SA-NT Technical Night

Title: Three-dimensional seismic imaging of shallow crustal volcanic plumbing systems

Presenter: Simon Holford
When: Wednesday, June 13th, 2018
Time: Drinks and food from 5:30 pm, presentation from 6:15 pm

Cost: Members: free, Non-members $10, Students: free
Where: Coopers Alehouse, 316 Pulteney St, Adelaide.

Abstract:

Developing a clear understanding of the movement of magma through Earth’s crust, where it is temporarily stored, to the surface where it erupts, is a grand challenge in the Earth Sciences. Detailed knowledge of the geometry and connectivity of the conduits and reservoirs (e.g. subsurface sheet intrusions such as sills, laccoliths and dykes) that form sub-volcanic plumbing systems (VPSs) is critical to understanding a range of fundamental, interdisciplinary research problems including continental breakup and the thermomechanical state of the mantle, the physiochemical evolution of magma and the forecasting of volcanic eruption dynamics. Addressing these problems is challenging because active VPSs are generally inaccessible. VPSs are traditionally viewed as comprising vertically stacked magma reservoirs linked by dykes, such that eruption sites of directly overlie the sources of melt generation in the upper mantle or lower crust. This presentation will show how the application of three-dimensional (3D) seismic reflection technology to permit the study of ancient, buried VPSs offshore Scotland and in the Great Australian Bight in unprecedented scale and detail, has challenged the traditional view of VPSs, suggesting that in certain cases, VPSs can be dominated by extensive, interconnected sill complexes that facilitate lateral upper crustal magma transport over distances of tens of km, in some cases leading to voluminous volcanic eruptions. It will also show how 3D seismic analysis of VPSs can help reduce exploration risk in energy-rich sedimentary basins.

Biography:

Simon Holford is an Associate Professor of Petroleum Geoscience at the Australian School of Petroleum. Prior to commencing an academic role at the University of Adelaide, Simon was an ARC Australian Postdoctoral Fellow. With Ros King, he jointly leads the Stress, Structure and Seismic Research Group. Simon has published over 80 papers on various aspects of sedimentary basin tectonics and petroleum geoscience. He is a past president of the SA/NT branch of the Petroleum Exploration Society of Australia.