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Evolution of the Taieri River catchment, East Otago, New Zealand
journal contribution
posted on 2023-05-18, 19:36 authored by Craw, D, Craw, L, Christopher BurridgeChristopher Burridge, Wallis, GP, Waters, JMThis paper synthesises geological and biological data to develop an evolutionary history for the Taieri River that currently follows a circuitous 200 km course as one of the main drainages in Otago. The ancestral Taieri River drained only coastal hills initiated in the Miocene, and much of what is now the upper Taieri catchment flowed into the ancestral Clutha River. Major river reorientation events occurred in the upper half of the catchment because of rise of antiformal fold mountains in the Pleistocene, forming a new divide between the Taieri and Clutha catchments. Coeval incision of a gorge through a volcanic rock barrier connected the upper catchment to the lower Taieri River. The sparse Pleistocene sedimentary record documents these drainage changes via contrasting distribution of distinctive clasts derived from greywacke mountains on the northern edge of the Otago Schist belt. These major capture events are also supported by distributions and genetic divergences of freshwater galaxiid fish species. Erosion during Pleistocene rise of the antiformal mountains caused recycling of placer gold into Clutha tributaries before the Taieri River evolved to its present geometry, thereby limiting the placer gold content of the modern Taieri catchment.
History
Publication title
New Zealand Journal of Geology and GeophysicsVolume
59Pagination
257-273ISSN
0028-8306Department/School
School of Natural SciencesPublisher
Taylor & Francis Asia PacificPlace of publication
Wellington, New ZealandRights statement
Copyright 2016 The Royal Society of New ZealandRepository Status
- Restricted