William sent in the link https://www.yahoo.com/lifestyle/largest-asteroid-impact-crater-earth-120000726.html … which is about verbatim to https://phys.org/news/2023-08-evidence-world-largest-asteroid-impact.html … the Deniliquin structure recently found in New South Wales. It is now thought it may be a giant impact crater, of indeterminate age. It spans 150 km in diameter – a big beast. It is also a crater with an uplifted core. These are thought to form from an impact. The thinking is that if you throw a pebble into a pool of water the splash will cause a whoosh of water, like a fountain, at the point of entry. Hence, an asteroid striking earth, it is theorised, will cause great heat and an upward whoosh of hot melted rock – forming the core as it cooled rapidly back down again. Suspended animation if you like. A spike of water would sink back into the pool – with rings of water spanning outwards. Super heated rock may not subside so quickly. The electric universe theory has a completely different take on this – especially surrounding the core of rock in the centre of a crater. No doubt, there are other ideas that have not been taken seriously, as well.
In order to confirm the impact it will be necessary for some deep drilling into the structure. At some point in the future.
Eric also sent in some odd geology from Australia. It was stimulated by a post at https://sis-group.org.uk/news/2023/07/31/a-puzzling-dilemma/ … He said a similar landscape occurs in the Blue Mountains, west of Sydney. Steep sided valleys that were an hindrance to early inhabitants of the Sydney settlement. They eventually found a route over a ridge that avoided the steep sided valleys. Such rock formations are assumed to have an origin in water – ancient river systems that have carved a route through solid rock. Grinding the rock down into gravel that is washed out to sea, eventually. Perhaps it occurred more rapidly – in the opposite direction [from sea to inland]. Again, the electric universe theory has a counter claim. Electric discharges between the heavens and the earth. Instant excavation of the valleys. Hence, it is conjectured, their steep sides with no apparent connection to a river system.
Eric also menions the Jenolan caves, around 60 km southwards. The web site https://www.jenolancaves.org.au/visitor-info/limestone-cave-geology/cave-formations-speleothems/ … which has some good images of flowstone, and columns and pillars, within the cave. Limestone forms such structures when it is in a liquid form – water seeping through the rock. In Europe some cave paintings can be seen that have been glossed over with flowstone. Eric suggests it might be formed quickly during a heating event – such as a volcanic eruption nearby, or an electrical discharge. One might also consider extraordinary wet events caused by goings on in other parts of the world. The standard geological explanation is that the formation of flowstone takes place in a uniformitarian and gradual manner. There is an excellent description of the processes involved.
Presumably, the local Aborigines, the Gundungurra people, may have explored the caves at some point in the past. Hence, they may also preserve an ancient record of a heating event in their version of the Dream Time [the mythical past]. However, on the face of it a heating event would not speed up the geological process. It is very unlikely. On the other hand, extremely wet weather over a sustained period might create the conditions for a more rapid formation.