View source for Darling Scarp

{{Short description|Scarp east of Perth, Western Australia}}
{{Use Australian English|date=December 2015}}
{{Use dmy dates|date=December 2015}}
{{Infobox mountain
| name = Darling Scarp
| other_name = {{lang |nys |Katta Moorda}}
| photo = Darling Scarp from Sullivan Rock.jpeg
| photo_alt = 
| photo_caption = Darling Scarp as viewed from Sullivan Rock (September 2022)
| country_type = <!-- Alternative label for country eg use "Continent" for ranges in Antarctica -->
| country = Australia
| country1 = 
| country2 = 
| region_type = State
| region = Western Australia
| region1 = 
| border = 
| border1 = 
| biome = 
| topo_map = 
| topo_maker = <!-- Highest point -->
| highest = [[Mount Cooke]]
| highest_location = 
| elevation_m = 582
| elevation_system = {{AHD}}
| elevation_note = 
| coordinates = {{coord |qid=Q6920235 |region:AU-WA_type:mountain_dim:1000 |name={{wikidata |property |eid=Q6920235 |P1448 }} |display=inline |format=dec}}
| coordinates_note = <!-- Range -->
| length_km = 345
| width_km = 
| area_km2 = 
| length_orientation = north-south
| width_orientation = east-west
| length_note = 
| width_note = 
| area_note = 
| parent = 
| range_coordinates = {{coord |region:AU-WA_type:mountain_dim:{{wikidata |property |qualifier |raw |P625 |P2386 |format=%q}} |display=inline,title |format=dec}}{{EditAtWikidata|pid=P625}}
| formed_by = [[Darling Fault]]
| geology = 
| period = [[Cenozoic]]
| orogeny = <!-- Locator map; takes coordinates from "highest point" (and perhaps "range"; need to experiment and then correct this comment) -->
| map = 
| map_alt = 
| map_caption = 
| map_relief = 
}}

The '''Darling Scarp''' ({{langx|nys|Katta Moorda}}),<ref>{{cite web |title=History of the Kattamorda Heritage Trail |year=2025 |website=Kattamorda Heritage Trail |url=https://kattamorda.org/history.html |access-date=2024-04-01 }}</ref> also referred to as the '''Darling Range''' or '''Darling Ranges''', is a low [[escarpment]] running north–south to the east of the [[Swan Coastal Plain]] and [[Perth]], [[Western Australia]]. The escarpment extends generally north of [[Bindoon, Western Australia|Bindoon]], to the south of [[Pemberton, Western Australia|Pemberton]]. The adjacent Darling Plateau goes easterly to include Mount Bakewell near [[York, Western Australia|York]] and Mount Saddleback near [[Boddington, Western Australia|Boddington]]. It was named after the [[Governor of New South Wales]], Lieutenant-General [[Ralph Darling]].

== History ==
[[Image:STS097-712-37.jpg|thumb|right|300px|Southwest Western Australia from space. The dark green is dense vegetation on and above the scarp, which has been retained for forest reserve and water catchment purposes. The sharp vegetation boundary on the coastal side coincides with the edge of the scarp.]]

The feature was first recorded as General Darling Range by [[Charles Fraser (botanist)|Charles Fraser]], Government Botanist with Captain [[James Stirling (Australian governor)|James Stirling]] aboard {{HMS|Success|1825|6}} in March 1827.

Maps from the 1830s show the scarp labelled ''[[Ralph Darling|General Darlings]] Range''; this later became ''Darling Range'', a name by which the formation was still commonly known in the late 20th century despite common understanding of it being an escarpment. There is also a tendency to identify the locations on or to the east of the scarp as being in the ''[[Perth Hills]]'' (or simply ''The Hills''), despite extending over hundreds of kilometers.

