Editing Western Australia (section)

===Geology===
The bulk of Western Australia consists of the extremely old [[Yilgarn craton]] and [[Pilbara craton]] which merged with the [[Deccan Plateau]] of India, [[Madagascar]] and the [[Kaapvaal craton|Kaapvaal]] and [[Zimbabwe]] cratons of Southern Africa, in the [[Archean]] Eon to form [[Ur (continent)|Ur]], one of the oldest [[supercontinent]]s on Earth (3 – 3.2 &nbsp;billion years ago). In May 2017, evidence of the [[Earliest known life forms|earliest known life]] [[Evolutionary history of life#Colonization of land|on land]] may have been found in 3.48-billion-year-old [[geyserite]] and other related mineral deposits (often found around [[hot spring]]s and [[geyser]]s) uncovered in the Pilbara craton.<ref name="PO-20170509">{{cite news |title=Oldest evidence of life on land found in 3.48-billion-year-old Australian rocks |url=https://phys.org/news/2017-05-oldest-evidence-life-billion-year-old-australian.html |date=9 May 2017 |website=[[Phys.org]] |access-date=13 May 2017 }}</ref><ref name="NC-20170509">{{cite journal |last1=Djokic |first1=Tara |last2=Van Kranendonk |first2=Martin J. |last3=Campbell |first3=Kathleen A. |last4=Walter |first4=Malcolm R. |last5=Ward |first5=Colin R. |title=Earliest signs of life on land preserved in ca. 3.5 Ga hot spring deposits |date=9 May 2017 |journal=[[Nature Communications]] |volume=8 |pages=15263 |doi=10.1038/ncomms15263 |pmid=28486437 |pmc=5436104 |bibcode=2017NatCo...815263D }}</ref>

Because the only [[orogeny|mountain-building]] since then has been of the [[Stirling Range]] with the rifting from [[Antarctica]], the land is extremely eroded and ancient, with no part of the state above 1,249 metres (4,098&nbsp;ft) [[Australian Height Datum|AHD]] (at [[Mount Meharry]] in the [[Hamersley Range]] of the [[Pilbara]] region). Most of the state is a low plateau with an average elevation of about 400 metres (1,200&nbsp;ft), very low relief, and no [[surface runoff]]. This descends relatively sharply to the coastal plains, in some cases forming a sharp escarpment (as with the Darling Range/[[Darling Scarp]] near Perth).

[[File:WAHighways.png|thumb|right|Western Australian cities, towns, settlements and [[List of highways in Western Australia|road network]].]]

The extreme age of the landscape has meant that the soils are remarkably infertile and frequently [[laterite|laterised]]. Even soils derived from [[granite|granitic]] [[bedrock]] contain an order of magnitude less available [[phosphorus]] and only half as much [[nitrogen]] as soils in comparable climates in other continents. Soils derived from extensive sandplains or [[ironstone]] are even less fertile, nearly devoid of soluble phosphate and deficient in [[zinc]], copper, [[molybdenum]] and sometimes [[potassium]] and [[calcium]].

The infertility of most of the soils has required heavy application by farmers of fertilisers. These have resulted in damage to [[invertebrate]] and bacterial populations.{{citation needed|date=November 2017}} The grazing and use of hoofed mammals and, later, heavy machinery through the years have resulted in [[soil compaction|compaction of soils]] and great damage to the fragile soils.

Large-scale land clearing for agriculture has damaged habitats for native flora and fauna. As a result, the [[Southwest Australia|South West region]] of the state has a higher concentration of rare, threatened or endangered flora and fauna than many areas of Australia, making it one of the world's biodiversity "hot spots". Large areas of the state's wheatbelt region have problems with [[Soil salinity control|dryland salinity]] and the loss of fresh water.