DOCSLIB.ORG

Geological and Structural Interpretation of the Konongo Area of the Ashanti Gold Belt of Ghana from Aeromagnetic and R

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Geological and Structural Interpretation of the Konongo Area of the Ashanti Gold Belt of Ghana from Aeromagnetic and R See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/312603586 Geological and structural interpretation of the Konongo area of the Ashanti gold belt of Ghana from aeromagnetic and r.... Article · January 2013 CITATIONS READS 3 82 3 authors: Benjamin Boadi David Dotse Wemegah 3 PUBLICATIONS 6 CITATIONS Kwame Nkrumah University Of Science and Te… 12 PUBLICATIONS 10 CITATIONS SEE PROFILE SEE PROFILE Kwasi Preko Kwame Nkrumah University Of Science and Te… 20 PUBLICATIONS 99 CITATIONS SEE PROFILE Some of the authors of this publication are also working on these related projects: Foresic Geophysics View project All content following this page was uploaded by David Dotse Wemegah on 11 September 2017. The user has requested enhancement of the downloaded file. International Research Journal of Geology and Mining (IRJGM) (2276-6618) Vol. 3(3) pp. 124-135, April 2013 Available online http://www.interesjournals.org/IRJGM Copyright©2013 International Research Journals Full Length Research Paper Geological and structural interpretation of the Konongo area of the Ashanti gold belt of Ghana from aero- magnetic and radiometric data Boadi B, Wemegah D.D and *Preko K Department of Physics, Geophysics Unit, Kwame Nkrumah University of Science and Technology, University post office, Private mail bag, Kumasi, Ghana Abstract Aeromagnetic and radiometric methods were used to investigate the Konongo area located at the north- eastern boundary of the prospective Ashanti Gold Belt in south-eastern Ghana. Datasets from these aerogeophysical methods proved vital for mapping geology and structure. The application of magnetic image enhancing techniques such as reduction to pole, analytical signal and first vertical derivative in processing the datasets helped in the delineation of folds, fractures, lithological boundaries and the two main Birimian tectonic structural deformation events D1 (NE-SW) / D2 (NNW-SSE) which are potential hydrothermal gold mineralization zones within the area. The contacts between Birimian meta- sedimentary and meta-volcanic rocks noted to host gold mineralization in the belt were also delineated. The radiometric datasets retrieving geochemical information on potassium (K), thorium (Th) and uranium (U) concentrations within the study area were used to delineate bedrock lithology of the Banso Batholith, Birimian meta-volcanics, Tarkwaian formation, as well as alteration and contact zones. High K, Th and U concentrations were mapped in the meta-sediments and the Banso batholith. The high- resolution airborne magnetic and radiometric data of the study area resulted in better definition of both geological structures and lithological boundaries. This work shows the usefulness of geophysical data in mapping possible geological structures that host hydrothermal gold mineralization within the Konongo area of the Ashanti Gold belt of Ghana. Keywords: Aeromagnetic, aeroradiometric, hydrothermal, alteration, mineralization. INTRODUCTION Airborne magnetic and radiometric surveys have been so that very subtle variations in the geophysical used extensively in the mineral exploration industry responses can be identified (Armstrong and Rodeghiero, predominantly for the delineation of metalliferous 2006). Geophysical techniques were used for prospecting deposits (Airo and Loukola-Ruskeeniemi, 2004). It as early as 1935 for extensive underground exploration application ranges from mineral exploration (Murphy, at the Konongo mines to maintain a reserve base 2007), structure mapping and rock characterization ahead of production. The surveys included Electrical (Telford et al., 1990). Recent advances in technology survey carried out by the Electrical Prospecting Company have substantially increased the accuracy and resolution of Sweden in 1935, Electromagnetics (Turam) and of these techniques so that they can be used to provide ground magnetic in 1967 and resistivity survey at useful enhanced information on lithology and geological Nanwa (extensions to Obenemase A and B lodes) in structures. Additionally, advances