DOCSLIB.ORG

Table of Contents (PDF)

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Table of Contents (PDF) GUIDEBOOK SERIES Volume 57 Gold Deposits of the Birimian and Tarkwaian in Ghana April 22 – May 1, 2018 Field Trip Leaders Rael Lipson and Raymond Kudzawu-D’Pherdd Guidebook Editors Rael Lipson, Borden Putnam, Simon Meadows Smith, and Ryan Taylor SOCIETY OF ECONOMIC GEOLOGISTS FOUNDATION, INC. SEGF STUDENT FIELD TRIP 17 GUIDEBOOK SERIES Volume 57 Gold Deposits of the Birimian and Tarkwaian in Ghana April 22 – May 1, 2018 Field Trip Leaders Rael Lipson and Raymond Kudzawu-D’Pherdd Guidebook Editors Rael Lipson, Borden Putnam, Simon Meadows Smith, and Ryan Taylor SOCIETY OF ECONOMIC GEOLOGISTS FOUNDATION, INC. SEGF STUDENT FIELD TRIP 17 GUIDEBOOK SERIES OF THE SOCIETY OF ECONOMIC GEOLOGISTS, INC. Guidebook 57 Print ISSN 1547-3090 ISBN 978-1-629490-72-4 Online ISSN 2374-6955 ISBN 978-1-629494-94-4 Digital version available from Society of Economic Geologists, Inc. 7811 Shaffer Parkway Littleton, Colorado 80127 Tel. 1.720.981.7882 Fax: 1.720.981.7874 Bookstore: www.segweb.org/store Publication date: April 2018 On the cover: Generalized regional geology of southwest Ghana. Modified after BRGM 1:2M Geological Map of West Africa. Contents List of Figures and Tables .......................................................................................................... iv Emergency and Other Contacts ..................................................................................................vii Sponsors West African Rescue Association ....................................................................................xi SEMS Exploration ........................................................................................................xiii WARA Clinic Maps ...................................................................................................................xv Special Request to Student Participants ....................................................................................xix The SEGF Student Field Trip Program ......................................................................................xx Foreword ................................................................................................................................... xxi Acknowledgments ....................................................................................................................xxii Field Trip Leaders ...................................................................................................................xxiii Professionals/Mentors Accompanying Student Field Trip 17 .................................................xxiv Student Participants ............................................................................................................... xxvi Itinerary ................................................................................................................................. xxvii Field Trip Route Map ...............................................................................................................xxx Syllabus – Field Guide Introduction ......................................................................................................................1 Southwest Ghana Regional Geology ................................................................................7 Site Visits Iduapriem (Teberebie) ..........................................................................................23 Damang ................................................................................................................33 Wassa ....................................................................................................................45 Prestea ..................................................................................................................59 Obuasi ..................................................................................................................73 Homase-Akrokerri ................................................................................................91 Obotan-Esaase ...................................................................................................105 Chirano ...............................................................................................................131 Ahafo...................................................................................................................145 Akyem .................................................................................................................157 References ...............................................................................................................................167 Appendices Appendix I: Cost Definitions ........................................................................................175 Appendix II: Chronology of Key Events .......................................................................180 iii List of Figures and Tables Figures 1-1. Simplified geological map of the West African craton with gold deposits .......................................................2 1-2. Cretaceous palinspastic reconstruction of the Guiana and south West Africa shields .....................................3 1-3. Simplified geological map of southwest Ghana with mineral belts .................................................................5 1-4. Comparison of the world’s 25 largest Precambrian orogenic Au deposits .......................................................6 1-5. Grade-tonnage diagram for West African orogenic Au deposit resources ........................................................6 1-6. Stratigraphic column of southwest Ghana ........................................................................................................8 