New Zealand Journal of Geology and Geophysics abstracts
New radiolarian age information for the Chrystalls Beach Complex, southwest of
Dunedin, New Zealand
MITSUMASA ITO
Division of Global Development Science
Graduate School of Science and Technology
Kobe University
Kobe 657-8501, Japan
YOSHIAKI AITA
Department of Geology
Faculty of Agriculture
Utsunomiya University
Utsunomiya 321-8505, Japan
SHIGEKI HADA
Research Institute for Higher Education
Kobe University
Kobe 657-8501, Japan
Abstract On the basis of lithology, structural style, and
fossil evidence, northern and southern units are recognised within the
Chrystalls Beach Complex exposed on the coast south of Akatore Creek, southwest
of Dunedin, South Island, New Zealand. Radiolarians including Spongopallium
sp. cf. S. contortum Dumitrica, Kozur & Mostler,
Eptingium(?) sp., Norispongus(?) sp., and
Pseudostylosphaera(?) sp. have been discovered in phosphatic nodules in
metamorphosed argillite of the northern unit of the complex. They are regarded
as characteristic species of the Middle Triassic (Anisian-Ladinian). It has
previously been known that the more weakly metamorphosed southern unit of the
Chrystalls Beach Complex contains moderately well preserved Middle Triassic
(Early Ladinian) radiolarian faunas. Together with forms of Tethyan affinity,
the faunas in the southern unit contain non-Tethyan forms including
Glomeropyle spp. Aita & Bragin, possibly of Southern Hemisphere
high-latitude origin. These non-Tethyan forms are also known from the Mahinepua
section of the Waipapa Terrane in Northland. Distinctive non-Tethyan forms such
as Glomeropyle Aita & Bragin have not yet been found in the northern
unit, the fauna of which includes species that are known from the European
Tethys area and which also occur in the southern unit.
Keywords Chrystalls Beach Complex; Middle Triassic;
radiolarians; Akatore Creek; Waipapa Terrane; Caples Terrane; Torlesse
Terrane
New Zealand Journal of Geology & Geophysics, 2000, Vol. 43:
349-354
0028-8306/00/4303-0349 $7.00/0 (c) The Royal Society of New Zealand
2000
PDF file of entire paper: medium quality (1282K); (scanned from paper original: notes about this process)
This year's abstracts |
Journal home page |
All abstracts |
Publishing home page
