Overbank sediments as appropriate geochemical sample media in regional stream sediment surveys for gold exploration in the savannah regions of northern Ghana     

Prosper M. Nude  Emmanuel Arhin 《Journal of Geochemical Exploration》2009

Conventional stream sediment sampling in which sediments are taken from the active channels during reconnaissance regional geochemical surveys in gold exploration has over the years failed to delineate prospective target zones in northern Ghana, where the relict is flat. Whereas the technique has been successful in the south western Ghana, which is characterised by moderate to high relief, generally the savannah north is associated with low relief, commonly with flat topographies and generally decoupled stream channels. Geochemical comparison of active stream and overbank sediments in this study demonstrate that active stream channels may contain contaminated materials of recent origin, but overbank sediments, except for the uppermost horizons, represent alluvial regolith of earlier depositional cycles over time. Based on gold value repeatability, composite samples taken from the overbank sediment layers were relatively less erratic and are considered to be an appropriate geochemical medium in delineating potential regional gold targets for follow up. The results show that overbank sediment sampling can be used as a cost-effective method to define broad anomalous zones; and the technique must be considered useful during reconnaissance geochemical surveys in the savannah regions.  相似文献   

A new biostratigraphic correlation for Late Cretaceous–Paleocene strata of the Gulf of Guinea: Evidence from dinoflagellate cysts     

Raquel Sánchez-Pellicer  Edwige Masure  Loïc Villier 《Comptes Rendus Geoscience》2017,349(1):32-41

A new biostratigraphic correlation for Late Cretaceous and Palaeocene strata of the Côte d’Ivoire–Ghana continental margin has been developed from the identification of significant dinoflagellate cyst events in ODP Hole 959D. The Late Cretaceous stage boundaries are mostly consistent with previous studies. However, the Maastrichtian/Danian boundary is placed much lower than previously recognized on the basis of the first occurrences of Carpatella cornuta and Damassadinium californicum. The base of the Selandian is recognized from the last occurrence of Cerodinium diebelii and the first occurrence of Adnatosphaeridium multispinosum. The base of the Thanetian is recognized from the first occurrence of Areoligera gippingensis. The rarity of the age-marker taxa is the main reason for different age determinations among studies of the same section.  相似文献   

Changing urban governance in Ghana: the role of resistance practices and activism in Kumasi     

《Urban geography》2012,33(10):1568-1595

ABSTRACT

This article examines traders’ resistance practices in Kumasi, Ghana and their significance for changing urban governance in Africa. Conceptually, we introduce “activism” as a new variable into the present concept of urban governance as decentralization, entrepreneurialism and democratization (DED). From an empirical study in Kumasi, Ghana, findings reveal that activism by non-state actors does not only occur at the crucial earlier phases of the urban regeneration process, but extends into the subsequent phases, because urban governance is a continuous process. We demonstrate that activism and a multiplicity of resistance practices are embedded and significant dimensions of everyday urban governance in Africa. This paper argues that the additional dimension – activism – is necessary in rethinking urban governance in Ghana and Africa. This conceptualization views non-state actors not as resisters of urban governance but as activists whose resistance practices and innovations produce tangible and far-reaching changes in city governance. We learn that non-state actors do not rely on the state to control all aspects of urban governance but invent new practices to secure their socio-economic interests and provide them with leverage where they have to negotiate with or stand up to authorities. The study shows that successful change in urban governance is a function of the complementary and strategic adoption of contention, subversion and co-production. When the state perceives that the intervention of other key stakeholders legitimizes the grievances of non-state actors, it responds positively.  相似文献   

Mapping the vulnerability of crop production to drought in Ghana using rainfall, yield and socioeconomic data     

Philip Antwi-Agyei  Evan D.G. Fraser  Andrew J. DougillLindsay C. Stringer  Elisabeth Simelton 《Applied geography (Sevenoaks, England)》2012,32(2):324-334

This study evaluates new multi-scale, multi-indicator methods for assessing the vulnerability of crop production to drought at a national and regional scale. It does this by identifying differences across and within ten regions of Ghana, a country that faces many climate and crop production challenges typical of sub-Saharan Africa. In particular, we illustrate how a quantitative national and regional study is a critical first step in assessing differences in the drought sensitivity of food production systems and show how such an assessment enables the formulation of more targeted district and community level research that can explore the drivers of vulnerability and change on a local-scale. Finally, we propose methodological steps that can improve drought sensitivity and vulnerability assessments in dynamic dryland farming systems where there are multiple drivers of change and thresholds of risk that vary in both space and time. Results show that the vulnerability of crop production to drought in Ghana has discernible geographical and socioeconomic patterns, with the Northern, Upper West and Upper East regions being most vulnerable. Partly, this is because these regions have the lowest adaptive capacity due to low socioeconomic development and have economies based on rain-fed agriculture. Within these regions we find considerable differences between districts that can be explained only partly by socioeconomic variables with further community and household-scale research required to explain the causes of differences in vulnerability status. Our results highlight that national and regional scale multi-indicator vulnerability assessments are a vital (and often ignored) first step in assessing vulnerability across a large area. These inputs can guide both local-level research and also demonstrate the need for region-specific policies to reduce vulnerability and to enhance drought preparedness within dryland farming communities.  相似文献   

Is groundwater in the Tarkwa gold mining district of Ghana potable?     

