The Educational Journal
- Date: 1983-02
- Subjects: Education –- South Africa , South Africa -- Politics and government , Government, Resistance to -- South Africa
- Language: English
- Type: text , Article
- Identifier: http://hdl.handle.net/10948/36584 , vital:34019 , Bulk File 7
- Description: The Educational Journal was the official organ of the Teachers' League of South Africa and focussed on education within the context of a racialized South Africa.
- Full Text: false
- Date Issued: 1983-02
- Date: 1983-02
- Subjects: Education –- South Africa , South Africa -- Politics and government , Government, Resistance to -- South Africa
- Language: English
- Type: text , Article
- Identifier: http://hdl.handle.net/10948/36584 , vital:34019 , Bulk File 7
- Description: The Educational Journal was the official organ of the Teachers' League of South Africa and focussed on education within the context of a racialized South Africa.
- Full Text: false
- Date Issued: 1983-02
Active learning for understanding land degradation : African Catchment Game and Riskmap
- Rowntree, Kate M, Fox, Roddy C
- Authors: Rowntree, Kate M , Fox, Roddy C
- Date: 2006
- Language: English
- Type: Conference paper
- Identifier: vital:6669 , http://hdl.handle.net/10962/d1006793
- Description: Land degradation is the result of the intersection of a complex set of biophysical and socio-economic factors. The capacity of an individual or community to address land degradation is likewise constrained. While it is quite possible for professionals and learners to grasp the main issues around land degradation from a theoretical perspective, internalizing the reality of what it means to be the resource degrader is more difficult. We have developed two active learning methods that aim to address this problem. The first is the African Catchment Game, a role-playing game based on Graham Chapman’s Green Revolution Game, adapted for the southern Africa context and incorporating a land degradation component. In this game participants play out the complex dynamics of rural-urban-global linkages against a background of environmental hazards. The second is based on Save the Children Fund’s RiskMap computer simulation that models risk in terms of rural livelihoods for different income groups. Ethiopia is used as the example. This paper evaluates the two active learning techniques as tools for exploring the relationships between land degradation and poverty through an evaluation of participants’ experiences.
- Full Text:
- Date Issued: 2006
- Authors: Rowntree, Kate M , Fox, Roddy C
- Date: 2006
- Language: English
- Type: Conference paper
- Identifier: vital:6669 , http://hdl.handle.net/10962/d1006793
- Description: Land degradation is the result of the intersection of a complex set of biophysical and socio-economic factors. The capacity of an individual or community to address land degradation is likewise constrained. While it is quite possible for professionals and learners to grasp the main issues around land degradation from a theoretical perspective, internalizing the reality of what it means to be the resource degrader is more difficult. We have developed two active learning methods that aim to address this problem. The first is the African Catchment Game, a role-playing game based on Graham Chapman’s Green Revolution Game, adapted for the southern Africa context and incorporating a land degradation component. In this game participants play out the complex dynamics of rural-urban-global linkages against a background of environmental hazards. The second is based on Save the Children Fund’s RiskMap computer simulation that models risk in terms of rural livelihoods for different income groups. Ethiopia is used as the example. This paper evaluates the two active learning techniques as tools for exploring the relationships between land degradation and poverty through an evaluation of participants’ experiences.
- Full Text:
- Date Issued: 2006
Some geochemical constraints upon models for the crystallization of the upper critical zone-main zone interval, northwestern Bushveld complex
- Eales, Hugh V, Marsh, Julian S, Mitchell, Andrew A, de Klerk, William J, Kruger, Floris J, Field, Matthew
- Authors: Eales, Hugh V , Marsh, Julian S , Mitchell, Andrew A , de Klerk, William J , Kruger, Floris J , Field, Matthew
- Date: 1986
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/136044 , vital:37331 , https://doi.org/10.1180/minmag.1986.050.358.03
- Description: Ratios between elements Mg, Fe, Co, Cr, Ni, V, and Sc are consistently different in mafic rocks of the upper critical zone, and those above the Bastard unit. Within the 300 m section above the Merensky Reef, 87Sr/86Sr ratios increase from c.0.7063 to c.0.7087, irrespective of rock type. Decoupling of Mg/(Mg + Fe2+) ratios and the Ca contents of plagioclase, and wide variations in the proportions of anorthosite within the Bastard, Merensky, and Merensky Footwall units, are inconsistent with anorthosite formation by simple fractional crystallization of magma batches of limited volume.
- Full Text:
- Date Issued: 1986
- Authors: Eales, Hugh V , Marsh, Julian S , Mitchell, Andrew A , de Klerk, William J , Kruger, Floris J , Field, Matthew
- Date: 1986
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/136044 , vital:37331 , https://doi.org/10.1180/minmag.1986.050.358.03
- Description: Ratios between elements Mg, Fe, Co, Cr, Ni, V, and Sc are consistently different in mafic rocks of the upper critical zone, and those above the Bastard unit. Within the 300 m section above the Merensky Reef, 87Sr/86Sr ratios increase from c.0.7063 to c.0.7087, irrespective of rock type. Decoupling of Mg/(Mg + Fe2+) ratios and the Ca contents of plagioclase, and wide variations in the proportions of anorthosite within the Bastard, Merensky, and Merensky Footwall units, are inconsistent with anorthosite formation by simple fractional crystallization of magma batches of limited volume.
- Full Text:
- Date Issued: 1986
Emplacement of inflated Pāhoehoe flows in the Naude’s Nek Pass, Lesotho remnant, Karoo continental flood basalt province: use of flow-lobe tumuli in understanding flood basalt emplacement
- Jay, A E, Marsh, Julian S, Fluteau, F, Courtillot, V
- Authors: Jay, A E , Marsh, Julian S , Fluteau, F , Courtillot, V
- Date: 2018
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/60752 , vital:27826 , https://link.springer.com/article/10.1007/s00445-017-1189-6
- Description: Physical volcanological features are presented for a 710-m-thick section, of the Naude’s Nek Pass, within the lower part of the Lesotho remnant of the Karoo Large Igneous Province. The section consists of inflated pāhoehoe lava with thin, impersistent sedimentary interbeds towards the base. There are seven discreet packages of compound and hummocky pāhoehoe lobes containing flow-lobe tumuli, making up approximately 50% of the section. Approximately 45% of the sequence consists of 14 sheet lobes, between 10 and 52-m-thick. The majority of the sheet lobes are in two packages indicating prolonged periods of lava supply capable of producing thick sheet lobes. The other sheet lobes are as individual lobes or pairs, within compound flows, suggesting brief increases in lava supply rate. We suggest, contrary to current belief, that there is no evidence that compound flows are proximal to source and sheet lobes (simple flows) are distal to source and we propose that the presence of flow-lobe tumuli in compound flows could be an indicator that a flow is distal to source. We use detailed, previously published, studies of the Thakurvadi Formation (Deccan Traps) as an example. We show that the length of a lobe and therefore the sections that are ‘medial or distal to source’ are specific to each individual lobe and are dependent on the lava supply of each eruptive event, and as such flow lobe tumuli can be used as an indicator of relative distance from source.
