ASHBURTON, a river in the north-west division of Western Australia. It drains north-westward from the interior plateau (average elevation : 2,000-3,000f t.) which its upper tributaries dissect. The greater part of its course of 400m., however, is through wide alluvial plains traversed by low ridges, though there are gorge sections along the main stream and its tribu taries. The highly-inclined and folded (Pre-Cambrian) rocks are traversed by quartz reefs in which gold, as well as some lead and copper, occur in widely scattered localities. Gold has been ex plbited but the yield has not been great. Along the lower course of the Ashburton, the wide coastal plains are utilised for pastoral purposes. The rainfall is here very unreliable (Onslow [1891— 191o] shows a variation of 1-2 Tin. annual fall) and the tempera tures are high (mean annual 75-80°). In the area inland from Onslow is one of the hottest parts of Australia, with an average of 90° for January. These drawbacks, however, have not proved prohibitive. Artesian water is available southwards from Onslow and the provision of a railway line would stimulate development. At the mouth of the Ashburton river the port of Onslow (924m. by sea from Fremantle) has a jetty (1,12oft. long), but a shah low and exposed anchorage. Its population includes some loo Europeans, and it exports cattle, sheep, wool, hides and skins, and mineral ores derived from its hinterland. Pearl fishing is also carried on in the adjoining coastal waters and pearl shell is shipped from Onslow. The Ashburton itself is not navigable.