Ewen Hill

This information has been obtained from the report: Eruption Points of the Newer Volcanic Province of Victoria by Neville Rosengren. This report was published in 1994 and was prepared for the National Trust of Australia (Victoria) and the Geological Society of Australia (Victorian Division). The review of eruption points was based on an earlier unpublished manuscript Catalogue of the post-Miocene volcanoes of Victoria compiled by O P Singleton and E B Joyce (Geology Department, University of Melbourne 1970).

Geological heritage sites, including sites of geomorphological interest and volcanic heritage sites, are under regular revision by the Geological Society of Australia, especially in the assessment of significance and value. Reference should be made to the most recent reports. See the Earth Science Heritage (external link) section of the Geological Society of Australia website for details of geological heritage reports, and a bibliography.

Location:	38 16 08S 143 01 35E (external link); 7521-3-4 (Cobden) 766626. 11 km SW of Camperdown. Kerrs Road. Hampden.
Land Tenure/Use:	Private with public land around Ewen Hill Reservoir. Scoria quarry.
Type 8:	Nested/buried tuff ring maar.
	Ewen Hill is an arcuate ridge which is the highest point of a broad circular hill of scoria and tuff that rests on an outcrop of Tertiary limestone on the eastern side of Mount Emu Creek. The hummocky ridge is the summit of two scoria cones that overlie a former maar crater. The maar was the initial eruption event blowing out blocks of limestone and phreatomagmatic tuff. Later, small flows of lava and substantial scoria eruptions built a cone that largely infills the maar crater and buried most of the tuff ring. The Ewen Hill Reservoir lies in a shallow valley that is a part of the tuff ring not covered by scoria. The site is noted for the abundance of Cr-diopside lherzolite series xenoliths and clinopyroxene megacrysts.
	160+m; 150 m.
Regional:	The site is an example of the burial of a tuff ring by substantial later scoria eruptions. It is also of significance as a xenolith and megacryst site.
References:	Grayson, H.J. & Mahony, D.J. 1910. The geology of the Camperdown and Mount Elephant districts. Geological Survey of Victoria Memoir 9. Ollier, C.D. & Joyce, E.B. 1964. Volcanic physiography of the Western Plains of Victoria. Proceedings of the Royal Society of Victoria 77, pp 357-376. Irving, A.J. 1974. Megacrysts from the Newer Basalts and other basaltic rocks of south-eastern Australia. Geological Society of America Bulletin 85, pp. 1503-1514.

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