New Zealand Journal of Geology and Geophysics abstracts
Triassic radiolarians from the ocean-floor sequence of the Waipapa Terrane
at Arrow Rocks, Northland, New Zealand
Atsushi Takemura1
Yoshiaki Aita2
Rie S. Hori3
Yasushi Higuchi3
K. Bernhard Spörli4
Hamish J. Campbell5
Kazuto Kodama6
Toyosaburo Sakai2
1Geoscience Institute
Hyogo University of Teacher Education
Yashiro-cho, Kato-gun
Hyogo 673-1494, Japan,
email: takemura@sci.hyogo-u.ac.jp
2Department of Geology
Faculty of Agriculture
Utsunomiya University
Utsunomiya 321-8505, Japan
3Department of Earth Sciences
Faculty of Science
Ehime University
Matsuyama 790-8577, Japan
4Department of Geology
University of Auckland
Private Bag 92 019
Auckland, New Zealand
5Institute of Geological & Nuclear Sciences
P.O. Box 30 368
Lower Hutt, New Zealand
6Department of Geology
Faculty of Science
Kochi University
Kochi 780, Japan
Abstract Triassic radiolarians are reported from two
horizons in Waipapa Terrane at Arrow Rocks, Whangaroa area, Northland. This
relatively undisturbed succession represents an ocean-floor sequence, consisting
(in ascending order) of basalt with limestone layers, bedded chert, black
shale, and red, maroon and green siliceous mudstone. The age of the lower
part of the section is Middle-Late Permian. The radiolarian assemblages reported
here indicate Early or Middle Triassic and Middle Triassic (Anisian) ages
for maroon siliceous mudstones in the upper part of the section. Between
strata of known Permian and Triassic age there is a thin potential Permian/Triassic
boundary interval consisting of alternating black shale and grey chert. Radiolarian
paleogeography indicates that the Arrow Rocks sequence experienced long distance
plate tectonic displacement from a position of relatively low latitude in
the Middle Permian and to a high latitude in mid-Triassic time.
Keywords New Zealand; Waipapa Terrane; Northland;
Arrow Rocks; Radiolaria; Permian; Triassic; Permian/Triassic boundary; chert;
siliceous mudstone; ocean-floor sequence
G00071 Received 21 December 2000; accepted 29 April 2002; published 27
September 2002
New Zealand Journal of Geology & Geophysics, 2002, Vol. 45: 289-296
0028-8306/02/4503-0289 $7.00/0 © The Royal Society of New Zealand
2002
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