Jerry?S.?KumaEmail author 《Environmental Geology》2004,45(3):391-400

Hand-pump wells in the Tarkwa gold mining district and the geologically similar Bui area were chemically analysed and compared in an effort to determine whether groundwaters in the Tarkwa area have been affected by mining. Significant chemical differences attributed to mine water discharges have been observed in streams in the Tarkwa area. Groundwater chemistry from hand-pump wells in Tarkwa and Bui areas reveal similar hydrochemical facies, predominantly Ca–Na–Mg–HCO₃–Cl. However, except for SO₄^2–, ionic concentrations of groundwaters from Bui are greater than those from Tarkwa probably due to differences in (1) water availability during sedimentation (2) water-rock interactions and/or residence times for water. No demonstrable impact of mining on groundwaters from hand-pumped wells in the Tarkwa area has been noted. Hydrogeological inference suggests that the main streams which receive mine water discharges are both gaining and are groundwater divides. The overwhelming majority of population centres and mining operations are located on opposite sides of these groundwater divides, therefore, it is unlikely aquifers tapped for drinking by these communities would be affected by mining.  相似文献   

The co-production of livelihoods and land use change: Case studies from South Africa and Ghana   总被引：4，自引：0，他引：4  

B. McCusker  E.R. Carr 《Geoforum》2006,37(5):790-804

Land use change and livelihood systems are often analyzed separately or with one “driving” the other. This “driver-feedback” relationship has been buttressed by approaches to social process that are often far too static. Actors are confronted with a bundle of choices that they must negotiate as they create pathways of change. These choices are always bound up in relations of power and the knowledges that are the conditions for and results of these relations. We suggest that land uses and livelihood are different manifestations of the social processes by which individuals and groups negotiate the everyday conditions that shape their lives. We propose a framework that extends current understandings of the relationship between land use change and livelihoods by treating social relations of power as the entry point into this complex relationship. We underpin our arguments with empirical examples from South Africa and Ghana that locate power/knowledge relations in the context of social change in both study areas.  相似文献   

SMALL‐SCALE INDUSTRY AS A SPONGE? EMPIRICAL SURVEY IN THE CENTRAL REGION,GHANA     

John V. Mensah 《Singapore journal of tropical geography》2005,26(2):212-226

It has been posited that small‐scale industry – businesses with less than 30 workers – provides a large share of employment and income in Ghana. This paper examines the proposition that while such enterprises in the informal sector are said to act as a sponge to soak up surplus labour in marginal activities, they are unprofitable. Using data from a survey in 1998 of 175 micro and small‐scale enterprises in the Central Region of Ghana, the paper also confirms problematic aspects of employment in this sector including the lack of formal contracts, irregular pay, low remuneration, non‐existent social protection and only marginal employment growth. The implication is that the small‐scale industry sector is not economically sustainable in its present form in Ghana.  相似文献   

The making and unmaking of gendered crops in northern Ghana   总被引：2，自引：0，他引：2  

Martina A. Padmanabhan 《Singapore journal of tropical geography》2007,28(1):57-70

In rural West Africa, the gendered division of labour extends to labelling certain crops as 'male' or 'female'. With the introduction of new varieties of crops and technologies, these constructions of gendered plants undergo a process of renegotiation at social intrafaces. This process of attaching meaning to new features in cultivation results in the remaking of gendered crops. These negotiations, in turn, have an effect on the construction of gender in specific ethnic and environmental settings, unlinking labour from its gendered connotations and, thus, unmaking the social meaning and creating room for manoeuvre. Based on fieldwork among the Dagomba and Kusasi people in northern Ghana, this study examines how gendered responsibilities and access to the cultivation of crops are linked and expressed in obligations related to the cultural ideal of a proper meal, in this case consisting of the food categories (male) staple and (female) soup, which serve as the blueprint for assigning crops to a specific gender.  相似文献   

What has Corruption Got to do with it? Understanding the Persistence of Rural-Urban and Inter-Regional Inequalities in Ghana and Zimbabwe     

Kwadwo?Konadu-AgyemangEmail author  Judith?Shabaya 《GeoJournal》2005,62(1-2):129-146

Inequalities are no respecter of countries, including the affluent ones. Nevertheless, these problems appear to prevail more in the developing countries, which have the dubious distinction of having the highest degrees of inequalities in the world. Inequalities exist between urban and rural areas, as well as between the various regions. This paper discusses inequalities in Ghana and Zimbabwe, emphasizing the rural–urban dichotomy. Using data from the Ghana Demographic and Health Surveys (GDHS) and the Zimbabwe Demographic and Health Surveys (ZDHS) conducted by the respective statistical authorities of both countries and Macro International, the paper analyses existing inequalities in both countries. The paper also attempts to elucidate and understand the causes. It concludes that the traditional explanation of disparities that attribute the conditions to aberrations in the operations of market forces, while having some validity, may not provide a full explanation for Ghana and Zimbabwe’s predicament. It argues that whilst the existing disparities may be rooted in history, their persistence and worsening in the post-independence era could only be understood with reference to the corruption, nepotism and the mismanagement that have characterized these states since they gained their independence.  相似文献   

Reviews     

《The Geographical journal》2002,168(1):74-94

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