1-7. Age dating from southwest Ghana ore deposits ...............................................................................................9 1-8. Tectonic evolution in southwestern Ghana .....................................................................................................10 1-9. Compilation of histograms presenting radiometric age data ..........................................................................11 1-10. Simplified geologic map of the Ashanti Belt ..................................................................................................14 1-11. Cross-section across the Ashanti Belt .............................................................................................................15 1-12. Total magnetic intensity reduced to pole over first vertical derivative of the Ashanti Belt ............................16 1-13. Bouguer gravity map over the Ashanti Belt ....................................................................................................17 2-1. Satellite image of the Tarkwa district .............................................................................................................24 2-2. Geology of the Tarkwa-Damang gold district.................................................................................................25 2-3. Type cross-section through Tarkwa ................................................................................................................26 2-4. Stratigraphic column of southwest Ghana ......................................................................................................28 2-5. Stratigraphic subdivisions of the Banket Series at the Tarkwa gold mine ......................................................29 2-6. Iduapriem mining blocks ................................................................................................................................31 3-1. Location map of Damang showing generalized geology................................................................................34 3-2. Stratigraphic succession of the Tarkwa Group at Damang .............................................................................35 3-3. Mining bench plan from the Damang deposit ................................................................................................36 3-4. Damang area regional geologic map and cross-section ..................................................................................37 3-5. Photos of drill core and outcropping shear zone at Damang ..........................................................................38 3-6. Styles of gold-bearing extensional quartz veins in walls of the Damang pit..................................................39 3-7. Diagrams of the various styles of mineralized quartz veins at Damang ........................................................40 3-8. Longitudinal projection of orebodies at Damang ...........................................................................................40 3-9. Kinematic model for gold-bearing quartz vein development at Damang.......................................................41 3-10. Structural model for quartz vein development at Damang .............................................................................42 4-1. Location map of Wassa showing generalized geology ...................................................................................46 4-2. Soil geochemistry anomaly map over the Wassa deposit ...............................................................................48 4-3. Detailed geology of the Wassa mine, showing resource model gold distribution ..........................................49 4-4. DD core samples and thin sections of main host rocks at Wassa ...................................................................50
Load more

Recommended publications
  • Arend J Hoogervorst1 B.Sc.(Hons), Mphil., Pr.Sci
    Audits & Training Eagle Environmental Arend J Hoogervorst1 B.Sc.(Hons), MPhil., Pr.Sci. Nat., MIEnvSci., C.Env., MIWM Environmental Audits Undertaken, Lectures given, and Training Courses Presented2 A) AUDITS UNDERTAKEN (1991 – Present) (Summary statistics at end of section.) Key ECA - Environmental Compliance Audit EMA - Environmental Management Audit EDDA -Environmental Due Diligence Audit EA- External or Supplier Audit or Verification Audit HSEC – Health, Safety, Environment & Community Audit (SHE) – denotes safety and occupational health issues also dealt with * denotes AJH was lead environmental auditor # denotes AJH was contracted specialist local environmental auditor for overseas environmental consultancy, auditing firm or client + denotes work undertaken as an ICMI-accredited Lead Auditor (Cyanide Code) No of days shown indicates number of actual days on site for audit. [number] denotes number of days involved in audit preparation and report write up. 1991 *2 day [4] ECA - AECI Chlor-Alkali Plastics, Umbogintwini, KwaZulu-Natal, South Africa. November 1991. *2 day [4] ECA - AECI Chlor-Alkali Plastics- Environmental Services, Umbogintwini, KwaZulu-Natal, South Africa. November 1991. *2 Day [4] ECA - Soda Ash Botswana, Sua Pan, Botswana. November 1991. 1992 *2 Day [4] EA - Waste-tech Margolis, hazardous landfill site, Gauteng, South Africa. February 1992. *2 Day [4] EA - Thor Chemicals Mercury Reprocessing Plant, Cato Ridge, KwaZulu-Natal, South Africa. March 1992. 2 Day [4] EMA - AECI Explosives Plant, Modderfontein, Gauteng, South Africa. March 1992. *2 Day [4] EMA - Anikem Water Treatment Chemicals, Umbogintwini, KwaZulu-Natal, South Africa. March 1992. *2 Day [4] EMA - AECI Chlor-Alkali Plastics Operations Services Group, Midland Factory, Sasolburg. March 1992. *2 Day [4] EMA - SA Tioxide factory, Umbogintwini, KwaZulu-Natal, South Africa.
