scanning electron microscope (SEM), thermogravimetric analysis (TGA) and differential thermal analysis (DTA)]. The mean features of their chemical composition are its deficiency of Al, water excess content, small replacement of K by Na and absence of impurities such as Fe. The X-ray diffraction pattern reveals the purity of the alunite samples. The SEM micromorphological study shows a compact facies which is made up by homogeneous pseudocubic microcrystals having approximately the same diameters of 1 μm. Thermal behaviour of El Gnater alunite closely matches published literature which shows two major endothermic peaks at 528 and 744 °C with total weight loss 17.27 and 29.09 %, respectively. The former corresponds to the dehydroxylation processes and the latter corresponds to sulphate decomposition reaction. The association of studied alunite with laminated primary gypsum, hematite and clay minerals implies its late diagenetic origin in reduced conditions and in evaporitic environment. However, jarosite was produced by oxidation of pyrite which was very abundant in the claystone host.
The NeoproterozoicCambrian transitional sequence in the Mussoorie and Garhwal Hills of the Lesse... more The NeoproterozoicCambrian transitional sequence in the Mussoorie and Garhwal Hills of the Lesser Himalaya is represented by dolomites of the Upper Krol Formation and chert-phosphorite assemblages of the lowermost Tal Formation. These rocks provide valuable information ...
The NeoproterozoicCambrian transitional sequence in the Mussoorie and Garhwal Hills of the Lesse... more The NeoproterozoicCambrian transitional sequence in the Mussoorie and Garhwal Hills of the Lesser Himalaya is represented by dolomites of the Upper Krol Formation and chert-phosphorite assemblages of the lowermost Tal Formation. These rocks provide valuable information ...
Die beobachtete lithologische Abfolge kann als eine Aufeinanderfolge von Sequenzen — durch Variat... more Die beobachtete lithologische Abfolge kann als eine Aufeinanderfolge von Sequenzen — durch Variationen eines chemischen Index hervorgerufen — erklart werden. Der chemische Index wird durch das Haufigkeitsverhaltnis von Material chemischer und biochemischer zu dem detritischer Herkunft bestimmt. Ebenso spiegeln die durch das Hauptmineral charakterisierten Fazies folgende Sequenz wider : Ton, Kalzit, Dolomit, Phosphat oder Gips. Die gesamte Gesteinsserie von El Haria -Metlaoui -Souar umfasst 3 Sequenzen, die nicht mit den stratigraphischen Grenzen zusammenfallen. Zwei Sequenzen, die untere und obere, sind gipsfuhrend ; sie umrahmen eine mittlere phosphatfuhrende Sequenz. Apatit und Gips konnen als zwei aquivalente Minerale angesehen werden, die im gleichen Augenblick der Entwicklung der Sequenz auftreten, das erste biochemisch mit den dafur typischen begleitenden Spurenelementen, das zweite chemisch. ; Die Natur der Ablagerungen und ihre Abfolge scheinen das Ergebnis des Zusammenspieles von drei Gleichgewichten : ein vertikales Gleichgewicht, das die Zufuhr detritischen Materials regelt, ein Gleichgewicht das von der Beckenrandschwelle gesteuert wird und entweder die chemische Anreicherung oder die biologische Entwicklung begunstigt, ein geochemisches Gleichgewicht, das durch den Gehalt an dem mehr oder weniger wichtigen Magnesium hervoigerufen wird.
The main scope of the present work is to investigate the potential of using ground calcium carbon... more The main scope of the present work is to investigate the potential of using ground calcium carbonate (GCC) from the Barre de Ghomrassene (BDG) in Southeast Tunisia in paint industry. In order to evaluate the performance of the material and the formulated paint films, representative raw specimens of main deposits of naturel GCCs in the Mediterranean basin and Middle East countries such as extra-white limestone from the Abiod Formation (Feriana region in West-Central Tunisia), Aşıgediği Formation (Niğde Group, South Central Turkey), and Samalut Formation (Elminea, South Cairo, Egypt) were considered. Samples were ground to specific surface of about 3000 cm2/g and were subjected to detailed characterization including chemical and mineral composition, physical, and chromaticity characteristics. Results show that the GCC from the lower part of the Barre de Ghomrassene is, in most, dark and grainstone in texture, which limit its use in paint and coating application. Elsewhere, it is marked by high purity degree (generally more than 97% calcite); high lightness (more than 86.5, 95.2 in average) with relatively low chromaticity (a* < 3.3, b* < 9.1); low oil intake (17.4 g/100 GCC); very low electrolyte levels; good pH buffering (close to 9); accepted ranges of density and abrasion (2.65–2.7 and 10–18, respectively); good grindability; low levels of harmful components such as MgO, SiO2, Fe2O3, and acid insoluble residue (less than 0.1% each); and improved rheological properties. The BDG seems to be a suitable filler for paint when mixed with water, styrene acrylic, and common additives. The formulated paint films meet all standard requirements, in that they have very good opacity, matt visual dualgloss 20/60°, high luminescence (L* = 96.4), suitable hardness (145 s), good adhesion (B5), and sufficient impact resistance (1.5 kg m). The performances of these films are analogous to those based on Abiod and Samalut formations (natural carbonate), but they are slightly less lighter than those based on Aşıgediği Formation (metamorphic carbonate). Hence, the studied GCC can be used to substitute them in particular for local GCCs from the Abiod Formation, which are limited and over exploited.
