Silica sand is one of the most common varieties of sand, and it is used in industrial application... more Silica sand is one of the most common varieties of sand, and it is used in industrial applications throughout the world. The application depends on the purity, grain size and chemical characteristics. In the present study, X-ray, chemical and petrographic analyses were used to study sand deposits from Tabuk area in Saudi Arabia. The collected samples from the site are composed of 98% quartz (SiO 2 ), with very minor traces of carbonate and dark minerals which account for the rest of the sample constituents. The examined individual quartz grains have excellent purity, and about 98% of the grains were white transparent pure silica. The grains are mainly rounded to sub-angular. The chemical analysis indicated that the percentages of major oxides of Si, Al, Cr, Fe, and Ti were 97%, 1.5%, % <0.006%; 0.035%, and 0.0531% respectively. The grains sizes are fine and their sizes concentrated mostly around the 0.155 mm. Due to its high quality, the inspected deposit meets the industrial standards.
Copper deposits in the ultramafic rocks of the Semail ophiolite massifs is found to be enormous i... more Copper deposits in the ultramafic rocks of the Semail ophiolite massifs is found to be enormous in the region of northern Oman Mountains, United Arab Emirates. For this study, samples of copper were gathered from 14 different sites in the investigation area and were analyzed in the laboratory using the X-ray diffraction, GER 3700 spectroradiometer, and Inductively Coupled Plasma-Mass Spectrometer. Detection and mapping of copperbearing mineralized zones were carried out using different image processing approaches of minimum noise fraction, principal component analysis, decorrelation stretch, and band ratio which were applied on Landsat 8 (OLI) data. The spectra of malachite and azurite samples were characterized by broad absorption features in the visible and near infrared region (0.6-1.0 µm). The results obtained from the principal component analysis, minimum noise fraction, band ratio, decorrelation stretch, spectral reflectance analyses, and mineralogical and chemical analyses were found to be similar. Thus, it can be concluded that multispectral Landsat 8 data are useful in the detection iron ore deposits in arid and semi-arid regions.
Remote sensing data can provide valuable information about the surface expression of regional geo... more Remote sensing data can provide valuable information about the surface expression of regional geomorphologic and geological features of arid regions. In the present study, several processing techniques were applied to reveal such in the Qatar Peninsula. Those included preprocessing for radiometric and geometric correction, various enhancement methods, classification, accuracy assessment, contrast stretching, color composition, and principal component analyses. Those were coupled with field groundtruthing and lab analyses. Field groundtruthing included one hundred and forty measurements of spectral reflectance for various sediment exposures representing main sand types in the four studied parts in Qatar. Lab investigations included grain size analysis, X-ray diffraction and laboratory measurements of spectral reflectance. During the course of this study three sand types have been identified: (i) sabkha-derived salt-rich, quartz sand, and (ii) beach-derived calcareous sand and (iii) aeolian dune quartz. Those areas are spectrally distinct in the VNIR, suggesting that VNIR spectral data can be used to discriminate them. The study found that the main limitation of the ground spectral reflectance study is the difficulty of covering large areas. The study also found that ground and laboratory spectral radiance are generally higher in reflectance than those of Landsat TM. This is due to several factors such as atmospheric conditions, the low altitude or different scales. Whereas for areas with huge size of dune sand, the Landsat TM spectral has higher reflectance than those from field and laboratory. The study observed that there OPEN ACCESS Remote Sens. 2009, 1 916 is a good correspondence or correlation of the wavelengths maximum sensitivity between the three spectral measurements i.e lab, field and space-borne measurements.
