Orientadores: Roberto Perez Xavier, Lena Virginia Soares Monteiro / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Geociencias / Made available in DSpace on 2018-08-14T22:53:15Z (GMT). No. of bitstreams: 1 Torresi_Ignacio_M.pdf: 10387814 bytes, checksum: 10ae1f36fa8d66f6046d5f1bb6d6a4aa (MD5) Previous issue date: 2009 / Resumo: O depósito de óxido de ferro-cobre-ouro (IOCG) Alvo 118 (170 Mt @ 1,0 wt% Cu, 0,3 g/t Au), junto aos depósitos de classe mundial de Sossego e Cristalino, situam-se no setor sul da Província Mineral de Carajás (PMC) alinhados e uma zona de cisalhamento subvertical regional, de direção WNW-ESE, e 60 km de extensão, próximo ao contato do Supergrupo Itacaiunas, uma sequência metavulcano-sedimentar (~2,76 Ga), com o embasamento arqueano (Complexo Xingu; ~3,0 Ga). A mineralização de Cu-Au no deposito Alvo118 e hospedada por rochas vulcanicas máficas e intermediarias, corpos de granitos e gabbros, que foram sujeitos a seguinte sequência de alteração hidrotermal em direção ao minério de Cu: (1) alteração sódica representada por albita e escapolita, o que indica circulação de fluidos quentes (>500°C) e salinos; (2) alteração potássica dominada pela presença de biotita e k-feldspato, respectivamente, nas rochas máficas e intermediarias, acompanhada de formação de magnetita e silicificação; (3) alteração a clorita, espacialmente associada brechas quartzo-carbonaticas mineralizadas a calcopirita e stockworks de veios que normalmente apresentam estruturas de preenchimento de espaço; (4) alteração a quartzo-sericita tardia a mineralizacao. A assembléia mineral da mineralizacao e dominada por calcopirita (80%), acompanhado de bornita (10%), magnetita (10%), hematita (10%), e traços de teluretos de Au-Ag, galena e cassiterita. Diferente de outros depósitos do tipo IOCG da PMC, onde ETRL estão presentes em apatita, allanita e monazita, no Alvo 118 o enriquecimento e em ETRP. Neste deposito os ETRP estão concentrados principalmente em apatite e em um mineral pobre em alumínio, um silicato de Be-B-ETRP do grupo da gadolinite, que nunca foi descrita em qualquer deposito do tipo IOCG do mundo. Estudos de inclusões fluidas em quartzo e calcite apontam pra um regime de fluidos, em que soluções hipersalinas e quentes, representada por inclusões trifásicas, fossem progressivamente esfriadas e diluídas por fluidos de baixa salinidade, representada por inclusões bifásicas, que dominam na mineralizacao do Alvo 118. Valores de d18OH2O em equilíbrio com calcita (-1.9¿ a 10.7¿ a 300°C) sugerem forte interação entre os fluidos mineralizantes e as rochas hospedeiras, como também prolongada mistura com fluidos meteóricos. A composição de d34S em calcopirita (5.1¿ a 6.3¿) difere daquela de fonte mantélica/magmática, reforçando a possibilidade de fontes de enxofre mais pesado (sulfatos de evaporitos?) para os sulfetos da brecha e dos veios mineralizados. A alteração sódica de alta temperatura, a sobreposição de alteração potássica e a alteração a clorita proximal, a brecha de quartzo-carbonatica mineralizada e os valores de d18O indicam que o Alvo 118 e um sistema IOCG que evoluiu em níveis estruturais superiores, nível crustal raso, envolvendo o influxo de águas meteóricas. / Abstract: The Alvo 118 iron oxide-copper-gold (IOCG) deposit (170 Mt @ 1,0 wt% Cu, 0,3 g/t Au), together with the world-class Sossego and Cristalino deposits, lie in the southern sector of the Carajas Mineral Province (CMP) along a steeply-dipping, WNW-ESE-striking, 60 km-long shear zone, close to the contact of the Itacaiunas Supergroup metavolcano-sedimentary sequence (~2,76 Ga) and the basement (Xingu Complex; ~3,0 Ga). The Cu-Au mineralization at the Alvo 118 is hosted by mafic and felsic metavolcanic rocks and crosscutting granitoid and gabbro bodies that have been subjected to the following hydrothermal alteration sequence towards the ore zones: (1) sodic alteration represented by albite and scapolite, indicating the circulation of hot (>500°C) and highly saline fluids; (2) potassium alteration dominated by biotite or Kfeldspar, respectively, in mafic and felsic volcanic and intrusive rocks, accompanied by the formation of magnetite and silicification; (3) chlorite alteration spatially associated with carbonate-quartz