Doctor Scientiae / Acid Mine Drainage (AMD) is identified as one of the contributors to environmental hazard in the gold mining region of South Africa, as caused by the mining operational activities performed by mining industries in South Africa. This effect motivates the development of AMD prediction techniques application and geochemistry modelling using gold tailing dams located in West Rand area, Witwatersrand Basin as a case study. Control strategies are devised to assess, understand and measure the acidic potential generation of waste materials in ensuring the right method required to analyse risks caused by AMD to environment. The method encompasses mineralogical and geochemical analysis of 93 samples collected, AMD prediction, test modification and geochemical modelling. This method was appropriately applied to understand the basic mechanisms involved in controlling acid generation, assessing prediction procedure and selecting the right prediction tools. Study objectives are attained by performing a series of experimental lab tests on the samples collected from the two major tailing dams (Mogale and Gold One_1 tailings). Results derived from the lab experiments (XRD and SEM-EDS) show presence of mineral phases characterised with the surface feature of samples, and unknown substances of samples were identified. Geochemical characterisation was performed by XRF and ICP-MS to determine the major oxides elements and trace elements, respectively. Leco test generate total sulphur and total carbon. Multistatistical analysis is used to interpret the data derived from geochemical characterisation process to explicate the metal and trace elements distribution and occurrence. Initial samples were screened and categorised based on paste pH and EC using kinetic tests to determine acid-forming and neutralising minerals in samples and static tests to determine acid generation potential in samples. Net Acid Producing (NAPP) was mathematically calculated from Acid Neutralising Capacity (ANC), Maximum Potential Acidity (MPA) and total Sulphur. Results obtained from the Paste pH demonstrate that samples collected from 1 meter downward the holes to 10 meters, with a few meters samples in hole T003 at Gold One_1 are non-acidic while the remaining tailing samples are acidic. ANC/MPA ratio was applied to assess the risk of acid generation from mine waste materials. Graphical illustrations of the Acid Base Account (ABA) are plotted to demonstrate the net acidic generation potential trends of samples, which were classified into non-acid forming, potential acid forming and uncertain categories. Results integration between ANC, Single Addition Net Acid Generation (NAG) test and NAPP were used to classify acid generation potential of the samples. Leachate collected from leaching column test were analysed for pH, EC and chemical element by ICP-MS. The leaching column test used to analyse samples (T004) and (T001) collected from the two major tailings was set up for a 4-month experiment. Study findings present environmental assessment report on the two investigated gold tailing dams in Witwatersrand Basin area. Other findings are improved understanding of the application and limitations of various existing AMD prediction methods for assessment of gold mine waste and conceptual geochemical modelling developed to test appropriate methodology for AMD potential at a given gold mine site.

The Gray Fossil Site (GFS) includes multiple karst sub-basins that are filled with lacustrine sediments. Early paleontologic work on one of the sub-basins (GFS-2) indicates a late Miocene/early Pliocene age based on an assemblage of well-preserved vertebrate fossils. However, detailed palynological analysis of the 38.7. m deep GFS-1 core recovered from another sub-basin indicates an older age. The presence of Caryapollenites imparalis, C. inelegans and C. prodromus association suggests a Paleocene to Eocene age for the GFS-1 core section. This age is also supported by the absence of pollen of the Poaceae, the grass family that is not commonly present until the Neogene. Age constraints from palynologic data suggest that the GFS has a more complex basin-fill history than previously suspected, and that multiple depo-centers within the basin may have been periodically active through the Cenozoic. Palynofacies analysis of the GFS-1 core indicates that phytoclasts and opaques are the most abundant organic constituents and have diluted both the palynomorph population and amorphous organic matter. Two possible scenarios can account for this observation: 1) an oxidizing depositional paleoenvironment; and 2) a localized high flux of charcoal following wildfires and subsequent increased runoff.