in data analysis, 1973. processing and image enhancement techniques have In 1960, Hunting Surveys Limited of the United improved the resolution of geophysical datasets further Kingdom undertook geophysical exploration for minerals in Ghana using airborne magnetic and radiometric survey with a total area coverage of 1.7 × 10 4 km 2.This included the Takoradi through Tarkwa and Prestea, Dunkwa and *Corresponding Author E-mail: [email protected] Obuasi to Konongo and Buem-Togo-Dahomeyan Boadi et al. 125 Figure 1. Geological map of the Konongo area (Modified From Griffis et al. (2002) contacts where chromite mineralization in serpentinite of Ghana. This is to help map the geology and to and iron ore in shale had been located (Kesse, 1985). delineate possible gold hosting structure within this part The survey provided magnetic maps showing detailed of the belt. The data used in this work was collected in geological structures of the area. Geoterrex (now owned 1997 as part of geophysical data collection programme in by Fugro Airborne Services) in 1993 used two airborne Ghana by Geological Survey of Finland (GKT) to support geophysical survey techniques namely a 125 Hz base- the mining sector in the country and other gold production frequency airborne time-domain electromagnetic belts of Ghana. This research seeks to review the (GEOTEM) and magnetic over the southernmost portion geology and to aid the delineation of regional and local of the Ashanti Greenstone Belt with an area cover of geological structures (shear zones and faults) that have about 2.7 × 10 3 km 2 (Asiamah, 2004). Sub-parallel the potential of hosting gold mineralization within the regional shear structures that traverse the study area study area. The work supplements the effort and allows continuously up to 40 km were delineated as well as a 5 the prediction of target areas for detailed exploration work km strike-length, section of the western-most shear zone. in search for metal ore mineralization within the Konongo According to Telford et al. (1990) the physical principles area that has not been extensively explored as compared of aeromagnetic methods are based on taking to the other parts of the Ashanti Belt. measurements of the ambient magnetic susceptibility of the surface geology and using the data to determine the distribution of magnetic minerals and hence changes in Geology and Mineralization lithology. Wilford et al. (1997) indicated that airborne radiometric survey similarly is used to measure variations Ghana falls mostly within the West African Craton which in the radioactive mineral composition in order to map stabilized in the early Proterozoic (2000 Ma) during the lateral lithological changes. This method involves the Eburnean Orogeny (Kesse, 1985). The Ghana shield measurement of naturally occurring radioactive elements area has two main rocks system, the Birimian with its that exist in rock forming minerals and soil profiles. These associated granitoid intrusives and the Tarkwaian elements are uranium (U), thorium (Th) and potassium Formation. The Birimian was deformed, metamorphosed (K), which can be found as trace elements in all rocks and intruded by syn- and post-granitoids during the and decay naturally giving off gamma radiation (gamma Eburnean orogeny at 2130-1980 Ma, (Feybesse et al., rays). The variation of magnetic and radiometric mineral 2006). In elongated basins which follow the north-easterly composition in rocks due to the different in lithological set trending Birimian belts, middle Proterozoic molasse type up and mineralization processes such as hydrothermal sediments of the Tarkwaian formation were deposited mineralization make the use of these methods in the (Kesse, 1985). mapping rock lithology, structures and mineral zones an The geology of the area (Figure 1) is dominated by NE important technique. trending bands of Birimian meta-sediments/volcanics and This paper discusses aeromagnetic and radiometric the Tarkwaian clastic formation. To the east, the datasets from the Konongo area of the Ashanti Gold Belt Tarkwaian formation widens out very substantially and to 126 Int. Res. J. Geo. Min. Figure 2. The Konongo Area (Study area) the west of the district, there are mainly Birimian meta- that the greenschist facies is widely retrograde after sedimentary units of the Kumasi