50thKaikoura05 -1- Kaikoura 2005 CHARACTERISATION OF NEW ...
50thKaikoura05 -1- Kaikoura 2005 CHARACTERISATION OF NEW ...
50thKaikoura05 -1- Kaikoura 2005 CHARACTERISATION OF NEW ...
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myrtaceous. One 20 mm diameter flower,<br />
Fouldenia staminosa Bannister, D.E.Lee and Raine,<br />
<strong>2005</strong>, was preserved complete with anthers from<br />
which excellently preserved pollen was collected<br />
and preparations made for both light and electron<br />
microscopy. Identification of pollen and spores<br />
from the matrix on the same bedding plane as the<br />
flower produced a list of more than 55 pollen types,<br />
including new taxa (Bannister et al. <strong>2005</strong>).<br />
Angiosperm leaves are numerous; those collected<br />
from the layers of diatom frustules are better<br />
preserved than those from darker, more organic<br />
layers and we surmise that mucus from the vast<br />
numbers of diatoms has assisted in preservation of<br />
the leaf material. Some leaves have both upper and<br />
lower surface cuticles present and cuticle<br />
preparations for over 150 individual leaves<br />
representing several families and genera, some with<br />
close affinities to extant genera, have been made.<br />
The leaves appear to be mainly from forest trees<br />
and lianes with moderately thick cuticles; as yet no<br />
herbaceous leaves or examples of leaves with thin<br />
cuticles have been found. Leaf venation is not<br />
always visible but various methods for clearing<br />
leaves to expose venation, and methods of leaf<br />
preservation, have been developed. A database<br />
incorporating cuticular features and leaf<br />
architecture is being compiled together with a<br />
reference collection of cuticles from extant trees<br />
and lianes from both New Zealand and Australia.<br />
Bannister, J.M., Lee, D.E., & Raine, J.I. <strong>2005</strong>:<br />
Morphology and palaeoenvironmental context of<br />
Fouldenia staminosa, a fossil flower with associated<br />
pollen from the Early Miocene of Otago, New<br />
Zealand. New Zealand Journal of Botany 43: 515-525<br />
ORAL<br />
TECTONIC EVOLUTION <strong>OF</strong> THE SOUTH<br />
FIJI BASIN: UNCLOS HELPS TACKLE<br />
REGIONAL TECTONICS<br />
D. Barker 1 ,R.Herzer 1 ,N.Mortimer 2 ,W.Roest 3 ,<br />
A. Mauffret 4 & Y. Lafoy 5<br />
1 GNS Science, P.O. Box 30368, Lower Hutt, New<br />
Zealand<br />
2 GNS Science, Private Bag 1930, Dunedin, New<br />
Zealand<br />
3 IFREMER, Géosciences Marines, 29280<br />
Plouzané, BP 70, France<br />
4 Lab. Tectonique Univ. P. et M. Curie, 4 Place<br />
Jussieu, 75256 Paris Cedex, France<br />
5 ServicedelaGéologieetdesMines(SGM),<br />
DIMENC, Nouméa, New Caledonia<br />
(d.barker*gns.cri.nz)<br />
Marine surveys to study the evolution of remnant<br />
arcs and backarc basins north of New Zealand have<br />
been complemented by United Nations Convention<br />
on the Law of the Sea (UNCLOS) surveys by three<br />
countries – France, New Zealand and Australia –<br />
with potential extended continental shelf claims in<br />
the region. The UNCLOS factor allowed 9 cruises<br />
to focus on the region in the past 9 years, collecting<br />
approximately 30,000 km of seismic reflection<br />
(5,000 deep crustal), 263,700 sq km of swath<br />
bathymetry, and 70 dredge samples. Feedback<br />
through sharing or publishing data and joint<br />
participation allowed efficient planning and<br />
deployment of academic and UNCLOS cruises.<br />
Two models for South Fiji and Norfolk basin<br />
evolution arise from current studies: at the level of<br />
the Three Kings Ridge – Norfolk Basin – southern<br />
South Fiji Basin both involve Pacific trench rollback<br />
and southward propagating spreading, but one<br />
also uses two subduction systems and arc-continent<br />
collision. Linked spreading of the Norfolk Basin<br />
and South Fiji Basin is invoked in both models, but<br />
the veracity and geodynamics of the link are not<br />
investigated. A growing body of petrological and<br />
radiometric evidence and the tectonics of the New<br />
Zealand continental margin point to tandem Early<br />
Miocene spreading of the South Fiji Basin and<br />
Norfolk Basin despite published magnetic<br />
interpretations that would confine South Fiji Basin<br />
spreading to the Oligocene. The Franco-NZ<br />
NOUCAPLAC-1 cruise, the last cruise relevant to<br />
UNCLOS in this region, included a scientific<br />
objective to investigate the South Fiji Basin–<br />
Norfolk Basin link in the critical area bounded by<br />
the Loyalty Ridge, the Cook Fracture Zone, the<br />
Bounty spreading centre and the Julia Lineament<br />
with swath mapping, magnetics and seismic<br />
reflection. Initial results show a complex<br />
bathymetry where a possible link between the<br />
Bounty spreading centre and the Cook Fracture<br />
Zone involves ridge propagation, overlapping<br />
spreading centres, rift blocks and overprinting<br />
volcanoes. The link to the Julia Lineament was not<br />
adequately tested due to sparse coverage. Closer to<br />
the Loyalty Ridge, a thick, faulted sedimentary<br />
basin was found.<br />
POSTER<br />
INITIAL WAVEHEIGHT <strong>OF</strong> LANDSLIDE<br />
TRIGGERED TSUNAMIS: APPLICATION<br />
<strong>OF</strong> A SIMPLISTIC EMPIRICAL APPROACH<br />
P. Barnes & A. Pallentin<br />
National Institute of Water & Atmospheric<br />
Research, Private Bag 14901, Wellington.<br />
(a.pallentin*niwa.co.nz)<br />
The seafloor associated with New Zealand’s active<br />
margin is locally susceptible to slope failure. In<br />
areas of frequent large earthquakes, steep slopes,<br />
and high sediment load, submarine landslides are<br />
extremely common. Large failures, particularly in<br />
50 th <strong>Kaikoura</strong>05 -3- <strong>Kaikoura</strong> <strong>2005</strong>