E3 Green Hill (Mount Mary) - Eruption Point, Limestone Blocks

This information has been developed from one or more of these publications:

Sites of Environmental Significance in the Flood Plain of the Upper Yarra Valley Region (1983) by Neville Rosengren, Douglas Frood and Kim Lowe (as part of a study of Sites of Environmental Significance by the University of Melbourne for the then Upper Yarra Valley and Dandenong Ranges Authority).

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	Eyensbury - 830133. Shire of Werribee. 6 km south of Melton Reservoir.
Access	Mount Mary Road, Springhill Road.
Ownership	Private land.
Site Description	Green Hill is an eruption point with a broad flattened summit enclosing a shallow, indistinct crater. Lava flows extend to the east and south, while the northern and western slopes consist of scoria and blocks of broken basalt. Many of these blocks of vesicular basalt, scoria and tuff include large fragments of clays containing casts of marine fossils including gastropods, bivalves, and brachiopods. These have been derived from the underlying Tertiary sediments and carried upward by the eruptive gasses and as inclusions in lava and scoria bombs.
Significance	Regional. The hill is one of the major topographic features of the Werribee Plains and the site includes an unusual example of inclusions of the country rock contained in erupted material. It illustrates the nature of the Tertiary sediments that lie below this part of the Werribee Plain.
Management	Class 2. Many of the erupted fragments have been gathered or cleared from the site or broken up during cultivation. To preserve the integrity of the site and retain the upper slopes that include the fossil blocks, it will be necessary to limit residential or other built environment development to below the 110 metre contour. Above this level the slopes should be retained in a public open space system.
References	Kitson, A.E. (1902). Observations on the Geology of Mount Mary and the Lower Werribee Valley. Proc. R. Soc. Vict. 14:153-165. Condon, M.A. (1951). The Geology of The Lower Werribee River, Victoria. Proc. R. Soc. Vict. 63:1-24.

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