ore breccia and vein stockworks that commonly display open-space filling textures; (4) local post-ore quartz-sericite alteration. The ore assemblage is dominated by chalcopyrite (80%), accompanied by bornite (10%), magnetite (10%), hematite (10%), and traces of Au-Ag tellurides, galena and cassiterite. Dissimilar from other IOCG deposits of the CMP where LREEs are commonly enriched in apatite, allanite and monazite, the Alvo 118 ore displays enrichments of HREEs. In this deposit the HREEs are mainly concentrated in apatite and in an Al-poor, Be-B-HREE silicate of the gadolinite group which has never been reported in IOCG systems worldwide. Fluid inclusion studies in quartz and calcite point to a fluid regime in which hot brine solutions, represented by < 10 vol.% of salt-bearing aqueous inclusions, were progressively cooled and diluted by lower temperature, low-salinity (< 10 wt% NaCl eq.) aqueous fluids defined by two-phase aqueous inclusions, by far the dominant type. d18OH2O values in equilibrium with calcite (- 1.9¿ to 10.7¿ at 300°C) suggest strong interaction between ore fluids and the host rocks, as well as prolonged mixing with meteoric fluids. The d34S composition of chalcopyrite (5.1¿ to 6.3¿) differs from a mantle/magmatic source adding the possibility of heavier sulfur sources (e.g., evaporite sulfate?) for the ore breccia and vein sulfides. The restricted high temperature sodic alteration, the pervasive overprinting of the potassic alteration minerals (biotite and K-feldspar) by chlorite proximal to the ore zones, quartz-calcite-chlorite ore breccias/veins with open-space filling textures in brittle structures, and the d18O data collectively indicate that the Alvo 118 IOCG system developed at structurally high levels and experienced the influx of evolved meteoric water. / Mestrado / Mestre em Geociências

Orientadores: Lena Virginia Soares Monteiro , Roberto Perez Xavier / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Geociências / Made available in DSpace on 2018-08-15T15:13:25Z (GMT). No. of bitstreams: 1 Moreto_CarolinaPenteadoNatividade_M.pdf: 6364154 bytes, checksum: 08d26b0642844f0ebe0c97e4f6816d34 (MD5) Previous issue date: 2010 / Resumo: O depósito de óxido de ferro-cobre-ouro Bacaba, situado no Cinturão de Cisalhamento Itacaiúnas, Província Mineral de Carajás, representa um alvo satélite do depósito de classe mundial Sossego, e possivelmente também representa as porções distais e profundas do mesmo sistema hidrotermal. O depósito Bacaba localiza-se ao longo de uma zona de cisalhamento com direção WNW-ESE que define o contato entre o embasamento, representado pelo Complexo Xingu (ca. 3,0 Ga), e a unidade metavulcano-sedimentar do Supergrupo Itacaiúnas (ca. 2,76 Ga). As principais rochas hospedeiras do minério no depósito Bacaba são representadas pelo Granito Serra Dourada, Tonalito Bacaba e por corpos gabróicos, que foram intensamente afetados por alterações hidrotermais sódica (albita-escapolita), potássica, clorítica e hidrolítica. Os dados de U-Pb LA-ICP-MS em zircão de uma amostra com alteração sódica do Granito Serra Dourada forneceram a idade de 2858 ± 30 Ma (MSWD = 9,7). Três amostras do Tonalito Bacaba, sendo uma com alteração potássica e duas com alteração potássica e mineralização de Cu-Au, forneceram idades em 2997,2 ± 4,7 Ma (MSWD = 1,15), 2993,1 ± 7,1 Ma (MSWD = 1,1) e 3004,7 ± 7,8 Ma (MSWD = 2,1), respectivamente. As idades em 2,86 e ca. 3,0 Ga são interpretadas como idade de cristalização do Granito Serra Dourada e do Tonalito Bacaba, respectivamente. As estruturas internas e morfologia dos cristais de zircão de ambas as rochas, observadas em imagens de catodoluminescência e de elétrons retro-espalhados, confirmam a ocorrência de processos de recristalização, que pode ser relacionado com episódios de hidrotermalismo e/ou deformação/metamorfismo que ocorreram na Província Mineral de Carajás. Contudo, esse (s) evento (s) não pode (puderam) ser datado (s) devido à ausência de abertura total do sistema isotópico U-Pb e ausência de cristais de zircão de origem hidrotermal.O Granito Serra Dourada e o Tonalito Bacaba são as rochas graníticas mais antigas até então reconhecidas no Cinturão de Cisalhamento Itacaiúnas. A presença dessas rochas tão