Ashfield Shale

Ashfield Shale
Stratigraphic range: Middle Triassic PreꞒ Ꞓ O S D C P T J K Pg N
Exposed Ashfield Shale of the Wianamatta group, near the Pacific Highway, Chatswood, Australia
Type	Geological formation
Unit of	Wiannamatta group
Sub-units	Kellyville Laminite Member, Mulgoa Laminite Member, Regentville Siltstone Member, Rouse Hill Siltstone Member
Overlies	Mittagong Formation
Thickness	up to 64 metres (210 ft)
Lithology
Primary	Shale
Location
Location	Sydney Basin
Country	Australia
Type section
Named for	Ashfield

Ashfield Shale is part of the Wianamatta group of sedimentary rocks in the Sydney Basin. It lies directly on contemporaneously eroded Hawkesbury sandstone or the Mittagong formation. These rock types were formed in the Triassic Period.^[1] It is named after the Sydney suburb of Ashfield. Some of the early research was performed at the old Ashfield Brickworks Quarry. This rock type is often associated with the Inner West and North Shore of the city. However, it has also been recorded at Penrith, Revesby, Bilpin and Mount Irvine.