The focus of this investigation is to assess the level of knowledge, attitude and practice (KAP) ... more The focus of this investigation is to assess the level of knowledge, attitude and practice (KAP) of workers on occupational health and safety issues in the industrial town of Mussafah, United Arab Emirates. A combination of personnel interviews in conjunction with t-test and logistic regressions were used to assess the KAP of the workers. Around 98% of the survey results indicate that the computed p-value of the responses is greater than the significance level alpha = 0.05, hence the null hypothesis H0 of the test of normality cannot be rejected. The risk to reject the null hypothesis H0 while it is true ranges 77.86% to 99%. The study revealed that there is an overall low awareness of health and safety issues among the studied sample. This therefore makes the workers generally more susceptible to accidents. Results have also shown that 48% of the managers were aware of the hazards taking place at their facilities, and 42.6% of them knew the possible harmful effects from their industrial processes. In terms of the health considerations of the visited sites, 55% of the workers were unaware about it and 48% of them rarely used their given protective equipment. The present study indicates the education level and years of experience did not impact the practices. The results have shown the need for training programs to build the capacity of workers in the field of health and safety. Resumo O foco do presente estudo é avaliar o nível de conhecimento, atitude e prática (CAP) dos trabalhadores sobre questões de segurança e saúde ocupacional na cidade industrial de Mussafah, Emirados Árabes Unidos. Uma combinação de entrevistas com o pessoal em conjunto com o teste-t e regressões logísticas foram utilizados para avaliar o CAP dos trabalhadores. Cerca de 98% do resultado da pesquisa indicam que o p-valor das respostas é maior que o nível de significância alfa = 0,05, daí a hipótese nula H0 do teste de normalidade não pode ser rejeitada. O risco para rejeitar a hipótese de nulidade H0 enquanto é verdade varia 77.86% a 99%. O estudo revelou que existe uma falta de conhecimento geral em relacao a questões de saúde e segurança entre a amostra estudada. Isso faz com que os trabalhadores sejam mais suscetíveis a acidentes. Os resultados também mostraram que 48% dos gestores estavam cientes dos perigos no local onde trabalham, t e 42,6% deles conhecia os possíveis efeitos nocivos dos processos industriais. Em termos de conhecimento dos services de saúde disponiveis nos sites visitados, 55% dos trabalhadores desconheciam sobre este dominio e 48% deles raramente usavam os equipamentos de proteção recebidos. O presente estudo indica que o nível de educação e anos de experiência não tem impacto na prática. Os resultados demonstraram a necessidade de programas de formação para preparar trabalhadores para o campo da segurança e da saúde.
The Florida phosphate deposits in Four Corners and Hardee County mines are composed mainly of pho... more The Florida phosphate deposits in Four Corners and Hardee County mines are composed mainly of phosphate minerals and quartz in addition to subordinate proportions of feldspars, dolomite, calcite, gypsum, kaolinite, attapulgite and montmorillonite. These phosphorites contain three structurally different types of mudclasts: massive mudclasts, mudclasts with concentric structure and mudclasts consisting of agglomerates of apatite mi-croparticles. The latter are represented by particles resembling phosphatized fossil bacteria associated with microbial filaments, and hollow apatite particles having surfacial coatings and connected to microbial filaments. The Florida phosphate particles are reworked and vary in mineral composition, color and shape. They are composed of a mixture of well-crystalline species including carbonate fluorapatite (francolite), carbonate apatite and fluorapatite. The color variation of the phosphate particles is related to difference in mineral composition, extent of diagenetic effects and reworking. The light-colored mudclasts are characterized by the presence of carbonate apatite and aluminum hydroxide phosphate minerals, whereas the dark mudclasts are rich in iron aluminum hydroxide phosphate minerals. The Florida phosphorites are suggested to be formed partially by authigenetic precipitation, replacement of the sea floor carbonate and diatomite, and microbial processes. With respect to elemental geochemistry, the analyzed particles contain small percentages of sulfur and iron which are related to the occurrence of pyrite. Traces of silica and alumina are recorded which may be attributed to the diagenetic. Some of the tested particles are relatively rich in phosphorous, fluorine, calcium, and magnesium, while poor in silicon, potassium and sulfur. Whereas, the bioclasts (especially teeth) are relatively rich in calcium, phosphorous and fluorine while poor in silicon, aluminum, magnesium and potassium. Hence, the microchemical analyses revealed that differential dia-genesis affected mudclasts more than bioclasts. There is a complete compositional gradation between clay and phosphate particles which reflects their interaction. This involved kaolinitization of the phosphate particles, phosphatization of the clay mineral particles and production of silica.
