The figure here shows an interpreted geological cross-section near Perth, Western Australia. It’s taken from the 1:250,000 scale geological map SH-50-14 publised in 1978 by the Geological Survey of Western Australia.


As I have mentioned before, I look at sections like these and interpret them using biblical history.

Section A-B is approximately 80 km long and shows a depth of 17 km (remember it’s an interpreted section). The vertical and horizontal scales are the same. The left hand (west) side of the section begins in the ocean some 43 km west of Perth and runs to the north-north-east for 80 km, ending about 37 km inland. As we look at the section we are looking to the north. The coastline is approximately half-way along the section (marked by an arrow visible on larger image).

The section is dominated by thick sediments (mauve, blue, green, etc) that are almost horizontal but have been broken and moved up and down by many near-vertical faults. The faults extend into the ‘basement’ (red).

The lowest horizontal layer has been labelled S? D? meaning it could be Silurian or Devonian. The next layers as we move up are labelled P, TR, Jl, Jmu, K, and T, meaning Permian, Triassic, Lower Jurassic and Middle to Upper Jurassic, Cretaceosu and Tertiary. The sediments sit on a basement (red) labelled as Precambrian. (The labels are visible in the larger image.)

Notice that these horizontal sediments stop abruptly at the east (right) side of the section against the Darling Fault (labelled Darling Fault Zone on the section, visible in the larger image)….

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