Blue Mountain Formation

The Blue Mountain Formation (previously the Whitby Formation) is a geological formation of Upper Ordovician age (Maysvillian Stage), which outcrops in Ontario, Canada from Nottawasaga Bay southeastward to the Toronto area.^[1][2]

Blue Mountain Formation
Stratigraphic range: Maysvillian PreꞒ Ꞓ O S D C P T J K Pg N
Blue Mountain Formation outcropping along the Little Rouge Creek.
Type	Geological formation
Sub-units	Rouge River Member
Underlies	Georgian Bay Formation
Overlies	Lindsay Formation
Thickness	Up to 76 metres (250 ft)
Lithology
Primary	Shale
Other	Limestone, siltstone
Location
Region	Southern Ontario,
Country	Canada
Type section
Named for	Blue Mountain
Named by	W. A. Parks
Year defined	1928