The physical properties of the bedrock influence widely the spatiotemporal evolution of the quarr... more The physical properties of the bedrock influence widely the spatiotemporal evolution of the quarry faces, the exploitation, the productivity of the quarry as well as the type of the ultimate rehabilitation. In this study, we propose a new method based on the statistical study of the fracture karstification couple of the bedrock, to initiate a harmonious exploitation which simultaneously gathers the investor, the natural environment and the local community. It does not only avoid the zones affected by fracture and karstification phenomena, but also adapts a long-term planning policy in order to benefit from the natural bedrock state, minimize the cost of extraction and the risk of eventual loss of high-quality materials. Furthermore, the environmental works should be managed at the rate of the exploitation in order to reduce the consecutive harmful effects of the excavation and to better integrate the site in its local socio-economic context.
At Zaghouan locality, north eastern Tunisia, significant sedimentary ores took place (e.g. sand, ... more At Zaghouan locality, north eastern Tunisia, significant sedimentary ores took place (e.g. sand, clay, limestone…). This sedimentary ores were largely extended and covered partially by quaternary deposits. In this paper, multidiscipline approaches with petrographic, mineralogical, chemical and geotechnical analyses were involved to valorize these materials in various industrial uses. The carbonates of the Lower Jurassic (Oust Formation) present good criteria and higher quality to be use in engineering application moreover huge reserves. The gray carbonates of the Lower Jurassic (Oust Formation) are constituted by limestones with packstone or grainstone texture, with relatively abundant lithoclasts which are well coated by a micritic matrix. Mineralogical studies reveal the presence of calcite with a small content of quartz and dolomite. The major element compositions of this limestone show higher content in CaO, ranging from 53% to 55%, and from 94.65% and 98.21% expressed as CaCO3. The limestone of Oust Formation display low amount of Al2O3, SiO2 and Fe2O3 which ranging from 2% to 5%. Other minor elements (Na2O and K2O) are also detected. Geotechnical tests (e.g. Los Angles, Humid Micro Deval, Density Index) conducted on the Lower Jurassic limestone at studied area show dense materials (2,55 to 2,81 g/cm3) and well resistant to the fragmentation. Depending on the provenance of the limestone rock of the Oust Formation, different employments can be proposed. The Bent SaNdane and Bou Garnine Mountains can be used to produce the aggregates while Rouas Mountains for marble manufactures. Either this applications, Lower Jurassic limestone from studied area can be used in the manufacture of Portland cement when mixed with Lower Cretaceous clay from the Zaghouan locality.
Des glauconies du Paléogëne de Tunisie ont été datées par la méthode K-Ar après une étude sédimen... more Des glauconies du Paléogëne de Tunisie ont été datées par la méthode K-Ar après une étude sédimentologique. Dans l'une des formations a été notée la présence de quartz automorphes bipyramidés dont certains renferment des minéraux verts. La contemporanéité des quartz et des grains verts, leur possible remaniement, sont les problèmes initialement posés. Les âges apparents calculés s'étagent de 40 à 65 Ma. On conclut que les grains verts ne sont pas repris de formations anté-crétacées. La signification de ces résultats est discutée en tenant compte de l'altération météorique et de l'évolution incomplète des grains verts qui font de ces glauconies des chronomètres imparfaits.
AbstractAlunite mineral was recently identified at the upper Eocene clay deposits associated with... more AbstractAlunite mineral was recently identified at the upper Eocene clay deposits associated with laminated primary gypsum and iron oxide in Central Tunisia, particularly at El Gnater site. The alunite characterization has been performed by several analytical techniques [atomic absorption spectroscopy (AAS), X- ray diffraction (XRD), scanning electron microscope (SEM), thermogravimetric analysis (TGA) and differential thermal analysis (DTA)]. The mean features of their chemical composition are its deficiency of Al, water excess content, small replacement of K by Na and absence of impurities such as Fe. The X-ray diffraction pattern reveals the purity of the alunite samples. The SEM micromorphological study shows a compact facies which is made up by homogeneous pseudocubic microcrystals having approximately the same diameters of 1 μm. Thermal behaviour of El Gnater alunite closely matches published literature which shows two major endothermic peaks at 528 and 744 °C with total weight loss 17.27 and 29.09 %, respectively. The former corresponds to the dehydroxylation processes and the latter corresponds to sulphate decomposition reaction. The association of studied alunite with laminated primary gypsum, hematite and clay minerals implies its late diagenetic origin in reduced conditions and in evaporitic environment. However, jarosite was produced by oxidation of pyrite which was very abundant in the claystone host.
