M.Sc. (Geology) / The south-easternmost Kaapvaal Craton is composed of scattered inliers of Archaean basement granitoid-greenstone terrane exposed through Phanerozoic cover successions. In addition, erosional remnants of the supracrustal Mesoarchaean Pongola Supergroup unconformably overlay this granitoid-greenstone terrane in the same inliers. Into this crust a variety of Precambrian intrusions occur. These are comprised of SE-, ENE- and NE-trending dolerite dykes. Also, the Hlagothi Complex intrudes into Pongola strata in the Nkandla region, particularly the quartzites of the basal Mantonga Formation. The whole area, including Phanerozoic strata, has in turn been intruded by Jurassic sills and dykes related to the Karoo Large Igneous Province. All the rocks of the Archaean inliers, with the exception of the Jurassic sills and dykes have been subjected to greenschist facies metamorphism and deformation, with petrographic, Ar-Ar geochronologic and palaeomagnetic studies attesting to this. This metamorphism and deformation is associated with the Mesoproterozoic orogeny from the nearby Namaqua-Natal Mobile Belt located to the south. This orogeny has a decreasing influence with distance from the cratonic margin, and is highly variable from locality to locality. However, it is generally upper greenschist facies up to a metamorphic isograd 50 km from the craton margin. Overprints directions seen within the palaeomagnetic data confirm directions associated with the post-Pongola granitoids across the region and the Namaqua-Natal Mobile Belt. The dolerite dykes consist of several trends and generations. Up to five different generations within the three Precambrian trends have potentially been recognised. SEtrending dykes represent the oldest dyke swarm in the area, being cross-cut by all the other dyke trends. These dykes consist of two possible generations with similar basaltic to basaltic andesite geochemistry. They provide evidence of a geochemically enriched or contaminated magma having been emplaced into the craton. This is similar to SE-trending dolerite dyke swarms across the Barberton-Badplaas region to the north from literature. In northern KwaZulu-Natal the SE-trending dolerite dyke swarms have been geochronologically, geochemically and paleomagnetically linked to either ca. 2.95 or ca. 2.87 Ga magmatic events across the Kaapvaal Craton. The 2866 ± 2 Ma Hlagothi Complex is composed of a series of layered sills intruding into Nkandla sub-basin quartzites of the Pongola Supergroup. The sills consist of meta-peridotite, pyroxenite and gabbro. At least two distinct pulses of magmatism have been recognised in the sills from their geochemistry. The distinct high-MgO units are compositionally different from the older Dominion Group and Nsuze Group volcanic rocks, as well as younger Ventersdorp volcanic rocks. This resurgence of high-MgO magmatism is similar to komatiitic lithologies seen in the Barberton Greenstone Belt. It is indicative of a more primitive magma source, such as one derived from a mantle plume. A mantle plume would also account for the Hlagothi Complex and the widespread distribution of magmatic events of possible temporal and spatial similarity across the craton. Examples include the layered Thole Complex, gabbroic phases of the ca. 2990 to 2870 Ma Usushwana Complex, and the 2874 ± 2 Ma SE-trending dykes of northern KwaZulu-Natal already described above and dated herein. A generation of NE-trending dolerite dykes in northern KwaZulu-Natal can also be palaeomagnetically linked to this event with either a primary or overprint direction. Flood basalts seen within the upper Witwatersrand and Pongola Supergroups (i.e., Crown, Bird, Tobolsk and Gabela lavas) may also be related. This large, voluminous extent of magmatism allows us to provide evidence for a new Large Igneous Province on the Kaapvaal Craton during the Mesoarchaean. This new Large Igneous Province would encompass all of the above mentioned geological units. It is possible that it could be generated by a shortlived transient mantle plume(s), in several distinct pulses. This plume would also explain the development of unconformities within the Mozaan Group. This is reasoned through thermal uplift from the plume leading to erosion of the underlying strata, culminating in the eruption of flood basalts coeval to the Hlagothi Complex. Marine incursion and sediment deposition would occur during thermal subsidence from the plume into the Witwatersrand-Mozaan basin. This magmatic event also assists in resolving the apparent polar wander path for the Kaapvaal Craton during the Meso- to Neoarchaean. Between existing poles established for the older ca. 2.95 Ga Nsuze event, to poles established for the younger ca. 2.65 Ga Ventersdorp event, a new magnetic component for this ca. 2.87 Ga magmatic event can be shown. This new component has a virtual geographic pole of 23.4° N, 53.4° E and a dp and dm of 8.2° and 11.8° for the Hlagothi Complex, with a similar magnetic direction seen in one generation of NE-trending dolerite dykes in the region. This new ca. 2870 Ma addition to the magmatic barcode of the Kaapvaal Craton allows for comparisons to be made to other coeval magmatic units on cratons from around the world. Specific examples include the Millindinna Complex and the Zebra Hills dykes on the Pilbara Craton. Precise age dating and palaeomagnetism on these magmatic units is needed to confirm a temporal and spatial link between all the events. If substantiated, this link would assist in further validating the existence of the Vaalbara supercraton during the Mesoarchaean. After the Hlagothi Complex event, different pulses of magma can be seen associated with the Neoarchaean Ventersdorp event. A generation of NE-trending dolerite dykes in the region was dated herein at 2652 ± 11 Ma. In addition, a primary Ventersdorp virtual geographic pole established in Lubnina et al. (2010) from ENE-trending dolerite dykes was confirmed in this study. This ENE-trending dolerite dyke has a virtual geographic pole of 31.7° S, 13.6° E and a dp and dm of 7.0° and 7.2°. This date and virtual geographic poles from NE- and ENE-trending dolerite dyke swarms in northern KwaZulu-Natal match up with NE- and E-trending palaeostress fields seen in the Neoarchaean Ventersdorp and proto- Transvaal volcanics by Olsson et al. (2010). Both generations of dolerite dykes also demonstrate variable geochemistry. The NE-trending dolerite dyke swarm is tholeiitic, and the ENE dolerite dyke swarm is calc-alkaline. In addition, some of the tholeiitic NE-trending dolerite dykes have a similar magnetic component to NE-trending dolerite dykes much further to the north in the Black Hills area according to Lubnina et al. (2010). This magnetic component is also similar to the Mazowe dolerite dyke swarm on the Zimbabwe Craton. The NE-trending dolerite dykes in the Black Hills area differ geochemically from those in northern KwaZulu-Natal though, but are also of ca. 1.90 Ga age. The Mazowe dolerite dyke swarm was linked to the dyke swarm of the Black Hills dyke swarm through palaeomagnetic studies. The Mazowe dolerite dyke swarm however is geochemically similar to the NE-trending dolerite dykes of northern KwaZulu-Natal, creating greater complexity in the relationship between the three dyke swarms. It is clear from the complex array of dolerite dyke swarms and other intrusions into these Archaean inliers of northern KwaZulu-Natal, that much more work on the dykes within the south-easternmost Kaapvaal Craton needs to be done. This will resolve these complex patterns and outstanding issues with regard to their palaeo-tectonic framework.