We have this ridge of sandstone cliffs down the middle of the block, just over one thousand feet above sea level. We often have groups of young people from our church out on Bar B Ques. I would love to have a little knowledge of the geology behind these formations to explain the layers to the young people, especially if they show evidence of the Flood.
I sent information to help the young people understand how the landscape connected with the Bible.
First, I included a geological map (above figure, which was an extract from the Moreton geological map available on the web). I marked where he lived on the map and briefly explained the legend:
- Jbm stands for Jurassic Marburg Formation, which is made of sandstone, siltstone, shale, conglomerate and coal plus some ironstone.
- Jw stands for the Jurassic Walloon Coal Measures and they sit underneath the Marburg Formation.
- Tv stands for Tertiary volcanics, which are mostly basalt.
- The yellow area (not labelled on the map) is called Tertiary Main Range Volcanics, which consists mostly of basalt.
Then I briefly explained the geological history of the Brisbane area outlining the sequence of events, and sent him print-outs of the relevant articles.
The rocks around your home (Jbm and Jw) were deposited as the waters of Noah’s Flood were rising. These are part of the sediments that form the Great Artesian Basin which stretches from the coast near Brisbane to the Northern Territory, to South Australia and to Cape York. (The area is shown in the third and fourth images on the article about the geological history of the Brisbane area.) They contain dinosaur fossils in various places as well as dinosaur footprints.
The sandstone layers in the top of your photo show the typical cross bedding that indicated flowing water (see description on Three Sisters article and its figure 6). The wide geographical extent of the layers indicates something of the huge area that the flowing covered.
The landscape with its hills and plains was eroded as the waters of the Flood were receding from the continent and flowing into the ocean. At this time basalt eruptions occurred and some of these cap the hills of the landscape south of your property. These basalt flows were also eroded by the receding floodwaters.
By obtaining geological maps pertinent to a particular area of the eastern part of Australia together with the geological history of the area nearby you can understand how the property where you live relates to biblical history.