Gold exploration in the laterite terrains of the Siguiri basin (Guinea-West Africa) is discussed in this thesis. It seeks to propose and develop effective and reliable geochemical exploration techniques applied in such laterite terrains. The study is also intended to investigate and provide some geological clues as to why, in some target areas, the reconnaissance test drilling across the geochemical anomalies couldn’t intersect economic gold mineralisation. Targets were generated based on soil geochemical results, some of which were drilled without delivering economic discoveries even on areas with strong and consistent geochemical signatures. To find the failure and define the appropriate methods to be used is the core of the thesis. More importantly, the geological observation is aimed at sourcing and establishing the nature and validity of geochemical anomalies within the license area and their relationship with the underlying lithologies and structural networks. The geological field work conducted during this study is mostly based on regolith and surface geological mapping. The thick laterite cover, deep weathering, bedrock geology, gold geochemistry (the gold geochemical anomalous results are defined according to historical data before 2007), soil formations and variations in climate conditions are emphasized to illustrate the importance of mineral element mobility and dispersion in the weathering profiles. The knowledge and experience in regolith geochemistry and regolith mapping provide the advantage to exploration geologists. The depletion of ore resources and reserves in Siguiri and the continuous decline of the gold price in comparison to the complexity of exploring for gold are demanding more scientific-related thoughts and techniques to be integrated in the available geological, geochemical and geophysical information so as to reduce costs. The integration of good exploration strategy and technique may result in the possibility of making viable discoveries in this highly competitive geological environment where the mineral resources become depleted every day.

The present study provides the results of detailed mapping and analysis of structures encountered in Seguelen pit of Siguiri gold mine, Guinea, where the Siguiri mine is geo-tectonically located in the Baoulé-Mossi domain of Man Shield in West African craton. The gold deposit is hosted in low-grade metamorphic sediments of turbidites sequences which form part of the Lower Proterozoic of Birimian Super group. Three rock formations of Balato, Fatoya and Kintinian underlay the overall pits. The Siguiri gold mine is characterized by the deep weathering profile, developed over the rocks reaching 200 m below the surface in some areas and often capped by the lateritic gravel or duricrust. The rock formations at Seguelen area are characterised by strong bedding monotonously dipping towards SW and trending NW-SE. The lithology of the host rocks has strong control on the disseminated mineralisation throughout the deposit. Two domains of rock formations are clearly distinguished at Seguelen:  Fatoya Formation(Ffm) domain ; and  Kintinian Formation (Kfm) domain. The two domains are separated by a contact zone of 1.7 m wide parallel to bedding and characterised by the presence of quartz fragments as well as thinly sheeted shale and black shale. This contact zone is identified as disconformity. The major tectonic deformation which has affected the region is known as D2 corresponding to the Eburnean orogeny. The major D2 related structures is the regional thrust striking N-S over an area of 12 km long and 3 km wide and within which corridors all Siguiri gold Mine open pits are located. In the N-S trending structures, there is east-northeast shortening and north-northwest extension. There is pervasive hydrothermal alteration (carbonatization and sideritization) and supergene alteration in the all pits. The hydrothermal alteration attests the intensity of hydrothermal fluid-flow over the host rocks. The hydrothermal fluids flowed along the fractures and within the wall rocks through bedding plans to form numerous auriferous quartz veins bearing disseminated sulphides through chemical reaction between fluids and wall rocks, which are remarkable at Seguelen pit. Three quartz vein sets are distinguished at Seguelen:  NNE-SSW quartz vein set  NE-SW quartz vein set  NW-SE quartz vein set The NE-SW and NNE-SSW quartz veins are often lenticular and associated with the bulk mineralisation.