- Full Text:
- Date Issued: 2018
- Authors: Jay, A E , Marsh, Julian S , Fluteau, F , Courtillot, V
- Date: 2018
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/60752 , vital:27826 , https://link.springer.com/article/10.1007/s00445-017-1189-6
- Description: Physical volcanological features are presented for a 710-m-thick section, of the Naude’s Nek Pass, within the lower part of the Lesotho remnant of the Karoo Large Igneous Province. The section consists of inflated pāhoehoe lava with thin, impersistent sedimentary interbeds towards the base. There are seven discreet packages of compound and hummocky pāhoehoe lobes containing flow-lobe tumuli, making up approximately 50% of the section. Approximately 45% of the sequence consists of 14 sheet lobes, between 10 and 52-m-thick. The majority of the sheet lobes are in two packages indicating prolonged periods of lava supply capable of producing thick sheet lobes. The other sheet lobes are as individual lobes or pairs, within compound flows, suggesting brief increases in lava supply rate. We suggest, contrary to current belief, that there is no evidence that compound flows are proximal to source and sheet lobes (simple flows) are distal to source and we propose that the presence of flow-lobe tumuli in compound flows could be an indicator that a flow is distal to source. We use detailed, previously published, studies of the Thakurvadi Formation (Deccan Traps) as an example. We show that the length of a lobe and therefore the sections that are ‘medial or distal to source’ are specific to each individual lobe and are dependent on the lava supply of each eruptive event, and as such flow lobe tumuli can be used as an indicator of relative distance from source.
- Full Text:
- Date Issued: 2018
Modelling transport of inshore and deep-spawned chokka squid (Loligo reynaudi) paralarvae off South Africa: the potential contribution of deep spawning to recruitment
- Downey-Breedt, Nicola, Roberts, Michael J, Sauer, Warwick H H, Chang, N
- Authors: Downey-Breedt, Nicola , Roberts, Michael J , Sauer, Warwick H H , Chang, N
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125183 , vital:35742 , https://doi.10.1111/fog.12132
- Description: The South African chokka squid, Loligo reynaudi, spawns both inshore (≤70 m) and on the mid-shelf (71–130 m) of the Eastern Agulhas Bank. The fate of these deep-spawned hatchlings and their potential contribution to recruitment is as yet unknown. Lagrangian ROMS-IBM (Regional Ocean Modelling System-Individual-Based Model) simulations confirm westward transport of inshore and deep-spawned hatchlings, but also indicate that the potential exists for paralarvae hatched on the Eastern Agulhas Bank deep spawning grounds to be removed from the shelf ecosystem. Using a ROMS-IBM, this study determined the transport and recruitment success of deepspawned hatchlings relative to inshore-hatched paralarvae. A total of 12 release sites were incorporated into the model, six inshore and six deep-spawning sites. Paralarval survival was estimated based on timely transport to nursery grounds, adequate retention within the nursery grounds and retention on the Agulhas Bank shelf. Paralarval transport and survival were dependent on both spawning location and time of hatching. Results suggest the importance of the south coast as a nursery area for inshore-hatched paralarvae, and similarly the cold ridge nursery grounds for deep-hatched paralarvae. Possible relationships between periods of highest recruitment success and spawning peaks were identified for both spawning habitats. Based on the likely autumn increase in deep spawning off the Tsitsikamma coast, and the beneficial currents during this period (as indicated by the model results) it can be concluded that deep spawning may at times contribute significantly to recruitment.
- Full Text:
- Date Issued: 2016
- Authors: Downey-Breedt, Nicola , Roberts, Michael J , Sauer, Warwick H H , Chang, N
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125183 , vital:35742 , https://doi.10.1111/fog.12132
- Description: The South African chokka squid, Loligo reynaudi, spawns both inshore (≤70 m) and on the mid-shelf (71–130 m) of the Eastern Agulhas Bank. The fate of these deep-spawned hatchlings and their potential contribution to recruitment is as yet unknown. Lagrangian ROMS-IBM (Regional Ocean Modelling System-Individual-Based Model) simulations confirm westward transport of inshore and deep-spawned hatchlings, but also indicate that the potential exists for paralarvae hatched on the Eastern Agulhas Bank deep spawning grounds to be removed from the shelf ecosystem. Using a ROMS-IBM, this study determined the transport and recruitment success of deepspawned hatchlings relative to inshore-hatched paralarvae. A total of 12 release sites were incorporated into the model, six inshore and six deep-spawning sites. Paralarval survival was estimated based on timely transport to nursery grounds, adequate retention within the nursery grounds and retention on the Agulhas Bank shelf. Paralarval transport and survival were dependent on both spawning location and time of hatching. Results suggest the importance of the south coast as a nursery area for inshore-hatched paralarvae, and similarly the cold ridge nursery grounds for deep-hatched paralarvae. Possible relationships between periods of highest recruitment success and spawning peaks were identified for both spawning habitats. Based on the likely autumn increase in deep spawning off the Tsitsikamma coast, and the beneficial currents during this period (as indicated by the model results) it can be concluded that deep spawning may at times contribute significantly to recruitment.