Basin. Within the basin amphibolite facies conditions. domain are large masses of basin-type granitoids belonging to the Kumasi Complex (Griffis et al., 2002). The south-east of the district is dominated by the MATERIALS AND METHODS unusually large Banso batholith, which is rich in radiometric potassium (Griffs, 1998). Early workers in the Study site description area (Hirst, 1942) believed this granitoid to be post- Birimian and pre-Tarkwaian because of the lack of The study area is located around Konongo (Figure 2), the contact metamorphic effects in Tarkwaian formation close capital of the Asante Akim North District. It is 50 km from to the batholith. However, recent work has challenged Kumasi (Ashanti Regional Capital) and about 230 km this view and it appears that the Banso batholith is a fairly from Accra, the capital of Ghana. The study area is late-stage intrusion that apparently post-dates the define by the pillar coordinates P1, P2, P3, P4 and P5 Tarkwaian formation (Griffis et al., 2002). (see Figure 3A respectively) (-1.0593 o, 6.7297 o), (- Gold mineralization is commonly associated with 1.1956 o, 6.7302
Load more

Recommended publications
  • The Impact of Matriarchal Traditions on the Advancement of Ashanti Women in Ghana Karen Mcgee
    The University of San Francisco USF Scholarship: a digital repository @ Gleeson Library | Geschke Center Listening to the Voices: Multi-ethnic Women in School of Education Education 2015 The mpI act of Matriarchal Traditions on the Advancement of Ashanti Women in Ghana Karen McGee Follow this and additional works at: http://repository.usfca.edu/listening_to_the_voices Part of the Education Commons Recommended Citation McGee, Karen (2015). The mpI act of Matriarchal Traditions on the Advancement of Ashanti Women in Ghana. In Betty Taylor (Eds.), Listening to the Voices: Multi-ethnic Women in Education (p. 1-10). San Francisco, CA: University of San Francisco. This Book is brought to you for free and open access by the School of Education at USF Scholarship: a digital repository @ Gleeson Library | Geschke Center. It has been accepted for inclusion in Listening to the Voices: Multi-ethnic Women in Education by an authorized administrator of USF Scholarship: a digital repository @ Gleeson Library | Geschke Center. For more information, please contact [email protected]. The Impact of Matriarchal Traditions on the Advancement of Ashanti Women in Ghana Karen McGee What is the impact of a matriarchal tradition and the tradition of an African queenmothership on the ability of African women to advance in political, educational, and economic spheres in their countries? The Ashanti tribe of the Man people is the largest tribe in Ghana; it is a matrilineal society. A description of the precolonial matriarchal tradition among the Ashanti people of Ghana, an analysis of how the matriarchal concept has evolved in more contemporary governments and political situations in Ghana, and an analysis of the status of women in modern Ghana may provide some insight into the impact of the queenmothership concept.
    [Show full text]
  • Table of Contents
    Table of Contents Page LIST OF ACRONYMS a EXECUTIVE SUMMARY I 1.0 Introduction 1 1.1 Scope of Study 1 1.2 Background – Volta River Authority 2 1.3 Proposed Aboadze-Volta Transmission Line Project (AVTP) 3 1.4 Legal, Regulatory and Policy Considerations 5 1.5 Future developments by VRA 8 2.0 Description of proposed development 10 2.1 Pre-Construction Activities 11 2.2 Construction Phase Activities 12 2.3 Operational Phase Activities 17 2.3.1 Other Operational Considerations 20 3.0 Description of Existing Environments 21 3.1 Bio-Physical Environment 21 3.1.1 Climate 21 3.1.2 Flora 25 3.1.3 Fauna 35 3.1.4 Water Resources 43 3.1.5 Geology and Soils 44 3.1.6 General Land Use 51 3.2 Socio-Economic/Cultural Environment 51 3.2.1 Methodology 53 3.2.2 Profiles of the Districts in the Project Area 54 3.2.2(a) Shama - Ahanta East Metropolitan Area 54 3.2.2(b) Komenda - Edina - Eguafo - Abirem (KEEA) District 58 i 3.2.2(c) Mfantseman District 61 3.2.2(d) Awutu-Effutu-Senya District 63 3.2.2(e) Tema Municipal Area 65 3.2.2(f) Abura-Asebu-Kwamankese 68 3.2.2(g) Ga District 71 3.2.2(h) Gomoa District 74 3.3 Results of Socio-Economic Surveys 77 (Communities, Persons and Property) 3.3.1 Information on Affected Persons and Properties 78 3.3.1.1 Age Distribution of Affected Persons 78 3.3.1.2 Gender Distribution of Affected Persons 79 3.3.1.3 Marital Status of Affected Persons 80 3.3.1.4 Ethnic Composition of Afected Persons 81 3.3.1.5 Household Size/Dependents of Affected Persons 81 3.3.1.6 Religious backgrounds of Affected Persons 82 3.3.2 Economic Indicators