The earliest traverses by [[United Kingdom|British]] [[settler]]s in the [[Swan River Colony]] occurred in the 1830s. The best known of these is the expedition of [[Robert Dale (explorer)|Ensign Robert Dale]], who appears to have gone from a point near [[Guildford, Western Australia|Guildford]], to the south side of [[Greenmount, Western Australia|Greenmount]] Hill and up through the [[Helena Valley]].<ref>{{cite book |title=Journals of Several Expeditions Made in Western Australia |last=Cross |first=Joseph |author-link= Joseph Cross (author)|year=1833 |chapter= Journal of the Proceedings of a party of Officers and men, for the purpose of crossing the Darling Range of Mountains, under the orders of Lieutenant Preston, R.N.|publisher=J. Cross |location=London |pages=6–14 |url=http://en.wikisource.org/wiki/Journals_of_Several_Expeditions_Made_in_Western_Australia,_During_the_Years_1829,_1830,_1831,_and_1832 |access-date=28 February 2009}}</ref>

== 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.

==Flora and fauna==
The scarp is part of the [[Jarrah Forest]] bioregion. The natural vegetation of the scarp is predominantly [[jarrah forest|jarrah–marri forest]], characterised by [[Eucalyptus marginata|jarrah]] (''Eucalyptus marginata'') and [[Corymbia calophylla|marri]] (''Corymbia calophylla''), with [[Eucalyptus megacarpa|bullich]] (''Eucalyptus megacarpa'') and [[Eucalyptus patens|blackbutt]] (''Eucalyptus patens'') in the valleys.<ref name = Williams/> The [[Eucalyptus laeliae|Darling Range ghost gum]] (''Eucalyptus laeliae'') is endemic to the western slopes of the scarp.

Heath is found on granite outcrops. Low woodlands of ''[[Banksia]]'' grow on sand sheets.<ref name = Williams/>

Native mammals include the [[quenda]] (''Isoodon fusciventer''), [[chuditch]] (''Dasyurus geoffroii''), [[woylie]] (''Bettongia penicillata ogilbyi''), and [[brush-tailed phascogale]] (''Phascogale tapoatafa wambenger''). [[Quokka]] (''Setonix brachyurus'') and [[western ringtail possum]] (''Pseudocheirus occidentalis'') are often restricted to [[riparian]] areas.<ref name = Williams/>

== Land use ==
The Darling escarpment has been exploited for stone [[mining|quarries]], [[forestry]] and [[bauxite]] mining.  Extensive [[timber]] railways and timber mills and the supporting communities existed along the escarpment because of the high quality [[Eucalyptus marginata|jarrah]] forests.<ref>Darling Range Study Group & Benson, W. D (1982).  Land use in the Darling Range, Western Australia : a report to the Premier of Western Australia  The Group], Perth, W.A</ref>

=== Dams ===
In the early twentieth century, most of the main rivers flowing off the escarpment had mainly been used for dams for water supply for metropolitan Perth. The dams on the scarp include:
{{Div col |colwidth=20em}}
* [[Mundaring Weir]] (on the [[Helena River]])
* [[Serpentine Dam (Western Australia)|Serpentine Dam]] and Pipehead (Serpentine River)
* Wungong Dam
* [[Churchman Brook Dam]]
* [[North Dandalup Dam]]
* [[South Dandalup Dam]] (on the two Dandalup branches)
* [[Canning Dam]] (on the [[Canning River]])
{{Div col end}}

The only free flowing water from the Darling Range in the Peel Region is the Dirk Brook in [[Keysbrook, Western Australia|Keysbrook]] and the [[Murray River (Western Australia)|Murray River]].

The scarp also defines the easternmost limit of the various [[aquifer]]s present in the Perth Basin sediments, most notably the Southwest [[Yarragadee Aquifer]]. The scarp forms a divide between the hypersaline groundwaters typical of the Yilgarn craton basement from the fresh ground waters of the Perth Basin. Some dams along the scarp are contaminated by seepage of saline water from the granite into the base of the dam's water column and must be periodically flushed to preserve water quality.

=== Rock quarries ===
Also in the early to mid-twentieth century numerous rock quarries existed on the edge of the escarpment - visible and affecting both the aesthetics and the environment of the escarpment.

