Field Trip

A field trip to the Northern Leeuwin Complex is scheduled for the Wednesday, August 22. 2001.

All conference participants are invited and encouraged to attend. This is a good opportunity for theoreticians and field geologists to develop (some) common ways of thinking about geological processes.

Early spring / winter in South West WA is likely to be windy, wet, sunny and cool. Please bring appropriate clothing.

The Leeuwin Complex is a fragment of Proterozoic continental crust at the extreme southwestern tip of Australia. It is dominated by granitic rocks emplaced into the crust over a time period spanning some 500 million years, and variably deformed after their emplacement to produce a range of rocks that vary from highly-strained gneiss to relatively undeformed granite.

These rocks have a geological history that sets the Leeuwin Complex apart from all other Precambrian basement terranes in Australia and provides information on the Proterozoic evolution of Australia's westernmost margin. This margin has a punctuated history of tectonic activity that stretches back at least 1100 million years, and represents a fundamental crustal structure that has been repeatedly reactivated since it first formed.

This short trip will visit three localities along the 30 km of coastline between Cape Naturaliste (the northern tip of the Leeuwin Complex) and Moses Rock. We will see excellent examples of ductile deformation at mid crustal levels, corresponding to depths of about 20 km below the Earth's surface, focusing on some of the complexities apparent on a centimetre-to-metre scale and relating these features to regional-scale processes. The trip will also show how rocks of very similar appearance can actually record quite different histories and emphasize the difficulties associated with the interpretation of field relationships in highly deformed mid-crustal rocks. All three localities are within the Leeuwin-Naturaliste National Park and very close to many of the Margaret River vineyards, and we will have the opportunity to appreciate some spectacular coastal scenery and a selection of local wines.

Ian Fitzsimons, Exploration Geodynamics Fieldtrip Leader
Tectonics Special Research Centre
Department of Applied Geology
Curtin University of Technology
GPO Box U1987, Perth, WA 6845
AUSTRALIA
Phone (Direct line): +61 8 9266 2455
Phone (Dept Office): +61 8 9266 7968
Fax: +61 8 9266 3153
E-mail: ianf@lithos.curtin.edu.au