antigas implica na existência de um importante magmatismo anterior à instalação da Bacia de Carajás (Supergrupo Itacaiúnas), e em uma história evolutiva mais complexa para o Cinturão de Cisalhamento Itacaiúnas. As similaridades petrográficas e geocronológicas dessas intrusivas félsicas do depósito Bacaba com suítes de rochas graníticas e tonalíticas reconhecidas no Terreno Granito-Greenstone Rio Maria, porção sul da Província Mineral de Carajás, implica na ocorrência de um magmatismo de ca. 3,0 e 2,86 Ga mais amplo e extenso. O Granito Serra Dourada e o Tonalito Bacaba não poderiam ser responsáveis pelo estabelecimento do sistema magmático-hidrotermal associado com a gênese do depósito Bacaba. Isso seria improvável porque outros depósitos com características similares são hospedados por unidades metavulcano-sedimentares mais novas (2,76 Ga). Nesse contexto, os depósitos de óxido de ferro-cobre-ouro do setor sul do Cinturão de Cisalhamento Itacaiúnas devem ser controlados principalmente por importantes descontinuidades crustais, como a zona de cisalhamento regional com direção WNW-ESE, ao invés de serem associados com um litotipo particular. Esses resultados indicam alto potencial de ocorrência de depósitos de óxido de ferro-cobre-ouro nas rochas mesoarqueanas do embasamento sob a Bacia de Carajás, particularmente aquelas cortadas por zonas de cisalhamento neoarqueanas. / Abstract: The Bacaba iron oxide-copper-gold deposit, situated in the Itacaiúnas Shear Belt, Carajás Mineral Province (Brazil), represents a satellite prospect of the world-class Sossego deposit, and might also represent a distal and deeper portion of the same or related hydrothermal system. The Bacaba deposit is located along a WNW-ESE-striking shear zone that defines the contact of the basement represented by the Xingu Complex (ca. 3.0 Ga) and the metavolcanosedimentary Itacaiúnas Supergroup (ca. 2.76 Ga). The main host rocks at Bacaba deposit comprise the Serra Dourada Granite, the Bacaba Tonalite and croscutting gabbro, which were intensely affected by sodic (albite-scapolite), potassic, chloritic and hydrolytic hydrothermal alterations. The U-Pb LA-ICP-MS data for zircon from sodic altered sample of the Serra Dourada Granite yielded an 2858 ± 30 Ma (MSWD = 9.7) age. Three samples from the Bacaba Tonalite, including one with potassic alteration and two with potassic alteration and Cu-Au mineralization rendered the 2997.2 ± 4.7 Ma (MSWD = 1.15), 2993.1 ± 7.1 Ma (MSWD = 1.1) and 3004.7 ± 7.8 Ma (MSWD = 2.1) ages, respectively. The 2.86 and ca. 3.0 Ga ages are interpreted as the igneous crystallization of the Serra Dourada Granite and the Bacaba Tonalite, respectively. The internal structures and external morphologies of zircon crystal from both rocks, observed in cathodoluminescence and backscattered electron images, attested the occurrence of zircon recrystallization, which could be related to hydrothermalism and/or deformation/metamorphism episodes that took place in the Carajás Mineral Province. However, the disturbing event (s) could not be dated due to the absence of the total resetting of the U-Pb system and hydrothermal crystallization of zircon. The 2.86 Ga Serra Dourada Granite and the ca. 3.0 Ga Bacaba Tonalite are the oldest granitic rocks so far recognized in the Itacaiúnas Shear Belt. The presence of such old rocks implies in the existence of an important magmatism before the Carajás Basin (Itacaiúnas Supergroup) deposition, and in a more complex evolutionary history for the Itacaiúnas Shear Belt. The petrographical and geochronological similarities of these felsic intrusions with granitic and tonalitic rock suites recognized in the Rio Maria granite-greenstone terrane, southern part of the Carajás Mineral Province, implies in a more widespread ca. 3.0 and 2.86 Ga magmatism in the province. The Serra Dourada Granite and the Bacaba Tonalite are interpreted not to be responsible for the genesis of the Bacaba deposit. This is likely because the Sossego and other deposits interpreted as part of the same hydrothermal system are hosted by younger ca. 2.76 Ga metavolcano-sedimentary units. On this context, the iron oxide-copper-gold deposit in the southern sector of the Itacaiúnas Shear Belt could be mainly controlled by important crustal discontinuities, such as the WNW-ESEstriking regional shear zone, rather than be associated with a particular rock type. These results expand the potentiality of occurrence of iron oxide-copper-gold deposits for the Mesoarchean basement rocks underlying the Carajás Basin, particularly those crosscut by Neoarchean shear zones. / Mestrado / Geologia e Recursos Naturais / Mestre em Geociências