In the area where the [[Helena River]] emerges from its valley to the [[Swan Coastal Plain|sandplain]], there are still four quarries evident, despite being unused as quarries for fifty years or more.  Mountain<ref>{{cite web |url=http://www.climberswa.asn.au/climbwa/crags.asp?region=Around+Perth&crag=Mountain_Quarry&sort=NAME |title=Climbs in WA |date=2005-08-15 |access-date=2010-06-14 |archive-url=https://web.archive.org/web/20091005024313/http://www.climberswa.asn.au/climbwa/crags.asp?region=Around%20Perth |archive-date=5 October 2009 |url-status=dead }}</ref> and Stathams<ref>{{cite web |url=http://www.climberswa.asn.au/climbwa/crags.asp?region=Around+Perth&crag=Stathams_Quarry&sort=NAME |title=Climbs in WA |date=2008-07-20 |access-date=2010-06-14 |archive-url=https://web.archive.org/web/20091005024313/http://www.climberswa.asn.au/climbwa/crags.asp?region=Around%20Perth |archive-date=5 October 2009 |url-status=dead }}</ref> quarries are now managed as rock climbing locations.

* ''Bluestone quarry'' (1850s name), later known as ''Greenmount Quarry'' (1850s to 1920s), at [[Greenmount Hill]] on the west side of [[Greenmount National Park]].
* ''Mountain Quarry'' (now usually signed as ''Boya Quarry''), south of Greenmount Hill, which ceased operation in 1963.
* ''Byford brickworks (State Brickworks)'', shale scar visible from early 20th century to WW2 quarrying.
* ''[[Fremantle Harbour]] Works Quarry''  (sometimes, ''[[C. Y. O'Connor]]'s Mole Reconstruction Quarry'', and later known as the ''Public Works Quarry''), now ''Hudman Road Amphitheatre'' at edge of [[Darlington, Western Australia|Darlington]] - [[Boya, Western Australia|Boya]] localities border, operated from the 1900s to the 1930s.
* [[Statham's Quarry]] at [[Gooseberry Hill, Western Australia|Gooseberry Hill]] at northern edge of the [[Kalamunda Zig Zag]] formation.
* ''Armadale brickworks (State Brickworks)'', Bedfordale Hill, shale scar visible from 20th century quarrying, with an underground rail bypassing the [[South Western Highway]] to transport the ore.

There have also been visible quarries on the scarp in the [[Gosnells, Western Australia|Gosnells]] and [[Herne Hill, Western Australia|Herne Hill]] areas.

Legislative restrictions upon such developments were initiated in the late twentieth century to prevent further visible scars on the western face of the scarp.

=== Bauxite mining ===
{{See also|Bauxite mining in Australia}}

In the late twentieth century, the proving of bauxite deposits correlating to the extensive [[jarrah forest]]s saw wide-ranging protests against the proposals to mine the forests. [[Campaign to Save Native Forests]] was one group to oppose the activity.

The lengthy process of protest forced the government and miners to check their original proposals, and wide-ranging processes to guard segments of the jarrah forests from mining ensued.

The current mining activity in the region is extensive - the main mines being Huntly and Willowdale.<ref>'Alcoa has two bauxite mines operating in the Darling Range in Western Australia: Huntly, which has been operating since the early 1970s and is the world's biggest bauxite mine, producing 20 million tonnes per annum; and Willowdale, established in 1984 and currently supplying 8.5 million tonnes per annum to Alcoa's Wagerup alumina refinery. source: {{cite web |url=http://aluminium.org.au/australian-bauxite/bauxite-jarrahdale-huntly-willowdale |title=Jarrahdale, Huntly, and Willowdale Mines |access-date=2014-04-05 |url-status=dead |archive-url=https://web.archive.org/web/20140302094013/http://aluminium.org.au/australian-bauxite/bauxite-jarrahdale-huntly-willowdale |archive-date=2 March 2014 |df=dmy-all }}</ref>
[[File:Darling Scarp from Serpentine Dam.jpg|thumb|Darling scarp from Serpentine Dam]]

=== Railways ===
The building and developing of rail access across the scarp developed three separate main routes over eighty years.<ref>Higham, G.J.(1968) ''Over the range:railways across the Darling range of Western Australia:Midland to Northam and York'' Bassendean, [[Rail Heritage WA]]</ref>

* The [[Eastern Railway (Western Australia)|Eastern Railway]] first traversed the Darling Scarp in the 1880s along its ''first route'' through Greenmount (where three of the above quarries  were later able to use the railway).
* By the 1890s, the ''second route'' passed through [[Swan View Tunnel]] and [[John Forrest National Park]].
* In the 1960s, the ''third route'' used easier grades through the [[Avon River (Western Australia)|Avon Valley]]
* The [[Kalamunda Zig Zag]] or [[Upper Darling Range railway]] ran up the southern steep side of the Helena Valley entrance until 1949.
* The [[Millars (company)|Millars]] timber lines operating south to Yarloop, north through Jarrahdale up to Jarrahglen east of Byford and the Chandler mill.

