Refined depositional history and dating of the Tongaporutuan reference section, north Taranaki, New Zealand: new volcanic ash U-Pb zircon ages, biostratigraphy and sedimentation rates

New Zealand Journal of Geology and Geophysics
By: , and 

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Abstract

This study presents new radiometric ages from volcanic ash beds within a c. 1900 m thick, progradational, deep-water clastic slope succession of late Miocene age exposed along the north Taranaki coast of the North Island, New Zealand. The ash beds yield U–Pb zircon ages ranging from 10.63 ± 0.65 Ma to 8.97 ± 0.22 Ma. The new ages are compatible with and provide corroboration of New Zealand Tongaporutuan Stage planktic foraminiferal and bolboformid biostratigraphic events identified in the same section. The close accord between these two age datasets provides a stratigraphically consistent and coherent basis for examining margin evolution. The arrival of a prograding clastic wedge and ensuing upward shoaling is recorded by sedimentation rates c. 2000 m/Ma–1 that are an order of magnitude higher than sedimentation rates on the precursor deep basin floor. This outcrop study provides new constraints for interpreting analogous subsurface deposits in Taranaki Basin and complements the regional late Miocene biostratigraphic dating framework.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Refined depositional history and dating of the Tongaporutuan reference section, north Taranaki, New Zealand: new volcanic ash U-Pb zircon ages, biostratigraphy and sedimentation rates
Series title New Zealand Journal of Geology and Geophysics
DOI 10.1080/00288306.2015.1132744
Volume 59
Issue 2
Year Published 2016
Language English
Publisher Taylor & Francis
Contributing office(s) Pacific Coastal and Marine Science Center
Description 17 p.
First page 313
Last page 329
Country New Zealand
Other Geospatial Taranaki
Online Only (Y/N) N
Additional Online Files (Y/N) N