Orientadores: Carlos Roberto de Souza Filho, Adalene Moreira Silva / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Geociencias / Made available in DSpace on 2018-08-11T04:31:13Z (GMT). No. of bitstreams: 1 Magalhaes_LuciolaAlves_M.pdf: 40248865 bytes, checksum: 334d3cf05db7133f70c68a2eaba439fc (MD5) Previous issue date: 2008 / Resumo: A área de estudo, compreendida nesta investigação, situa-se no estado do Amapá e possui uma importância especial visto que se trata de uma das últimas fronteiras exploratórias do país, onde grande parte do estado é protegida por parques nacionais e reservas indígenas. Inserida na Província Maroni-Itaicaiúnas, palco de uma variedade de mineralizações como ferro, manganês, cromita, ouro, diamante, bauxita, caolim e cassiterita, na área são reconhecidos terrenos do embasamento Arqueano, seqüências do tipo greenstone-belts (Província Vila Nova) e suítes intrusivas, coletivamente de evolução geológica complexa e com amplo potencial metalogenético. O Depósito Amapari é caracterizado como um depósito do tipo lode orogenético, onde os maiores teores de ouro são associados às zonas mais deformadas, encaixadas em um sistema de veios sulfetados, principalmente pirrotita. O objetivo desta dissertação compreendeu a investigação de métodos de análise e modelagem espacial guiada pelos dados e pelo conhecimento, visando o mapeamento de áreas com favorabilidade mineral para ouro na região do depósito Amapari. À etapa de modelagem precedeu-se o processamento e a interpretação dos dados aerogeofísicos (magnetometria e gamaespectrometria) de alta resolução espacial e densidade de amostragem (Projeto Rio Araguari-CPRM), visando a geração de produtos para o mapeamento geológico e exploração mineral na porção centro-sul do estado do Amapá. Com base no processamento dos dados aerogeofísicos, foram gerados mapas de domínios e lineamentos magnéticos e domínios gamaespectrométricos, a partir dos quais novas unidades litogeofísicas foram reconhecidas, assim como redefinida, com grande precisão, a extensão de unidades previamente mapeadas (e.g., corpos enderbíticos, complexos máficos ultramáficos e intrusivas graníticas). As estruturas magnéticas são multi-orientadas. O extenso lineamento denominado Cupixi Alto Jari aparece com destaque nos mapas aerogeofísicos, separando o Terreno Cinturão Jari e o Terreno Antigo Cupixi- Tartarugal Grande. As estruturas de direção NNW são predominantes e se associam, com maior freqüência, às mineralizações auríferas da região. Dados geológicos (1:100.000), dados aerogeofísicos e análises de ouro em amostras de sedimentos de corrente foram utilizados para a geração de modelos de favorabilidade. Os mapas gerados pelos métodos de pesos de evidência, lógica fuzzy e redes neurais artificiais, destacaram a área do depósito Amapari como um sítio altamente favorável à ocorrência de ouro, condição necessária para que o resultado fosse coerente com a premissa dos modelos, além de indicarem novos alvos potenciais à mineralização. Estes novos alvos foram validados no campo e através de mapas de detalhe de anomalias geoquímicas de Au contido no solo, gerados pela MPBA. As áreas identificadas pela modelagem espacial estão em franca concordância com as principais anomalias geoquímicas, demonstrando, desta forma, que a determinação de alvos exploratórios mais favoráveis baseada em métodos indiretos é coerente com a prospecção através de métodos diretos / Abstract: The study area is situated in the Amapá State and has a special interest since it comprises one of the last exploration frontiers in Brazil, where much of the state is protected by national parks and indigenous reserves. It is placed within the Maroni-Itacaiunas Province, where a variety of mineralizations as iron, manganese, chromite, gold, diamond, bauxite, kaolin and cassiterite have