The extrusive and intrusive members of the St. Helena rock suite (SHRS) are formed in an intra-oceanic plate tectonic setting as part of two shield volcanoes. The SHRS vary from picrobasalts to phonofites. The former represent mantle derived melts, whereas the remainder of the suite have undergone differing degrees of crystal fractionation. A stratigraphic framework is developed to illustrate temporal geochemical variations over 2 Ma of subaerial activity. This is accomplished in conjunction with a detailed field study of the SHRS by Baker(1968) which is shown to be largely accurate. It is demonstrated that ascending magma batches are substantially modified by crystal fractionation and subsequent alteration processes. Petrogenetic modelling shows that the genesis of the SHRS is consistent with small degree (1-10%) melting of an olivine - clinopyroxene - orthopyroxene - garnet source containing a residual K-rich phase. Combined Sr-Nd-Pb isotope and fractionation corrected trace element data for fresh rocks enable consideration of changing thermal and chemical fluxes impinging on and interacting with the base of the lithosphere over a period of at least 2 Ma. The existence of two geochemically distinct components in the source region is indicated. A H/MU (high 238U /104Pb)c omponent has extremely radiogenic Pb isotopes (206Pb/104Pb> 20.8) with 143Nd/'44Nd and 87S8r,6 Sr displaced below the mantle array. The complementary depleted component has less radio genic Pb and Sr isotopic compositions and more radio genic Nd compositions. The limited variation of geochemical compositions in the SHRS (caused by mixing of these components) is attributed to the dissimilarity of the components in terms of their trace element abundance and their similarity in terms of ratios of highly incompatible elements. Coupled trace element and isotope variations are evident during the activity of each volcano. During shield development an increase in incompatible trace element enrichment occurs. This is coupled to a decrease in 143Nd/'44Nd, whilst Sr and Pb become progressively more radiogenic. The time dependent variations are thought to be consistent with mixing and melting processes occurring at the base of, or within the lithosphere. A decrease in the signature of the depleted component at the end of activity of the NE volcano and SW volcano is the inferred result of a decreasing thermal flux acting on the base of the lithosphere. With lower heat input less fusion of the depleted component (from the asthenosphere or lithosphere) occurs resulting in an increased H/MU signature in the erupted products through time. Previous explanations for the development of the dominant HIMU component are critically reviewed by considering shared isotope and trace element characteristics for HIMU OIB. U-Th-Pb systematics suggest the HIMU component has remained discrete from other mantle components for approximately 2 Ga. The fractionation event producing the H/MU component is shown to cause an increase in U/Pb and a decrease in Rb/Sr and Th/U.. This is thought to be consistent with a model suggested by Hofmann and White(1980,1982). in which HIMU represents ancient recycled altered oceanic crust. It is demonstrated that other models are less tenable. It is thought that the HIMU characteristics necessitate modification of oceanic crust in subduction zones in addition to the geochemical changes caused by hydrothermal alteration of oceanic crust.

Thesis (M.A.)--Stellenbosch University, 1951. / ENGLISH ABSTRACT: no abstract available / AFRIKAANSE OPSOMMING: geen opsomming

Magister Artium - MA (History) / In the following two chapters I will attempt to offer a more systemic account of St. Helena immigration to South African between 1838 and 1948. To date, no such study has been undertaken, despite a vibrant oral tradition amongst the descendants of St. Helena immigrants celebrating their St. Helenian heritage and often, in peculiar fashion, romanticise their Island of provenance. The commencement date for my chosen timeframe emerges from a need to authenticate rather tenuous historical accounts of St. Helena’s first mass emigration for the Cape of Good Hope in 1838. Where cases of migration are discussed, these are either incidences of large-­scale 41, often aided, migration and settlement, or of those St. Helena migrant workers initially employed under temporary contacts to work in South Africa, specifically within burgeoning industrial sectors of the late-­nineteenth or early-­twentieth century South Africa.

Magister Artium - MA / For an Island measuring merely 128 square kilometers, and in spite of its remote location in the mid-­South Atlantic, St. Helena “punches way above its weight in history”, earning and occupying a privileged place in British scholarship of its imperial thalassocratic age. However, prior to this period in which the Island was indispensible to British Empire formation, it had passed through the hands of at least two former European naval nations before it was eventually laid claim to and effectively colonised by the British. The Portuguese, who were the first to stumble upon the uninhabited Island in 1502 -­ naming it St. Helena in honour of Roman Emperor Constantine the Great’s mother -­ managed to keep its existence a closely guarded secret for over eight years. For nearly a century, the Island was reserved for exclusive use by the Portuguese as a port for recuperation, replenishing and re-­provisioning, which they usually visited on their homebound journey from trading (and conquering) in the East Indies. This Portuguese monopoly of use of the Island, however, ended during the last decade of the sixteenth century when other maritime nations, particularly Dutch and later English traders, became aware of and started frequenting the Island. The initial overlap period, constituting the first three decades of the seventeenth century when mostly the Dutch and Portuguese shared use of the Island, was cause for occasional hostile encounters between the two nations. Apparently, continued Dutch and English harassment of Portuguese (and Spanish) ships made visiting the Island untenable for the Portuguese who opted to avoid St. Helena and instead make use of a number of their other port ‘possessions’ along the West African coastline to replenish and repair their ships.

