Cobrico Swamp

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 The review of eruption points was based on an earlier unpublished manuscript Catalogue of the post-Miocene volcanoes of Victoria compiled by O P Singleton and E B Joyce (Geology Department, University of Melbourne 1970).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 19 00S 143 01 00E (external link); 7521-3-4 (Cobden) & 7421-2-1 (Dixie) 767582. 6 km NW of Cobden. Cobden - Terang Road. Heytesbury.	Cobrico Swamp.
	Small lake on eastern side is public land. Crater rim and most of crater floor is private land.
Type 7:	Tuff ring and maar crater.
	The Cobrico Swamp site comprises a tuff ring 2 km in diameter and 15 m high enclosing the shallow crater of maar. The tuff ring is semi-circular and of even height in the north and west but is lower and less distinct in the south-west. There are a few exposures of laminated tuff. The crater floor is occupied by a small lake on the eastern side and the rest is drained swampland. The floor is peaty and overlies white clay. Recent mapping indicates the tuff is surrounded by limestone.
	120+m; 15 m.
Regional:	This is an excellent example of a simple maar with enclosing tuff ring. It is one of the few that have not been quarried and the tuff ring is little disturbed and contains a small enclave of public land (Cobrico Lake). It may contain sedimentary/organic material in the floor that is significant for palaeoclimatic studies of western Victoria.
References:	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. Ollier , C.D.1967b. Maars: their characteristics, varieties and definition. Bulletin volcanologique 31, pp. 45-73. Edwards, J. 1991b. Geology of the Cudgee 1:25 000 map, Port Campbell Embayment, East Otway Basin, Victoria. Geological Survey of Victoria Unpublished Report 1991/7.

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