A B S T R A C T The chemical composition and natural radioactivity of the northern area of the we... more A B S T R A C T The chemical composition and natural radioactivity of the northern area of the western desert groundwater were determined to evaluate hydrogeochemical facies and assess groundwater quality for different uses. Many the groundwater samples belong to the Na +-Cl − , Na 2 SO 4 − type, followed by Ca 2+-Mg 2+-Cl − type. Only a few samples are of the Na +-HCO 3 − type. The spatial distributions of the major ions describe similar anomalies, with the highest concentrations found at the extreme northeastern margin of the oasis, as well as in its northern and northwestern parts. Fe is the most abundant toxic metal, followed by Cu and Mn. Anomalies of Cr, Ni and Zn are also detected. Rock/water interactions strongly affect the chemical composition of the groundwater. Dissolution and cation exchange are the main processes controlling the hydrogeochemistry. Most of the irrigation groundwater problems in the study area may be resolved using an effective drainage system. The estimated total annual dose due to ingestion of 238 U, 232 Th and 40 K in groundwater samples reveals that the groundwater is safe for human consumption. However, the toxic metal content of the Bahariya groundwater exceeds the permissible levels for both irrigation and consumption, and the water must be filtered through suitable membranes to exclude these toxic metals. Regular monitoring of the quality of this water for drinking is strictly required.
The study area located in Florida, USA and emphasized on low-grade phosphorites in Hardee County ... more The study area located in Florida, USA and emphasized on low-grade phosphorites in Hardee County (HC) and Four Corners (FC) mining areas. The main purpose of this study is to apply a standard geochemical technique to understand the diagenetic history and paleo-environmental aspects of phosphates within one of the major phosphate deposits in the USA. The effect of diagenesis on the phosphate minerals was studied by isotope analysis of the phosphate bone fragments and phosphatized mudclasts and rods. The environmental conditions that prevailed during the life of organisms were assessed by isotope analysis of the shark teeth. In this paper, variation in stable isotope (δ 18 O and δ 13 C) signatures of structural carbonate in rocks and shark teeth were studied in Florida phosphate. The studied samples show negative values for both δ 13 C and δ 18 O isotopes of structural carbonate. The light mudclast samples shows higher oxygen ratios (−1.6) than the dark mudclasts (−2.3) in Hardee County, whereas those values were lower, −2.3 and −3, respectively, in Four Corners samples. The shark teeth found in the deposits show narrow variations in values of δ 13 C (−3.4 to −4.9%o) and δ 18 O (−1.4 to 2.1%o) isotope. The bone fragments in the deposits are more similar to the light mudclasts regarding the isotope ratios and carbonate content. The alteration is evident in the Florida phosphorites where δ 18 O values of bulk teeth are higher than those of bones and mudclast. This alteration could be because of increasing crystallinity and decreasing carbonate content with increasing depth of burial.
Silica sand is one of the most common varieties of sand, and it is used in industrial application... more Silica sand is one of the most common varieties of sand, and it is used in industrial applications throughout the world. The application depends on the purity, grain size and chemical characteristics. In the present study, X-ray, chemical and petrographic analyses were used to study sand deposits from Tabuk area in Saudi Arabia. The collected samples from the site are composed of 98% quartz (SiO 2 ), with very minor traces of carbonate and dark minerals which account for the rest of the sample constituents. The examined individual quartz grains have excellent purity, and about 98% of the grains were white transparent pure silica. The grains are mainly rounded to sub-angular. The chemical analysis indicated that the percentages of major oxides of Si, Al, Cr, Fe, and Ti were 97%, 1.5%, % <0.006%; 0.035%, and 0.0531% respectively. The grains sizes are fine and their sizes concentrated mostly around the 0.155 mm. Due to its high quality, the inspected deposit meets the industrial standards.
Copper deposits in the ultramafic rocks of the Semail ophiolite massifs is found to be enormous i... more Copper deposits in the ultramafic rocks of the Semail ophiolite massifs is found to be enormous in the region of northern Oman Mountains, United Arab Emirates. For this study, samples of copper were gathered from 14 different sites in the investigation area and were analyzed in the laboratory using the X-ray diffraction, GER 3700 spectroradiometer, and Inductively Coupled Plasma-Mass Spectrometer. Detection and mapping of copperbearing mineralized zones were carried out using different image processing approaches of minimum noise fraction, principal component analysis, decorrelation stretch, and band ratio which were applied on Landsat 8 (OLI) data. The spectra of malachite and azurite samples were characterized by broad absorption features in the visible and near infrared region (0.6-1.0 µm). The results obtained from the principal component analysis, minimum noise fraction, band ratio, decorrelation stretch, spectral reflectance analyses, and mineralogical and chemical analyses were found to be similar. Thus, it can be concluded that multispectral Landsat 8 data are useful in the detection iron ore deposits in arid and semi-arid regions.
