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Dolomitos são rochas carbonáticas abundantes no registro sedimentar Pré-Cambriano, porém raras no registro Fanerozóico e sua gênese até hoje permanece como um enigma da geologia, conhecido como o \"Problema Dolomito\". As rochas sedimentares fosfáticas são amplamente estudadas por fornecerem dados importantes sobre a evolução sedimentar e condições físico-químicas e biológicas da água do mar durante a sedimentação e a diagênese, além de constituírem os maiores depósitos econômicos de fósforo do mundo. Os dolomitos e fosforitos da Formação Bocaina foram estudados com base na individualização de fácies sedimentares e petrografia, complementado com investigações geoquímicas (elementar e de isótopos de C e O), a fim de discutir os processos envolvidos na gênese destas rochas. As fácies sedimentares da Formação Bocaina, caracterizadas principalmente por grainstonesoolíticos, pisolíticos, e estromatólitos, indicam ambiente de águas rasas, límpidas e agitadas, interpretado como uma laguna, propícia à proliferação microbiana, com conexão restrita ao mar aberto. Estruturas tepeese pseudomorfos de cristais de gipsita sugerem condições evaporíticas para a bacia, com eventos de exposição subaérea dos sedimentos. Os dolomitos da Formação Bocaina são interpretados como secundários, originados da substituição de sedimentos calcíticos na eodiagênese, provavelmentedevido a elevada taxa de evaporação e refluxo das águas oceânicas. Modelos organogênicos para estes dolomitos não são descartados, devido à assinatura isotópica de C ser ligeiramente positiva (\'delta\' POT.13C IND.VPDB\' entre 0,95 e 3,15%o). A fosfogênese é interpretada como um processo eodiagenético, ocorrido em ambiente geoquímico anóxico, corroborado pelas anomalias positivas de Ce. O excesso de matéria orgânica permitiu a formação da apatita, provavelmente bioinduzida, durante eventos de subida do nível do mar, e desta forma, os fosforitos representam um marco estratigráfico para a bacia, como uma superfície condensada. Subseqüentemente, há rebaixamento do nível do mar, registrado nas fácies de fosfarenito e de conglomerado polimítico da base da Formação Tamengo, unidade que se justapõe à Formação Bocaina, marcando o fim do ambiente lagunar restrito e a instalação de uma plataforma francamente marinha. / Dolomites are carbonatic rocks abundant in the Precambrian but rarely found in the Phanerozoic sedimentary record. Their genesis has remained as a long-standing enigma in geology, often called the \"Dolomite Problem\". The phosphatic rocks, which represent the largest economic deposits of phosphorus in the world, have been studied to provide some important data about the sedimentary evolution and physical-chemical and biological condition of seawater during the sedimentation and diagenesis. The dolomites and phosphorites of the Bocaina Formation were studied based on sedimentary facies, petrography, geochemistry and carbon and oxygen isotopes investigations, to understand the process involved in the genesis of both rocks. The sedimentary facies of the Bocaina Formation are characterized by stromatolites, oolitic and pisolitic grainstones, which indicate shallow, clear and agitated water, favorable to microbial growth. The paleoenvironment was interpreted as a lagoon with restrict connection to the sea. Tepees structures and pseudomorphs of gypsum crystals suggest evaporitic condition to this basin, and also show evidences of aridity. The Bocaina Formation\'s dolomites have been interpreted as secondary, from replacement of limestones during eodiagenesis by reflux of oceanic waters. Organogenic models are also consideraded as a process to form these dolomites, based on the positive carbon isotope signature (\'delta\' POT.13 IND.CVPDB\' between 0.95 and 3.15%o). The phosphogenesis has been interpreted as eodiagenetic process occurred in anoxic geochemical environment, due to the excess oforganic matter, mediated by microbial process. The positive Ce anomalies support this interpretation. This process occurs during rising of sea level and the phosphorites represent a stratigraphic mark as a condensed surface. Subsequently, it is observed a sea level lowering, recorded in phospharenite facies and in basal polymict conglomerate of Tamengo Formation, unit which overlies the Bocaina Formation. This lowering event marks the end of the restrict lagoon environment and the installation of a marine platform.