The NeoproterozoicCambrian transitional sequence in the Mussoorie and Garhwal Hills of the Lesse... more The NeoproterozoicCambrian transitional sequence in the Mussoorie and Garhwal Hills of the Lesser Himalaya is represented by dolomites of the Upper Krol Formation and chert-phosphorite assemblages of the lowermost Tal Formation. These rocks provide valuable information ...
The NeoproterozoicCambrian transitional sequence in the Mussoorie and Garhwal Hills of the Lesse... more The NeoproterozoicCambrian transitional sequence in the Mussoorie and Garhwal Hills of the Lesser Himalaya is represented by dolomites of the Upper Krol Formation and chert-phosphorite assemblages of the lowermost Tal Formation. These rocks provide valuable information ...
Die beobachtete lithologische Abfolge kann als eine Aufeinanderfolge von Sequenzen — durch Variat... more Die beobachtete lithologische Abfolge kann als eine Aufeinanderfolge von Sequenzen — durch Variationen eines chemischen Index hervorgerufen — erklart werden. Der chemische Index wird durch das Haufigkeitsverhaltnis von Material chemischer und biochemischer zu dem detritischer Herkunft bestimmt. Ebenso spiegeln die durch das Hauptmineral charakterisierten Fazies folgende Sequenz wider : Ton, Kalzit, Dolomit, Phosphat oder Gips. Die gesamte Gesteinsserie von El Haria -Metlaoui -Souar umfasst 3 Sequenzen, die nicht mit den stratigraphischen Grenzen zusammenfallen. Zwei Sequenzen, die untere und obere, sind gipsfuhrend ; sie umrahmen eine mittlere phosphatfuhrende Sequenz. Apatit und Gips konnen als zwei aquivalente Minerale angesehen werden, die im gleichen Augenblick der Entwicklung der Sequenz auftreten, das erste biochemisch mit den dafur typischen begleitenden Spurenelementen, das zweite chemisch. ; Die Natur der Ablagerungen und ihre Abfolge scheinen das Ergebnis des Zusammenspieles von drei Gleichgewichten : ein vertikales Gleichgewicht, das die Zufuhr detritischen Materials regelt, ein Gleichgewicht das von der Beckenrandschwelle gesteuert wird und entweder die chemische Anreicherung oder die biologische Entwicklung begunstigt, ein geochemisches Gleichgewicht, das durch den Gehalt an dem mehr oder weniger wichtigen Magnesium hervoigerufen wird.
The main scope of the present work is to investigate the potential of using ground calcium carbon... more The main scope of the present work is to investigate the potential of using ground calcium carbonate (GCC) from the Barre de Ghomrassene (BDG) in Southeast Tunisia in paint industry. In order to evaluate the performance of the material and the formulated paint films, representative raw specimens of main deposits of naturel GCCs in the Mediterranean basin and Middle East countries such as extra-white limestone from the Abiod Formation (Feriana region in West-Central Tunisia), Aşıgediği Formation (Niğde Group, South Central Turkey), and Samalut Formation (Elminea, South Cairo, Egypt) were considered. Samples were ground to specific surface of about 3000 cm2/g and were subjected to detailed characterization including chemical and mineral composition, physical, and chromaticity characteristics. Results show that the GCC from the lower part of the Barre de Ghomrassene is, in most, dark and grainstone in texture, which limit its use in paint and coating application. Elsewhere, it is marked by high purity degree (generally more than 97% calcite); high lightness (more than 86.5, 95.2 in average) with relatively low chromaticity (a* < 3.3, b* < 9.1); low oil intake (17.4 g/100 GCC); very low electrolyte levels; good pH buffering (close to 9); accepted ranges of density and abrasion (2.65–2.7 and 10–18, respectively); good grindability; low levels of harmful components such as MgO, SiO2, Fe2O3, and acid insoluble residue (less than 0.1% each); and improved rheological properties. The BDG seems to be a suitable filler for paint when mixed with water, styrene acrylic, and common additives. The formulated paint films meet all standard requirements, in that they have very good opacity, matt visual dualgloss 20/60°, high luminescence (L* = 96.4), suitable hardness (145 s), good adhesion (B5), and sufficient impact resistance (1.5 kg m). The performances of these films are analogous to those based on Abiod and Samalut formations (natural carbonate), but they are slightly less lighter than those based on Aşıgediği Formation (metamorphic carbonate). Hence, the studied GCC can be used to substitute them in particular for local GCCs from the Abiod Formation, which are limited and over exploited.
Uploads
Papers by fredj chaabani