Dates: 21/03 - 01/04 2022

Times: all day

Location: Parkville campus (University of Melbourne) and FIELD EXCURSION (Area of Port Campbell / Apollo Bay, Victoria)

Pre-Reading

Edwards J., Leonard J.G., Pettifer G.R. & McDonald P.A. 1996. Colac 1:250,000 Map Geological Report, Geological Survey of Victoria Report 98, 168 pages.

Tickell S.J., Edwards J. and Abele C. 1992. Port Campbell Embayment 1:100,000 Map Geological Report, Geological Survey of Victoria Report 95, 97 pages. 

SUBJECT OVERVIEW (to be changed for 2022)

This course is a 6-day field trip along the Otway Coast. The field excursion visits spectacular outcrops between Port Campbell and Anglesea and integrates the field geology with seismic, remote sensing, potential field, well, geochemistry and topographic data.  The aim is to teach geologists and geophysicists the skills needed to analyse the evolution, stratigraphy and structure of a basin and hence be able to assess its economic and resource potential in terms of hydrocarbons, gas-storage, minerals and water. Otway Basin gas exploration has recently been very successful offshore, with the Geographe, Thylacine, Minerva, Casino-Henry and Annie discoveries as well as several small onshore gasfields.

The sequence stratigraphy and depositional environments of outcrops are examined, with a focus on stratigraphic sections measured in the field. The outstanding geological structures observed are analysed to determine the nature and timing of events and their influence on deposition.  Each area utilises nearby seismic sections to illustrate key aspects of the structure, stratigraphy and basin evolution.  Potential field, remote sensing and topographic data are also studied to define regional structural and stratigraphic trends. Geochemical data (VR) help to assess relative amounts of uplift and denudation, particularly across faults.  The challenge for participants is to integrate all their observations into a comprehensive understanding of the evolution of this part of the Otway Basin and apply this to determine resource potential.

Attendees will learn and apply the following techniques in the field:-

  • Measuring stratigraphic sections and interpreting environment of deposition including; aeolian dunes, fluvial, lacustrine + coals, shallow and deep marine shale, limestone and sandstone, with condensed sequences.
  • Measuring structural sections and determining structural style in the basin
  • Relating field observations to seismic, well, geochemical, remote sensing and potential field data and topography
  • Analysing extension, inversion and compression structures with minor strike-slip
  • Determining 2D and 3D stratigraphic relationships and variations
  • Observing and predicting onlap onto variably deformed and eroded surfaces
  • Assessing source, reservoir and seal potential
  • Summarising the basin’s tectonic evolution and its relevance for resources.

NOTE THE TRIP INCLUDES SCRAMBLING DOWN AND UP SOME STEEP 100 METRE SLOPES TO THE BEACH (SEE PHOTOS IN SAFETY BRIEFING). PARTICIPANTS MUST BE FIT AND AGILE ENOUGH TO DO THIS.  THE TRIP LEADER RESERVES THE RIGHT TO REFUSE ACCESS TO SELECTED AREAS FOR ATTENDEES THAT MIGHT BE AT RISK.

Course assessment is based on stratigraphic and structural sections completed in the field and handed in on the day (50%) and on a post field trip assignment (50%) handed in ~2 weeks after the course.

Accommodation:-

Stay two nights of in Port Campbell and three nights at Apollo Bay, both in the Hostel in shared dormitories for 4-6 people.

COST

~$300-$500/ STUDENT FOR ACCOMMODATION AND TRANSPORT. 

Sunday – Day 1 9am Pick up from Earth Sciences, University of Melbourne, drive to Port Campbell stopping at interesting geological points en route. Examine seismic from the Colac Trough. See the upstream Pebble Point fluvial facies. Look at faults in the 12 Apostles area. Stay in Port Campbell. Buy food at supermarket for tomorrow’s meals. Dinner in the hostel.

Monday  - Day 2. Visit Point Margaret and Buckley’s Point, near Princetown, to look at the Pebble Point and Dilwyn Formation, including measuring a section. If time, see the 12 Apostles and Loch Ard Gorge. Head towards Peterborough to see coastal structure. Stay in Port Campbell. Dinner in the hostel.

Tuesday  - Day 3 Drive along the Old Coach Track to Above Dilwyn Bay in the bus. Climb down a very steep slope to Dilwyn Bay to see the inversion structure in the Eumeralla – Pebble Point. Return to bus and drive to the Gable for structural view, then on to Johanna Beach for a discussion of the structure wrt an offshore seismic line. Drive to Apollo Bay and stay at Apollo Bay in hostel. Dinner in the hostel.

Wednesday - Day 4 Drive to Johanna Beach and walk along beach to Browns Creek. Measure a stratigraphic section in the Eocene-Oligocene carbonates. Visit Cape Otway Lighthouse in afternoon to see regional structure and discuss magnetics and thermochronology data. Stay at Apollo Bay in hostel. Dinner in the hostel.

Thursday – Day 5 Castle Cove structural transect, including constructing a structural cross section and working out the evolution. Marengo Eumeralla outcrops showing rare quartzose sediments in the Eumeralla and dinosaur footprints? Stay at Apollo Bay in hostel. Dinner in the hostel.

Friday – Day 6 Beacon Point and Skenes Creek road to see Eumeralla structure and stratigraphy, compared to the foreshore at Apollo Bay (east). Cumberland River. Airey’s Inlet to see limestone on Oligocene volcanics at Split Point. Coal mine Creek and Anglesea coal mine for Eocene environment of deposition. Drive to Earth Sciences at the University of Melbourne and aim to be there by 5 pm.

Teacher: Kevin Hill

https://www.findanexpert.unimelb.edu.au/profile/12884-kevin-hill