At the beginning of the XIXth century, the sandstones in the Ville de Québec area were quarried to build some well-to-do residences of the city and to erect various military buildings such as the walls surrounding the old town, the Martello Towers and the Citadelle. These green or greenish grey sandstones are named Sillery Sandstones or Cap-Rouge Sandstones, their grain-size ranges from fine to very coarse and they consist mainly of quartz, feldspar and various rock fragments. The thickness of its beds facilitates the exploitation. Indeed, smooth surfaces are easily obtained by chiselling ( Jacob and Ledoux, 2003, p. 6).
Other similar sandstones, assigned to the Saint-Nicolas Formation (Sillery Group), are quarried farther east in the Province, namely:
- the sandstones of the Saint-Roch Group, in L’Islet;
- the sandstones of the Tourelle Formation, in Sainte-Félicité and Ruisseau-Castor;
- the sandstones of the Armagh Group, in Saint-Raphaël – Armagh.
Moreover, the sandstones quarried in Ruisseau-Castor were used to restore the walls of the Citadelle of Québec in 2003 and 2004.
In southwestern Québec, the sandstone of the Cairnside Formation was intensely exploited in the Havelock and Saint-Canut areas. It consists of quartz sandstone, usually white or grey, medium to coarse-grained, with a low porosity. The stone was destined to the production of flagstone used either to make buildings (facade stone), sidewalks or patios, or either as riprap revetment of viaducts talus. This sandstone has also been exploited in other areas, such as:
- Beauharnois – Melocheville;
Brightly coloured sandstones are extracted in more limited quantity in a few localities in Québec. Formerly used to build churches and residences, they are now used as landscaping stone for borders (flagstone paving, low wall) or as building stone for fireplaces. The Robitaille Formation sandstones have been modestly exploited in the Saint-Mathieu-de-Rimouski area, but they were recently further developed by exploration work. Brightly coloured sandstones have also been extracted in the following localities:
- Béarn (Lorrain Formation);
- Causapscal (Lake Branch Formation);
- Franklin-Centre (Covey Hill Formation);
- Papineauville - Montebello (Potsdam Group);
- Saint-Guy (Robitaille Formation);
- Ville-Marie (Lorrain Formation).
The fine-grained sandstones and siltstones of the Saint-Léon Formation are similar to the Blue Stone variety which has been exploited in northeastern U.S.A. for several decades. These stone, which have been used as building stone for house facades and as landscaping stone for driveways, low walls and culverts, are quarried near Saint-Cléophas and Sainte-Blandine. They were also quarried in the Humqui township.
Location map of the architectural
sandstone quarries in Québec