Geology of the Arckaringa Basin
The Arckaringa Basin is a large stable sedimentary basin containing predominantly late Carboniferous 310MYa to early Permian sedimentary rocks 290MYa. The basin is 80,000 square kilometres in area (about the size and shape of Austria). Like Austria the basin is girt by land. The Arckaringa Basin is bound to the east by the Denison and Davenport Range, to the south by the Gawler Ranges and Stuart Shelf and to the north and west by the Officer Basin. The thickest parts of the basin deposits are located around Coober Pedy Ridge, Mabel Creek Ridge and Central Basin High. The depth of the basin in these areas is up to 1.3km thick. The western Arckaringa Basin is thin, geologically simple and only moderately faulted while the eastern Arckaringa Basin is deep and geologically complex. Additionally, the base of the Permian strata displays a complex, glacially-scoured surface with significant erosional relief.
Thanks to Freddo for help with the geology of the area. More technical information can be gained from the Australian Government Bioregional Assessment of Arckaringa Basin. https://www.bioregionalassessments.gov.au/assessments/11-context-statement-arckaringa-subregion/1131-geological-structural-framework
The Earthcache
It’s flat and might be considered dull to drive through, but the geology above indicates that there is more going on in this area than at first may meet the eye. Look carefully and you will see differences in soil colour, terrain and vegetation.
Your task is to observe the differences in the two nominated locations and suggest what has caused these differences. You may use the above geological information or you may prefer to use your own words and knowledge. (Note that Owl is not a geologist and would advocate the latter!)
Both waypoints are located at rest areas, so this will also help to break the journey.
The Questions
To log this Earthcache you will need to answer the following:
- What differences can you see in terrain, soil colour and vegetation between the two locations?
- What does this suggest about the difference in formation, rainfall and soil content?
Please do not put your answers in your logs, but email them to Doctor Owl for approval. Logs that have not been accompanied by the correct answers or which appear to be the result of armchair caching will be discretely queried and (if necessary) deleted.