been described. The area hosts in the area are recognized Archaean basements, greenstone belts (Province Vila Nova) and intrusive rocks that collectively show a complex geological evolution and with an ample metallogenic potential. The Amapari deposit is characterized as an orogenic-type gold mineralization, where the highest contents of gold are associated with the most deformed rocks in a system of sulfide veins, mainly composed of pyrrhotite. This research is focused in the investigation of spatial data modelling by data-driven and knowledge-driven predictive methods, aiming the identification of potential areas for gold mineralization in the proximities of Amapari region. High spatial resolution airborne geophysical data (magnetometry and gama-spectrometry) (Project Rio Araguari-CPRM) was processed and interpreted, aiming to provide products for geologic mapping and mineral exploration for a large area in the central-south portion of the Amapa State, Brazil. The processing of the geophysical data yielded maps of magnetic lineaments and magnetic and gamma-spectrometric domains, from which new litho-geophysical units were recognized and previously mapped units were redefined (e.g., enderbitic bodies, mafic-ultramafic complexes and granitic intrusives). The magnetic structures are multi-oriented. The extensive Alto Cupixi Jari lineament shows prominently in the magnetic maps, separating the Cinturao Jari and the Atingo-Cupixi-Tartarugal Grande terranes. The NNW-trending structures appear ubiquitously in these maps and are often associated to gold mineralizations in the region. The inputs maps for the modelling process were geological and airbone geophysical data and gold in stream sediments. The results, using weights of evidence, artificial neural networks and fuzzy logic, show that Amapari deposits were classified as a hight potential site as expected and, most importantly, new targets with similar signatures were identified throughout the area. These new targets were validated in the field and using maps of detail geochemical anomalies for Au in the soil, generated by the MPBA. The areas identified by the spatial modeling methods are in agreement with the main geochemical anomalies, demonstrating that the determination of new potential targets based on indirect methods is consistent with the prospecting through direct methods / Mestrado / Geologia e Recursos Naturais / Mestre em Geociências

Os recursos minerais são considerados bens públicos dominicais por serem estes os únicos passíveis de exploração econômica para geração de receitas pelo Estado, em razão de não estarem afetados a uma destinação específica do Estado e, tampouco, poderem ser livremente utilizados pela coletividade. A Constituição Federal autoriza a concessão da lavra dos recursos minerais, incidindo sobre o faturamento líquido advindo da exploração destes bens a denominada Compensação Financeira pela Exploração de Recursos Minerais (CFEM), receita originária patrimonial da União, cujo regime jurídico encontra-se delimitado pela Constituição Federal, nos seus artigos 5o, II; 20, IX, e § 1o; 176; 37; 155, X, b e 225, § 2o. A competência para legislar sobre a CFEM é privativa da União Federal. Tem-se como inconstitucionais, em consequência, leis de Estados e do Distrito Federal que disponham sobre a CFEM, por não se incluírem nos casos de exercício da competência concorrente. É do DNPM a competência para fiscalização e arrecadação da CFEM e é da Procuradoria Federal junto à autarquia, a inscrição do débito em dívida ativa e o ajuizamento da competente execução. São dedutíveis, para efeito de apuração da base de cálculo da CFEM, todas as despesas pagas ou incorridas pelo minerador, relativas ao transporte e ao seguro, desde a extração da substância mineral até a entrega do produto mineral comercializado, bem como o valor integral do ICMS destacado nas notas fiscais (incidido), e não apenas do montante recolhido ao Estado (apurado e pago); e o IOF, devido em razão das vendas da mencionada substância mineral como ativo financeiro. No caso de mora no pagamento da CFEM são devidos os juros, na forma estabelecida no artigo 406 do Código Civil, no período em que inexistente lei específica acerca do assunto. Entre julho de 