Sedimentary rocks are an important source of information about previous orogenic conditions and the composition of which may describe the evolution of provenance and tectonic setting. Many factors influence sediment composition, namely, source rock composition, chemical weathering, climate, transport burial, and diagenesis. As the sediment composition changes through time, the geochemical characteristics of the sediment can be used to understand its geologic history. The geochemical characteristics of clastic sedimentary rocks are useful in determining the depositional setting and its associated provenance. Although many different studies have used geochemical discriminants to evaluate provenance and tectonic settings, none have used a defined geochemical method. This study evaluates the present-day geochemical approaches to see which, if any, are the most useful.

Nos últimos anos, estudos de prospecção geoquímica aliados à análise estatística e a técnicas de geoprocessamento tornaram-se imprescindíveis na busca por novos depósitos minerais. O Serviço Geológico do Brasil (CPRM) executou o levantamento geoquímico na porção leste do Estado do Rio Grande do Sul, em uma área de aproximadamente 32.481 km², e disponibilizou dados de sedimentos de corrente e de concentrado de bateia. A área desse estudo está situada sobre o Escudo Sul-rio-grandense, mais especificamente no Cinturão Dom Feliciano Leste. Trata-se de uma área formada por um volumoso magmatismo granítico com características de retrabalhamento crustal, na qual predominam rochas de idades proterozóicas. Apesar de pesquisas pontuais haverem encontrado indícios para a descoberta de novas ocorrências minerais na porção leste do escudo, esta tem sido pouco estudada. Sendo assim, este trabalho objetivou investigar possibilidades de novos alvos a partir da identificação de valores anômalos nesta região, empregando técnicas estatísticas e de geoprocessamento. Foram analisadas 1528 amostras de sedimentos de corrente e 1477, de concentrados de bateia, disponibilizadas no banco de dados digital da CPRM (Geobank) Determinaram-se os limiares para elementos químicos de sedimentos de corrente que possibilitaram identificar áreas anômalas. Os dados de concentrados de bateia foram tratados de forma distinta, a partir da construção de mapas de densidade do tipo Kernel. As áreas anômalas foram apresentadas de duas formas distintas. As Anomalias Puramente Estatísticas correspondem às regiões que apresentaram elementos químicos com valores acima do limiar e consideram apenas a posição geográfica destes, independentemente da afinidade existente entre os mesmos. Já as Anomalias Prospectivas foram assim denominadas, pois a delimitação da área anômala foi baseada no agrupamento de elementos que possuem afinidade, utilizando conceitos de prospecção como assinatura geoquímica e elementos farejadores. Os resultados encontrados apontam para seis áreas anômalas na porção leste do escudo sul-riograndense, os quais apresentam assinaturas de depósitos IOCG, Pórfiro-epitermal e depósitos relacionados a granitos estaníferos. Este estudo geoquímico de escala regional revelou áreas anômalas inéditas no escudo sul-riograndense. Fica claro que existe um alto potencial na área da metalogenia a ser ainda estudado. / In the last few years, geochemical prospective studies allied to statistical analysis and geoprocessing techniques became indispensable in the search for new mineral deposits. The Brazilian Geological Survey (CPRM) performed a geochemical survey in the eastern portion of the Rio Grande do Sul State, in an area that covers 32.481 km², and provided stream sediment and pan concentrate data. The studied area is situated in the Rio Grande do Sul’s Shield, more specifically in the Dom Feliciano Eastern belt. The area is constituted by a massive granitic magmatism with crustal reworking characteristics, in which rocks of Proterozoic age prevail. Although some researches had found clues of new mineral occurrences in the eastern part of the Shield, it is still understudied. Thus, this study aimed to investigate the possibilities of new targets from the identification of anomalous values in the region, employing statistical and geoprocessing techniques. 1528 stream sediment and 1477 pan concentrate samples are available in the digital database of CPRM (Geobank) were analysed. The threshold values for stream sediment chemical elements were determined, which allowed identifying the anomalous areas The pan concentrate data was analysed differently, from the construction of Kernel density maps. The resulting anomalous areas of this study were presented in two different ways, as Purely Statistical Anomalies (PSA) and Prospective Anomalies (PA). The regions that presented chemical elements above the threshold value, considering just their geographical position, regardless of the chemical affinity between the elements, were denominated Purely Statistical Anomalies. In the Prospective Anomalies, the delimitation of the anomalous area was based on the grouping of the elements that had chemical affinity, using prospective concepts as geochemical signature and pathfinder elements. The results pointed to six anomalous areas in the Sul-Riograndense Shield, which presented signatures of Iron oxide copper-gold (IOCG), porphyry-epithermal and stanniferous granites deposits. This regional scale geochemical study revealed unprecedented anomalous areas in the Sul-Riograndense Shield. Besides that, it became clear that there is a great metallogenic potential that still need to be studied.

