McIntyre, A.2025-08-122025-08-122023https://hdl.handle.net/2440/146730This item is only available electronically. Whole thesis (as available).The Lokhone Block metasedimentary belt in Turkana, NE Kenya, lies within an understudied region of the Mozambique Belt on the margin of the Congo-Tanzania craton. Phase equilibria modelling indicates that this high-grade belt comprising intercalated pelitic metasediments and calc-silicate rocks underwent peak granulite-facies metamorphism at pressures of 8.4– 10.6 kbar and temperatures of 750–830°C. Peak metamorphic conditions have been directly dated by Lu – Hf isotopic analysis of garnet (625 ± 7 Ma and 621 ± 5 Ma), and by U – Pb isotopic analysis of metamorphic titanite (604 ± 8 Ma and 622 ± 16 Ma) and metamorphic zircon rims (612 ± 14 Ma). This is coeval with high-grade metamorphism recorded throughout the Mozambique Belt associated with the formation of the East African Orogen during the Neoproterozoic amalgamation of Gondwana. P-T conditions indicate a moderate geothermal gradient of 78 – 98°C/kbar (17-30°C/km), consistent with metamorphism during crustal thickening. U – Pb apatite geochronology yields ages between ca. 540 and ca. 560 Ma, interpreted as post-peak cooling after metamorphism. These data suggest slow cooling of 2.5 - 9.5°C/Myr, consistent with slow exhumation over several tens of million years. U – Pb dating of detrital zircons suggest that at the time of formation, the Lokhone region was not connected to any pre-Neoproterozoic terrane. These findings highlight the complexity of the processes shaping the East African Orogen and provide important constraints with which to improve plate tectonic reconstructions for the Neoproterozoic Earth.enHonoursGeologyKenyageochronologyP–T modellingorogenesisEast African OrogenGondwanapseudosectionhigh-grade metamorphismThesis