    [Show full text]
  • A Review of the Birimian Supergroup- and Tarkwaian Group-Hosted Gold Deposits of Ghana
    177 A review of the Birimian Supergroup- and Tarkwaian Group-hosted gold deposits of Ghana Albertus J. B. Smith1,2*, George Henry1,2 and Susan Frost-Killian3 1 DST-NRF Centre of Excellence for Integrated Mineral and Energy Resource Analysis, Department of Geology, University of Johannesburg, Auckland Park, 2006, South Africa. *Corresponding author e-mail address: [email protected] 2 Palaeoproterozoic Mineralisation Research Group, Department of Geology, University of Johannesburg, Auckland Park, 2006, South Africa 3 The MSA Group, 20B Rothesay Avenue, Craighall Park, 2196, South Africa DOI: 10.18814/epiiugs/2016/v39i2/95775 Ghana is the largest producer of gold in West Africa, veins. The vein- and sulphide-hosted gold is strongly a region with over 2,500 years of history with regards to associated with deformational fabrics formed by the gold production and trade. Modern exploration for and Eburnean extensional and compressional events, mining of gold in Ghana dates from 1874 with the respectively, suggesting that disseminated sulphide establishment of the British Gold Coast Colony, which mineralisation predates quartz vein-hosted was followed in 1957 by the independence of Ghana and mineralisation. The fluid from which the gold precipitated increased gold production since the early 1980s through is believed to have been of metamorphic origin and Ghana’s Economic Recovery Plan. At the time of writing, carbon dioxide (CO2) dominated, with lesser water (H2O) gold production (108.2 tonnes or 3.48 million ounces and nitrogen (N2) and minor methane (CH4). Gold [Moz] in 2014) accounted for approximately one-third precipitation was probably caused by decrease in of Ghana’s export revenues, with 36% of gold production pressure, temperature and CO2-H2O immiscibility, at coming from small-scale mining.
    [Show full text]
  • Engineering & Mining Journal
    Know-How | Performance | Reliability With MineView® and SmartFlow® Becker Mining Systems offers two comprehensive and scalable data management solutions for your Digital Mine. MineView® is a powerful state-of-the-art 3D SCADA system, that analyses incoming data from various mine equipment and visualises it in a 3D mine model. SmartFlow® takes Tagging & Tracking to a new level: collected asset data is centrally processed and smart software analytics allow for process optimization and improved safety. MINEVIEW BECKER MINING SYSTEMS AG We have been at the forefront of technology in Energy Distribution, Automation, Communication, Transportation and Roof Support since 1964. Together with our customers we create and deliver highest quality solutions and services to make operations run more profi tably, reliably and safely. For more information go to www.becker-mining.com/digitalmine Becker Mining is a trademark of Becker Mining Systems AG. © 2018 Becker Mining Systems AG or one of its affi liates. DECEMBER 2018 • VOL 219 • NUMBER 12 FEATURES China’s Miners Promote New Era of Openness and Cooperation Major reforms within the mining sector and the government will foster green mines at home and greater investment abroad ....................................42 Defeating the Deleterious Whether at the head of a circuit or scavenging tailings, today’s flotation innovations address challenges presented by declining grades, rising costs and aging plants ..................................................................................52 Staying on Top of
    [Show full text]
  • Quarter 1 2020 GROUP - Operating and Financial Review
    AngloGold Ashanti Limited (Incorporated in the Republic of South Africa) Reg. No. 1944/017354/06 ISIN. ZAE000043485 – JSE share code: ANG CUSIP: 035128206 – NYSE share code: AU (“AngloGold Ashanti” or “AGA” or the “Company”) Market update report for the quarter ended 31 March 2020 Johannesburg, 11 May 2020 - AngloGold Ashanti is pleased to provide an operational update for the quarter ended 31 March 2020. • COVID-19 impact to production limited due to early management intervention and portfolio diversification at 11,000oz in Q1 2020 • Production of 716,000oz, supported by strong performances from Kibali, Geita and Iduapriem • All-in sustaining costs (AISC) of $1,047/oz up 4% year-on-year; AISC margin improved to 34%, up from 22% in Q1 2019 • Adjusted EBITDA up 54% year-on-year to $473m; Adjusted net debt to Adjusted EBITDA improves to 0.85 times • Free cash flow before growth capital increased 231% year-on-year to $94m; Cash flow from operating activities up 227% to $219m • Liquidity of $2bn at 31 March 2020; Settled $700m principal and final coupon on 10-year bond; Secured $1bn standby facility in April 2020 • Obuasi Phase 2 ramp-up completion expected towards end Q1 2021 due to equipment delivery delay; Colombia studies now seen in Q1 2021 • Critical spares inventories now average four months across sites to mitigate possible COVID-19 disruptions • AngloGold Ashanti involved in important humanitarian efforts in the fight against the COVID-19 pandemic • Sale processes for SA portfolio and Sadiola making steady progress; Decision taken
    [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]
  • Perception of Family Planning Use Among Married Men and Women in Ghana
    Research Article iMedPub Journals Journal of Contraceptive Studies 2018 www.imedpub.com ISSN 2471- 9749 Vol.3 No.3:21 DOI: 10.21767/2471-9749.100054 Perception of Family Planning Use among Armah-Ansah EK* Married Men and Women in Anomabu Community University of Cape Coast, Ghana *Corresponding author: Armah-Ansah EK Abstract [email protected] Despite the launching of a family planning programme in Ghana about 5 decades ago, the country’s family planning prevalence rate remains relatively low and its University of Cape Coast, Ghana total fertility rate is still considerably high compared with other African countries. One of the factors that may contribute to the low family planning prevalence rate Tel: +233502271880 and thus the slow fertility decline in Ghana is the perception of family planning use among married men and women in Ghana. This study sought to examine the perception of family planning use among married men and women at Anomabu Citation: Armah-Ansah EK (2018) community in the Mfantseman Municipality of the Central Region of Ghana. Data Perception of Family Planning Use among were collected among married men and women who were in their reproductive Married Men and Women in Anomabu ages (15-49 years). Questionnaires were administered to 200 randomly selected Community. J Contracept Stud Vol.3 No.3:21 respondents. The data collected were analyzed with Statistical Product and Service Solution (SPSS) software version 21 and presented using graphs and tables. The results revealed that 82.5% of the respondents had knowledge about family planning with media (radio, TV and internet) being the major source of information about family planning.
    [Show full text]
  • Rain Rate and Rain Attenuation Geographical Map for Satellite System Planning in Ghana
    International Journal of Computer Applications (0975 – 8887) Volume 177 – No. 41, March 2020 Rain Rate and Rain Attenuation Geographical Map for Satellite System Planning in Ghana Stephen Akobre Mohammed Ibrahim Daabo Abdul-Mumin Salifu Dept. of Computer Science Dept. of Computer Science Dept. of Computer Science University for Development Studies University for Development Studies University for Development Studies Navrongo, Ghana Navrongo, Ghana Navrongo, Ghana ABSTRACT the rain rate and attenuation. These studies have been carried Good signal reception depends on a reliable communication out mostly in the temperate regions. But the severity of rain link. However, as the signal travels through the effect on the signal, are more pronounce at the tropics and communication medium, several factors affect the quality of equatorial regions where intense rainfall events are common the signal at the receiver. In Ku band digital satellite as compared to the temperate regions. This is reported in the transmission, rain is the major cause of link impairment. work of Ajayi (1996), Moupfouma (1985) and Ojo and Global rain rate and rain attenuation prediction models have Omotosho (2013). been developed to predict rain rate and rain attenuation at Satellite system design requires as input 1-minute rain rate various locations. These models have not been applied and data with various exceedance probabilities. Based on this tested with measured data to determine their prediction many researchers have conducted experiments on their local accuracy in the Ghanaian tropical region. In this paper, the climatological regions to measure 1-minute rain rate and Moupfouma and International Telecommunication Union attenuation. In regions where there are enough data coverage, Recommendation (ITU-R) rain rate models were applied and prediction models have been proposed.