Thesis (Ph. D.)--Oregon State University, 2009. / Printout. Includes bibliographical references (leaves 161-169). Also available on the World Wide Web.

Nos últimos anos, estudos de prospecção geoquímica aliados à análise estatística e a técnicas de geoprocessamento tornaram-se imprescindíveis na busca por novos depósitos minerais. O Serviço Geológico do Brasil (CPRM) executou o levantamento geoquímico na porção leste do Estado do Rio Grande do Sul, em uma área de aproximadamente 32.481 km², e disponibilizou dados de sedimentos de corrente e de concentrado de bateia. A área desse estudo está situada sobre o Escudo Sul-rio-grandense, mais especificamente no Cinturão Dom Feliciano Leste. Trata-se de uma área formada por um volumoso magmatismo granítico com características de retrabalhamento crustal, na qual predominam rochas de idades proterozóicas. Apesar de pesquisas pontuais haverem encontrado indícios para a descoberta de novas ocorrências minerais na porção leste do escudo, esta tem sido pouco estudada. Sendo assim, este trabalho objetivou investigar possibilidades de novos alvos a partir da identificação de valores anômalos nesta região, empregando técnicas estatísticas e de geoprocessamento. Foram analisadas 1528 amostras de sedimentos de corrente e 1477, de concentrados de bateia, disponibilizadas no banco de dados digital da CPRM (Geobank) Determinaram-se os limiares para elementos químicos de sedimentos de corrente que possibilitaram identificar áreas anômalas. Os dados de concentrados de bateia foram tratados de forma distinta, a partir da construção de mapas de densidade do tipo Kernel. As áreas anômalas foram apresentadas de duas formas distintas. As Anomalias Puramente Estatísticas correspondem às regiões que apresentaram elementos químicos com valores acima do limiar e consideram apenas a posição geográfica destes, independentemente da afinidade existente entre os mesmos. Já as Anomalias Prospectivas foram assim denominadas, pois a delimitação da área anômala foi baseada no agrupamento de elementos que possuem afinidade, utilizando conceitos de prospecção como assinatura geoquímica e elementos farejadores. Os resultados encontrados apontam para seis áreas anômalas na porção leste do escudo sul-riograndense, os quais apresentam assinaturas de depósitos IOCG, Pórfiro-epitermal e depósitos relacionados a granitos estaníferos. Este estudo geoquímico de escala regional revelou áreas anômalas inéditas no escudo sul-riograndense. Fica claro que existe um alto potencial na área da metalogenia a ser ainda estudado. / In the last few years, geochemical prospective studies allied to statistical analysis and geoprocessing techniques became indispensable in the search for new mineral deposits. The Brazilian Geological Survey (CPRM) performed a geochemical survey in the eastern portion of the Rio Grande do Sul State, in an area that covers 32.481 km², and provided stream sediment and pan concentrate data. The studied area is situated in the Rio Grande do Sul’s Shield, more specifically in the Dom Feliciano Eastern belt. The area is constituted by a massive granitic magmatism with crustal reworking characteristics, in which rocks of Proterozoic age prevail. Although some researches had found clues of new mineral occurrences in the eastern part of the Shield, it is still understudied. Thus, this study aimed to investigate the possibilities of new targets from the identification of anomalous values in the region, employing statistical and geoprocessing techniques. 1528 stream sediment and 1477 pan concentrate samples are available in the digital database of CPRM (Geobank) were analysed. The threshold values for stream sediment chemical elements were determined, which allowed identifying the anomalous areas The pan concentrate data was analysed differently, from the construction of Kernel density maps. The resulting anomalous areas of this study were presented in two different ways, as Purely Statistical Anomalies (PSA) and Prospective Anomalies (PA). The regions that presented chemical elements above the threshold value, considering just their geographical position, regardless of the chemical affinity between the elements, were denominated Purely Statistical Anomalies. In the Prospective Anomalies, the delimitation of the anomalous area was based on the grouping of the elements that had chemical affinity, using prospective concepts as geochemical signature and pathfinder elements. The results pointed to six anomalous areas in the Sul-Riograndense Shield, which presented signatures of Iron oxide copper-gold (IOCG), porphyry-epithermal and stanniferous granites deposits. This regional scale geochemical study revealed unprecedented anomalous areas in the Sul-Riograndense Shield. Besides that, it became clear that there is a great metallogenic potential that still need to be studied.

