A Geochemical Comparison of Southern African Stromatolites and Stromatolite Pools
- Authors: Dodd, Carla
- Date: 2020
- Subjects: Stromatolites
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/48235 , vital:40527
- Description: Microbialite accretion takes place via either mineral precipitation, the trapping and binding of mineral and sediment grains, or a combination of the two. Recently, the geochemistry of carbonate deposits, including microbialites, has been used to reconstruct palaeoenvironments and infer biogenicity. Numerous modern stromatolite (layered microbialites) systems are located on the southern African coastline and are formed predominantly by mineral precipitation with minor detrital input. In order to better understand the environmental and biological processes influencing the formation of microbialites, the geochemistry of southern African coastalstromatolites is examined. This is done by a spatial comparison of the hydrochemistry as well as the major and trace element geochemistry of various coastal stromatolite systems. The influence of the underlying geology on the composition of the stromatolites forms a particular focus of the study. In addition, the effect of metazoans on the micro-fabrics and sediment incorporation into the stromatolite matrix is assessed. Finally, the trace element geochemistry of active, inactive, and ancient stromatolites is compared with a speleothem sample in order to test the validity of using trace elements as a means to determine biogenicity of deposition. Results show that the bulk geochemistry of the South African stromatolites is not a simple function of the associated bedrock lithologies, although certain parallels do exist. It was found that metazoans indirectly influence sediment incorporation by increasing porosity and thereby accommodation space for detrital input. Furthermore, trace element signatures could not be directly attributed to microbial influence in the deposition of the carbonates. Ultimately, this study provides valuable insights into the formation processes of the active South African stromatolites and the use of trace elements as a geochemical tool to investigate the evolution of life and determine past environmental conditions.
- Full Text:
- Date Issued: 2020
A case study: the role of a positive school climate in the enhancement of parental and community involvement at a primary school in Port Elizabeth
- Authors: Cloete, Jacqueline
- Date: 2015
- Subjects: Education -- Parent participation , Community and school , Home and school
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10948/8735 , vital:26425
- Description: This study examines the phenomenon of parental and community involvement in a primary school and the benefits thereof to the learners, teachers and community members. The aim of this study is to investigate how a positive school climate can improve the involvement of parents and community members in a school’s activities. The research attempted to determine what the role of a positive school climate is; the strategies schools could apply to enhance parental and community involvement, the possible benefits of involvement and reasons for non-involvement of parents and community members in school activities. The theoretical frameworks of Urie Bronfenbrenner’s ecological model and Joyce Epstein’s overlapping spheres of influence were used in the study. A case study was used as the qualitative research methodology. The data for the research was gathered from a purposive sample of teachers, community volunteer workers, parents and the principal. Semi-structured interview schedules and pre-designed questionnaires including open and closed questions, were used to collect data. The data was analysed inductively by using a descriptive open coding method to identify emerging themes. The findings of the research suggest that a positive school climate to improve parent and community involvement can be created by applying the strategies of effective communication, good working relationships, creating opportunities for involvement, ensuring a healthy and safe environment, formulating a school policy for parent and community involvement, creating a friendly and welcoming atmosphere as well as upholding an ethos of good moral values. The study found that parent and community involvement in a school’s activities offers various benefits to all stakeholders.
- Full Text:
- Date Issued: 2015