2000 e janeiro de 2001, os juros são aqueles fixados em lei especial a respeito do tema: a Lei nº 9.993/00. E, no pertinente a fatos geradores ocorridos após o início da vigência e eficácia da Lei nº 11.941/09, deve ser observada a legislação aplicável aos tributos federais, qual seja, a Lei nº 9.430/96, que determina a incidência da taxa SELIC, acrescido o percentual de 1% no mês do efetivo recolhimento. Tem-se como legítima a inscrição do devedor de CFEM no CADIN, contanto que este cadastro seja visto como veículo meramente informativo e não constitua sanção política a compelir o particular ao pagamento de importâncias, não podendo caracterizar-se como modo indireto de cobrança, à margem do devido processo legal. O prazo de decadência para que o DNPM constituía créditos de CFEM é de cinco anos. Em que pese a CFEM constituir obrigação pecuniária de natureza não tributária, sua cobrança obedecerá ao rito estabelecido na Lei nº 6.830/80, por se tratar de receita financeira de autarquia federal DNPM. / Mineral resources are considered to be assets belonging to the public domain, once they are the only ones that may be economically exploited by the State to obtain revenues, since they are not affected by a specific destination given by the State, nor may they be freely used by society. The Federal Constitution allows the granting of mining permits, exacting the so-called Financial Compensation for the Exploitation of Mineral Resources (CFEM, local acronym) which is levied over the net revenues obtained from the exploitation of these assets. This income is paid into the coffers of the Federal Union, the legal regime whereof has been delimited by the Federal Constitution (articles 5, II, 20, IX, and § 1, 176, 37, 155, X, b and 225, § 2). The competence to enact laws regarding the CFEM pecuniary obligation befalls exclusively upon the Federal Union. As result, any laws enacted by the individual States, by the Federal District and the Districts regarding said CFEM are construed to be unconstitutional, since they cannot be handled by competing supplementary competence. The DNPM has the necessary competence to inspect and collect the CFEM pecuniary obligation, while the Attorney Generals Office, responsible for controlling said quasi-government company, must post the debt into the active debts roster, as well as bringing suit the appropriate lawsuit to collect it. In order to compute the CFEM, all expenses paid or incurred into by the mining concern pertaining to transportation and freight, from the extraction to the delivery of the product, are deductible from the basis of calculation of the CFEM. This deduction also includes the full amount of the ICMS which is highlighted on the invoices and not of the amount determined and paid to the individual State. There is also the IOF tax which falls due as result of the sale of gold since they are considered to be financial assets. In case of arrears in the payment of the CFEM, arrears interest is charged pursuant to article 406 of the Civil Code, covering the period when no specific laws governing the matter were in effect. Between July, 2000 and January, 2001, interest rates were established by special law governing the matter (Law 9.993/00). And, as regards the tax triggering events that took place after the enactment and the effectiveness of Law 11.941/09, the legislation applying to federal taxes became the supervening law (Law 9.430/96) which determines the usage of the SELIC rate, accreted of a percentage of 1% per month, dunned until the date of its effective payment. The enrollment of the CFEM debtor in the CADIN roster is considered to be legitimate, provided this roster is used for informative purposes only and provided it is not used as a political sanction to compel the company to pay. The CFEM may not be characterized as a kind of indirect dunning of the contribution which falls out of due process. The timeframe of prescription for the DNPM to include the CFEM in the debtors roster is of five years. Since said CFEM is a pecuniary obligation that does not have the characteristics of a tax, its exaction is to comply with the rite set forth in Law 6.830/80 since it constitutes financial revenues of a quasi-government owned company (DNPM).