Remote sensing data can provide valuable information about the surface expression of regional geo... more Remote sensing data can provide valuable information about the surface expression of regional geomorphologic and geological features of arid regions. In the present study, several processing techniques were applied to reveal such in the Qatar Peninsula. Those included preprocessing for radiometric and geometric correction, various enhancement methods, classification, accuracy assessment, contrast stretching, color composition, and principal component analyses. Those were coupled with field groundtruthing and lab analyses. Field groundtruthing included one hundred and forty measurements of spectral reflectance for various sediment exposures representing main sand types in the four studied parts in Qatar. Lab investigations included grain size analysis, X-ray diffraction and laboratory measurements of spectral reflectance. During the course of this study three sand types have been identified: (i) sabkha-derived salt-rich, quartz sand, and (ii) beach-derived calcareous sand and (iii) aeolian dune quartz. Those areas are spectrally distinct in the VNIR, suggesting that VNIR spectral data can be used to discriminate them. The study found that the main limitation of the ground spectral reflectance study is the difficulty of covering large areas. The study also found that ground and laboratory spectral radiance are generally higher in reflectance than those of Landsat TM. This is due to several factors such as atmospheric conditions, the low altitude or different scales. Whereas for areas with huge size of dune sand, the Landsat TM spectral has higher reflectance than those from field and laboratory. The study observed that there OPEN ACCESS Remote Sens. 2009, 1 916 is a good correspondence or correlation of the wavelengths maximum sensitivity between the three spectral measurements i.e lab, field and space-borne measurements.
The focus of this investigation is to assess the level of knowledge, attitude and practice (KAP) ... more The focus of this investigation is to assess the level of knowledge, attitude and practice (KAP) of workers on occupational health and safety issues in the industrial town of Mussafah, United Arab Emirates. A combination of personnel interviews in conjunction with t-test and logistic regressions were used to assess the KAP of the workers. Around 98% of the survey results indicate that the computed p-value of the responses is greater than the significance level alpha = 0.05, hence the null hypothesis H0 of the test of normality cannot be rejected. The risk to reject the null hypothesis H0 while it is true ranges 77.86% to 99%. The study revealed that there is an overall low awareness of health and safety issues among the studied sample. This therefore makes the workers generally more susceptible to accidents. Results have also shown that 48% of the managers were aware of the hazards taking place at their facilities, and 42.6% of them knew the possible harmful effects from their industrial processes. In terms of the health considerations of the visited sites, 55% of the workers were unaware about it and 48% of them rarely used their given protective equipment. The present study indicates the education level and years of experience did not impact the practices. The results have shown the need for training programs to build the capacity of workers in the field of health and safety. Resumo O foco do presente estudo é avaliar o nível de conhecimento, atitude e prática (CAP) dos trabalhadores sobre questões de segurança e saúde ocupacional na cidade industrial de Mussafah, Emirados Árabes Unidos. Uma combinação de entrevistas com o pessoal em conjunto com o teste-t e regressões logísticas foram utilizados para avaliar o CAP dos trabalhadores. Cerca de 98% do resultado da pesquisa indicam que o p-valor das respostas é maior que o nível de significância alfa = 0,05, daí a hipótese nula H0 do teste de normalidade não pode ser rejeitada. O risco para rejeitar a hipótese de nulidade H0 enquanto é verdade varia 77.86% a 99%. O estudo revelou que existe uma falta de conhecimento geral em relacao a questões de saúde e segurança entre a amostra estudada. Isso faz com que os trabalhadores sejam mais suscetíveis a acidentes. Os resultados também mostraram que 48% dos gestores estavam cientes dos perigos no local onde trabalham, t e 42,6% deles conhecia os possíveis efeitos nocivos dos processos industriais. Em termos de conhecimento dos services de saúde disponiveis nos sites visitados, 55% dos trabalhadores desconheciam sobre este dominio e 48% deles raramente usavam os equipamentos de proteção recebidos. O presente estudo indica que o nível de educação e anos de experiência não tem impacto na prática. Os resultados demonstraram a necessidade de programas de formação para preparar trabalhadores para o campo da segurança e da saúde.
