Texture and Compositional Evidence for Epigenetic Alteration in Mn Carbonate Protore at the Palaeo-proterozoic Nsuta Manganese Deposit, Western Ghana”

This communication is the first to report the presence of significant epigenetic alteration in protore manganese carbonate at the Palaeo-proterozoicNsuta manganese deposit in the Birimian of Ghana. The alteration is recognisable macroscopically by strong veining of quartz and/or pink rhodochrosite and, in some cases, in slightly sheared or deformed carbonate rock. Under the ore microscope, the alteration assemblage commonly consists of micro-granular rhodochrosite, occasionally coexisting with one or more of alabandite, mangano-cummingtonite, alleganyite and jacobsite. The compositions of carbonate minerals also demonstrably show an increase in the MnCO3 end-member in the altered compared to the least altered carbonate protore. These textural and compositional features sharply contrast with low regionally metamorphosed protore that shows remarkable preservation of primary sedimentary features including lamination and is, in addition, dominated by micro-concretionary to microcrystalline rhodochrosite ± kutnahorite ± mixed Ca-Mg carbonates ± spessartine garnet. The alteration is not only suggested to be post-metamorphic (low-metamorphosed) and pre-supergene but may also, contrary to the interpretations of some previous workers, have introduced unusual manganese-bearing minerals (e.g. alabandite and mangano-cummingtonite) as well as possibly enriched the protore carbonate

Perspectives on migration patterns in Ghana's mining industry

This paper examines migration patterns in Ghana's mining sector, and briefly highlights linkages between stages of mine development and migration flows. The growth, stagnation and closure phases of mine development may each be characterised by distinct migration patterns. The paper concludes with policy-relevant implications of the dynamics of migration patterns in the mining sector, arguing in particular that Ghana is, in addition to traditionally being a country of destination, becoming a transit area for prospective migrant miners. © 2008 Elsevier Ltd. All rights reserved

Perspectives on migration patterns in Ghana's mining industry

This paper examines migration patterns in Ghana's mining sector, and briefly highlights linkages between stages of mine development and migration flows. The growth, stagnation and closure phases of mine development may each be characterised by distinct migration patterns. The paper concludes with policy-relevant implications of the dynamics of migration patterns in the mining sector, arguing in particular that Ghana is, in addition to traditionally being a country of destination, becoming a transit area for prospective migrant miners. © 2008 Elsevier Ltd. All rights reserved

'Agricultural poverty' and the expansion of artisanal mining in sub-Saharan Africa: Experiences from southwest Mali and southeast Ghana

Why do people engage in artisanal and small-scale mining (ASM) – labour-intensive mineral extraction and processing activity – across sub-Saharan Africa? This paper argues that ‘agricultural poverty’, or hardship induced by an over-dependency on farming for survival, has fuelled the recent rapid expansion of ASM operations throughout the region. The diminished viability of smallholder farming in an era of globalization and overreliance on rain-fed crop production restricted by seasonality has led hundreds of thousands of rural African families to ‘branch out’ into ASM, a move made to secure supplementary incomes. Experiences from Komana West in Southwest Mali and East Akim District in Southeast Ghana are drawn upon to illustrate how a movement into the ASM economy has impacted farm families, economically, in many rural stretches of sub-Saharan Africa