Queenston Formation

The Queenston Formation is a geological formation of Upper Ordovician age (Maysvillian to Richmondian Stage), which outcrops in Ontario, Canada (along the northern and eastern flanks of the Niagara Escarpment, as well as east of Ottawa) and New York, United States (just south of Lake Ontario). A typical outcrop of the formation is exposed at Bronte Creek just south of the Queen Elizabeth Way. The formation is a part of the Queenston Delta clastic wedge, formed as an erosional response to the Taconic Orogeny. Lithologically, the formation is dominated by red and grey shales with thin siltstone, limestone and sandstone interlayers. As materials, comprising the clastic wedge, become coarser in close proximity to the Taconic source rocks, siltstone and sandstone layers are predominant in New York.