Site 9 Capp Reserve, Preston - Melbourne Formation

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:	YARRA 5000/04.08 E21625 N19840
	Vertical cliff (quarry face remnant) on two sides of the tennis courts at the southern end of Halwyn Cr at the eastern side of A.H. Capp Reserve, Preston.
Access:	Miller Street and Strettle Street, Thornbury and Halwyn Crescent, Preston.
Ownership & Municipality:	Public Land, City of Preston
Site Description:	The cliffs are the remaining faces of the large clay quarry that occupied this site. They form an “L” shape around the northern and eastern sides of the tennis courts and provide two excellent sections, at different angles, into dipping Silurian sedimentary rocks of the Melbourne Formation. Differences in lithology, as well as bedding, jointing, weathering and small thrust faults are very clearly displayed. Fractures and some beds are enriched by red-brown limonite which contrasts with the original pale colour of the sediments. The true dip of the beds is uniformly towards the east-south-east as the site lies just east of the axis of the Whittlesea Anticline, one of the major fold areas of the Silurian rocks in the Melbourne area. Because the cliffs provide adjacent sections at right angles, the true dip (i.e. the real dip to the E-S-E) is seen only on the northern face, while the eastern face shows an apparent dip to the south. The sedimentary rocks are cut by two small decomposed dykes.
Significance Rating:	Regional.
	This is an excellent section of the Silurian sedimentary rocks of the Melbourne district. Many of the exposures of these rocks are in road or rail cuttings and access is often hazardous. By contrast this is a recent, clear and clean section that is always safely accessible. Its open nature and westerly aspect mean that the rock faces are well illuminated. It is an excellent site for geological study of the composition, deformation and alteration of the bedrock of the Melbourne area and for illustrating true and apparent dip. It is the best locality to see one of the small, decomposed dykes that are common in the Melbourne Formation.
Site Sensitivity:	Class 2.
	As the site is a relatively recent exposure the features are fresh and clear. The main threats are from natural deterioration, vegetation growth and visitor pressure. This mudstone deteriorates relatively quickly on exposure and some flaking and spalling is already apparent and small talus piles and fans are accumulating at the base of the cliffs. The faces are easily damaged by climbing and geological hammering. The closeness of the tennis court fence interrupts the view of the faces and hinders photography. These exposures should be managed as significant geological features and given priority over other forms of land use in the area.
References:	Bell, G. et al. 1967, Geology of the Melbourne District, Bull. Geol. Surf. Vict., 59.

Page top