St Helena Island in the South Atlantic Ocean has been changing for over a decade. The way the people on the Island respond to the change affects the way in which the Gospel is communicated, and this has missiological implications. This raises the question; what influence does change have on the way the Gospel is communicated? If people are resistant to social change, will they be open to change required by the Gospel? How will good intercultural skills help? To fully address the Island's response to change, one needs to look at the interplay of change, culture and communication. It also important to consider how these three elements can be monitored and managed by both the Saints and the clergy alike. This will become the basis for my proposal of focusing the intercultural communication of the Gospel on the ever-changing world of the youth. / Christian Spirit, Church History, Missiology / M.Th. (Missiology)

<p>The results of the multivariate analyses suggest that most of the variation in the composition of the samples was of an intra-sample nature, illustrating large scale patchiness in foraminiferal distribution. There were, however, definite differences between communities around Robben Island and in St Helena Bay, and least variation was found between the control and pipeline sites, and between the stations of each site. When the trace metal concentrations and the percentage nitrogen increased, the richness, diversity and abundance of foraminifera tended to decrease. Sediment grain size positively affected abundance but negatively affected diversity and richness. In both areas mean grain size did not, however, appear to play a very large role in influencing diversity. Cadmium, copper, chromium, the percentage nitrogen and the mean grain size were identified as the most important variables influencing the community structure by the BIOENV BEST routine in PRIMER. The trace metals and percentage nitrogen only had negative effects on the diversity and abundance as well as on the abundance of the dominant genera, whereas the mean grain size had variable effects.</p>

<p>The results of the multivariate analyses suggest that most of the variation in the composition of the samples was of an intra-sample nature, illustrating large scale patchiness in foraminiferal distribution. There were, however, definite differences between communities around Robben Island and in St Helena Bay, and least variation was found between the control and pipeline sites, and between the stations of each site. When the trace metal concentrations and the percentage nitrogen increased, the richness, diversity and abundance of foraminifera tended to decrease. Sediment grain size positively affected abundance but negatively affected diversity and richness. In both areas mean grain size did not, however, appear to play a very large role in influencing diversity. Cadmium, copper, chromium, the percentage nitrogen and the mean grain size were identified as the most important variables influencing the community structure by the BIOENV BEST routine in PRIMER. The trace metals and percentage nitrogen only had negative effects on the diversity and abundance as well as on the abundance of the dominant genera, whereas the mean grain size had variable effects.</p>

St Helena Island in the South Atlantic Ocean has been changing for over a decade. The way the people on the Island respond to the change affects the way in which the Gospel is communicated, and this has missiological implications. This raises the question; what influence does change have on the way the Gospel is communicated? If people are resistant to social change, will they be open to change required by the Gospel? How will good intercultural skills help? To fully address the Island's response to change, one needs to look at the interplay of change, culture and communication. It also important to consider how these three elements can be monitored and managed by both the Saints and the clergy alike. This will become the basis for my proposal of focusing the intercultural communication of the Gospel on the ever-changing world of the youth. / Christian Spirit, Church History, Missiology / M.Th. (Missiology)

Philosophiae Doctor - PhD / The results of the multivariate analyses suggest that most of the variation in the composition of the samples was of an intra-sample nature, illustrating large scale patchiness in foraminiferal distribution. There were, however, definite differences between communities around Robben Island and in St Helena Bay, and least variation was found between the control and pipeline sites, and between the stations of each site. When the trace metal concentrations and the percentage nitrogen increased, the richness, diversity and abundance of foraminifera tended to decrease. Sediment grain size positively affected abundance but negatively affected diversity and richness. In both areas mean grain size did not, however, appear to play a very large role in influencing diversity. Cadmium, copper, chromium, the percentage nitrogen and the mean grain size were identified as the most important variables influencing the community structure by the BIOENV BEST routine in PRIMER. The trace metals and percentage nitrogen only had negative effects on the diversity and abundance as well as on the abundance of the dominant genera, whereas the mean grain size had variable effects. / South Africa

This study performs a critical analysis of the representation of Afrikaner and British masculinity in the first season of the South African War (1899-1902) television series Arende (1989-1993). The study first identifies key concepts in both western identity and masculinity and then moves on to build an historical theoretical base from which season one is analysed. This theoretical base is created through the assimilation of historical sources dealing with masculinity and masculine events from both the Afrikaners and the British. In order to provide a suitable foundation for the investigation into masculinity, the study first briefly explores the concept of identity and how it manifests in both the Afrikaner and British society represented in the first season of Arende. This was done by using a psychological model designed by Roy F Baumeister (1986) which involves both individual and societal identity. Identity as a social construct is also investigated, and the question why identity matters in society is discussed Arguments for a structuralist semiotic approach to identity in a particular society are presented. In dealing with the overview of dominant western masculinity a number of key terms were identified and discussed. These include patriarchy, the female body and masculine control, social labelling, gender order and ‘women watching,’ the family unit, division of labour and public and private space, hegemonic masculinity and the male hero. After this overview, the study conducted an assimilation exercise into historic Afrikaner and British masculinity during the time before and after the South African War. This discussion centres on a number of points dealing with both societies, namely the model male, male military tradition, masculine rebels/outcasts and other masculine issues, and male relations with women. The final part of this study involves the analysis of the masculine theory, generated in the previous chapter, on the Arende text. This was done by selecting six characters from each of the two societies in season one and describing how they represent themselves in a masculine manner (or not). / Dissertation (MA)--University of Pretoria, 2013. / gm2014 / Visual Arts / unrestricted