Nos últimos anos, estudos de prospecção geoquímica aliados à análise estatística e a técnicas de geoprocessamento tornaram-se imprescindíveis na busca por novos depósitos minerais. O Serviço Geológico do Brasil (CPRM) executou o levantamento geoquímico na porção leste do Estado do Rio Grande do Sul, em uma área de aproximadamente 32.481 km², e disponibilizou dados de sedimentos de corrente e de concentrado de bateia. A área desse estudo está situada sobre o Escudo Sul-rio-grandense, mais especificamente no Cinturão Dom Feliciano Leste. Trata-se de uma área formada por um volumoso magmatismo granítico com características de retrabalhamento crustal, na qual predominam rochas de idades proterozóicas. Apesar de pesquisas pontuais haverem encontrado indícios para a descoberta de novas ocorrências minerais na porção leste do escudo, esta tem sido pouco estudada. Sendo assim, este trabalho objetivou investigar possibilidades de novos alvos a partir da identificação de valores anômalos nesta região, empregando técnicas estatísticas e de geoprocessamento. Foram analisadas 1528 amostras de sedimentos de corrente e 1477, de concentrados de bateia, disponibilizadas no banco de dados digital da CPRM (Geobank) Determinaram-se os limiares para elementos químicos de sedimentos de corrente que possibilitaram identificar áreas anômalas. Os dados de concentrados de bateia foram tratados de forma distinta, a partir da construção de mapas de densidade do tipo Kernel. As áreas anômalas foram apresentadas de duas formas distintas. As Anomalias Puramente Estatísticas correspondem às regiões que apresentaram elementos químicos com valores acima do limiar e consideram apenas a posição geográfica destes, independentemente da afinidade existente entre os mesmos. Já as Anomalias Prospectivas foram assim denominadas, pois a delimitação da área anômala foi baseada no agrupamento de elementos que possuem afinidade, utilizando conceitos de prospecção como assinatura geoquímica e elementos farejadores. Os resultados encontrados apontam para seis áreas anômalas na porção leste do escudo sul-riograndense, os quais apresentam assinaturas de depósitos IOCG, Pórfiro-epitermal e depósitos relacionados a granitos estaníferos. Este estudo geoquímico de escala regional revelou áreas anômalas inéditas no escudo sul-riograndense. Fica claro que existe um alto potencial na área da metalogenia a ser ainda estudado. / In the last few years, geochemical prospective studies allied to statistical analysis and geoprocessing techniques became indispensable in the search for new mineral deposits. The Brazilian Geological Survey (CPRM) performed a geochemical survey in the eastern portion of the Rio Grande do Sul State, in an area that covers 32.481 km², and provided stream sediment and pan concentrate data. The studied area is situated in the Rio Grande do Sul’s Shield, more specifically in the Dom Feliciano Eastern belt. The area is constituted by a massive granitic magmatism with crustal reworking characteristics, in which rocks of Proterozoic age prevail. Although some researches had found clues of new mineral occurrences in the eastern part of the Shield, it is still understudied. Thus, this study aimed to investigate the possibilities of new targets from the identification of anomalous values in the region, employing statistical and geoprocessing techniques. 1528 stream sediment and 1477 pan concentrate samples are available in the digital database of CPRM (Geobank) were analysed. The threshold values for stream sediment chemical elements were determined, which allowed identifying the anomalous areas The pan concentrate data was analysed differently, from the construction of Kernel density maps. The resulting anomalous areas of this study were presented in two different ways, as Purely Statistical Anomalies (PSA) and Prospective Anomalies (PA). The regions that presented chemical elements above the threshold value, considering just their geographical position, regardless of the chemical affinity between the elements, were denominated Purely Statistical Anomalies. In the Prospective Anomalies, the delimitation of the anomalous area was based on the grouping of the elements that had chemical affinity, using prospective concepts as geochemical signature and pathfinder elements. The results pointed to six anomalous areas in the Sul-Riograndense Shield, which presented signatures of Iron oxide copper-gold (IOCG), porphyry-epithermal and stanniferous granites deposits. This regional scale geochemical study revealed unprecedented anomalous areas in the Sul-Riograndense Shield. Besides that, it became clear that there is a great metallogenic potential that still need to be studied.