The role of natural resources in African conflicts has been subject to extensive scholarly analysis. However, much of this analysis has taken a narrow economic reductionist bias. As such, it is imperative that the dominant assumptions and accepted concepts and theories about the role of natural resources in African conflicts be re-examined. The aim of this thesis is to offer a revaluation of the role of coltan during the Democratic Republic of Congo’s (DRC) Second War (1998-2003) through a critical engagement with the resource wars literature. The purpose is to offer a re-reading of the role of coltan in the DRC Second War and the broader regional and global economic context in which this conflict took place. It rejects the commonly cited assumption that the presence of coltan in the DRC means it is an initiator of conflict. Rather, this thesis argues that the central role of coltan in the DRC Second War was as an aggravator of conflict in that its exploitation was used by different parties to fund their military and political ambitions. This thesis also argues that the DRC’s weak state structures and pivotal role within the Great Lakes region, as well as the international trade of coltan and the nature of the DRC coltan mining industry are all key factors in understanding coltan exploitation in the country’s Eastern Region during the Second War.

M.Sc. (Environmental Management) / Any change in land-use goes hand-in-hand with changes in the prevailing ambient conditions such as a change in the prevailing environmental noise and ground vibration levels. This increase may have an impact on the health and well-being of people and may furthermore result in structural damage to houses. The level of exposure will depend on the type of activity, distance from the source and the attitude of the people exposed to the land-change activities. The main objective of this research was to identify, compare and determine what the impact of mine establishment could have on a residential area some 900m from the mine footprint area. The results of the survey would assist management in employing engineering control measures which would control the exposure levels. Mines are generally established in frontier regions where there are already formal and informal residential areas. These residential areas are usually in rural districts with low prevailing ambient noise levels or, if in fact perceptible, insignificant ones at the most. This study dealt with the evaluation of physical aspects such as environmental noise and ground vibration levels and the determination of exposure levels, an issue of environmental impact and of concern to public health. The village which is being exposed to increased noise and ground vibration levels is a formal housing area with infrastructural components such as roads, water and electricity connections. The exposure levels before and during the construction phase gave an indication of the positive or negative exposure levels that the people were enduring during the establishment phase of the mine...

