Specialist Group in Tectonics and Structural Geology
2026 Meeting
9-13 November 2026
Email: SGTSG2026@gmail.com
Mid-conference field trip
Ross Cayley & Alanis Olesch-Byrne
This full-day field trip will introduce delegates to a series of exceptional field localities across central Victoria, highlighting Ordovician deep-marine turbidites, chevron fold and limb thrust architecture, structurally controlled quartz reefs of the Bendigo goldfield, the deeply weathered granite landscape of the Pink Cliffs, and granite carapace textures near Malmsbury.
The excursion will depart from the Ballarat Goods Shed at 7:30 am and return by approximately 5:00 pm. Travel will be by coach. Clive Willman will join us as local expert at the Bendigo and Heathcote sites.
Please note that the itinerary has changed from the one originally advertised. Unprecedented filling of Lake Eppalock has drowned the glacial pavements and spillway exposures, so these sites have been replaced. A detailed guide to the Victoria Hill site is available online (link below) and delegates are encouraged to download it to their phones before the day.
Proposed itinerary
7:30 am – Depart Ballarat Goods Shed
Delegates will travel northeast from Ballarat towards Bendigo, via Daylesford, Malmsbury and the surrounding central Victorian goldfields landscape.
SITE 1
9:00 am – 11:00 am | Site 1 and morning tea: Victoria Hill Mining Reserve, Bendigo
Victoria Hill sits on the New Chum anticline, one of the great gold-producing structures of the Bendigo goldfield, from which around 500,000 oz of gold was won. The reserve exposes Ordovician Castlemaine Group turbidites folded into an upright chevron anticline, with the axial plane picked out by a weathered mafic dyke and by cleavage refraction across sandstone and shale beds. Delegates will see bedding-parallel laminated quartz veins formed by flexural slip, limb thrust faults with associated tension veins, neck reefs, quartz-filled joints and cleavage, and an arsenopyrite alteration halo. The historic workings include Rae’s open cut, the Great Central Victoria shaft, Lansell’s Big 180 mine (the first in the world to find payable gold below 600 m) and the first steel poppet head erected in Bendigo. Toilets are available at the reserve.
A detailed geological and heritage guide to the site (Boucher, AIG) can be downloaded here: https://aigjournal.aig.org.au/wp-content/uploads/2019/12/AIG-Victoria-Hill-Mining-Reserve_FinalWeb.pdf
Site 8. Geology of part of the south side or Rae’s open cut showing weakly developed limb thrusts faults with very little offset and some quartz veining. Some mine fill on limb thrusts can be seen. The eastern side of the cutting is a thick shaley succession of ripple-bedded silts at the base grading to laminated and massive shale, the latter hosting a 10 cm laminated quartz vein
Site 4. Fine grained sandstone. 1: Bedding. 2: Anastomos ing solution cleavage
3D block models of Victoria Hill depicting the gently northerly plunging limb thrust fault system and accompanying workings.
11:00 am – 11:40 am | Transfer to Site 2
SITE 2
11:40 am – 1:00 pm | Site 2: Pink Cliffs Geological Reserve, Heathcote
The Pink Cliffs lie just south of Heathcote on the edge of the Heathcote-Graytown National Park. Hydraulic sluicing for alluvial gold between the 1870s and 1890, fed by a 26 mile water race, stripped the cover and carved a small badlands landscape into deeply weathered, kaolinised granite, leaving the pink and pastel coloured clays and ironstone that give the reserve its name. The site offers a striking look at the deep weathering profile of central Victoria and at the environmental legacy of the goldfields, the sludge from this operation having prompted one of Victoria’s first Sludge Inquiry Boards. A 1.1 km circuit walk links upper and lower lookouts.
Delegates will visit transitional blueschist-grade Cambrian Heathcote Volcanics, part of the oceanic succession that conformably underlies the Ordovician turbidites across the Bendigo Zone, and see an outcrop of the southwest-dipping Heathcote Fault that, locally, juxtaposes metamorphosed Heathcote Volcanics against Ordovician Castlemaine Group turbidites. This sequence is intruded by a Middle Devonian age granite, and the intrusion contact is exposed and we will visit that to!
Pink Cliffs Geological Reserve
1:00 pm – 1:10 pm | Transfer to Heathcote
LUNCH
1:10 pm – 2:00 pm | Lunch stop: Heathcote
Lunch and public toilet stop in Heathcote.
2:00 pm – 3:00 pm | Transfer to Site 3 via Redesdale
The route to Site 3 may include a short stop to view the historic Redesdale Bridge, subject to time.
SITE 3
3:00 pm – 3:45 pm | Site 3: Bell-Topper Hill, near Malmsbury (weather dependent)
This stop examines the Devonian Missing Link Granite, including accessible examples of unidirectional solidification textures in a pluton carapace, sheeted vein complexes, and the transition into the main granite body. The locality provides an excellent opportunity to discuss the realities of geological mapping in central Victoria, where cryptic outcrop can preserve highly significant structural and magmatic features.
Novo Resources may also provide drill core trays at the coach turnaround to complement the outcrop geology. Access to this site is via unsealed tracks and depends on dry conditions in the preceding days. If it is too wet, Site 3 will be skipped, an extra 20 minutes will be allocated at each of Sites 1 and 2, lunch will sit between those two sites, and the coaches will return directly to Ballarat from Site 2.
Figure caption: UST's in the carapace of the Missing Link Granite at Belltopper Hill
Additional geological context: Bell-Topper Hill
The Bell-Topper Hill locality includes contorted, heterogranular unidirectional solidification texture, or UST, development. These textures comprise multi-banded, inward-growing quartz crystal layers nucleated along subparallel geochemical interfaces close to the upper contact of the intrusion. The repeated precipitation episodes are interpreted to reflect episodic pressure drops and induced fluid boiling during crystallisation. The distinctive wavy or “brain-like” appearance of the textures is attributed to post-crystallisation distortion of the crystal mush, producing a highly unusual and visually striking outcrop expression.
Figure caption: these are type f - contorted heterogranular, from Muller et al., 2023
Figure caption: UST
Figure caption: UST
3:45 pm – 5:00 pm | Return to Ballarat Goods Shed
The excursion concludes at approximately 5:00 pm.