8424-8 Macfarlane Lookout and The Brothers

This information has been developed from the publications:

Sites of Geological and Geomorphological Significance in Central Gippsland (1981) by Neville Rosengren, M.S McRae-Williams and S.M Kraemers.
Sites of Geological and Geomorphological Significance in the Gippsland Lakes Catchment (1984) by Neville Rosengren.
Sites of Geological and Geomorphological Significance in East Gippsland, Victoria (1981) by Neville Rosengren, M.S McRae-Williams

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 values. Reference should be made to the most recent reports. See the Earth Science Heritage section of the Geological Society of Australia website for details of geological heritage reports, and a bibliography.

Location:	715180- 672145. Approximately 10 kilometres north- east of Benambra.	The Brothers Range (Triassic syenite) and Morass Creek alluvial basin - Benambra.
Abstract:	Exposures of Triassic Syenites and Trachytes, alluvial basin and river gorge.
Access:	Mount Leicester Road and McKinnon road from Mathew Lane.
Ownership:	Crown Land on The Brothers and McFarlane Lookout, Privately Land in the Morass Creek Valley.
Geology:	Triassic Syenites from prominent hills at The Brothers, and MacFarlane Lookout. At The Brothers, the syenite varies markedly in texture from medium grained equigranular roda-syenite and soda-granite to strongly porphyritic varieties with phenocrysts of alkali felspar up to 8 centimetres in length. In contrast, the strongly porphyritic varieties are absent at MacFarlane Lookout. At this locality, fine to medium grained rocks with feldspar phenocrysts up to 4mm long are common.
Geomorpholgy:	Prominent cliffs mark the north eastern sides of both The Brothers and MacFarlane Lookout. These cliffs have resulted from weathering and block collapse along steeply dipping joint planes, which strikes approximately north west. Weathering along joint lines has also resulted in the formation of large tors up to 10 metres in height, on the steep slopes of The Brothers Range. Morass Creek dissects the Syenite mass between The Brothers and MacFarlane Lookout. The Morass Creek valley in this area has developed a small alluvial basin enclosed between short river gorge section.
Significance:	Regional. Exposures of the youngest acid intrusives in Victoria.
Management:	Because of the area covered by the site, the value of the significance geological/ geomorphological features is unlikely to be seriously reduced by localised land disturbance, eg. Road works or extractive industries.
References:	Crohn, P.W. 1950. 'The geology, petrology and physiography of the Omeo District, North-Eastern Victoria', Proc. R. Soc. Vict., 62 :1-70.

Site 8424-8

Image: East Gippsland Sites of Significance

Triassic syenite forming McFarlanes Lookout, Benambra.

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