- Full Text:
- Date Issued: 2016
Peer tutors as learning and teaching partners: a cumulative approach to building peer tutoring capacity in higher education
- Authors: Clarence, Sherran
- Date: 2016
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/61335 , vital:28016 , http://cristal.epubs.ac.za/index.php/cristal/article/view/69
- Description: Peer tutors in higher education are frequently given vital teaching and learning work to do, but the training or professional development and support opportunities they are offered vary, and more often than not peer tutors are under-supported. In order to create and sustain teaching and learning environments that are better able to facilitate students’ engagement with knowledge and learning, the role of peer tutors needs to be recognised differently, as that of learning and teaching partners to both lecturers and students. Tutors then need to be offered opportunities for more in-depth professional academic development in order to fully realise this role. This paper explores a tutor development programme within a South African writing centre that aimed at offering tutors such ongoing and cumulative opportunities for learning and growth using a balanced approach, which included scholarly research and practice-based training. Using narrative data tutors provided in reflective written reports, the paper explores the kinds of development in tutors’ thinking and action that are possible when training and development is theoretically informed, coherent, and oriented towards improving practice.
- Full Text:
- Date Issued: 2016
- Authors: Clarence, Sherran
- Date: 2016
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/61335 , vital:28016 , http://cristal.epubs.ac.za/index.php/cristal/article/view/69
- Description: Peer tutors in higher education are frequently given vital teaching and learning work to do, but the training or professional development and support opportunities they are offered vary, and more often than not peer tutors are under-supported. In order to create and sustain teaching and learning environments that are better able to facilitate students’ engagement with knowledge and learning, the role of peer tutors needs to be recognised differently, as that of learning and teaching partners to both lecturers and students. Tutors then need to be offered opportunities for more in-depth professional academic development in order to fully realise this role. This paper explores a tutor development programme within a South African writing centre that aimed at offering tutors such ongoing and cumulative opportunities for learning and growth using a balanced approach, which included scholarly research and practice-based training. Using narrative data tutors provided in reflective written reports, the paper explores the kinds of development in tutors’ thinking and action that are possible when training and development is theoretically informed, coherent, and oriented towards improving practice.
- Full Text:
- Date Issued: 2016
“Not the story you wanted to hear": reading chick-lit in JM Coetzee’s Summertime
- Moonsamy, Nedine, Spencer, Lynda G
- Authors: Moonsamy, Nedine , Spencer, Lynda G
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/138915 , vital:37685 , https://doi.org/10.1080/02533952.2017.1390878
- Description: J.M. Coetzee’s Summertime has been widely explored – both for its controversy and merits – as engaging in “acts of genre” where the inscription of an autobiographical narrative simultaneously serves as a metatextual and ideological critique of its form. Similarly, this article is intrigued by generic instability, but our terrain lies further afield, exploring how the narrative lapses from the lofty ideals of romance to the baser “truth” of chick-lit. In Summertime, all the female characters besmirch Mr. Vincent, the biographer, for wanting to cast John Coetzee in the role of a romantic hero. Yet, their resistance results in a series of romantic failures which then situates Summertime in the generic ambit of chick-lit. In embodying a spirit that is as playful as it is critical, we suggest that Coetzee offers an opportunity to cast aside a literary critical tradition of suspicion and, in doing so, passes critical comment on how we approach a popular genre like chick-lit.
- Full Text:
- Date Issued: 2017
- Authors: Moonsamy, Nedine , Spencer, Lynda G
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/138915 , vital:37685 , https://doi.org/10.1080/02533952.2017.1390878
- Description: J.M. Coetzee’s Summertime has been widely explored – both for its controversy and merits – as engaging in “acts of genre” where the inscription of an autobiographical narrative simultaneously serves as a metatextual and ideological critique of its form. Similarly, this article is intrigued by generic instability, but our terrain lies further afield, exploring how the narrative lapses from the lofty ideals of romance to the baser “truth” of chick-lit. In Summertime, all the female characters besmirch Mr. Vincent, the biographer, for wanting to cast John Coetzee in the role of a romantic hero. Yet, their resistance results in a series of romantic failures which then situates Summertime in the generic ambit of chick-lit. In embodying a spirit that is as playful as it is critical, we suggest that Coetzee offers an opportunity to cast aside a literary critical tradition of suspicion and, in doing so, passes critical comment on how we approach a popular genre like chick-lit.
- Full Text:
- Date Issued: 2017
New Unity Movement Bulletin
- Date: 1993-07
- Subjects: Government, Resistance to -- South Africa , South Africa -- History -- 20th century , South Africa -- Politics and government
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10948/31230 , vital:31341 , Box File 7
- Description: The Bulletin was the official newsletter of the New Unity Movement. It was published about twice a year and contained articles reflecting the organisation's views on resistance to the Apartheid government.
- Full Text: false
- Date Issued: 1993-07
- Date: 1993-07
- Subjects: Government, Resistance to -- South Africa , South Africa -- History -- 20th century , South Africa -- Politics and government
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10948/31230 , vital:31341 , Box File 7
- Description: The Bulletin was the official newsletter of the New Unity Movement. It was published about twice a year and contained articles reflecting the organisation's views on resistance to the Apartheid government.
- Full Text: false
- Date Issued: 1993-07
Nature and source of suspended particulate matter and detritus along an austral temperate river–estuary continuum, assessed using stable isotope analysis
- Dalu, Tatenda, Richoux, Nicole B, Froneman, P William
- Authors: Dalu, Tatenda , Richoux, Nicole B , Froneman, P William
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68012 , vital:29181 , https://doi.org/10.1007/s10750-015-2480-1
- Description: Publisher version , Ecologists are interested in the factors that control, and the variability in, the contributions of different sources to mixed organic materials travelling through lotic systems. We hypothesized that the source matter fuelling mixed organic pools in a river–estuary continuum varies over space and time. Samples of the mixed organic pools were collected along a small temperate river (Kowie River) in southern Africa during early and late spring, summer and winter. The C:N ratios of suspended particulate matter (SPM) collected during summer and winter indicated that the lower reaches of the system had similar organic matter contributions. Stable isotope analysis in R revealed that aquatic macrophytes were significant contributors to SPM in the upper reaches. Bulk detritus had large allochthonous matter components in the lower reaches, and contributions of aquatic macrophytes and benthic algae were high (>50%) in the upper to middle reaches. The evaluation of organic matter contributions to SPM and detritus along the river–estuary continuum provided a baseline assessment of the nature and sources of potential food for consumers inhabiting different locations during different seasons. Incorporating SPM and detritus spatio-temporal variations in food web studies will improve our understanding of carbon flow in aquatic systems.