Dolomitos são rochas carbonáticas abundantes no registro sedimentar Pré-Cambriano, porém raras no registro Fanerozóico e sua gênese até hoje permanece como um enigma da geologia, conhecido como o \"Problema Dolomito\". As rochas sedimentares fosfáticas são amplamente estudadas por fornecerem dados importantes sobre a evolução sedimentar e condições físico-químicas e biológicas da água do mar durante a sedimentação e a diagênese, além de constituírem os maiores depósitos econômicos de fósforo do mundo. Os dolomitos e fosforitos da Formação Bocaina foram estudados com base na individualização de fácies sedimentares e petrografia, complementado com investigações geoquímicas (elementar e de isótopos de C e O), a fim de discutir os processos envolvidos na gênese destas rochas. As fácies sedimentares da Formação Bocaina, caracterizadas principalmente por grainstonesoolíticos, pisolíticos, e estromatólitos, indicam ambiente de águas rasas, límpidas e agitadas, interpretado como uma laguna, propícia à proliferação microbiana, com conexão restrita ao mar aberto. Estruturas tepeese pseudomorfos de cristais de gipsita sugerem condições evaporíticas para a bacia, com eventos de exposição subaérea dos sedimentos. Os dolomitos da Formação Bocaina são interpretados como secundários, originados da substituição de sedimentos calcíticos na eodiagênese, provavelmentedevido a elevada taxa de evaporação e refluxo das águas oceânicas. Modelos organogênicos para estes dolomitos não são descartados, devido à assinatura isotópica de C ser ligeiramente positiva (\'delta\' POT.13C IND.VPDB\' entre 0,95 e 3,15%o). A fosfogênese é interpretada como um processo eodiagenético, ocorrido em ambiente geoquímico anóxico, corroborado pelas anomalias positivas de Ce. O excesso de matéria orgânica permitiu a formação da apatita, provavelmente bioinduzida, durante eventos de subida do nível do mar, e desta forma, os fosforitos representam um marco estratigráfico para a bacia, como uma superfície condensada. Subseqüentemente, há rebaixamento do nível do mar, registrado nas fácies de fosfarenito e de conglomerado polimítico da base da Formação Tamengo, unidade que se justapõe à Formação Bocaina, marcando o fim do ambiente lagunar restrito e a instalação de uma plataforma francamente marinha. / Dolomites are carbonatic rocks abundant in the Precambrian but rarely found in the Phanerozoic sedimentary record. Their genesis has remained as a long-standing enigma in geology, often called the \"Dolomite Problem\". The phosphatic rocks, which represent the largest economic deposits of phosphorus in the world, have been studied to provide some important data about the sedimentary evolution and physical-chemical and biological condition of seawater during the sedimentation and diagenesis. The dolomites and phosphorites of the Bocaina Formation were studied based on sedimentary facies, petrography, geochemistry and carbon and oxygen isotopes investigations, to understand the process involved in the genesis of both rocks. The sedimentary facies of the Bocaina Formation are characterized by stromatolites, oolitic and pisolitic grainstones, which indicate shallow, clear and agitated water, favorable to microbial growth. The paleoenvironment was interpreted as a lagoon with restrict connection to the sea. Tepees structures and pseudomorphs of gypsum crystals suggest evaporitic condition to this basin, and also show evidences of aridity. The Bocaina Formation\'s dolomites have been interpreted as secondary, from replacement of limestones during eodiagenesis by reflux of oceanic waters. Organogenic models are also consideraded as a process to form these dolomites, based on the positive carbon isotope signature (\'delta\' POT.13 IND.CVPDB\' between 0.95 and 3.15%o). The phosphogenesis has been interpreted as eodiagenetic process occurred in anoxic geochemical environment, due to the excess oforganic matter, mediated by microbial process. The positive Ce anomalies support this interpretation. This process occurs during rising of sea level and the phosphorites represent a stratigraphic mark as a condensed surface. Subsequently, it is observed a sea level lowering, recorded in phospharenite facies and in basal polymict conglomerate of Tamengo Formation, unit which overlies the Bocaina Formation. This lowering event marks the end of the restrict lagoon environment and the installation of a marine platform.

