Good for a healthy debate. Only 3 opinions??. I saw near fist fights at one site with a Monash Geo (sediment based curricular) vs James Cooke trained Geo (mainly structural). We all bring our past experiences to the "Elephant" in question.
Some images below to give visuals to what is being discussed. Most of what is below will be familiar to explorationists though not to Oz geos who operate in a very weathered, red, and hot environment much of the time..
Can/did you find any reference to volcanic/volcaniclastic lithologies you interpret within the literature of the Paterson province?
Proterozoic sediments (need to be prefixed with Meta to perhaps amphibolite grade) yes, and some intrusives ranging from granite to diorite and more. The 'diorite' does form irregular bodies reported at Havieron and Minyari that may have some genetic relation to mineralisation. Only a relatively recent observation though mafic lithologies were often considered important for Minyari. Ongoing research which is probably well known by local workers but not readily disseminated beyond.
Without the bias of thinking the photo showed a glacial contact I'm not certain what I would log this as. From the photo alone one interp is the one you suggest.
Havieron, Winu and Calibre are deposits with unconformities interpreted between Canning Basin related sediments and the underlying proterozoic basement. Is Tetris going to be different? Could be, but I doubt it, and AZY interpret this as '"The unconformity" based on direct visuals, experience?. Do you discount their observations - seems so.
Having worked in glacial terrains in Northern Canada I saw polished surfaces which a 3 Kg hammer failed to get a sample out of. Need a jackhammer for BIF such as that at the Lupin Gold Mine which was discovered in the 1950s and this work is still visible (well was 40 years ago). Images from Canada occasionally show fieldies using diamond saws to cut a shallow channel for sampling. Need water and diamond saw as our team did back in the 80's Image of fieldies channel sampling for Patriot Lithium at their Gorman project in Ontario.
The recent continental glaciation of the Northern Hemisphere impacted millions of square kilometers. Maybe much larger than the Permian glaciation in Australia which is around 400+My younger than the underlying Paterson province units. Many examples of unconformities with this image from a 2007 visit to Colorado - known as The Great Unconformity apparently. Probably not as sharp as example in the core though there is a 1000 my gap here between the vertical foliated gneiss (below) and the sub horizontal "sedimentation" above. Not a younger glacial unit here.
Tourist image
AZY/RIO/GGP/NCM all subscribe to an unconformity between Permian sediments+- glacials and the Proterozoic basement. The sharpness of the contact in the image provided from Tetris is amazing and needs some form of explanation whatever it is. IMO a Permian glacial polished outcrop with a variety of material deposited above it is one distinct possibility. Accounts for the sharp contact (as in recent Canada) with a variety of sediments above. Continental glaciers can move material for many kilometers so the absence of local material is Not a game changer and more likely the norm. The early days of uranium exploration in the Athabasca involved dragging 'geiger' counters around and looking for radioactive "boulders" [Why I have a longer right arm...]. Get lucky, it did happen early on, and you find a boulder field spreading out in a fan from a near point source which got drilled. However, much of the time the source was not located being anywhere "up" ice. Fascinating to see all the glacial features.
Do these features apply to the Paterson Unconformity? Possible with a glacier scraping the Proterozoic clean and then locally depositing various tillite/diamectite deposits up to hundreds of meters thick.
From a post after the 2019 AGM which I alluded to in my previous post.
Another issue I raised was about the presence of weathering at Calibre. RM said there is none with fresh rock immediately below the Permian cover rocks. Effectively a glacial pavement as is present in much of the Canadian Shield. This rules out oxide and supergene enrichment/depletion effects at Calibre that are seen at Winu below the unconformity.Given significant weathering at Winu, “SPOR [Serrano/Poblano/Reaper]”, and near Telfer (Chicken Ranch <=200m? from memory) the palaeo environment at the Permian/Proterozoic unconformity is complex. It can impact on exploration methods so may be important. [At Kintyre, some 80 Kms south of Telfer, there is apparently evidence of glacial pavement (passing comment from a former site geo)]
(20min delay)