- Full Text: false
- Date Issued: 2016
- Authors: Dalu, Tatenda , Richoux, Nicole B , Froneman, P William
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68012 , vital:29181 , https://doi.org/10.1007/s10750-015-2480-1
- Description: Publisher version , Ecologists are interested in the factors that control, and the variability in, the contributions of different sources to mixed organic materials travelling through lotic systems. We hypothesized that the source matter fuelling mixed organic pools in a river–estuary continuum varies over space and time. Samples of the mixed organic pools were collected along a small temperate river (Kowie River) in southern Africa during early and late spring, summer and winter. The C:N ratios of suspended particulate matter (SPM) collected during summer and winter indicated that the lower reaches of the system had similar organic matter contributions. Stable isotope analysis in R revealed that aquatic macrophytes were significant contributors to SPM in the upper reaches. Bulk detritus had large allochthonous matter components in the lower reaches, and contributions of aquatic macrophytes and benthic algae were high (>50%) in the upper to middle reaches. The evaluation of organic matter contributions to SPM and detritus along the river–estuary continuum provided a baseline assessment of the nature and sources of potential food for consumers inhabiting different locations during different seasons. Incorporating SPM and detritus spatio-temporal variations in food web studies will improve our understanding of carbon flow in aquatic systems.
- Full Text: false
- Date Issued: 2016
Planning adaptation to climate change in fast-warming marine regions with seafood-dependent coastal communities
- Hobday, Alistair J, Cochrane, Kevern, Howard, James, Aswani, Shankar, Byfield, Val, Duggan, Greg, Duna, Elethu, Dutra, Leo X, Frusher, Stewart D, Fulton, Elizabeth A, Gammage, Louise, Gasalla, Maria A, Griffiths, Chevon, Guissamulo, Almeida, Haward, Marcus, Jarre, Astrid, Jennings, Sarah M, Jordan, Tia, Joyner, Jessica, Ramani, Narayana K, Shanmugasundaram, Swathi L P, Malherbe, Willem, Ortega-Cisneros, Kelly, Paytan, Adina, Pecl, Gretta T, Plagányi, Éva E, Popova, Ekaterina E, Razafindrainibe, Haja, Roberts, Michael, Rohit, Prathiba, Sainulabdeen, Shyam S, Sauer, Warwick H H, Valappil, Sathianandan T, Zacharia, Paryiappanal U, Van Putten, E Ingrid
- Authors: Hobday, Alistair J , Cochrane, Kevern , Howard, James , Aswani, Shankar , Byfield, Val , Duggan, Greg , Duna, Elethu , Dutra, Leo X , Frusher, Stewart D , Fulton, Elizabeth A , Gammage, Louise , Gasalla, Maria A , Griffiths, Chevon , Guissamulo, Almeida , Haward, Marcus , Jarre, Astrid , Jennings, Sarah M , Jordan, Tia , Joyner, Jessica , Ramani, Narayana K , Shanmugasundaram, Swathi L P , Malherbe, Willem , Ortega-Cisneros, Kelly , Paytan, Adina , Pecl, Gretta T , Plagányi, Éva E , Popova, Ekaterina E , Razafindrainibe, Haja , Roberts, Michael , Rohit, Prathiba , Sainulabdeen, Shyam S , Sauer, Warwick H H , Valappil, Sathianandan T , Zacharia, Paryiappanal U , Van Putten, E Ingrid
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125675 , vital:35806 , https://doi.10.1007/s11160-016-9419-0
- Description: Many coastal communities rely on living marine resources for livelihoods and food security. These resources are commonly under stress from overfishing, pollution, coastal development and habitat degradation. Climate change is an additional stressor beginning to impact coastal systems and communities, but may also lead to opportunities for some species and the people they sustain. We describe the research approach for a multi-country project, focused on the southern hemisphere, designed to contribute to improving fishing community adaptation efforts by characterizing, assessing and predicting the future of coastal-marine food resources, and codeveloping adaptation options through the provision and sharing of knowledge across fast-warming marine regions (i.e. marine ‘hotspots’). These hotspots represent natural laboratories for observing change and concomitant human adaptive responses, and for developing adaptation options and management strategies. Focusing on adaptation options and strategies for enhancing coastal resilience at the local level will contribute to capacity building and local empowerment in order to minimise negative outcomes and take advantage of opportunities arising from climate change. However, developing comparative approaches across regions that differ in political institutions, socio-economic community demographics, resource dependency and research capacity is challenging. Here, we describe physical, biological, social and governance tools to allow hotspot comparisons, and several methods to evaluate and enhance interactions within a multi-nation research team. Strong partnerships within and between the focal regions are critical to scientific and political support for development of effective approaches to reduce future vulnerability. Comparing these hotspot regions will enhance local adaptation responses and generate outcomes applicable to other regions.
- Full Text:
- Date Issued: 2016
- Authors: Hobday, Alistair J , Cochrane, Kevern , Howard, James , Aswani, Shankar , Byfield, Val , Duggan, Greg , Duna, Elethu , Dutra, Leo X , Frusher, Stewart D , Fulton, Elizabeth A , Gammage, Louise , Gasalla, Maria A , Griffiths, Chevon , Guissamulo, Almeida , Haward, Marcus , Jarre, Astrid , Jennings, Sarah M , Jordan, Tia , Joyner, Jessica , Ramani, Narayana K , Shanmugasundaram, Swathi L P , Malherbe, Willem , Ortega-Cisneros, Kelly , Paytan, Adina , Pecl, Gretta T , Plagányi, Éva E , Popova, Ekaterina E , Razafindrainibe, Haja , Roberts, Michael , Rohit, Prathiba , Sainulabdeen, Shyam S , Sauer, Warwick H H , Valappil, Sathianandan T , Zacharia, Paryiappanal U , Van Putten, E Ingrid
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125675 , vital:35806 , https://doi.10.1007/s11160-016-9419-0
- Description: Many coastal communities rely on living marine resources for livelihoods and food security. These resources are commonly under stress from overfishing, pollution, coastal development and habitat degradation. Climate change is an additional stressor beginning to impact coastal systems and communities, but may also lead to opportunities for some species and the people they sustain. We describe the research approach for a multi-country project, focused on the southern hemisphere, designed to contribute to improving fishing community adaptation efforts by characterizing, assessing and predicting the future of coastal-marine food resources, and codeveloping adaptation options through the provision and sharing of knowledge across fast-warming marine regions (i.e. marine ‘hotspots’). These hotspots represent natural laboratories for observing change and concomitant human adaptive responses, and for developing adaptation options and management strategies. Focusing on adaptation options and strategies for enhancing coastal resilience at the local level will contribute to capacity building and local empowerment in order to minimise negative outcomes and take advantage of opportunities arising from climate change. However, developing comparative approaches across regions that differ in political institutions, socio-economic community demographics, resource dependency and research capacity is challenging. Here, we describe physical, biological, social and governance tools to allow hotspot comparisons, and several methods to evaluate and enhance interactions within a multi-nation research team. Strong partnerships within and between the focal regions are critical to scientific and political support for development of effective approaches to reduce future vulnerability. Comparing these hotspot regions will enhance local adaptation responses and generate outcomes applicable to other regions.