    [Show full text]
  • An Epidemiological Profile of Malaria and Its Control in Ghana
    An Epidemiological Profile of Malaria and its Control in Ghana Report prepared by National Malaria Control Programme, Accra, Ghana & University of Health & Allied Sciences, Ho, Ghana & AngloGold Ashanti Malaria Control Program, Obuasi, Ghana & World Health Organization, Country Programme, Accra, Ghana & The INFORM Project Department of Public Health Research Kenya Medical Research Institute - Wellcome Trust Progamme Nairobi, Kenya Version 1.0 November 2013 Acknowledgments The authors are indebted to the following individuals from the MPHD, KEMRI-Oxford programme: Ngiang-Bakwin Kandala, Caroline Kabaria, Viola Otieno, Damaris Kinyoki, Jonesmus Mutua and Stella Kasura; we are also grateful to the help provided by Philomena Efua Nyarko, Abena Asamoabea, Osei-Akoto and Anthony Amuzu of the Ghana Statistical Service for help providing parasitological data on the MICS4 survey; Catherine Linard for assistance on modelling human population settlement; and Muriel Bastien, Marie Sarah Villemin Partow, Reynald Erard and Christian Pethas-Magilad of the WHO archives in Geneva. We acknowledge in particular all those who have generously provided unpublished data, helped locate information or the geo-coordinates of data necessary to complete the analysis of malaria risk across Ghana: Collins Ahorlu, Benjamin Abuaku, Felicia Amo-Sakyi, Frank Amoyaw, Irene Ayi, Fred Binka, David van Bodegom, Michael Cappello, Daniel Chandramohan, Amanua Chinbua, Benjamin Crookston, Ina Danquah, Stephan Ehrhardt, Johnny Gyapong, Maragret Gyapong, Franca Hartgers, Debbie Humphries, Juergen May, Seth Owusu-Agyei, Kwadwo Koram, Margaret Kweku, Frank Mockenhaupt, Philip Ricks, Sylvester Segbaya, Harry Tagbor and Mitchell Weiss. The authors also acknowledge the support and encouragement provided by the RBM Partnership, Shamwill Issah and Alistair Robb of the UK government's Department for International Development (DFID), Claude Emile Rwagacondo of the West African RBM sub- regional network and Thomas Teuscher of RBM, Geneva.
    [Show full text]
  • Ghana Gazette
    GHANA GAZETTE Published by Authority CONTENTS PAGE Facility with Long Term Licence … … … … … … … … … … … … 1236 Facility with Provisional Licence … … … … … … … … … … … … 201 Page | 1 HEALTH FACILITIES WITH LONG TERM LICENCE AS AT 12/01/2021 (ACCORDING TO THE HEALTH INSTITUTIONS AND FACILITIES ACT 829, 2011) TYPE OF PRACTITIONER DATE OF DATE NO NAME OF FACILITY TYPE OF FACILITY LICENCE REGION TOWN DISTRICT IN-CHARGE ISSUE EXPIRY DR. THOMAS PRIMUS 1 A1 HOSPITAL PRIMARY HOSPITAL LONG TERM ASHANTI KUMASI KUMASI METROPOLITAN KPADENOU 19 June 2019 18 June 2022 PROF. JOSEPH WOAHEN 2 ACADEMY CLINIC LIMITED CLINIC LONG TERM ASHANTI ASOKORE MAMPONG KUMASI METROPOLITAN ACHEAMPONG 05 October 2018 04 October 2021 MADAM PAULINA 3 ADAB SAB MATERNITY HOME MATERNITY HOME LONG TERM ASHANTI BOHYEN KUMASI METRO NTOW SAKYIBEA 04 April 2018 03 April 2021 DR. BEN BLAY OFOSU- 4 ADIEBEBA HOSPITAL LIMITED PRIMARY HOSPITAL LONG-TERM ASHANTI ADIEBEBA KUMASI METROPOLITAN BARKO 07 August 2019 06 August 2022 5 ADOM MMROSO MATERNITY HOME HEALTH CENTRE LONG TERM ASHANTI BROFOYEDU-KENYASI KWABRE MR. FELIX ATANGA 23 August 2018 22 August 2021 DR. EMMANUEL 6 AFARI COMMUNITY HOSPITAL LIMITED PRIMARY HOSPITAL LONG TERM ASHANTI AFARI ATWIMA NWABIAGYA MENSAH OSEI 04 January 2019 03 January 2022 AFRICAN DIASPORA CLINIC & MATERNITY MADAM PATRICIA 7 HOME HEALTH CENTRE LONG TERM ASHANTI ABIREM NEWTOWN KWABRE DISTRICT IJEOMA OGU 08 March 2019 07 March 2022 DR. JAMES K. BARNIE- 8 AGA HEALTH FOUNDATION PRIMARY HOSPITAL LONG TERM ASHANTI OBUASI OBUASI MUNICIPAL ASENSO 30 July 2018 29 July 2021 DR. JOSEPH YAW 9 AGAPE MEDICAL CENTRE PRIMARY HOSPITAL LONG TERM ASHANTI EJISU EJISU JUABEN MUNICIPAL MANU 15 March 2019 14 March 2022 10 AHMADIYYA MUSLIM MISSION -ASOKORE PRIMARY HOSPITAL LONG TERM ASHANTI ASOKORE KUMASI METROPOLITAN 30 July 2018 29 July 2021 AHMADIYYA MUSLIM MISSION HOSPITAL- DR.
