AIG - ASEG - GSA - WOMEESA Victoria Joint Event

WOMEESA is proud to partner with ASEG, AIG, and GSA to present a fascinating talk by Ross Cayley (Senior Geologist, Geological Survey of Victoria):

A journey through the wealth of new geological stories revealed by the Southern Lachlan Crustal Transect across the Australian Alps - consequences of the 629 km long deep reflection seismic survey interpretation for mineral explorers

When: Tuesday 26 August, 6:15 pm

Where: Fritz Loewe Theatre, McCoy Building, University of Melbourne

Join us afterwards for casual drinks and snacks at The Clyde Hotel from 7:00 pm.

Please note: This is a members-only event. We look forward to welcoming our WOMEESA, ASEG, AIG, and GSA community!

Talk abstract: SLaCT (the Southern Lachlan Crustal Transect) is a series of east-west oriented deep seismic reflection surveys and other data acquisitions totalling 629km long conceived in 2012 as a collaboration between the GSV (principal $ funders), Geoscience Australia (funders in-kind, enabling and managing data acquisition and processing) and Auscope ($ funding) to (1) test key aspects of the newly-emerging Lachlan Orocline hypothesis and (2) to image the Tabberabbera, Omeo, Deddick, Kuark and Mallacoota zones and the Buchan Rift to depth, thus completing a transect of modern 2D deep seismic across the full width of the State. In 2016 the project was rescoped to bring in the NSW geological survey as technical collaborators and proportional $ funders, with the project transect location modified to cross into NSW near Bendoc-Delegate in order to image NSW geology between Delegate and Eden. As acquired, SLaCT extends from near Swanpool (Benalla) in NE Victoria to the coast near Eden in NSW in Ben Boyd Igneous Complex geology, imaging geology through the very heart of the Australian Alps. The first regional-scale deep reflection seismic transects acquired in central Victoria in 2006 introduced a new research philosophy to Australian acquisitions: imaging areas of greatest existing geological control (exposed bedrock with modern detailed geological mapping, supported by modern high-resolution potential field geophysics) to reduce ambiguity of seismic interpretations as much as possible and leverage / test existing understandings. We thought this approach should produce geological data and knowledge that could be extrapolated away from this single 'line of control' into adjacent less-well understood (often buried) geology, and would be more effective than single lines of seismic reflection acquired directly over the regions of buried poorly constrained geology. In the GSV's opinion this approach really delivered, and so was replicated in far western Victoria in 2009, and again for SLaCT in 2018. To say SLaCT has advanced understanding of eastern Victoria and SE NSW's well mapped geology and tectonics is an understatement. This talk will showcase some of the biggest results revealed by this spectacular data, with new insights for all the geological zones in eastern Victoria/NSW, and with implications that extend well beyond the western limits of the project to drive a complete reappraisal of Melbourne Zone evolution, including the origin and drivers for the formation of the Woods Point Dyke swarm and associated ~8m Oz Walhalla-Woods Point goldfield.

Ross Cayley has worked at the Geological Survey of Victoria for 35 years, principally as a field geologist specialising in structure and tectonics and structural geophysics and implications for mineral prospectivity. A long-term continental-scale research project has been the development of the Lachlan Orocline hypothesis, in collaborations with various other researchers.