- Full Text:
- Date Issued: 2016
The Educational Journal
- Date: 1992-02
- Subjects: Education –- South Africa , South Africa -- Politics and government , Government, Resistance to -- South Africa
- Language: English
- Type: text , Article
- Identifier: http://hdl.handle.net/10948/39512 , vital:35283 , Bulk File 7
- Description: The Educational Journal was the official organ of the Teachers' League of South Africa and focussed on education within the context of a racialized South Africa.
- Full Text: false
- Date Issued: 1992-02
- Date: 1992-02
- Subjects: Education –- South Africa , South Africa -- Politics and government , Government, Resistance to -- South Africa
- Language: English
- Type: text , Article
- Identifier: http://hdl.handle.net/10948/39512 , vital:35283 , Bulk File 7
- Description: The Educational Journal was the official organ of the Teachers' League of South Africa and focussed on education within the context of a racialized South Africa.
- Full Text: false
- Date Issued: 1992-02
Rhodes University Graduation Ceremony 1974
- Authors: Rhodes University
- Date: 1974
- Language: English
- Type: text
- Identifier: vital:8108 , http://hdl.handle.net/10962/d1004563
- Description: Rhodes University Graduation Ceremonies on Friday 5th April 1974 at 8 p.m. [and] on Saturday 6th April 1974 at 10:30 a.m. in the University Great Hall.
- Full Text:
- Date Issued: 1974
- Authors: Rhodes University
- Date: 1974
- Language: English
- Type: text
- Identifier: vital:8108 , http://hdl.handle.net/10962/d1004563
- Description: Rhodes University Graduation Ceremonies on Friday 5th April 1974 at 8 p.m. [and] on Saturday 6th April 1974 at 10:30 a.m. in the University Great Hall.
- Full Text:
- Date Issued: 1974
The recognition of unenumerated rights in South Africa
- Krüger, Rósaan, Govindjee, Avinash
- Authors: Krüger, Rósaan , Govindjee, Avinash
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/71093 , vital:29783 , https://hdl.handle.net/10520/EJC153177
- Description: In 1997 a South African man married a woman who, at the time of the conclusion of their marriage, was a national of a foreign country. The couple decided to set up home and start a family in South Africa. They were advised that the granting of a permanent residence permit to the wife would only be considered upon payment of a hefty application fee, and that she had to apply for the permit from outside South Africa. The couple was of the view that the high cost of the application coupled with their temporary separation at the time of the lodging of the application amounted to an unjustifiable limitation of their right to family life. One of the obstacles faced by the couple was the silence of the South Africa Constitution on the right to family life.
- Full Text: false
- Date Issued: 2012
- Authors: Krüger, Rósaan , Govindjee, Avinash
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/71093 , vital:29783 , https://hdl.handle.net/10520/EJC153177
- Description: In 1997 a South African man married a woman who, at the time of the conclusion of their marriage, was a national of a foreign country. The couple decided to set up home and start a family in South Africa. They were advised that the granting of a permanent residence permit to the wife would only be considered upon payment of a hefty application fee, and that she had to apply for the permit from outside South Africa. The couple was of the view that the high cost of the application coupled with their temporary separation at the time of the lodging of the application amounted to an unjustifiable limitation of their right to family life. One of the obstacles faced by the couple was the silence of the South Africa Constitution on the right to family life.
- Full Text: false
- Date Issued: 2012
From global to regional and back again: common climate stressors of marine ecosystems relevant for adaptation across five ocean warming hotspots
- Popova, Ekaterina, Yool, Andrew, Byfield, Valborg, Cochrane, Kevern, Coward, Andrew C, Salim, Shyam S, Gasalla, Maria A, Henson, S.A, Hobday, Alistair J, Pecl, Gretta T, Sauer, Warwick H H, Roberts, Michael J
- Authors: Popova, Ekaterina , Yool, Andrew , Byfield, Valborg , Cochrane, Kevern , Coward, Andrew C , Salim, Shyam S , Gasalla, Maria A , Henson, S.A , Hobday, Alistair J , Pecl, Gretta T , Sauer, Warwick H H , Roberts, Michael J
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124514 , vital:35623 , https://doi.10.1111/gcb.13247
- Description: Ocean warming ‘hotspots’ are regions characterized by above-average temperature increases over recent years, for which there are significant consequences for both living marine resources and the societies that depend on them. As such, they represent early warning systems for understanding the impacts of marine climate change, and test-beds for developing adaptation options for coping with those impacts. Here, we examine five hotspots off the coasts of eastern Australia, South Africa, Madagascar, India and Brazil. These particular hotspots have underpinned a large international partnership that is working towards improving community adaptation by characterizing, assessing and projecting the likely future of coastal-marine food resources through the provision and sharing of knowledge. To inform this effort, we employ a high-resolution global ocean model forced by Representative Concentration Pathway 8.5 and simulated to year 2099. In addition to the sea surface temperature, we analyse projected stratification, nutrient supply, primary production, anthropogenic CO2-driven ocean acidification, deoxygenation and ocean circulation. Our simulation finds that the temperature-defined hotspots studied here will continue to experience warming but, with the exception of eastern Australia, may not remain the fastest warming ocean areas over the next century as the strongest warming is projected to occur in the subpolar and polar areas of the Northern Hemisphere. Additionally, we find that recent rapid change in SST is not necessarily an indicator that these areas are also hotspots of the other climatic stressors examined. However, a consistent facet of the hotspots studied here is that they are all strongly influenced by ocean circulation, which has already shown changes in the recent past and is projected to undergo further strong change into the future. In addition to the fast warming, change in local ocean circulation represents a distinct feature of present and future climate change impacting marine ecosystems in these areas.
