2 NEW ZEALAND Figure Simplified present day on land geology of New Zealand The black lines are faults Many of the lakes and valleys of the South Island are the result of Quaternary glacial erosion G, locations of Devonian to Jurassic Gondwanan sequences; Ã, locations of Cretaceous metamorphic core complexes the terranes and batholiths (Figure 4) Figure shows the names, age ranges, and mutual geometric relationships of the constituent basement units on an Early Cretaceous reconstruction (Figure 3A) No Precambrian rocks are exposed; New Zealand has been near a continent–ocean margin throughout the Phanerozoic Western Province Terranes The Western Province terranes lie west of the Median Batholith and comprise the Early Palaeozoic Buller and Takaka terranes The Buller Terrane consists of variably metamorphosed siliciclastic sandstones and mudstones, of continental Gondwanan provenance, and is the westernmost recognized terrane in New Zealand (i.e the terrane closest to the Gondwanan cratonic core) Rare fossils are of Ordovician age, but a Buller Terrane paragneiss contains detrital zircons as old as 3400 Ma (Archean; New Zealand’s oldest known geological material) Intercalated volcanics are absent The Takaka Terrane consists of siliciclastic, carbonate, and volcanic rocks Middle Cambrian trilobites in the Takaka Terrane are New Zealand’s oldest known fossils The Takaka Terrane is generally well stratified and lithologically diverse, and includes Cambrian ultramafics and boninites, Ordovician limestones, and Silurian orthoquartzites The Buller and Takaka Terranes were accreted to Gondwana by the Devonian Eastern Province Terranes The Eastern Province terranes lie east of the Median Batholith and comprise the Brook Street, Murihiku,