The aim of this research was to identify and assess the extent to which AngloGold Ashanti (AGA) Mining Company has been able to apply its corporate social responsibility (CSR) policies in its operations, in a participatory manner, in contributing to sustainable development in its area of operation. The mixed method approach was used. Cluster sampling under the random sampling and purposive sampling methods were used to select both the respondentsand communities affected by mining. Six communities were surveyed from the Obuasi Municipality in the Ashanti region of Ghana. Participatory interviews, questionnaires, focus group discussions and participant observation techniques were used to gather data. The study identified that the CSR initiatives of AGA are evaluated on five main principles, namely commitment to core values, compliance with legal provisions, managerial discretion in taking actions, economic contributions and participatory mechanisms. The study found that, to some extent, the local people have been engaged in the implementation of AGA’s CSR activities. 25.2% were involved in project planning and design, and more than 80% were informed before the start of projects. Also, the results reveal that AGA’s mining activities have had both positive and negative impacts on the economic well-being of residents within the selected communities. The impact of AGA’s mining activities on the environment, especially on water quality, soil quality, sanitation and noise levels, was found to be negative, resulting in major health problems for residents in mining communities. As a contribution to knowledge, the study shows how community members (respondents) perceive AGA’s CSR activities as fulfilling just one aspect of CSR (philanthropic dimension) and not necessarily rectifying the effect of their mining activities on the environment (ethical dimension). The study therefore recommends that comprehensive CSR measures principled through the lens of nonphilanthropic considerations be developed to reverse the general negative outcomes of mining on communities economically, socially and environmentally, especially regarding the growing unemployment and displacement of communities. / Inhloso yalolu cwaningo kwakuwukuhlonza nokuhlola ukuthi iNkampani yeMayini iAngloGold Ashanti (AGA) ikwaze kanjani ukusebenzisa izinqubomgomo zayo zegunya lokubambisana kwezenhlalo (GLK) ekusebenzeni kwayo, ngendlela yokubamba iqhaza, ekunikelweni entuthukweni esimeme emkhakheni esebenza kuyo. Kusetshenziswe indlela ehlanganisiwe. Iqoqo lamasampula ngaphansi kwesampula engahleliwe nezindlela zokwenza amasampula ahlosiwe asetshenziselwe ukukhetha bobabili abaphendulayo kanye nemiphakathi ethintekayo ezimayini. Kuhlolwe imiphakathi eyisithupha ivela kuMasipala wase-Obuasi esifundeni i-Ashanti eGhana. Izingxoxo zokubamba iqhaza, iqoqo lemibuzo, izingxoxo zamaqembu okugxilwe kuwo kanye namasu wokubuka ababambiqhaza asetshenziselwe ukuqoqa idatha. Ucwaningo lukhombe ukuthi izinhlelo ze(GLK) le-AGA zihlolwa ngemigomo engqala emihlanu, okungukuthi ukuzibophezela kumanani ayisisekelo, ukuhambisana nezinhlinzeko zomthetho, ukuqonda ekuthatheni izinyathelo ezithile, iminikelo yezomnotho nezindlela zokubamba iqhaza. Ucwaningo luthole ukuthi, ukuya ezingeni elithile, abantu bendawo babambe iqhaza ekwenzeni imisebenzi ye-AGA's ne GLK. Ama-25.2% abambe iqhaza ekuhleleni nasekuklanyweni kwamaphrojekthi, kwathi abangaphezu kuma80% aziswa ngaphambi kokuqala kwamaphrojekthi. Futhi, imiphumela iveza ukuthi imisebenzi yezimayini ye-AGA ibe nemithelela emihle