- Full Text:
- Date Issued: 2016
- Authors: Popova, Ekaterina , Yool, Andrew , Byfield, Valborg , Cochrane, Kevern , Coward, Andrew C , Salim, Shyam S , Gasalla, Maria A , Henson, S.A , Hobday, Alistair J , Pecl, Gretta T , Sauer, Warwick H H , Roberts, Michael J
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124514 , vital:35623 , https://doi.10.1111/gcb.13247
- Description: Ocean warming ‘hotspots’ are regions characterized by above-average temperature increases over recent years, for which there are significant consequences for both living marine resources and the societies that depend on them. As such, they represent early warning systems for understanding the impacts of marine climate change, and test-beds for developing adaptation options for coping with those impacts. Here, we examine five hotspots off the coasts of eastern Australia, South Africa, Madagascar, India and Brazil. These particular hotspots have underpinned a large international partnership that is working towards improving community adaptation by characterizing, assessing and projecting the likely future of coastal-marine food resources through the provision and sharing of knowledge. To inform this effort, we employ a high-resolution global ocean model forced by Representative Concentration Pathway 8.5 and simulated to year 2099. In addition to the sea surface temperature, we analyse projected stratification, nutrient supply, primary production, anthropogenic CO2-driven ocean acidification, deoxygenation and ocean circulation. Our simulation finds that the temperature-defined hotspots studied here will continue to experience warming but, with the exception of eastern Australia, may not remain the fastest warming ocean areas over the next century as the strongest warming is projected to occur in the subpolar and polar areas of the Northern Hemisphere. Additionally, we find that recent rapid change in SST is not necessarily an indicator that these areas are also hotspots of the other climatic stressors examined. However, a consistent facet of the hotspots studied here is that they are all strongly influenced by ocean circulation, which has already shown changes in the recent past and is projected to undergo further strong change into the future. In addition to the fast warming, change in local ocean circulation represents a distinct feature of present and future climate change impacting marine ecosystems in these areas.
- Full Text:
- Date Issued: 2016
Conceptualising knowledge for access in the sciences: academic development from a social realist perspective
- Authors: Ellery, Karen
- Date: 2017
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/59863 , vital:27671 , https://doi.org/10.1007/s10734-016-0085-x
- Description: Whilst arguing from a social realist perspective that knowledge matters in academic development (AD) curricula, this paper addresses the question of what knowledge types and practices are necessary for enabling epistemological access. It presents a single, in-depth, qualitative case study in which the curriculum of a science AD course is characterised using Legitimation Code Theory (LCT). Analysis of the course curriculum reveals legitimation of four main categories of knowledge types along a continuum of stronger to weaker epistemic relations: disciplinary knowledge, scientific literacies knowledge, general academic practices knowledge and everyday knowledge. These categories are ‘mapped’ onto an LCT(Semantics)(how meaning relates to both context and empirical referents) topological plane to reveal a curriculum that operates in three distinct but interrelated spaces by facing towards both the field of science and the practice of academia. It is argued that this empirically derived differentiated curriculum framework offers a conceptual means for considering the notion of access to ‘powerful’ knowledge in a range of AD and mainstream contexts.
- Full Text:
- Date Issued: 2017
- Authors: Ellery, Karen
- Date: 2017
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/59863 , vital:27671 , https://doi.org/10.1007/s10734-016-0085-x
- Description: Whilst arguing from a social realist perspective that knowledge matters in academic development (AD) curricula, this paper addresses the question of what knowledge types and practices are necessary for enabling epistemological access. It presents a single, in-depth, qualitative case study in which the curriculum of a science AD course is characterised using Legitimation Code Theory (LCT). Analysis of the course curriculum reveals legitimation of four main categories of knowledge types along a continuum of stronger to weaker epistemic relations: disciplinary knowledge, scientific literacies knowledge, general academic practices knowledge and everyday knowledge. These categories are ‘mapped’ onto an LCT(Semantics)(how meaning relates to both context and empirical referents) topological plane to reveal a curriculum that operates in three distinct but interrelated spaces by facing towards both the field of science and the practice of academia. It is argued that this empirically derived differentiated curriculum framework offers a conceptual means for considering the notion of access to ‘powerful’ knowledge in a range of AD and mainstream contexts.
- Full Text:
- Date Issued: 2017
Life history strategy and population characteristics of an unexploited riverine cyprinid, Labeo capensis, in the largest impoundment in the Orange River Basin
- Winker, A Henning, Weyl, Olaf L F, Booth, Anthony J, Ellender, Bruce R
- Authors: Winker, A Henning , Weyl, Olaf L F , Booth, Anthony J , Ellender, Bruce R
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124910 , vital:35709 , https://doi.10.3377/004.047.0124
- Description: Common carp (Cyprinus carpio) is one of the world’s most widely introduced and established freshwater fishes (Casal 2006). The species is considered to be one of the eight most invasive freshwater fishes (Lowe et al. 2000) and worldwide, it accounts for most of the records of successful establishments and adverse ecological effects (Casal 2006; Kulhanek et al. 2011). This invasive success suggests that feral C. carpio is equipped with a set of adaptable life history attributes that allow it to successfully colonise a wide range of habitats (Koehn 2004; Zambrano et al. 2006; Britton et al. 2007). Where feral C. carpio occurs in high densities, it is often perceived as an invasive pest species (Sivakumaran et al. 2003; Brown and Walker 2004; Koehn 2004) because it can have severe impacts on habitat heterogeneity and biodiversity by increasing water turbidity through its bottom feeding behaviour, increasing nutrient availability, decreasing benthic and macrophyte density and diversity, altering zooplankton assemblages and decreasing endemic fish abundance (Zambrano et al. 2001; Khan 2003; Kulhanek et al. 2011). Within south-east Australia, for example, C. carpio comprises the largest proportion of the ichthyobiomass in the continent’s largest river system – the Murray–Darling Basin (Gehrke et al. 1995). As a consequence, serious concerns about its threat to endemic freshwater species (Koehn 2004) have prompted several of the most recent investigations into its life history (e.g. Sivakumaran et al. 2003; Smith and Walker 2004; Brown et al. 2005). Other potential threats posed also include competition with indigenous species and the spread of diseases and parasites (Dudgeon et al. 2006). In South Africa, for example, Asian tapeworm Bothriocephalus acheilognathi is now widely distributed in seven river systems and has infected eight novel cyprinid hosts due to the translocation of infected by C. carpio from a centralized aquaculture facility (Stadtlander et al. 2011).
