Research Activities
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Introduction
2004 yeilded the following important results
SHRIMP SI funded
In the 2004 ARC LIEF round, we were successful in obtaining support for the SHRIMP SI, an ion microprobe that will be dedicated to stable isotope analysis of geological materials. SHRIMP SI was supported by contributions from Universities of Curtin University, University of Melbourne , Queensland University, University of Wollongong , Geoscience Australia , CSIRO Exploration and Mining, and Australian Scientific Instruments.
SHRIMP II Multiple Collector developments
We continue to make good progress of the multiple collector and a stable isotope analysis capability on SHRIMP II. The multiple collector is now used routinely in the search for 4 billion year-old zircons and developments in stable isotope analysis will aid us in the design of SHRIMP SI.
Solar Wind Oxygen-Isotope Composition
One of the outstanding parameters in cosmochemistry is an oxygen isotope measurement of the Sun. Oxygen shows a wide variation in enrichments of 16O with proposed solar compositions at the extreme ends of the array (close to terrestrial or enriched in 16O by 6%). We have measured metal grains from the Moon that have been implanted with solar wind. The composition measured in these grains is different from anything previously measured and is depleted in 16O relative to the terrestrial composition. It appears likely that the oxygen isotope variations in the solar system are inherited from the molecular cloud and star-forming region.
PSI White Conference
In February, an international group of scientists came to Canberra to celebrate the birth of the Planetary Science Institute (PSI), a collaboration between RSES and RSAA. Held under the auspices of the Australian Academy of Sciences White Conferences , the theme of the conference was “Planetary timescales: from stardust to continents. The meeting was opened by the Science Minister Mr Peter McGauran and included public lectures.
Key directions for 2005
Development of SHRIMP SI from a concept to detailed design drawings.
Integrating research between RSES and RSAA PSI members.
Research Activities
Toothpaste & Tibet: deformation, anatexis and doming in the eastern Tethyan Himalaya A.B. Aikman
Direct geochemical evidence for a very early (>3.85 billion year old) oxidised terrestrial mantle Vickie Bennett, Allen Nutman and Marc Norman
Age constraints and tectonic implications from detrital zircon U-Pb geochronology of early Palaeoproterozoic sediments of the Tanami Basin. Andrew Cross
Dating of Australian arid landforms using cosmogenic 21 Ne surface exposure dating. T. Fujioka, J. Chappell, M. Honda, I. Yatsevich, K. Fifield and D. Fabel
A primordial solar-neon enriched component in the source of EM1-type ocean island basalts from the Pitcairn Seamounts, Polynesia. M. Honda and J.D. Woodhead 1
Field Distributions of Homogeneous Magnetic Sectors. Ben Jenkins
The oxygen isotopic composition of the Sun. Trevor Ireland, Peter Holden, Marc Norman, Jodi Clarke
Dating of Archaean amphibolite facies gold mineralisation in West Greenland – using metamorphic zircons coexisting with gold-bearing arsenopyrite. Allen P. Nutman, Ole Christiansen and Clark R.L. Friend.
An Igneous Application For In-situ Strontium Isotopic Laser Ablation. Amanda Stoltze, Ian Campbell, Wolfgang Muller, Malcom McCulloch