A knowledge of the underlying rocks and their history explains why the landscape and vegetation of Foxes Lair changes more over a short area than other places like Dryandra Yilliminning and Harrismith.
I guess that you need a good imagination to picture continental plates smashing together and separating again to repeatedly form and destroy supercontinents over hundreds of millions of years, and the associated earthquakes, volcanoes and mountain ranges that have formed and then weathered away.
Geology is very relevant!
For example did you know that Darwin could be a suburb in Indonesia in 500 million years, and a visit to Bali will be a different experience, as it may be a new Mt Everest or a blob of melting rock underneath the encroaching Australasian plate?.
So here is a very simplified story!
In the wheatbelt we are on the Yilgarn Craton, a very old and stable slab of mainly granite (sandy soils) with greenstone strips (red soils, mineral fields). Since its formation (2,800 million years ago?) the craton has been stressed as it and then as part of Australia has collided with others to form supercontinents and then separated again at least five times.
These stresses caused faults in the bedrock and cracks that filled with magma from the earth’s mantle that we commonly see today as narrow lines of black rock (like dolerite) containing dark minerals that form reddish loam and clay soils (dykes).
About 2,400 million years ago a series of east/west dykes formed, with the biggest being the huge Binneringie Dyke (600 km long and up to 3km wide. The dyke aligns with the road from Quindanning to Williams and then the Williams Kondinin Road and on to Hyden and further east. Commonly driving on these main roads, I used to overestimate the amount of red soil in the district, but one soon comes into sandy soils on side roads
Narrogin and Foxes Lair sit right on this dyke that can be seen from the air as a discontinuous often double line of hills. The hills have resulted from intruded magma ‘cooking’ the surrounding rock making it more resistant to erosion, and stonier more resistant laterites formed on dolerites remaining as the surrounding landscape eroded away. The line is discontinuous because the extruded magma formed different rock types from quartz to ultramafic rock, and the dyke has since been cut by numerous younger faults and dykes.
Granite is actually an interesting rock. Here it formed by the collision of continental blocks. As one block slides under another it melts and huge “pools” of granite rise up and solidify as large domes like Yilliminning rock up to 2 kilometres below the surface of the plate above.
You can climb Yilliminning Rock now because over the hundreds of millions of years the overlying kilometres of bedrock have weathered and the soil washed away into the ocean.
Mind blowing stuff!
Some light reading- Geology of Granite , Overview of Granite Outcrops
The image below shows my guesstimate of the Binneringie Dyke at Narrogin.