- Full Text:
- Date Issued: 2012
- Authors: Winker, A Henning , Weyl, Olaf L F , Booth, Anthony J , Ellender, Bruce R
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124910 , vital:35709 , https://doi.10.3377/004.047.0124
- Description: Common carp (Cyprinus carpio) is one of the world’s most widely introduced and established freshwater fishes (Casal 2006). The species is considered to be one of the eight most invasive freshwater fishes (Lowe et al. 2000) and worldwide, it accounts for most of the records of successful establishments and adverse ecological effects (Casal 2006; Kulhanek et al. 2011). This invasive success suggests that feral C. carpio is equipped with a set of adaptable life history attributes that allow it to successfully colonise a wide range of habitats (Koehn 2004; Zambrano et al. 2006; Britton et al. 2007). Where feral C. carpio occurs in high densities, it is often perceived as an invasive pest species (Sivakumaran et al. 2003; Brown and Walker 2004; Koehn 2004) because it can have severe impacts on habitat heterogeneity and biodiversity by increasing water turbidity through its bottom feeding behaviour, increasing nutrient availability, decreasing benthic and macrophyte density and diversity, altering zooplankton assemblages and decreasing endemic fish abundance (Zambrano et al. 2001; Khan 2003; Kulhanek et al. 2011). Within south-east Australia, for example, C. carpio comprises the largest proportion of the ichthyobiomass in the continent’s largest river system – the Murray–Darling Basin (Gehrke et al. 1995). As a consequence, serious concerns about its threat to endemic freshwater species (Koehn 2004) have prompted several of the most recent investigations into its life history (e.g. Sivakumaran et al. 2003; Smith and Walker 2004; Brown et al. 2005). Other potential threats posed also include competition with indigenous species and the spread of diseases and parasites (Dudgeon et al. 2006). In South Africa, for example, Asian tapeworm Bothriocephalus acheilognathi is now widely distributed in seven river systems and has infected eight novel cyprinid hosts due to the translocation of infected by C. carpio from a centralized aquaculture facility (Stadtlander et al. 2011).
- Full Text:
- Date Issued: 2012
Enigmatic trace fossils from the Aeolian lower Jurassic Clarens formation, Southern Africa
- Authors: Bordy, Emese M
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6730 , http://hdl.handle.net/10962/d1007538
- Description: The Lower Jurassic aeolienites of the Clarens Formation in southern Africa contain unique sedimentary structures that are unlikely to be non-biogenic. They are also unlike any known modern or ancient trace fossils. Here, some nigmatic, horizontal,regularly-oriented sedimentary structures are described, which occur in association with other trace fossils as well as features that were previously nterpreted as nests of termites or termite-like ancient social nsects. These spectacular structures are exposed in enormous profusion as straight, ~5 mm cylinders with strong compass orientation, in parallel alignment with one another and to ancient horizontal bedding planes. Their fill is identical to that of the host rock: clean, well-sorted, very fine- to finegrained quartz-arenite. In cross-section, each structure is defined by a subtle, ~0.1 mm thin, concentric gap. Without comparable modern biogenic structures, the biological origin of the structures is uncertain. Their strong compass orientations are, however, also inconsistent with an inorganic origin, even though they may resemble pipey concretions generated by flowing groundwater. Nonetheless, this paper, based on spatiotemporal distribution patterns of the oriented structures, their locally high abundance and association with obvious trace fossils, as well as other sedimentological and palaeontological lines of evidence, argues that the compass structures may be products of ancient social invertebrates living in a resource-limited, semi-arid to arid environment. Furthermore, the compass structures as well as the accompanying structures of the predominantly aeolian Clarens Formation collectively imply the recurrence of favourable ecological parameters (e.g., moist ubstrates) related to episodic climate fluctuations in the Early Jurassic of southern Pangaea (i.e., southern Gondwana).
- Full Text:
- Date Issued: 2008
- Authors: Bordy, Emese M
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6730 , http://hdl.handle.net/10962/d1007538
- Description: The Lower Jurassic aeolienites of the Clarens Formation in southern Africa contain unique sedimentary structures that are unlikely to be non-biogenic. They are also unlike any known modern or ancient trace fossils. Here, some nigmatic, horizontal,regularly-oriented sedimentary structures are described, which occur in association with other trace fossils as well as features that were previously nterpreted as nests of termites or termite-like ancient social nsects. These spectacular structures are exposed in enormous profusion as straight, ~5 mm cylinders with strong compass orientation, in parallel alignment with one another and to ancient horizontal bedding planes. Their fill is identical to that of the host rock: clean, well-sorted, very fine- to finegrained quartz-arenite. In cross-section, each structure is defined by a subtle, ~0.1 mm thin, concentric gap. Without comparable modern biogenic structures, the biological origin of the structures is uncertain. Their strong compass orientations are, however, also inconsistent with an inorganic origin, even though they may resemble pipey concretions generated by flowing groundwater. Nonetheless, this paper, based on spatiotemporal distribution patterns of the oriented structures, their locally high abundance and association with obvious trace fossils, as well as other sedimentological and palaeontological lines of evidence, argues that the compass structures may be products of ancient social invertebrates living in a resource-limited, semi-arid to arid environment. Furthermore, the compass structures as well as the accompanying structures of the predominantly aeolian Clarens Formation collectively imply the recurrence of favourable ecological parameters (e.g., moist ubstrates) related to episodic climate fluctuations in the Early Jurassic of southern Pangaea (i.e., southern Gondwana).