The Florida phosphate deposits in Four Corners and Hardee County mines are composed mainly of pho... more The Florida phosphate deposits in Four Corners and Hardee County mines are composed mainly of phosphate minerals and quartz in addition to subordinate proportions of feldspars, dolomite, calcite, gypsum, kaolinite, attapulgite and montmorillonite. These phosphorites contain three structurally different types of mudclasts: massive mudclasts, mudclasts with concentric structure and mudclasts consisting of agglomerates of apatite mi-croparticles. The latter are represented by particles resembling phosphatized fossil bacteria associated with microbial filaments, and hollow apatite particles having surfacial coatings and connected to microbial filaments. The Florida phosphate particles are reworked and vary in mineral composition, color and shape. They are composed of a mixture of well-crystalline species including carbonate fluorapatite (francolite), carbonate apatite and fluorapatite. The color variation of the phosphate particles is related to difference in mineral composition, extent of diagenetic effects and reworking. The light-colored mudclasts are characterized by the presence of carbonate apatite and aluminum hydroxide phosphate minerals, whereas the dark mudclasts are rich in iron aluminum hydroxide phosphate minerals. The Florida phosphorites are suggested to be formed partially by authigenetic precipitation, replacement of the sea floor carbonate and diatomite, and microbial processes. With respect to elemental geochemistry, the analyzed particles contain small percentages of sulfur and iron which are related to the occurrence of pyrite. Traces of silica and alumina are recorded which may be attributed to the diagenetic. Some of the tested particles are relatively rich in phosphorous, fluorine, calcium, and magnesium, while poor in silicon, potassium and sulfur. Whereas, the bioclasts (especially teeth) are relatively rich in calcium, phosphorous and fluorine while poor in silicon, aluminum, magnesium and potassium. Hence, the microchemical analyses revealed that differential dia-genesis affected mudclasts more than bioclasts. There is a complete compositional gradation between clay and phosphate particles which reflects their interaction. This involved kaolinitization of the phosphate particles, phosphatization of the clay mineral particles and production of silica.
A B S T R A C T The chemical composition and natural radioactivity of the northern area of the we... more A B S T R A C T The chemical composition and natural radioactivity of the northern area of the western desert groundwater were determined to evaluate hydrogeochemical facies and assess groundwater quality for different uses. Many the groundwater samples belong to the Na +-Cl − , Na 2 SO 4 − type, followed by Ca 2+-Mg 2+-Cl − type. Only a few samples are of the Na +-HCO 3 − type. The spatial distributions of the major ions describe similar anomalies, with the highest concentrations found at the extreme northeastern margin of the oasis, as well as in its northern and northwestern parts. Fe is the most abundant toxic metal, followed by Cu and Mn. Anomalies of Cr, Ni and Zn are also detected. Rock/water interactions strongly affect the chemical composition of the groundwater. Dissolution and cation exchange are the main processes controlling the hydrogeochemistry. Most of the irrigation groundwater problems in the study area may be resolved using an effective drainage system. The estimated total annual dose due to ingestion of 238 U, 232 Th and 40 K in groundwater samples reveals that the groundwater is safe for human consumption. However, the toxic metal content of the Bahariya groundwater exceeds the permissible levels for both irrigation and consumption, and the water must be filtered through suitable membranes to exclude these toxic metals. Regular monitoring of the quality of this water for drinking is strictly required.
The study area located in Florida, USA and emphasized on low-grade phosphorites in Hardee County ... more The study area located in Florida, USA and emphasized on low-grade phosphorites in Hardee County (HC) and Four Corners (FC) mining areas. The main purpose of this study is to apply a standard geochemical technique to understand the diagenetic history and paleo-environmental aspects of phosphates within one of the major phosphate deposits in the USA. The effect of diagenesis on the phosphate minerals was studied by isotope analysis of the phosphate bone fragments and phosphatized mudclasts and rods. The environmental conditions that prevailed during the life of organisms were assessed by isotope analysis of the shark teeth. In this paper, variation in stable isotope (δ 18 O and δ 13 C) signatures of structural carbonate in rocks and shark teeth were studied in Florida phosphate. The studied samples show negative values for both δ 13 C and δ 18 O isotopes of structural carbonate. The light mudclast samples shows higher oxygen ratios (−1.6) than the dark mudclasts (−2.3) in Hardee County, whereas those values were lower, −2.3 and −3, respectively, in Four Corners samples. The shark teeth found in the deposits show narrow variations in values of δ 13 C (−3.4 to −4.9%o) and δ 18 O (−1.4 to 2.1%o) isotope. The bone fragments in the deposits are more similar to the light mudclasts regarding the isotope ratios and carbonate content. The alteration is evident in the Florida phosphorites where δ 18 O values of bulk teeth are higher than those of bones and mudclast. This alteration could be because of increasing crystallinity and decreasing carbonate content with increasing depth of burial.
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