The rehabilitation and restoration of degraded landscapes adjacent to gold tailings disposal facilities (TDFs) that have suffered loss of efficiency through anthropogenic forces has become a primary concern to environmental sciences and management in recent decades. Due to the lack of environmental legislation and enforcement thereof, minimal surface rehabilitation took place on the Mine Waste Solutions (MWS) No. 5 TDF prior to 1992, a commonplace occurrence in South Africa at the time. In 2000, MWS intervened and committed to the rehabilitation of the entire site with profits generated by the reprocessing (extraction of residual gold and uranium) of certain TDFs. However, the adjacent grazing land north of the MWS No. 5 TDF had already been subjected to pollution from the TDF which resulted in a pollution plume on the land. Although it has been inactive since April 2011, the pollution plume can be seen from the north-eastern corner of MWS No. 5 TDF, with a north-eastern/south-western direction on the farm Stilfontein. During dry periods, significant amounts of sulphate salts accumulate on the soil surface on the farm Stilfontein over a distance of at least 3.5 km from the TDF. The presence of sulphate salts in association with gold TDFs is highly common but not particularly common, in the chert-poor dolomites of the Oaktree Formation itself, in which the presence of sulphate salts is a rarity. The primary concern of this study was to determine both the quantitative and extent of the pollution observed on the farm Stilfontein over a period of 30 months via monthly monitoring of the different soil geochemical assessments across twelve fixed points, and quarterly interval assessments of three transect lines. In addition, the study was also concerned with the identification of potential linear structure anomalies associated with the pollution plume and weathered zones (fractures, joints and cavities) in the Oaktree Formation dolomites. These zones may be associated with, or may result in, the pollution extending over the area despite a topography as well as geological dip and strike that is adverse. These features and weathered zones create pathways for groundwater to flow and it was anticipated that, if present, these anomalies and weathered zones may be primary contributing factors to the pollution plume forming in a north-easterly direction and extending over the farm Stilfontein. The MWS No. 5 TDF has a hydraulic pressure head of approximately 40 m; the elevations of the north-eastern corner of the TDF and fixed point (FP) 8 (the farthest FP from the TDF) are 1368 m and 1360 m respectively, falling in close range of each other. It is anticipated that as the TDF material dries, the phreatic water level inside the TDF will lower; causing the pressure exerted by the hydraulic head of the TDF to lower over time, which will eventually end the pollution process on the soil. This study discusses the results of a holistic approach towards the evaluation of soil, vegetation and water pollution by utilizing soil quality parameters and indicators, geohydrology, geophysical surveys, Landscape Function Analysis (LFA) and other means of vegetation assessments. Salt accumulation on the soil surface was common in specific areas from 2010 – 2012. X ray diffraction (XRD) analyses confirmed that the salts originated from the No. 5 TDF due to the similarity in mineralogy. The pH values from the start of the 30-month monitoring period remained neutral to slightly alkaline due to the neutralising effect of the dolomitic bedrock. The electrical conductivity (EC) values of the soil decreased significantly from 2010 to 2014; during dry seasons since 2012, no sulphate salts accumulated on the soil surface. Joints, fractures and cavities were found within the bedrock dolomites which created pathways for the polluted TDF water and groundwater to flow towards the study area. It was also established that there were no adverse effects on the natural vegetation, other than encroachment by Seriphium plumosum which affected the grazing quality (overgrazed sites) of the area. It was therefore concluded that after the TDF became dormant in April 2011, the pollution plume in this area is decreasing in magnitude and severity due the lowering of the phreatic water level inside the TDF to significantly lower levels. Consequently, the decrease of the hydraulic pressure head of the TDF as well as rainwater infiltration and high percolation due to the presence of fractures, joints and cavities in the dolomites resulted in the leaching of the sulphate salts to a significant extent. It was also concluded that while there were no apparent adverse effects of the pollution on the functionality of the land, additional monitoring and maintenance would be required for at least the next five years in order to ensure the continuance of current conditions. / MSc (Environmental Sciences), North-West University, Potchefstroom Campus, 2015