    [Show full text]
  • City Governance and Poverty: the Case of Kumasi
    KUMASI City governance and poverty: the case of Kumasi Nick Devas and David Korboe Nick Devas is a senior SUMMARY: This paper discusses the factors that influence the scale and nature lecturer in the International of poverty in Kumasi, with a special focus on the role of city government and other Development Department of the School of Public governmental bodies. It reviews critically the impact of city government’s policies Policy, University of Birm- on the livelihoods of poorer groups and their access to essential services, and notes ingham, specializing in the limited impact of democratization and decentralization on improving the urban development, urban governance, public finance performance of government agencies, particularly in relation to the urban poor. It and local government also discusses what factors have helped to limit the scale and extent of poverty, finance. He is coordinating including the role of traditional land allocation systems, donor involvement and the DFID-ESCOR funded supportive ethnic networks. research project on urban governance, partnerships and poverty. I. INTRODUCTION(1) Address: IDD, School of Public Policy, University of Birmingham, Birmingham KUMASI, GHANA’S SECOND city, has a long and proud history as the B15 2TT, UK; e-mail: centre of the Asante kingdom.(2) Officially, Kumasi has a population of [email protected] around 700,000 but most estimates put the population at just over one David Korboe’s work is million.(3) Kumasi is often regarded as the commercial capital of Ghana, concerned with poverty and with its Keteja market rivalling Onitsha in Nigeria as West Africa’s largest social deprivation.
    [Show full text]
  • Coalition of Domestic Election Observers (CODEO) CONTACT Mr
    Coalition of Domestic Election Observers (CODEO) CONTACT Mr. Albert Arhin, CODEO National Coordinator +233 (0) 24 474 6791 / (0) 20 822 1068 Secretariat: +233 (0)244 350 266/ 0277 744 777 Email:[email protected]: Website: www.codeoghana.org CODEO’s Pre-election Environment Observation Statement ( 15th July- 31st August, 2016) STATEMENT ON THE VOTER REGISTER Introduction The Coalition of Domestic Election Observers (CODEO) is pleased to release its findings on the pre-election environment for the period mid July to 31st August, 2016. This report is the first in the series of CODEO’s pre-election environment observations for the 2016 presidential and parliamentary elections, and captures bi-weekly reports filed by CODEO’s Long Term Observers (LTOs) deployed across the country. The findings in this report are based on bi-weekly field reports submitted in the month of July and August from 134 out of the 138 constituencies randomly selected from the 10 regions of Ghana. Guided by a checklist, CODEO’s LTOs observe the general political environment, including election-related preparatory activities by state and non-state actors, civic/voter education programs as well as political party campaign activities. The LTOs also observe the conduct of the security agencies, electoral irregularities and pre-election disputes adjudication. Summary of Findings: The National Commission on Civic Education (NCCE) and the Electoral Commission (EC) have stepped-up civic/voter education across the country using radio as the main medium for educating the public. There is low visibility of Civil Society Organizations (CSOs) working in the areas of election violence monitoring, and peace promotion activities.
