Journal article
Reconnaissance Basement Geology and Tectonics of South Zealandia
AJ Tulloch, N Mortimer, TR Ireland, TE Waight, R Maas, JM Palin, T Sahoo, H Seebeck, MW Sagar, A Barrier, RE Turnbull
Tectonics | AMER GEOPHYSICAL UNION | Published : 2019
DOI: 10.1029/2018TC005116
Abstract
We report new U-Pb zircon ages, geochemical and isotopic data for Mesozoic igneous rocks, and new seismic interpretations of mostly submerged South Zealandia (1.5 Mkm 2 ). We use these data, along with existing geological and geophysical data sets, to refine the extent and nature of geological units. Our new 1:25 M geological map of South Zealandia provides a regional framework to investigate the rifting and breakup that formed Zealandia, Earth's most submerged continent. Samples of prerift (pre-100 Ma) plutonic rocks can be matched with on-land New Zealand igneous suites and indicate an east-west strike for the subduction-related 260 to 105-Ma Median Batholith across the Campbell Plateau. T..
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Funding Acknowledgements
We thank Hamish Campbell, Moses Turnbull, James Scott, New Zealand Oceanographic Institute (now NIWA), and Randall McDonnell for help in obtaining samples. Technical and analytical assistance was provided by Nick Walker (TIMS geochronology), Dave Parkinson (radiogenic isotopes), John Simes (rock crushing and mineral separations), Belinda Smith Lyttle (mineral separations and graphics), Steve Tulloch (photomacrographs), and Jenny Black (magnetic data sets). We thank Fred Davey, Karsten Gohl, Bryan Davy, Christine Siddoway, and Donna Eberhart-Phillips for discussion and comments. Keith Klepeis provided a reconnaissance structural analysis of Bounty Island and discussion of Paparoa core complex development. Journal reviewers Quinten van der Meer and Fausto Ferraccioli are thanked for comments that significantly improved the manuscript. Christine Siddoway generously provided analyses of granite samples from the Colbeck Trough. The work was supported by Core Research Funding to GNS Science by the New Zealand Government Ministry of Business, Employment and Innovation. More context for data reported here may be found in the Petlab database: https://pet.gns.cri.nz/pet/.