The rehabilitation and restoration of degraded landscapes adjacent to gold tailings disposal facilities (TDFs) that have suffered loss of efficiency through anthropogenic forces has become a primary concern to environmental sciences and management in recent decades. Due to the lack of environmental legislation and enforcement thereof, minimal surface rehabilitation took place on the Mine Waste Solutions (MWS) No. 5 TDF prior to 1992, a commonplace occurrence in South Africa at the time. In 2000, MWS intervened and committed to the rehabilitation of the entire site with profits generated by the reprocessing (extraction of residual gold and uranium) of certain TDFs. However, the adjacent grazing land north of the MWS No. 5 TDF had already been subjected to pollution from the TDF which resulted in a pollution plume on the land. Although it has been inactive since April 2011, the pollution plume can be seen from the north-eastern corner of MWS No. 5 TDF, with a north-eastern/south-western direction on the farm Stilfontein. During dry periods, significant amounts of sulphate salts accumulate on the soil surface on the farm Stilfontein over a distance of at least 3.5 km from the TDF. The presence of sulphate salts in association with gold TDFs is highly common but not particularly common, in the chert-poor dolomites of the Oaktree Formation itself, in which the presence of sulphate salts is a rarity. The primary concern of this study was to determine both the quantitative and extent of the pollution observed on the farm Stilfontein over a period of 30 months via monthly monitoring of the different soil geochemical assessments across twelve fixed points, and quarterly interval assessments of three transect lines. In addition, the study was also concerned with the identification of potential linear structure anomalies associated with the pollution plume and weathered zones (fractures, joints and cavities) in the Oaktree Formation dolomites. These zones may be associated with, or may result in, the pollution extending over the area despite a topography as well as geological dip and strike that is adverse. These features and weathered zones create pathways for groundwater to flow and it was anticipated that, if present, these anomalies and weathered zones may be primary contributing factors to the pollution plume forming in a north-easterly direction and extending over the farm Stilfontein. The MWS No. 5 TDF has a hydraulic pressure head of approximately 40 m; the elevations of the north-eastern corner of the TDF and fixed point (FP) 8 (the farthest FP from the TDF) are 1368 m and 1360 m respectively, falling in close range of each other. It is anticipated that as the TDF material dries, the phreatic water level inside the TDF will lower; causing the pressure exerted by the hydraulic head of the TDF to lower over time, which will eventually end the pollution process on the soil. This study discusses the results of a holistic approach towards the evaluation of soil, vegetation and water pollution by utilizing soil quality parameters and indicators, geohydrology, geophysical surveys, Landscape Function Analysis (LFA) and other means of vegetation assessments. Salt accumulation on the soil surface was common in specific areas from 2010 – 2012. X ray diffraction (XRD) analyses confirmed that the salts originated from the No. 5 TDF due to the similarity in mineralogy. The pH values from the start of the 30-month monitoring period remained neutral to slightly alkaline due to the neutralising effect of the dolomitic bedrock. The electrical conductivity (EC) values of the soil decreased significantly from 2010 to 2014; during dry seasons since 2012, no sulphate salts accumulated on the soil surface. Joints, fractures and cavities were found within the bedrock dolomites which created pathways for the polluted TDF water and groundwater to flow towards the study area. It was also established that there were no adverse effects on the natural vegetation, other than encroachment by Seriphium plumosum which affected the grazing quality (overgrazed sites) of the area. It was therefore concluded that after the TDF became dormant in April 2011, the pollution plume in this area is decreasing in magnitude and severity due the lowering of the phreatic water level inside the TDF to significantly lower levels. Consequently, the decrease of the hydraulic pressure head of the TDF as well as rainwater infiltration and high percolation due to the presence of fractures, joints and cavities in the dolomites resulted in the leaching of the sulphate salts to a significant extent. It was also concluded that while there were no apparent adverse effects of the pollution on the functionality of the land, additional monitoring and maintenance would be required for at least the next five years in order to ensure the continuance of current conditions. / MSc (Environmental Sciences), North-West University, Potchefstroom Campus, 2015

This study investigates host community attitudes towards tourism in South Tyrol’s Puster Valley in Italy along with predispositions against the emerging phenomenon of overtourism and explores the factors influencing its formations, as similar research in the same European context with a more mature tourism industry is still underdeveloped. Applying quantitative methods, data was collected through an online survey between May and June 2021. A total of 17 attitude statements were analyzed using IBM’s SPSS and the results indicate that tourism impacts in the valley are perceived evenly throughout the whole community while it was proven with Social Exchange Theory that people involved within the tourism industry are less inclined to perceive negative impacts. Choosing the Pragser Wildsee as a case, the analysis further reveals that overtourism is not only affecting residents in its vicinity put has more far-reaching consequences. Even the results not being very surprising, the study is confirming tourism-related issues and suggests more need in investigating resident attitudes in similar environments.

No description available.