=== Perth suburbs on the scarp ===
The localities or suburbs on the "edge" of the scarp are those that sit at its western edge, and in most cases command excellent views of the [[Swan Coastal Plain]]:

The suburbs near Midland and Kalamunda are often referred to as the [[Perth Hills]].
{| class="wikitable" style="width:600px;"
|-
! Near [[Midland, Western Australia|Midland]]
! Near [[Kalamunda, Western Australia|Kalamunda]]
! Near [[Armadale, Western Australia|Armadale]]
|- style="text-align:center;"
|  [[Stratton, Western Australia|Stratton]]
|  [[Carmel, Western Australia|Carmel]]
|  [[Martin, Western Australia|Martin]]
|- style="text-align:center;"
| [[Swan View, Western Australia|Swan View]]
| [[Gooseberry Hill, Western Australia|Gooseberry Hill]]
| [[Roleystone, Western Australia|Roleystone]]
|- style="text-align:center;"
| [[Greenmount, Western Australia|Greenmount]]
| [[Lesmurdie, Western Australia|Lesmurdie]]
| [[Karragullen, Western Australia|Karragullen]]
|- style="text-align:center;"
| [[Darlington, Western Australia|Darlington]]
| [[Walliston, Western Australia|Walliston]]
| [[Bedfordale, Western Australia|Bedfordale]]
|- style="text-align:center;"
| [[Boya, Western Australia|Boya]]
| [[Bickley, Western Australia|Bickley]]
| [[Jarrahdale, Western Australia|Jarrahdale]]
|- style="text-align:center;"
| [[Helena Valley, Western Australia|Helena Valley]]
| [[Pickering Brook, Western Australia|Pickering Brook]]
| [[Wungong, Western Australia|Wungong]]
|}

=== Television transmission towers ===
The suburbs to the south of Kalamunda are the locations of the main Perth Metropolitan television station transmission towers. There is also another site at Mount Lennard near [[Collie, Western Australia|Collie]] that Services the Southwest areas including [[Bunbury, Western Australia|Bunbury]].

==Conservation==

=== Dieback and fire ===
Also in the late twentieth century, [[Phytophthora cinnamomi|dieback]] affecting jarrah timber in particular infected large tracts of the forest.  Currently only the restriction of vehicle access has proved effective in slowing the spread of this disease. This gained greater acceptance and publicity through the decision to allow [[Rally Australia]] to operate along services roads provided that the vehicles had a thorough wash including the under carriage at the end of each stage.

In late 2004, the largest bushfire in the northern [[Jarrah Forest]] for at least 100 years created significant issues for the forest as well.  As a result of this fire intensity the Government increased the volume of controlled burns along the entire escarpment to reduce the buildup of flammable materials.

In the early 2000s, [[Greenmount National Park]] and [[John Forrest National Park]] were repeatedly burnt by bushfires - in most cases through suspected arson.

=== Darling Range Regional Park ===
[[Image:DarlingScarp southern 2010.jpg|thumb|500px|Darling scarp from South West Highway between Armadale and Pinjarra]]
A network of reserves of crown lands on the escarpment have been connected into a regional park to maintain and conserve parts of the escarpment.

In most cases the reserves or parks had individual names prior to being incorporated into the larger park, for example the [[Serpentine National Park]], [[John Forrest National Park]] and the [[Greenmount National Park]], or were simply known as State Forests (e.g. State Forest No.42).

