http://www.smh.com.au/news/specials/...770800829.html
"A RETIRED geologist searching on Google Earth for a place to mine opals may have discovered something much bigger: a meteorite crater in outback NSW. Mike Fry was using the Google site last month to survey terrain when he saw an unusual structure in the red dust..."
White Cliffs being a working opal deposit, and the town existing there because of it, I can't imagine that the whole area wouldn't have been extensively surveyed before this to gauge its suitability for mining. Maybe it just wasn't thought to be important at all.... ?
Interesting crescent shape. Looks like heavy erosion to the SW, but is the ejector just more prevalent in the NW corner because, maybe, the impact was from the SW? Great find. Lots of meteor chunk hunters heading to White Cliffs I guess...
I accept that there are a lot of impact craters out there waiting to be found and the looking at satellite imagery is a good way to do it but I'm going to pour cold water on this 'discovery'.
The first think that struck me when I read the article is that this bloke may be a geologist but he isn't a geomorphologist. He has the silcrete forming at the upper level after the comet impact. Silcrete forms in the B horizon of soils when water containing dissolved silica evoporates and it forms at the local base level. The area can subsequently be eroded to leave the silcrete high in the landscape and this is very common in Australia. Anyone who has seen Mt Connor on the way to Ayres Rock or the painted valley near Coober Pedy has seen an anologious phenomena. Although silcrete is forming today most Australian silcrete is much much older than 2 million years. There is about 60m of local relief and, given the notoriously slow rate of erosian in Australia, this likely represents some tens of millions of years of downcutting.
Of course the obvious feature is the circular arc. A prof who works in the arid areas told me that such shapes are common in the 'jump-up' regions around the Simpson desert. I also vaguely recall hearing about them in the ranges of southern NSW. It's hard to describe why, but the formation of such shapes by erosion seems reasonable to me.
So until someone has a close look at the morphology of the purported crater rim, or finds some shocked quartz or tektites I will remain unconvinced.
