The geological section shown here is from the Wollongong 1:250,000 sheet (SI 56 09, second edition, New South Wales Department of Mines, Sydney, 1966). It cuts from the west to the east across the southern corner of the Sydney basin, 150 km south of Sydney. The vertical exaggeration on the section is 10.42 times.
The section shows Permian strata (P—coloured blue). With the vertical exaggeration we can see the strata dip strongly to the east, but they are almost horizontal in the field. They cover a large geographic area, show little deformation and disturbance, and contain many fossils including lots of coal. Further, they sit under the Triassic to Cretaceous sediments that cover a large part of eastern Australia, which contain dinosaur trackways. These features lead me to regard these sediments as Flood deposits, laid down as the floodwaters were rising but before the deposition of the Triassic to Cretaceous sediments of the Great Australian Basin (which was before all air-breathing animals had perished).
These Permian sediments sit on top of rocks classified as Ordivician (O) and Devonian (D) (coloured pink on the section), which are folded and deformed. That fossils are in these sediments indicate they were also laid down during the Flood, but their relative position indicates it was before the Permian sediments. They were folded and deformed as a result of the tectonic movements connected with the Flood catastrophe, and shaved off again and again by the huge water flows across the area during this period.
It’s interesting to look at the land surface on this section. The western portion consists of a plateau about 2000 feet (600 m) above sea level. This drops sharply at an escarpment in the east to a coastal plain.
This is the classic form of landscape expected from the receding waters of Noah’s Flood. First, the floodwater flowed in wide sheets and cut the horizontal plateau. Note how it cuts across the Oridvician and Devonian rocks as well as the Permian ones. Then, as the water flow reduced, it became confined to channels. These cut the wide, deep valleys that dissect the plateau. The volume of water now flowing in those valleys is tiny by comparison with what flowed during the Flood.
Compare the profile of the present land surface with the profiles of ‘previous’ land surfaces as illustrated by the dotted lines delineating the Permian strata (blue). The present landscape is highly irregular with many valleys 1000 feet (300 m) deep or so. Yet the contacts between the different layers in the Permian strata are smooth and even by comparison (between Psb and Psn for example).
This illustrates the differences between the processes operating during the early stage of the Flood (large scale, geographically extensive) and the processes during the final phase of the Flood and post-flood (small scale and geographically restricted). These illustrate some of the characteristics that help us classify sediments within the biblical geological model (see Geological environments and compare the Dispersive rocks with Inundatory rocks).
Once again, the cross sections on these geological maps provide a good overview that allows us to connect the geology within the biblical Flood paradigm. I have found it is much easier to examine these sorts of cross sections rather than to work from the geological column. I think this is because the geological column involves multiple layers of interpretation that tend to mask the processes that are so obvious in the sections. It’s the cross sections allow us to get closer to the raw data in the field.