Earthquake Seismology: Exploring the Continental Crust in Western Australia

Australian Institute of Geoscientists > Events > earthquake, lithosphere, orogenic terranes, Pilbara, seismology, Yilgarn > Earthquake Seismology: Exploring the Continental Crust in Western Australia

Earthquake Seismology: Exploring the Continental Crust in Western Australia


1 CPD HourThe Centre for Exploration Targeting (CET) is pleased to invite you to a Guest Lecture in the CET Seminar Series given by Macquarie University/CET-UWA/GSWA’s Dr Huaiyu Yuan

ABSTRACT

The Western Australian craton is composed of the Archean Pilbara and Yilgarn cratons and the surrounding Proterozoic orogens. Early seismic studies found that the Archean blocks are characterized as a signature type of simple crust and sharp crust-mantle transition, while the orogenic terranes have rather complex crustal structure and much diffused Moho, posing a question whether a possible change in the crustal forming processes occurred between Archean and Proterozoic. Using receiver function technique, we estimate the bulk thickness and the Vp/Vs ratio of the WA crust. Our findings show that systematic lateral variations in the bulk crustal properties correlate well with the cratonic sub-provinces, reinforcing the early proposal that individual sub-units had gained their unique seismic originality BEFORE the craton amalgamation. Along the Proterozoic orogens, thicker crust and weaker and possibly dipping Moho interfaces are observed, with indications of lower crustal magmatic underplating in some areas. As part of the SIEF “Distal Footprints of Giant Ore systems” Program, a 36-site 2D seismic array is currently in place in the Capricorn region which joined Pilbara and Yilgarn around ~1.8 Ga. The threeyear deployment will bring unprecedented resolution to uncover the crustal and lithospheric architecture and help to better understand the long and complex tectonic history of the Orogen.

ABOUT THE SPEAKER

Dr Yuan received his PhD in 2007 from the University of Wyoming, USA, and then worked at the Berkeley Seismological Laboratory, UC Berkeley as a post-doc and then an assistant researcher until joining the CCFS in April 2013. Dr. Yuan is a research associate at Macquarie University, but is stationed in Perth to collaborate closely with the Geological Survey of Western Australia and the Centre for Exploration Targeting UWA, engaged in lithosphericscale imaging of seismic structure in Western Australia using earthquake seismology. His current research focuses on imaging the lithosphere of the Western Australian craton. Other projects target continental structure at multiple scales: a global tomographic inversion for cratons lithosphere worldwide; a high-resolution tomographic model of Australia; and the crust and lithosphere structure beneath the Capricorn Orogen in WA.

Pay parking is available along Fairway (approx. $1.50 per hour).  You are invited to join CET staff and students afterwards for refreshments provided by the local SEG Student Charter in the Resource Room, Robert Street Building.