Editing Darling Scarp (section)

== Geology ==
The Darling Scarp originated as the local expression, in the Perth area, of the extensive [[Darling Fault]], a major and ancient geological discontinuity separating the [[Archean|Archaean]] [[Yilgarn craton]] in the east from the younger [[Pinjarra Orogen]] and overlying [[Phanerozoic]] [[Perth Basin]] to the west. The Darling Fault is exposed for over {{convert|1000|km}}, from the area east of [[Shark Bay]], to the southern coast of Western Australia east of [[Albany, Western Australia|Albany]]. The location of the scarp must once have coincided with the location of the [[Fault (geology)|fault]], but the scarp has since eroded about {{convert|15|km}} eastwards. The original location of the scarp is indicated in places by an unusual landform known as the [[Ridge Hill Shelf]].

The Darling Plateau is covered by lateritic materials that cover the underlying geology.<ref>{{Citation | author1=Johnston, C. D. (Colin Douglas) | author2=CSIRO. Division of Groundwater Research | title=Water movement through preferred paths in lateritic profiles of the Darling Plateau, Western Australia | publication-date=1983 | publisher=CSIRO | isbn=978-0-643-03496-9 }}</ref><ref>{{Citation | author1=Gozzard, J. R. (John Robert) | author2=Geological Survey of Western Australia | author3=Gossard, J. R | title=Geology and landforms of the Perth region | year=2007 | publication-date=2007 | publisher=Geological Survey of Western Australia | isbn=978-1-74168-072-0 }}  pages 11–14 specifically about the plateau</ref>

The Archaean [[granite]]s and [[gneiss]]es of the Yilgarn craton form the high ground of the Perth Hills and can be observed in road cuts, with good examples in the [[Mundaring Weir]] area. The only exposed sediments of the Perth Basin, west of the fault, are of [[Cenozoic]] age, and are composed of materials such as sandy [[limestone]], [[travertine]] and dune sand on which the city of Perth is built, including sand dunes of [[Pleistocene]] age formed during the [[last glacial period]].

This area is also a distinct physiographic section of the larger [[Yilgarn craton|Yilgarn Block]] province, which in turn is part of the larger [[Australian Shield|West Australian Shield]] division.

===Climate===
The Scarp, like the rest of south west Australia, has a Mediterranean climate, with mild rainy winters and warm dry summers. Average annual rainfall is 1300 mm along the scarp, declining to the east and north.<ref name = Williams>Williams, Kim and David Mitchell (2001)"Jarrah Forest 1 ( JF1 – Northern Jarrah Forest subregion)" in ''A Biodiversity Audit of Western Australia’s 53 Biogeographical Subregions in 2002'', The Department of Conservation and Land Management, September 2001. Accessed 10 May 2022. url = https://www.dpaw.wa.gov.au/images/documents/about/science/projects/waaudit/jarrah_forest01_p369-381.pdf</ref>

Often the [[Bureau of Meteorology]] identifies different weather for "the hills" in comparison to that of the [[Swan Coastal Plain]].<ref>{{cite web |url=http://www.bom.gov.au/wa/forecasts/perth.shtml|title=Fire Danger is identified in this page for "Coastal Plain" and for "Hills" |publisher=Bom.gov.au |access-date=2010-06-14 }}</ref>

Also, in traditionally hot summers, strong easterly winds travelling across the scarp have presented serious issues for planes using the [[Perth Airport]] because of the alignment of the runways.<ref>{{cite web|url=https://sites.google.com/site/motoguzzimackers/home/air-traffic-in-western-australia/perth-geography-and-weather|title=specifically stated as "Significant turbulence is caused by the passage of easterly winds over the escarpment" |first=David|last=McMillan|access-date=2016-09-14}}</ref> On 2 September 1999, the number one engine of a [[Qantas]] [[Boeing 747]], en route from [[Sydney Airport]] coming into land on Runway 06/24, struck the runway surface upon landing, due to [[wind shear]] caused by rolling winds on the Darling Scarp.<ref>{{ATSBLink | type =A | year = 1999 | occno = 199904384 | title = Boeing Co 747-238B, VH-EBS | accessdate =9 June 2023}}</ref> In addition, orographic uplift is produced when rain clouds move over the hills, giving higher rainfalls in settlements in the ranges compared with their coastal neighbours.