L6 - Mortons Quarry, Main Quarry - Permian Deposits

This information has been developed from this publication:

Sites of Geological and Geomorphological Significance in the Western Region of Melbourne (1986) by Neville Rosengren

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 (external link) section of the Geological Society of Australia website for details of geological heritage reports, and a bibliography.

Location:	Lerderderg - 715298. Shire of Bacchus Marsh. Southern slopes of Bald Hill (Bacchus Marsh) extending to Grey Street by Tramway lane.	Mortons Quarry, Main Quarry - Permian Deposits
Access:	Tramway Land and Grey Street.
Ownership:	Private land
Site Description:	The denuded slopes and the quarries (Mortons Quarry and Main Quarry) south of Bald Hill (Bacchus Marsh) expose a wide section of Permian sediments including glacial tillies, outwash conglomerate and fluvial sandstones. Numerous unusual structures include a sedimentary dyke, folds, slumped and contorted beds, and a possible fossil soil. The beds have revealed plant fossils and spores allowing age determination.
	Lower in the cliff are beds that are the type locality of the Morton Conglomerate Member. Several specimens of a marine fossil have been collected from these beds, indicating a minor marine incursion into this otherwise terrestrial depositional environment.
	Several major publications refer to the detailed stratigraphy and geological history of the Permian deposits at Korkuperrimul Creek.
Significance:	International. The site is a major exposure of the Permian deposits of the Bacchus Marsh district. It includes depositional and structural features not observed elsewhere in the Permian rocks and is the type locality for the only known marine beds in the sequence. The deposits are therefore unique in the Permian in Victoria and important in the global context of determining the palaeogeography of the glacial period.
Management:	Class 2. The quarries should not be reclaimed, filled or used for a purpose that would cover the unusually extensive exposure of Permian rocks. The steep degraded slops are not suited for agriculture or housing development, and the massive soil conservation measures needed to allow these would lead to the concealment of the significant outcrops. Further limited quarrying could be permitted, but the sandstones appear not to be suitable for building stone. Part of the significance of this site lies in the clear and accessible exposures on moderate slopes, as most other Permian exposures occur on high steep cliffs which are difficult or even dangerous to access as teaching sites. Management should therefore aim to maintain the accessibility and exposure of the Permian sediments.
References:	Bowen RL and Thomas GA (in Douglas JC and Ferguson JE) (1976) Crowell JC and Frakes LA (1971) Roberts P (1984, 1985) Jacobson R and Scott TR (1937)

Image: Sites of Significance Werribee L6a

Mortons Quarry, Main Quarry

Site - L6

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