Evolution of the Intra-Arc Taupo-Reporoa Basin Within the Taupo Volcanic Zone of New Zealand
Evolution of the intra-arc Taupo-Reporoa Basin within the Taupo Volcanic Zone of New Zealand D.T. Downs1,*, J.V. Rowland1, C.J.N. Wilson2, M.D. Rosenberg3, G.S. Leonard4, and A.T. Calvert5 1School of Environment, University of Auckland, Private Bag 92019, Auckland 1142, New Zealand 2School of Geography, Environment, and Earth Sciences, Victoria University, PO Box 600, Wellington 6140, New Zealand 3GNS Science, Private Bag 2000, Taupo 3352, New Zealand 4GNS Science, PO Box 30368, Lower Hutt 5040, New Zealand 5U.S. Geological Survey, Volcano Science Center, 345 Middlefi eld Road, Menlo Park, California 94025, USA ABSTRACT 58 ± 26 k.y. of Paeroa Subgroup emplace- of eruptions can provide readily datable and ment, but in two stages. The northern Paeroa identifi able time horizons that allow for high The spatial and temporal distributions block underwent uplift and associated tilting resolution (e.g., 10 to 100 k.y.) interpretation of volcaniclastic deposits in arc-related fi rst, followed by the southern Paeroa block. of a basin’s evolution (e.g., Houghton et al., basins refl ect a complex interplay between Elevations (>500 m above sea level) of lacus- 1995; Smith et al., 2008). However, these same tectonic, volcanic, and magmatic processes trine sediments within the southern Paeroa rates of volcanic production, in combination that is typically diffi cult to unravel. We take block are consistent with elevations of rhyo- with varying vent locations, positions of avail- advantage of comprehensive geothermal drill lite lavas in the Ongaroto Gorge, the outlet to able accommodation space, and extreme post- hole stratigraphic records within the Taupo- the paleolake in which these sediments were eruptive sedimentation rates, generally result in Reporoa Basin (TRB), and integrate them deposited, and indicate that the Paeroa block rapid lateral facies changes and burial of strata, with new 40Ar/39Ar age determinations, exist- has remained relatively stable since develop- greatly complicating the stratigraphic architec- ing age data, and new mapping to develop a ment.
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