Amabel Formation
Description
The Amabel Formation is an erosionally-resistant dolostone that forms the caprock (a harder or more resistant rock type overlying a weaker or less resistant rock type) at the Niagara Escarpment. The Formation is the surface rock unit which is exposed along the Escarpment brow and the Escarpment face, and it occurs near ground surface for several kilometres to the south and west of the Escarpment. It is characterized by white to blue-grey, thick- to massive-bedded, dolostones, which form the white cliffs of the Niagara Escarpment north from the Dundas Burlington area to Manitoulin Island. The light coloured, massive-bedded dolostones of the Amabel include crinoidal grainstones and fossiliferous biohermal facies.
The Amabel Formation is quarried at the existing quarry operation, and it is the Amabel Formation that is proposed to be quarried at the expansion lands. The Amabel Formation is recognized as a provincially significant aggregate resource, and has been used to manufacture a variety of products, including crushed granular, asphalt and concrete products, building stone and lime.
How it is Formed
The Amabel Formation is a dolostone, which is a variation of limestone, in which some calcium in the rock has been substituted by magnesium making the rock more resistant to weathering. The Formation, deposited by seas during the mid-Silurian period, some 420 million years ago, is the predominant strata of the Niagara Escarpment.
Hydrology
The fractured limestone and dolomite of the Amabel and Guelph formations readily permit groundwater flow and are among the most significant aquifers in Southern Ontario, including north Burlington.
The bedrock – the Guelph and Amabel Formations - extend in a wide band across Southern Ontario from the Bruce Peninsula to Niagara Falls. The bedrock formation is a good aquifer because it has large open spaces and cracks in some of the layers of rock. Wells in this aquifer are capable of providing sufficient water for individual houses or for large municipalities.