Alluvial diamond resource potential and production capacity assessment of Guinea

Abstract

In May of 2000, a meeting was convened in Kimberley, South Africa, by representatives of the diamond industry and leaders of African governments to develop a certification process intended to assure that export shipments of rough diamonds were free of conflict concerns. Outcomes of the meeting were formally supported later in December of 2000 by the United Nations in a resolution adopted by the General Assembly. By 2002, the Kimberley Process Certification Scheme (KPCS) was ratified and signed by diamondproducing and diamond-importing countries. The goal of this study was to estimate the alluvial diamond resource endowment and the current production capacity of the alluvial diamond mining sector of Guinea. A modified volume and grade methodology was used to estimate the remaining diamond reserves within Guinea's diamondiferous regions, while the diamond-production capacity of these zones was estimated by inputting the number of artisanal miners, the number of days artisans work per year, and the average grade of the deposits into a formulaic expression. Guinea's resource potential was estimated to be approximately 40 million carats, while the production capacity was estimated to lie within a range of 480,000 to 720,000 carats per year. While preliminary results have been produced by integrating historical documents, five fieldwork campaigns, and remote sensing and GIS analysis, significant data gaps remain. The artisanal mining sector is dynamic and is affected by a variety of internal and external factors. Estimates of the number of artisans and deposit variables, such as grade, vary from site to site and from zone to zone. This report has been developed on the basis of the most detailed information available at this time. However, continued fieldwork and evaluation of artisanally mined deposits would increase the accuracy of the results. During the Seventh Annual Plenary Session of the KPCS, held in Swakopmund, Namibia, in November 2009, an Administrative Decision (AD) pertaining to Guinea was adopted. The Swakopmund AD on Guinea was the result of concerns relating to Guinea's exponential increase in diamond production in the years 2007 and 2008 (table 1). The AD requested that Guinean authorities relaunch a system of internal controls, which include stopping any exports of rough diamonds of suspicious origin. With the passing of the AD, the plenary group agreed that further efforts should be made to assess Guinea's diamond-production capacity (KPCS, 2009).

The influence of geomorphology on the role of women at artisanal and small‐scale mine sites

“…Primary and eluvial deposits generally have minimal overburden, and mining takes place in the consolidated or semi‐consolidated source rocks. Secondary alluvial deposits have varying overburden thicknesses, though in general, high terraces have the thinnest overburden layers, followed by low terraces and alluvial flats (Chirico et al ., 2010b; 2012). Overburden thickness in West and Central Africa can range from several centimetres to more than 30 metres.…”

Metallogenic portfolio of the West Africa craton

“…The Eburnean Orogeny is associated with significant gold mineralisation in volcanic, volcano-sedimentary and sedimentary rocks of the Birimian Supergroup (Milési et al, 1989;Béziat et al, 2008). The emplacement of kimberlite bodies took place probably during the Paleoproterozoic (Hastings, 1982) although the main event occurred in the Early Cretaceous during the break-up of Gondwana (Bardet and Vachette, 1966;Rombouts, 1987;Chirico et al, 2010aChirico et al, , 2010bChirico et al, , 2014.…”

“…The majority of primary and secondary diamond deposits are reported from the Archean Kénéma-Man domain (e.g., Koidu Pipe and Tongo fields in eastern Sierra Leone; Banankoro in Guinea; and Mano River in Liberia), with some occurrences in the Baoulé-Mossi domain (e.g., Basalogo diamond field in Burkina Faso; diamond-bearing tuffisite dykes in Ghana; Delor et al, 2004). Although diamond-bearing kimberlite dykes and pipes are generally emplaced during the Jurassic to Cretaceous (Bardet and Vachette, 1966;Rombouts, 1987;Chirico et al, 2010aChirico et al, , 2014, and are associated with the break-up of Gondwana, there is also evidence that suggests they were Paleoproterozoic in age (Hastings, 1982).…”

A Review of the Scope of Artisanal and Small‐Scale Mining Worldwide, Poverty, and the Associated Health Impacts

“…There has been useful progress in both directions. For example, researchers at the U.S. Geological Survey demonstrated the potential of remote sensing and geological modeling techniques for quantitatively monitoring ASM activities in Côte d'Ivoire and Guinea, respectively (Chirico et al, 2014; Chirico & Malpeli, 2013). Their analyses filled in significant gaps in knowledge concerning diamond production in both countries and identified shifts in production capacity from one region to another in Guinea.…”