The Koulekoun Gold project is the most important prospect of Avocet Mining plc. It is one of the projects within the TriK-block in Guinea (West Africa) for which an exploration permit has been granted. The Koulekoun deposit is located within the Siguiri basin of Birimian age in the Eastern Guinea region; where most Guinea’s gold mines are situated. The present study involves the investigation of structural elements (S₀, S₁, S₂, intrusive contacts, faults and veins) from selected drill cores from drill sections that intersect the Koulekoun orebody in four parts of the deposit; characterizes the principal orientations of measured structures and determines their relationships using stereonet; in order to predict important intersections to focus on in exploration programs within the TriK-block and suggests a possible structural model of the Koulekoun deposit. Raw data used for the present research was collected from half-core samples due to the absence of surface outcrop from which direct measurements could have been made. Measured data were interpreted using stereographic projection. Often no preferred orientations of structural elements exist in the area, suggesting a complex structural situation, particularly with regard to hydrothermal vein attitudes. Thus, it has been illustrated from structural data analysis and S₀ data 3d interpolation of the four sub-structural domains (North-East, North-West, Central and South) that NE-SW structures (S₂, intrusive contact, fault and vein) have controlled the occurrency of gold mineralization in the Koulekoun deposit area. Geometrical relationships between structure main cluster orientation from stereonet analysis show the majority of S₀ moderately E-dipping; intrusive contacts dip at moderate angle to the SE in all zones, except in the North-East zone where they are sub-vertical and SE-dipping. Fault planes show variable orientation of NE-SW, NW-SE and E-W, and steeply SE-dipping. Vein planes correspond to fault systems and show high variability in their orientation with numerous orders of vein direction in each domain. The cross-cutting relationships suggest two principal generations of faults: the NE-SW fault (F1) and the NW-SE fault (F2). These two fault systems and their associated vein intersection areas preferably define the ore shoot zones within the Koulekoun deposit. The proposed structural model of the Koulekoun deposit suggests the intersection and interference of major NW-SE and minor NE-SW structures. The interference of folds formed basin-dome structures with oval shape geometries striking NW-SE and that dominantly occur in North-East, North-West and Central zones. The South Zone is characterized by NE-SW gently plunging and moderately inclined folds with NW-SE striking axial surface. Gold mineralization occurs at the edges of basin-dome structures in North-East, North-West and Central zones. Mineralized porphyry intrusions are likely located within the axial surface of the South zone folds and extend toward the Central zone. The proposed model is compliant with the earlier model of the Koulekoun deposit presented by Tenova (2013); Fahey et al. (2013) describing the Koulekoun deposit as an auriferous NE-SW trending fault zone, intersecting a major NW-striking and steeply E-dipping porphyry units. The model also fits within the regional structural context suggested by Lahondere et al. (1999a) related to the E-W vein structures attributed to NW-SE fractures and to the conjugated fault of NE-SW direction. Comparatively to the three industrial gold deposits (Siguiri, Lero, Kiniero) being currently mined in the Siguiri Basin, and defined as mesothermal vein and lode mineralization hosted in Birimian meta-sedimentary rocks (Lalande, 2005), the Koulekoun gold deposit appears to be a porphyry hosted orogenic disseminated style mineralization system (Fahey et al., 2013). Although, similarities between the Koulekoun gold deposit and these three industrial deposits (Siguiri, Lero, Kiniero) constitute of the intensive extends of the weathering profile and at some stages, by the existence of numerous ring-shaped and curved lineaments enhanced by drag folding (Lero deposit for instance). It is therefore recommended that targets selection around the Koulekoun deposit and within the TriK-block for further exploration programs be concentrated along NW-SE structures, in objective to determine possible intersection zones with NE-SW structures.

The Mining industry in South Africa is viewed as the backbone of the country’s economy, while benefiting from this engine of economic development, its impact on the environment and health has been of a major concern to different stakeholders. The majority of people acknowledge the role of mining in the economy and the country. Others put more emphasis on public health and the environment. The aim of the study was then to assess the impact of environmental pollution and public health on the Sasolburg community from a developmental perspective. The present study can be described as a quantitative descriptive survey that uncovered serious levels of pollution in Sasolburg that had dire health consequences for people involved. The findings of the study indicate that residents live with the constant smell of a variety of chemical pollutants released both by normal production and by periodic incidents. They experience chronic respiratory symptoms, burning eyes, hearing deficiency and skin irritations. The study revealed that environmental pollution consequences affecting residents are inversely related to distance from the mines. The results obtained in this study are evidence that environmental pollution in the Sasolburg area is a definite risk to the health of people living within the surrounding area. Although indicating the need to carry out a comprehensive study, the results call for immediate action to prevent continued public over-exposure to environmental pollution.

MSc (Botany) / Department of Botany

MESMEG / Department of Mining and Environmental Geology / See the attached abstract below