- Full Text:
- Date Issued: 2008
The relationship between Accounting 1 and Accounting 3 results
- Mazwi, Zukile, Stack, Elizabeth M
- Authors: Mazwi, Zukile , Stack, Elizabeth M
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: Conference paper
- Identifier: vital:6064 , http://hdl.handle.net/10962/d1004609
- Full Text:
- Date Issued: 2006
- Authors: Mazwi, Zukile , Stack, Elizabeth M
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: Conference paper
- Identifier: vital:6064 , http://hdl.handle.net/10962/d1004609
- Full Text:
- Date Issued: 2006
Synthesis, structure and in vitro anti-trypanosomal activity of non-toxic Arylpyrrole-Based Chalcone derivatives:
- Zulu, Ayanda I, Oderinlo, Ogunyemi O, Kruger, Cuan, Isaacs, Michelle, Hoppe, Heinrich C, Smith, Vincent J, Veale, Clinton G L, Khanye, Setshaba D
- Authors: Zulu, Ayanda I , Oderinlo, Ogunyemi O , Kruger, Cuan , Isaacs, Michelle , Hoppe, Heinrich C , Smith, Vincent J , Veale, Clinton G L , Khanye, Setshaba D
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/179017 , vital:40096 , https://doi.org/10.3390/molecules25071668
- Description: With an intention of identifying chalcone derivatives exhibiting anti-protozoal activity, a cohort of relatively unexplored arylpyrrole-based chalcone derivatives were synthesized in moderate to good yields. The resultant compounds were evaluated in vitro for their potential activity against a cultured Trypanosoma brucei brucei 427 strain. Several compounds displayed mostly modest in vitro anti-trypanosomal activity with compounds 10e and 10h emerging as active candidates with IC50 values of 4.09 and 5.11 µM, respectively. More importantly, a concomitant assessment of their activity against a human cervix adenocarcinoma (HeLa) cell line revealed that these compounds are non-toxic.
- Full Text:
- Date Issued: 2020
- Authors: Zulu, Ayanda I , Oderinlo, Ogunyemi O , Kruger, Cuan , Isaacs, Michelle , Hoppe, Heinrich C , Smith, Vincent J , Veale, Clinton G L , Khanye, Setshaba D
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/179017 , vital:40096 , https://doi.org/10.3390/molecules25071668
- Description: With an intention of identifying chalcone derivatives exhibiting anti-protozoal activity, a cohort of relatively unexplored arylpyrrole-based chalcone derivatives were synthesized in moderate to good yields. The resultant compounds were evaluated in vitro for their potential activity against a cultured Trypanosoma brucei brucei 427 strain. Several compounds displayed mostly modest in vitro anti-trypanosomal activity with compounds 10e and 10h emerging as active candidates with IC50 values of 4.09 and 5.11 µM, respectively. More importantly, a concomitant assessment of their activity against a human cervix adenocarcinoma (HeLa) cell line revealed that these compounds are non-toxic.
- Full Text:
- Date Issued: 2020
Sedimentary facies and geomorphic evolution of a blocked‐valley lake: Lake Futululu, northern Kwazulu‐Natal, South Africa
- Grenfell, Suzanne E, Ellery, William F N, Grenfell, Michael C, Ramsay, Lisa F, Flügel, Tyrel J
- Authors: Grenfell, Suzanne E , Ellery, William F N , Grenfell, Michael C , Ramsay, Lisa F , Flügel, Tyrel J
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/126826 , vital:35928 , https://doi.10.1111/j.1365-3091.2009.01141.x
- Description: Blocked-valley lakes are formed when tributaries are impounded by the relatively rapid aggradation of a large river and its floodplain. These features are common in the landscape, and have been identified in the floodplains of the Solimo˜es-Amazon (Brazil) and Fly-Strickland Rivers (Papua New Guinea), for example, but their inaccessibility has resulted in studies being limited to remotely sensed image analysis. This paper documents the sedimentology and geomorphic evolution of a blocked-valley lake, Lake Futululu on the Mfolozi River floodplain margin, in South Africa, while also offering a context for the formation of lakes and wetlands at tributary junctions. The study combines aerial photography, elevation data from orthophotographs and field survey, and longitudinal sedimentology determined from a series of cores, which were sub-sampled for organic content and particle size analysis. Radiocarbon dating was used to gauge the rate and timing of peat accumulation. Results indicate that following the last glacial maximum, rising sea-levels caused aggradation of the Mfolozi River floodplain. By 3980 years bp, aggradation on the floodplain had impounded the Futululu drainage line, creating conditions suitable for peat formation, which has since occurred at a constant average rate of 0Æ13 cm year)1. Continued aggradation on the Mfolozi River floodplain has raised the base level of the Futululu drainage line, resulting in a series of backstepping sedimentary facies with fluvially derived sand and silt episodically prograding over lacustrine peat deposits. Blocked-valley lakes form where the trunk river has a much larger sediment load and catchment than the tributary stream. Similarly, when the relative difference in sediment loads is less, palustrine wetlands, rather than lakes, may be the result. In contrast, where tributaries drain a steep, well-connected catchment, they may impound much larger trunk rivers, creating lakes or wetlands upstream.
- Full Text:
- Date Issued: 2010
- Authors: Grenfell, Suzanne E , Ellery, William F N , Grenfell, Michael C , Ramsay, Lisa F , Flügel, Tyrel J
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/126826 , vital:35928 , https://doi.10.1111/j.1365-3091.2009.01141.x
- Description: Blocked-valley lakes are formed when tributaries are impounded by the relatively rapid aggradation of a large river and its floodplain. These features are common in the landscape, and have been identified in the floodplains of the Solimo˜es-Amazon (Brazil) and Fly-Strickland Rivers (Papua New Guinea), for example, but their inaccessibility has resulted in studies being limited to remotely sensed image analysis. This paper documents the sedimentology and geomorphic evolution of a blocked-valley lake, Lake Futululu on the Mfolozi River floodplain margin, in South Africa, while also offering a context for the formation of lakes and wetlands at tributary junctions. The study combines aerial photography, elevation data from orthophotographs and field survey, and longitudinal sedimentology determined from a series of cores, which were sub-sampled for organic content and particle size analysis. Radiocarbon dating was used to gauge the rate and timing of peat accumulation. Results indicate that following the last glacial maximum, rising sea-levels caused aggradation of the Mfolozi River floodplain. By 3980 years bp, aggradation on the floodplain had impounded the Futululu drainage line, creating conditions suitable for peat formation, which has since occurred at a constant average rate of 0Æ13 cm year)1. Continued aggradation on the Mfolozi River floodplain has raised the base level of the Futululu drainage line, resulting in a series of backstepping sedimentary facies with fluvially derived sand and silt episodically prograding over lacustrine peat deposits. Blocked-valley lakes form where the trunk river has a much larger sediment load and catchment than the tributary stream. Similarly, when the relative difference in sediment loads is less, palustrine wetlands, rather than lakes, may be the result. In contrast, where tributaries drain a steep, well-connected catchment, they may impound much larger trunk rivers, creating lakes or wetlands upstream.
- Full Text:
- Date Issued: 2010