Following a change in 2005, the separate parks have been known as the "Parks of the Darling Range", and take up 23,948 hectares on the scarp.<ref>Mitchell, Samille (2008-9) ''What's in a name? Parks of the Darling Range'' ''Landscope'' Volume 24 number 2, pp.40-46.</ref>  Further in August 2008 the parks were given indigenous names:<ref>{{cite web|url=http://www.roleybushcare.com/bush-topics/109-new-aboriginal-names-for-regional-parks.html |title=including a press release no longer available - regarding the component reserves within the parks |publisher=Roleybushcare.com |date=2009-06-23 |access-date=2010-06-14}}</ref>
* [[Beelu National Park]]
* [[Korung National Park]]
* Midgegoroo National Park (formerly known as Canning National Park<ref>{{cite web|url=http://www.roleybushcare.com/bush-reserves/58-canning-national-park.html |title=Midgegoroo National Park |publisher=Roleybushcare.com |date=2008-10-07 |access-date=2010-06-14}}</ref>)
* [[Banyowla Regional Park]]  (formerly known as Kelmscott-Martin Regional Park)
* [[Mundy Regional Park]] (formerly known as Kalamunda Regional Park)
* Wooroloo Regional Park (formerly known as Chidlow Regional Park)
* Wungong Regional Park

==Highest points==
* [[Mount Cooke]]{{spaced endash}}{{coord|32|25|S|116|18|E}}, with an elevation of {{convert|582|m}} {{AHD}}<!--another?-->
* [[Mount Dale]]{{spaced endash}}{{coord|32|08|S|116|18|E}}, with an elevation of {{convert|546|m}} {{AHD}}

==See also==
*[[List of escarpments]]

==General references==
{{Refbegin |30em}}
* Bean, Alison.(1993) ''A brief history of the Darling Range : for the Department of Planning and Urban Development.''  Perth, W.A. : The Dept. Darling Range Regional Park supplementary report; no. 4. {{ISBN|0-7309-5304-1}}
* Blainey, Geoffrey.(1997)  ''White gold : the story of Alcoa of Australia''  St. Leonards, N.S.W. : Allen & Unwin. {{ISBN|1-86448-355-5}}
* (1970)''The Darling Scarp : a natural entity: proceedings of symposium held at the Geography Department of the University of Western Australia, November 1969'' Perth, W.A.: Nature Conservation Council of Western Australia,
* Department of Planning and Urban Development, Western Australia.(1993) ''The Natural resources of the Darling Ranges''  Perth, W.A. : The Dept., Darling Range Regional Park supplementary report; no. 2. {{ISBN|0-7309-5302-5}}
* Murphy, Mike.(1998) ( Coles, Helena - editor)  '' Jarrahdalians : the story of the Jarrahdale Mine'' Booragoon, W.A. Alcoa of Australia. {{ISBN|0-646-36670-X}}
* Myers JS (1992) Pinjarra Orogen, in Geology and Mineral Resources of Western Australia: Western Australia Geological Survey, Memoir 3, 77-119.
* Schur, Basil.  (1985)''Jarrah forest or bauxite dollars? : a critique of bauxite mine rehabilitation in the jarrah forests of southwestern Australia'' Perth, W.A. : Campaign to Save Native Forests (W.A.). {{ISBN|0-9597449-7-5}} (pbk.)
* Watson, Lindsay (1995) ''The Railway History Of Midland Junction : Commemorating The Centenary Of Midland Junction, 1895-1995'' Swan View, W.A : L & S Drafting in association with the Shire of Swan and the Western Australian Light Railway Preservation Association.
{{Refend}}

==References==
{{Reflist |30em}}

==External links==
* [https://web.archive.org/web/20080411053504/http://ghd.com.au/aptrixpublishing.nsf/AttachmentsByTitle/PP%2BPrecambrianRocks%2BPDF/%24FILE/Bulley_PrecambrianRocks.pdf  Engineering Geology of the Precambrian Rocks of the Darling Scarp]
* [https://web.archive.org/web/20050701131556/http://www.nacc.com.au/calci/Downloads/Stage%20One%20Report%20-%20Section%204.pdf Hydrology of the Perth Basin]
* [https://web.archive.org/web/20070708103058/http://www.naturebase.net/component/option,com_hotproperty/task,view/id,19/Itemid,755 Serpentine National Park]
* [https://web.archive.org/web/20081205043643/http://www.walkgps.com/Darling%20Scarp%20Walk.htm Darling Scarp Walk, bushwalk]

{{subject bar |auto=y |portal1=Western Australia |portal2=Geography |portal3=Mountains }}
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[[Category:Geology of Western Australia]]
[[Category:Physiographic sections]]
[[Category:Darling Range]]