    [Show full text]
  • Geometry and Genesis of the Giant Obuasi Gold Deposit, Ghana
    Geometry and genesis of the giant Obuasi gold deposit, Ghana Denis Fougerouse, BSc, MSc This thesis is presented for the degree of Doctor of Philosophy. Centre for Exploration Targeting School of Earth and Environment The University of Western Australia July 2015 Supervisors: Dr Steven Micklethwaite Dr Stanislav Ulrich Dr John M Miller Professor T Campbell McCuaig ii "It never gets easier, you just go faster" Gregory James LeMond iv Abstract Abstract The supergiant Obuasi gold deposit is the largest deposit hosted in the Paleoproterozoic Birimian terranes of West Africa (62 Moz, cumulative past production and resources). The deposit is hosted in Kumasi Group sedimentary rocks composed of carbonaceous phyllites, slates, psammites, and volcaniclastic rocks intruded by different generations of felsic dykes and granites. In this study, the deformation history of the Obuasi district was re-evaluated and a three stage sequence defined based on observations from the regional to microscopic scale. The D1Ob stage is weakly recorded in the sedimentary rocks as a layer-parallel fabric. The D2Ob event is the main deformation stage and corresponds to a NW-SE shortening, involving tight to isoclinal folding, a pervasive subvertical S2Ob cleavage striking NE, as well as intense sub-horizontal stretching. Finally, a N-S shortening event (D3Ob) formed an ENE-striking, variably dipping S3Ob crenulation cleavage. Three ore bodies characteristic of the three main parallel mineralised trends were studied in details: the Anyankyerem in the Binsere trend; the Sibi deposit in the Gyabunsu trend, and the Obuasi deposit in the main trend. In the Obuasi deposit, two distinct styles of gold mineralisation occur; (1) gold-bearing sulphides, dominantly arsenopyrite, disseminated in metasedimentary rocks and (2) native gold hosted in quartz veins up to 25 m wide.
    [Show full text]
  • Yemen Mineral Sector Review
    Report No. 47985-YE Report No. 47985-YE Yemen Mineral Sector Review Public Disclosure Authorized June 2009 Oil, Gas, Mining Policy Division, Oil, Gas, Mining and Chemicals Department Middle East and North Africa Region Yemen Public Disclosure Authorized Mineral Sector Review Mineral Public Disclosure Authorized Document of the World Bank Public Disclosure Authorized ACKNOWLEDGEMENTS This report was prepared by a team led by Alexandra Pugachevsky, Operations Officer, (COCPO). The report team comprised Bryan Land, Senior Mining and Petroleum Specialist (COCPO) and three international consultants, John Cole-Baker (Metals Mining Consultant), Marco Cosi (Industrial Mining Consultant) and Henry Thompson (Mining and Oil Social and Environmental Issues Consultant). The task team was ably supported by three local consultants: Safwan Al-Sanabani, Dr. Khaled Mohammed Thabet Al-Selwi and Ibrahim Mahmood Al- Saghiry. Maria Handal, Nagwan Sharhan and Ali Ali Hassan Salamah, all from the World Bank Sana’a office, provided invaluable support to the team while in Sana’a. Dr. Gaber Ali Mohamed Al-Sanabani, Associate Operations Officer, PEP-MENA, based in Sana’a, contributed extensively to this report and deserves a separate mention. The team also benefited greatly from cooperating with the PEP-MENA team and Frank Sader, Principal Strategist, in particular. Somin Mukherji, Senior Financial Analyst (MNSSD) consulted the team on Yemen’s power sector and Jean- Charles Crochet, Senior Transport Economist (MNSSD) provided feedback on transport issues. Amanda Green, Consultant, World Bank, edited the document. We would like to acknowledge and thank the Government of Yemen - the Ministry of Oil and Minerals and especially the Geological Survey and Mineral Resources Board (GSMRB) for the courtesies extended to the various missions, prompt response to our requests for information and data and for their participation in developing the analysis and conclusions of this report.
    [Show full text]
  • Recent Government Contracts Representations
    Recent Government Contracts Representations Quinn Emanuel successfully settled criminal and civil litigation venued in the Northern District of Georgia for client, Agility, a Kuwaiti multi-billion dollar logistics company. The litigation arose from allegations that Agility defrauded the federal government in the performance of Prime Vendor Contracts to supply food to United States troops during the Iraq war from 2003-2010. Despite Agility’s near perfect performance of the mission to feed the U.S. troops, the government alleged that Agility engaged in a $10 billion fraud on the government. In 2017, Agility announced a global settlement. The criminal fraud action, involving an alleged $10 billion fraud was resolved with a single count misdemeanor plea in connection with a single invoice valued at $551. The misdemeanor, unrelated to any of the original criminal charges, required Agility to pay a maximum of $551 in restitution, but no criminal fine. As part of the global settlement, Agility and its subsidiaries around the world were removed from the list of entities suspended from contracting with the U.S. government. We currently represent South African mining company AngloGold Ashanti in ICSID arbitration proceedings against the government of Ghana. We have accused the government of Ghana of withdrawing military protection from the Obuasi gold mine and permitting hundreds of illegal miners to access the mine and carry away gold ore, with cumulative losses of millions to date. We also represented AngloGold Ashanti Limited and its subsidiaries in a London- seated, UNCITRAL arbitration against the United Republic of Tanzania. The claims arose out of legislation passed by the Republic of Tanzania, purporting to force mining companies to list their shares and subjecting their agreements to review and renegotiation by the Government, in breach of stabilisation and other provisions contained in our clients’ development agreement with the Government, which was governed by Tanzanian law.
