Wed 29th September 2021 @ 12:00 nn in 312.222 and online via Webex (meeting #: 2518 636 1317 and password: wmSWYpYU324)

Abstract:

The presence of dinosaur footprints in the Early Cretaceous aged Broome Sandstone of northwestern Western Australia has been known for decades. Previous work has focussed on the discovery of sites, identification of species from the footprints and recording various forms of sedimentary deformation (dinoturbation). Prior global studies into dinoturbation deal with the identification of footprints, species recognition, and morphology, not their sedimentology. This talk reviews the extent and types of dinoturbation observed in the Broome Sandstone by the author as well as observations from engineering core behind outcrops and the key identification criteria of these features in petroleum core. Depositional settings and their relevance to preservation are also reviewed. Dinoturbation varies from individual footprints up to 1.4m in diameter to massive sauropod trackways, wallows and the total destruction of primary sedimentation over whole large outcrops. The sandstone substrate can be fluidised and mobilised to form broad synforms and tight antiforms that may be large enough to be identified on seismic. From this work a new lithofacies association SSDD (SandStone Deformed Dinoturbation) has been characterised and the key identification criteria have been determined to support more effective recognition of dinoturbation in the rock record, including the subsurface.

Short bio:

Robert worked as a petroleum geologist for over 40 years since graduating in geology.  He worked for BHP Petroleum, Oil Company of Australia, BMR (now GA), Santos,  as a consultant, Woodside Energy and has now retired into an Adjunct Professor role at Curtin University together with some consulting.  Robert has been a successful explorer and a development/production geologist. His expertise includes high resolution sequence stratigraphy, structure, hydrodynamics, appraisal co-ordination, and commercial.  For over 20 years Robert focussed on applying high resolution core based sedimentology and sequence stratigraphy to reservoir development and exploration as well as mentoring and improving outcomes for teams.  His current lines of research are into dinoturbation and the global tectonostratigraphy of the Triassic. He has run courses for AAPG, Nautilus, PESA and SPE, has published numerous papers, and presented and chaired at conferences.  He is a member of AAPG,  and PESA and has held executive and editorial positions.