    [Show full text]
  • Western Region Eastern Region
    Public Disclosure Authorized GHANA WATER COMPANY LIMITED (Urban Water Project) Assessment of Resettlement Related Issues on the SYIP in Area 2 Public Disclosure Authorized ASHANTI REGION WESTERN REGION EASTERN REGION PHASE 2 Public Disclosure Authorized (WESTERN REGION) RESETTLEMENT ACTION PLAN REVISED Public Disclosure Authorized SAL Consult Limited, P O Box GP20200, Accra August 2011 SAL Consult Ltd GWCL/PMU TABLE OF CONTENTS ABBREVIATIONS AND ACRONYMS ........................................................................................................................ III EXECUTIVE SUMMARY .......................................................................................................................................... IV 1.0 DESCRIPTION OF PROJECT AND IMPACTS .................................................................................................. 1 1.1 PROJECT DESCRIPTION ....................................................................................................................................... 1 1.1 OBJECTIVES ...................................................................................................................................................... 2 2.0 DESCRIPTION OF THE WESTERN REGION PROJECT AND IMPACTS ............................................................. 5 2.1 PROJECT COMPONENTS AND BENEFICIARY TOWNS .................................................................................................. 5 2.1.1 Axim ........................................................................................................................................................
    [Show full text]
  • Offinso Municipality
    OFFINSO MUNICIPALITY Copyright © 2014 Ghana Statistical Service ii PREFACE AND ACKNOWLEDGEMENT No meaningful developmental activity can be undertaken without taking into account the characteristics of the population for whom the activity is targeted. The size of the population and its spatial distribution, growth and change over time, in addition to its socio-economic characteristics are all important in development planning. A population census is the most important source of data on the size, composition, growth and distribution of a country’s population at the national and sub-national levels. Data from the 2010 Population and Housing Census (PHC) will serve as reference for equitable distribution of national resources and government services, including the allocation of government funds among various regions, districts and other sub-national populations to education, health and other social services. The Ghana Statistical Service (GSS) is delighted to provide data users, especially the Metropolitan, Municipal and District Assemblies, with district-level analytical reports based on the 2010 PHC data to facilitate their planning and decision-making. The District Analytical Report for the Offinso Municipality one of the 216 district census reports aimed at making data available to planners and decision makers at the district level. In addition to presenting the district profile, the report discusses the social and economic dimensions of demographic variables and their implications for policy formulation, planning and interventions. The conclusions and recommendations drawn from the district report are expected to serve as a basis for improving the quality of life of Ghanaians through evidence- based decision-making, monitoring and evaluation of developmental goals and intervention programmes.
    [Show full text]
  • Ghana Poverty Mapping Report
    ii Copyright © 2015 Ghana Statistical Service iii PREFACE AND ACKNOWLEDGEMENT The Ghana Statistical Service wishes to acknowledge the contribution of the Government of Ghana, the UK Department for International Development (UK-DFID) and the World Bank through the provision of both technical and financial support towards the successful implementation of the Poverty Mapping Project using the Small Area Estimation Method. The Service also acknowledges the invaluable contributions of Dhiraj Sharma, Vasco Molini and Nobuo Yoshida (all consultants from the World Bank), Baah Wadieh, Anthony Amuzu, Sylvester Gyamfi, Abena Osei-Akoto, Jacqueline Anum, Samilia Mintah, Yaw Misefa, Appiah Kusi-Boateng, Anthony Krakah, Rosalind Quartey, Francis Bright Mensah, Omar Seidu, Ernest Enyan, Augusta Okantey and Hanna Frempong Konadu, all of the Statistical Service who worked tirelessly with the consultants to produce this report under the overall guidance and supervision of Dr. Philomena Nyarko, the Government Statistician. Dr. Philomena Nyarko Government Statistician iv TABLE OF CONTENTS PREFACE AND ACKNOWLEDGEMENT ............................................................................. iv LIST OF TABLES ....................................................................................................................... vi LIST OF FIGURES .................................................................................................................... vii EXECUTIVE SUMMARY ........................................................................................................
