Geological and Archaeological Resources

Lower FallsBall’s Falls is recognized as a unique and outstanding geographical and geological feature in the Niagara Region and of the Niagara Escarpment. With Lake Ontario to the north and Lake Erie to the south, the Niagara Peninsula has one of the mildest climates in Ontario. Twenty Mile Creek has the largest drainage area of all creeks emptying into Lake Ontario in the Niagara Peninsula.

The rich archaeological resources located at Ball’s Falls and the former Glen Elgin hamlet offer excellent opportunities for unique interpretation and public education. Many of the various Silurian and Ordovician rock strata of the Niagara Peninsula are exposed in the gorge.

The lower, main Ball’s Falls plunges over the Irondequoit limestone, which is a resistant layer overlying several weaker shale and sandstone units (Reynales, Thorold, Grimsby, Power Glen formations). The upper falls is formed by the Lockport Dolostone, which is the same unit that forms the crest of Niagara Falls.


The lower falls have the following formations:

  1. Irondiquoit Formation: Crystalline crinoidal limestone forming the lip of the cataract and acting as a resistant cap rock.
  2. Reynales Formation: A thick to thin bedded dolomite with dark grey shale partings.
  3. Thorold Formation: A green-gray, cross-bedded sandstone with green shale partings; these units intermingle with the underlining red sandstones and shales of the Grimsby formation.
  4. Grimsby Formation: Red sandstones and shales which blend in the overlying Thorold Formation; the lower half of this unit is mostly red shale.
  5. Power Glen Formation: Green-gray siltstones alternating with shale bands, this unit is exposed at the base of the waterfall and exposures continue downstream for approximately 95m.

The upper falls have the following formations:

  1. Decew Formation: A fine-grained, grey dolomite, which shows conchoidal fracture patterns on a weathered surface.
  2. Lockport Formation: Fine-grained, crinoidal, grey-brown dolomite, which is the cap rock for the cataract.
  3. Rochester Formation: Dark grey shale forming the base of the cataract; it has a blocky, weathered appearance