nemibi enhlalweni yezomnotho yabahlali emiphakathini ekhethiwe. Umthelela wemisebenzi yezimayini ye-AGA emvelweni, ikakhulukazi kwizinga lamanzi, ikhwalithi yenhlabathi, ukuthuthwa kwendle namazinga omsindo, kutholakale kukubi, okuholele ezinkingeni ezinkulu zezempilo kubahlali emiphakathini yezimayini. Njengokunikela olwazini, ucwaningo lukhombisa ukuthi amalungu omphakathi (abaphendulayo) bayibona kanjani imisebenzi ye-AGA's CSR njengokufeza isici esisodwa seGLK (ubukhulu bokusiza) hhayi ukuthi kulungiswe umthelela wemisebenzi yabo yezimayini emvelweni (ubukhulu bokuziphatha).Ngakho-ke ucwaningo luncoma ukuthi izinyathelo eziphelele ze-GLK eziqondiswa ngokusebenzisa ukuqondwa kwezinto ezingenkulu ezingezona zokusiza zithuthukiswe ukuguqula imiphumela emibi ejwayelekile yezimayini emiphakathini ngokwezomnotho, kwezenhlalo nangokwezemvelo, ikakhulukazi maqondana nokwanda kwemiphakathi engasebenzi kanye nokufundiswa kwayo. / Maikemišetšo a dinyakišišo tše ke go tseba le go sekaseka bogolo bjo ka bjona Khamphani ya Moepo ya AngloGold Ashanti (AGA) e kgonnego go phethagatša melawana ya ona ya maikarabelo a khamphani setšhabeng (CSR) ka mešomong ya yona, ka mokgwa wa go kgatha tema ga badudi, ka nepo ya go tsenya letsogo go tlhabollo ya go ya go ile ka lefelong leo e šomelago go lona. Mokgwa wo o hlakantšego mekgwa o šomišitšwe ka mo dinyakišišong tše. Go dira sampole sehlopha ka fase ga mekgwa ya go dira sampole ka sewelo le go dira sampole ka maikemišetšo go šomišitšwe go kgetha bobedi baarabi le ditšhaba tšeo di amilwego ke meepo. Go ile gwa dirwa dinyakišišo go metse ye tshela ka Masepaleng wa Obuasi ka seleteng sa Ashanti sa Ghana. Dipoledišano tšeo baarabi ba kgathago tema ka go tšona, lenaneo la dipotšišo tša dinyakišišo, dipoledišano tša dihlopha tšeo di nepišitšwego le mekgwa ya go lekola bakgathatema e šomišitšwe go kgoboketša tshedimošo. Dinyakišišo di utollotše gore maitekelo a CSR a AGA a sekasekwa go melawana ye mehlano ye megolo, e lego boikgafo go maitshwaro a bohlokwa, go obamela ditlhagišo tša melao, sephetho sa ba taolo sa go tšea dikgato, seabe sa ekonomi le mekgwa ya go kgatha tema. Dinyakišišo di utollotše gore, go fihla mo go itšego, go rerišanwe le batho ba tikologo ka go phethagatšeng ga ditiro tša CSR tša AGA. 25.2% ya bona e kgathile tema ka peakanyong le tlhamo ya protšeke, gomme palo ya go feta 80% e tsebišitšwe pele ga ge diprotšeke di ka thoma. Gape, dipoelo di utolla gore mešomo ya meepo ya AGA e bile le bobedi diabe tše botse le tše mpe go seemo sa ekonomi sa badudi ka metseng ye e kgethilwego. Seabe sa mešomo ya meepo ya AGA go tikologo, kudukudu go boleng bja meetse, go boleng bja mobu, go kelelatšhila le go maemo a lešata, go hweditšwe gore e bile ao a sego a loka, gomme se ile sa feletša ka mathata a magolo a tša maphelo go badudi ba ka metseng yeo meepo e lego gona. Bjalo ka seabe go tsebo, dinyakišišo di bontšha ka fao maloko a setšhaba (baarabi) ba bonago mešomo ya CSR ya AGA e lego yeo e phethagatšago fela selo se tee sa CSR (e lego ditiro tša go abela setšhaba) e sego go phošolla seabe sa mešomo ya bona ya meepo go tikologo (e lego ditiro tša maitshwaro). Dinyakišišo ka fao di šišinya gore magato ka kakaretšo a CSR ao a beilwego go se gwa lebelelwa go abela setšhaba a phethagatšwe ka nepo ya go phošolla dipoelo tša kakaretšo tšeo di sego tša loka tša mešomo ya meepo go ditšhaba mabapi le tša ekonomi, tša leago le tikologo, kudukudu mabapi le go tlhokego ya mešomo ye e golago le go tloša ditšhaba mafelong a tšona. / Development Studies / D. Phil. (Developmental Studies)