    [Show full text]
  • Future of Obuasi
    FUTURE OF OBUASI AngloGold Ashanti is working on a development plan to rebuild the Obuasi Mine into a viable, long-life mining business with an attractive cost structure and returns. A feasibility study, currently underway, is required to determine whether the mine can be redeveloped into a profitable, productive operation that can once again be a significant employer and sustainable contributor to the local, regional and national economies in Ghana. Obuasi, located in the Ashanti region of Ghana 320 kilometres northwest of the capital Accra, is a large, high-grade deposit with proven and probable ore reserves (as reported by AngloGold Ashanti in their 2014 Annual Report) of 24.53Mt at 6.70g/t for 5.29Moz, part of a substantial mineral resource base. In 2012, AngloGold Ashanti initiated the programme to modernise the mine, principally by starting to develop the ramp access to run from surface to high-grade blocks of ore underground. The ramp will supplement current vertical hoisting infrastructure and help debottleneck the underground operation by allowing for greater ease in transporting people and materials underground, and transporting ore to surface. This was a necessary step ahead of the envisaged transformation of the mine The company envisages that the more modern mine design and operating methodology will be complemented by the ramp from surface to provide additional flexibility in moving men and materials underground, and in moving ore from underground to surface. This ramp, along with a refurbished plant, would form the centre piece of the ‘new’ mine on a concentrated footprint, greatly reduced from the sprawling acreage that Obuasi has occupied for more than 100 years.
    [Show full text]
  • The Geology of the Gold Deposits of Prestea Gold Belt of Ghana*
    The Geology of the Gold Deposits of Prestea Gold Belt of Ghana* K. Dzigbodi-Adjimah and D. Nana Asamoah Dzigbodi-Adjimah, K. and Nana Asamoah, D., (2009), “The Geology of the Gold Deposits of Prestea Gold Belt of Ghana”, Ghana Mining Journal, Vol. 11, pp. 7 - 18. Abstract This paper presents the geology of the gold deposits along the Prestea gold belt of Ghana to assist exploration work for new orebodies along the belt. Prestea district is the third largest gold producer in West Africa after Obuasi and Tarkwa districts (over 250 metric tonnes Au during the last century). The gold deposits are structurally controlled and occur in a deep-seated fault or fissure zone that is regarded as the ore channel. This structure, which lies at the contact between metavolcanic and metasedimentary rocks in Birimian rocks, is more open (and contains more quartz lodes) at the southern end around Prestea than at Bogoso to the north. The gold deposits consist of the Quartz Vein Type, (QVT) and the Dis- seminated Sulphide Type (DST). The QVT orebodies, which generally carry higher Au grades, lie within a graphitic gouge in the fissure zones whilst the DST is found mostly in sheared or crushed rocks near the fissure zones. Deposits were grouped into three in terms of geographic location and state of development; The deposits south of Prestea are the least developed but have been extensively explored by Takoradi Gold Company. Those at Prestea have been worked exclusively as underground mines on QVT orebodies by Prestea Goldfields Limited and its forerunners; Ariston and Ghana Main Reef companies until 1998 whilst the deposits north of Prestea, which were first worked as surface mines (on DST orebodies) by Marlu Mines up to 1952, were revived by Billiton Bogoso Gold in 1990.
    [Show full text]
  • Small and Medium Forest Enterprises in Ghana
    Small and Medium Forest Enterprises in Ghana Small and medium forest enterprises (SMFEs) serve as the main or additional source of income for more than three million Ghanaians and can be broadly categorised into wood forest products, non-wood forest products and forest services. Many of these SMFEs are informal, untaxed and largely invisible within state forest planning and management. Pressure on the forest resource within Ghana is growing, due to both domestic and international demand for forest products and services. The need to improve the sustainability and livelihood contribution of SMFEs has become a policy priority, both in the search for a legal timber export trade within the Voluntary Small and Medium Partnership Agreement (VPA) linked to the European Union Forest Law Enforcement, Governance and Trade (EU FLEGT) Action Plan, and in the quest to develop a national Forest Enterprises strategy for Reducing Emissions from Deforestation and Forest Degradation (REDD). This sourcebook aims to shed new light on the multiple SMFE sub-sectors that in Ghana operate within Ghana and the challenges they face. Chapter one presents some characteristics of SMFEs in Ghana. Chapter two presents information on what goes into establishing a small business and the obligations for small businesses and Ghana Government’s initiatives on small enterprises. Chapter three presents profiles of the key SMFE subsectors in Ghana including: akpeteshie (local gin), bamboo and rattan household goods, black pepper, bushmeat, chainsaw lumber, charcoal, chewsticks, cola, community-based ecotourism, essential oils, ginger, honey, medicinal products, mortar and pestles, mushrooms, shea butter, snails, tertiary wood processing and wood carving.
    [Show full text]