The aim of this dissertation is an attempt to' provide a general guide for future gold exploration in tropical and sub-tropical terrains. The dissertation includes a brief discussion of the various exploration techniques used in regional and local exploration. This provide the necessary background knowledge to discriminate between the constraints and applications and to be able to select the techniques which are more suitable for gold exploration in tropical and sub-tropical terrains. Weathering, gold geochemistry and soil formation, fields often neglected, are emphasized to illustrate the importance of the mobility and dispersion of gold in the weathering of the lateritic soil profile. A sound knowledge and experience in regolith mapping is to the advantage of the explorationist. Case studies with special emphasis on Central- and Western Africa are included to illustrate the effectiveness of some of the gold exploration techniques in tropical and sub-tropical terrains. Gold exploration is a highly complex and demanding science and to be successfull involves the full intergration of all geological, geochemical and geophysical information available. An intergrated exploration method and strategy would enhance the possibility of making viable discoveries in this highly competative environment where our mineral resources become more depleted every day. Where applicable, the reader is refered to various recommended literature sources to provide the necessary background knowledge which form an integral part of gold exploration.

The conservation of freshwater resources is fundamental in supporting modern society and preserving natural habitats and ecosystems. Deterioration of water quality in urban landscapes and loss of municipal water to leaky water distribution infrastructure are two substantial challenges to water-resource sustainability. I examine the geochemistry of streamwater, municipal water, wastewater, soil, and bedrock from the Bull Creek watershed, a rapidly urbanizing watershed in Austin, Texas, to achieve a better understanding of the processes of geochemical evolution as anthropogenically-sourced water recharges natural systems. Urbanization patterns in the Bull Creek watershed have created a contiguous expanse of urban development that covers roughly two thirds of the watershed, whereas the remaining third is rural, enabling direct comparison between urban and rural streamwater from a single watershed. Results indicate that Na, Cl, K, and SO₄ in urban springs and tributaries are elevated more than two-fold in comparison with rural springs and tributaries. A comparison of Sr concentration and Sr isotopic composition for spring and tributary samples indicates that municipal water and wastewater provide a substantial contribution to the urbanized stream branches of Bull Creek. This water is reactive in the subsurface after it leaks from the municipal system, evolving via a pathway of water-rock interaction with limestone. / text

The study of archaeology within an ecological and evolutionary framework began with the study of changes in human subsistence through time. Within the last few decades archaeologists have expanded applications of evolutionary ecology (EE) beyond the dietary emphasis of the prey choice model toward increasingly complex and novel applications. The chapters in this dissertation provide several examples of this expansion, through novel examinations of the complex relationships between humans and their environment, as well as thoughtful examinations of social systems and non-subsistence related behavior through the prism of EE. Appendix A asks at what transport distance from a central place does big game become costly to procure relative to smaller local game? Results from this study show that big game is an economical choice at a one-way transport distance of over 100 km. These results are then used in Appendix B where isotope geochemistry is used to show both large and small game from Pueblo Bonito, Chaco Canyon were transported over 70 km to the Canyon. Without the results from Appendix A, one would be inclined to describe the long-distance transport of large game as a costly signal, when in fact it is an economical choice, particularly in a depressed or low productivity habitat. Appendix C, demonstrates the applicability of costly signaling theory to non-dietary artifacts, by showing how geochemically sourced non-local goods contain a variety of social meaning.