    [Show full text]
  • Report on Anglo American's Track Record
    By Philip Mattera For more information on Anglo American’s track record or the proposed Pebble mine, go to www.eyeonpebblemine.org. Cover photo: Iduapriem Mine Courtesy of Jamie Keen, Mining Watch Canada COMMUNITY, WORKER SAFETY, PUBLIC HEALTH, AND ENVIRONMENTAL PROBLEMS AT ANGLO AMERICAN MINING OPERATIONS By Philip Mattera July 2008 Philip Mattera is a veteran corporate researcher who works with a variety of public interest groups and labor unions. Earlier in his career he was a reporter-researcher for a major business magazine. He is the author of four books—including World Class Business: A Guide to the 100 Most Powerful Global Corporations—and is a member of the National Writers Union. He can be reached at: [email protected]. © 2008 Philip Mattera The following organizations - representing Alaska Native corporations, commercial fishing companies, sportsmen, conservation interests, and businesses - are committed to the protection of the Bristol Bay watershed and the tremendous salmon fishery that it sustains. This report was commissioned by these organizations to gain a better understanding of Anglo American’s corporate history and track record. While the organizations commissioned this research, they are not responsible for its content, which is the sole responsibility of the author. Nunamta Aulukestai (Caretakers of Our Land) Renewable Resources Coalition Table of Contents Executive Summary . 4 Introduction ............................................................................ 5 A Short History of Anglo American........................................................... 6 Key Financials . 7 Anglo American’s Record on Environmental Protection, Worker Safety, Community Impacts and Human Rights at Its Hardrock Mining Operations:........................................... 8 1. Sulfur dioxide emissions and spills at platinum mines in South Africa.................................. 8 2.
    [Show full text]
  • Trace Elements Contamination of Soils Around Gold Mine Tailings Dams at Obuasi, Ghana
    African Journal of Environmental Science and Technology Vol. 3(11), pp. 353-359, November, 2009 Available online at http://www.academicjournals.org/ajest ISSN 1991-637X © 2009 Academic Journals Full Length Research Paper Trace elements contamination of soils around gold mine tailings dams at Obuasi, Ghana P. Antwi-Agyei1*, J. N. Hogarh1 and G. Foli2 1Department of Environmental Science, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana. 2Department of Earth and Environmental Science, University for Development Studies, P. O. Box 24, Navrongo Campus; Navrongo, Ghana. Accepted 18 October, 2009 This study investigated the issue of tailings dams as a potential source of trace elements contamination in soils at the Obuasi gold mine in Ghana. Soil samples taken from depths of up to 12 cm and within a radius of 400 m from the tailings dams (active and decommissioned), were analysed for As, Cu, Pb and Zn using atomic absorption spectrometry. Average concentrations of As, Cu, Pb and Zn in soils around the active tailings dams were respectively 581±130, 39.64 ± 3.02, 24.22 ± 2.62 and 72.64 ± 8.01 mg/kg. Soils in the vicinity of the decommissioned tailings dam registered increased values - 1711 ± 172, 71.44 ± 5.27, 38.67 ± 3.59 and 168.1 ± 36.2 mg/kg for As, Cu, Pb and Zn respectively. Both types of tailings dams impacted adjoining soils with greater concentrations of the trace elements when compared to undisturbed control soils. Arsenic was above the Netherlands intervention value of 55 mg/kg dry weight, even in control soils. The following trend of accumulation was observed in the soils: As>Zn>Cu>Pb.
    [Show full text]