D.Litt. et Phil. / Very little has been written on this subject, especially during the exile period, which is covered by the research. As a result, a lacuna exists in our understanding of 20th century history of the liberation struggle in South Africa. This study is an attempt to reconstruct aspects of the missing link. It locates the exile history of the Pan Africanist Congress within a broader framework of political developments in Southern Africa. By so doing a wide canvas of factors essential to the colouring of this period are brought to the fore. The study therefore focuses on the internal conflicts in the PAC and how they impacted on the functioning of the organisation during the exile period. The thesis traces the events which led to the banning of the PAC and demonstrates how the organisation re-established itself in exile. Most importantly, it focuses on a critical period which existing scholarly works and even popular literature has overlooked, i.e. the period between 1960 to 1962. The thesis traces the re-formation of the PAC’s official infrastructure in Lesotho. It proceeds to examine the organisational developments and internal conflicts at the headquarters of the PAC in Tanzania from 1964 to 1990. It examines sources of conflict during various periods of leadership, i.e. from P.K. Leballo (1962 - 1979), Vusumzi Make period (1979-1981), Nyathi John Pokela (1981-1985) to Johnson Mlambo (1985-1990). In the last two chapters the thesis examines conditions inside PAC camps and the evolution of the PAC’s military strategy as sources of conflict. In all the chapters, the permeating theme is that the PAC lacked solid organisational foundations, which manifested in the lack of clear organisational policies respected by everyone, including the leadership of the organisation. The thesis concludes that the history of the PAC in exile is an example of how poor organisational structures can immobilize the progress of a liberation movement. / Prof. G. Verhoef

The Arabian–Nubian Shield (ANS) represents a major site of juvenile Neoproterozoic crustal addition on Earth and documents Neoproterozoic tectonics bracketed by two supercontinent cycles, namely the fragmentation of Rodinia and the amalgamation of Gondwana. There is general consensus that the ANS formed by juvenile magmatic arc accretion and subsequent shield–wide post–tectonic magmatism. However, detailed understanding about the timing of events and the nature of magma sources in parts of the shield are lacking. To date, there are no isotopic data from the Paleozoic sedimentary sequences of the ANS, except those from the northern part. New zircon U–Pb, δ18O and whole–rock Nd isotopes are presented for plutonic rocks from the eastern Ethiopia, Yemen and southernmost Arabian Shield in Saudi Arabia. This thesis also presents the first combined in situ zircon U–Pb–O–Hf isotope data on the Cambrian–Ordovician sandstones of the Arabian Shield. The results are used to elucidate the crustal evolution of these parts of the ANS and to evaluate terrane correlations. Specifically, the nature of crustal growth, i.e., relative proportions of juvenile magmatic additions vs. crustal reworking, nature of the magma source and mechanism of crust formation (plume material vs. subduction zone enrichment) and understanding the provenance of the Cambrian–Ordovician sandstone sequences were important research questions addressed. The results from Paper I suggest that the eastern Ethiopian Precambrian basement is dominated by reworking of pre-Neoproterozoic supracrustal material unlike contemporaneous rocks in the remaining parts of Ethiopia— indicating the presence of two distinct lithospheric blocks of contrasting isotopic compositions in Ethiopia. Metamorphic age distributions suggest that the eastern Ethiopian block was amalgamated with the juvenile Western Ethiopian Shield during ca. 580–550 Ma. Importantly, the suture between them may represent the northern continuation of a major suture identified further south in Africa along which Gondwana amalgamated. Similarly, the Abas terrane in Yemen (Paper II) is dominated by reworking of pre–Neoproterozoic crust and shows age and isotopic compositions that are inconsistent with the Afif terrane of Saudi Arabia, precluding correlation between the two regions. The trace element systematics of plutonic rocks from the southernmost Arabian Shield (paper III) point to enrichment due to subduction component, bear no evidence of a plume component, and are consistent with the adakite-like chemistry of some of the subduction–related plutonic samples. This reinforces the notion that the shield grew through juvenile magmatic arc additions. The combined zircon U–Pb–O–Hf data of the Cambrian–Ordovician sandstones (Paper IV) indicate their derivation from both the adjacent juvenile ANS and the more southerly crustal blocks that are dominated by reworking of pre–Neoproterozoic crust. The remarkable similarity in age spectra and homogeneity of Cambrian sandstones deposited across the northern margin of Gondwana point to continental–scale sediment mixing and dispersal regulated by the supercontinent cycle. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 3: Manuscript. Paper 4: Manuscript.</p>