There was more Heavitree Quartz at our next stop, where a ridge has been bisected by Ellery Creek, flowing south on its way to join the Finke River. The Creek took advantage of a fault in the ridge rock. Faults were created during a major mountain-building period when sediments that had previously been laid down beneath a shallow sea were tilted and contorted. Faulted rock is more easily eroded. When the Creek was in flood, it carried rock fragments that carved the Creek bed deeper and further widened the gap in the ridge.
Ellery Big Hole is beautiful; at one end a small beach; at the other tortured rock walls. The vegetation is almost as twisted as the rock. We came across quartzite boulders just as striking as at Ormiston Gorge.
The Larapinta Trail passes right by Ellery Creek Big Hole, and part of it forms a section of the Dolomite Loop Walk (3 km, 1.5 hours, moderate), the only walk to do here apart from the 5-minutes-there-and-back to the waterhole. The Dolomite offers good views of the geology of the area, allegedly, but it was decision time again, and a 1.5-hour walk – probably at least two hours for us, my friend being a geology buff – would have meant either Standley Chasm or Simpsons Gap had to go.
It still surprises me that in places renowned for their beauty and – as in Glen Helen's case – high conservation value – it's taken as read that people will use the pristine waters for swimming. You cannot keep Aussies out of water, of course: it's in their genes. Understandably. The weather, in all states at least some of the time, is invitingly warm, if not hot. There were more people at Ellery Creek than we'd seen for a while. A couple of them couldn't resist a paddle, but their reaction suggested the water temperature was not to their liking.
Winter is the most popular season for trekking in this region, but it is worth noting that, if a creek is running high following rain, and happens to be in a high-walled gorge where a low sun doesn't reach, wading in icy water can be risky. I have read a couple of accounts in which the writers were barely able to walk after even a short time in such waters.
As we walked back to the car, this struck me as a quintessentially Australian landscape.