Alloway, Brent V. et al. (2003): Offshore-onshore correlation of Pleistocene rhyolitic eruptions from New Zealand; implications for TVZ eruptive history and paleoenvironmental construction
Leg/Site/Hole:
Related Expeditions:
ODP 181
Identifier:
ID:
2007-026872
Type:
georefid
Creator:
Name:
Alloway, Brent V.
Affiliation:
Institute of Geology and Nuclear Sciences, Wairakei Research Centre, Taupo, New Zealand
Role:
author
Name:
Carter, Lionel
Affiliation:
National Institute of Water and Atmospheric Research, New Zealand
Role:
author
Name:
Westgate, John
Affiliation:
University of Toronto, Canada
Role:
author
Name:
Pillans, Brad
Affiliation:
Australian National University, Australia
Role:
author
Name:
Naish, Tim
Affiliation:
Role:
author
Identification:
Title:
Offshore-onshore correlation of Pleistocene rhyolitic eruptions from New Zealand; implications for TVZ eruptive history and paleoenvironmental construction
Year:
2003
Source:
In: Anonymous, XVI INQUA congress; shaping the Earth, a Quaternary perspective
Publisher:
[International Union for Quaternary Research], International
Volume:
16
Issue:
Pages:
204-205
Abstract:
Deep-sea cores retrieved from Ocean Drilling Program sites 1123 and 1124, located east of New Zealand, have provided an unpreceded 12 m.y. record of major rhyolitic eruptions from the Coromandel (CVZ) and Taupo Volcanic Zones (TVZ). A total of 197 macroscopic tephras have been dated by a combination of magnetostratigraphy, orbitally tuned stable-isotope data and isothermal plateau fission track ages. The widespread occurrence of ash offshore to the east of New Zealand is favoured by the small size of New Zealand, the explosivity of the mainly plinian and ignimbritic eruptions and vigorous prevailing westerly winds. In cores 1124 and 1123, c. 100 tephra beds are recognised post-dating the Plio-Pleistocene boundary at 1.81 Ma. Though some tephras can be directly attributed to known TVZ eruptions, there are many more tephras represented with the ODP-cores that have yet to be recognised in near-source sequences. This can be attributed to proximal source area erosion and/or deep burial as well as the adverse effect of vapour phase alteration and devitrification within near-source welded ignimbrites. Despite these difficulties, a number of key deep-sea tephras can be reliably correlated to equivalent-aged tephra exposed in uplifted marine back arc successions of Wanganui Basin where an excellent chronology also exists based on magnetostratigraphy, orbitally tuned stable-isotope data and isothermal plateau fission track ages. Significant Pleistocene tephra markers include: Kawakawa, Rangitawa, Onepuhi, Kupe, Kaukatea, Potaka, Ridge, Pakihikura, Birdgrove, Ototoka, Table Flat and Vinegar Hill Tephras. The identification of these Pleistocene TVZ-sourced tephras within the ODP-cores, and their correlation to Wanganui Basin is a significant advance for two reasons. Firstly, it provides an even higher-resolution history of the TVZ than can be currently achieved from the near-source record and secondly, it yields a detailed and reliable tephrochronologic framework essential for future paleoenvironmental reconstructions.
Language:
English
Genre:
Rights:
URL:
Coverage: Geographic coordinates: North:-39.2954 West:-176.3154 East:
-171.2956 South:-41.4710
Keywords: Quaternary geology; Igneous and metamorphic petrology; Australasia; back-arc basins; basins; Cenozoic; cores; Coromandel Peninsula; Coromandel volcanic zone; eruptions; fission-track dating; geochronology; igneous rocks; ignimbrite; Leg 181; magnetostratigraphy; marker beds; Miocene; Neogene; New Zealand; North Island; Ocean Drilling Program; ODP Site 1123; ODP Site 1124; offshore; onshore; paleoenvironment; paleogeography; Pleistocene; plinian-type eruptions; pyroclastics; Quaternary; reconstruction; relative age; rhyolites; rhyolitic composition; stratigraphic units; Taupo volcanic zone; tephrochronology; Tertiary; volcanic ash; volcanic rocks; volcanism; Wanganui Basin;
.