The Quebec Stratigraphic Lexicon is a collection of all stratigraphic units identified in the Province of Quebec. It contains information coming from geological surveys conducted by the Government of Quebec and its partners for over 100 years. It is an essential tool for understanding and preparing geological maps published in the Système d’information géominière du Québec (SIGÉOM).
The list of stratigraphic units is constantly updated with the progress of geoscientific works and stratigraphy. Regularly, geological units are created, updated or abandoned.
In North America, the nomenclature and classification of stratigraphic units are governed by the North American Stratigraphic Code (1983, 2005) developed by the North American Commission on Stratigraphic Nomenclature (NACSN). This code provides several categories of geological units; in Quebec, however, only lithostratigraphic and lithodemic units are in use. The former meet the law of superposition (volcanic and sedimentary rocks, weakly or non-metamorphosed), while the latter do not (intrusive, heavily metamorphosed and/or intensely deformed rocks). The adjacent conceptual sketch illustrates this difference in a very simplified way, as well as the hierarchical ranks applied in each case.
Since 2016, descriptions of these units are published on the web in stratigraphic sheets, which also offer direct and rapid access to SIGÉOM data and maps. In addition to the list of stratigraphic units of Quebec, these sheets are also accessible through search engines (e.g., Google, Bing or Yahoo), SIGÉOM à la carte and the SIGÉOM interactive map.
The stratigraphic units are listed in the original French version of this page by geological province. The names of formal units are capitalized and those of informal units are lowercased, while abandoned units are italicized. Subprovinces and geological domains are in bold. A hyperlink refers to the stratigraphic sheet and, if available, to the English version (in brackets). Please use your browser search tool (CTRL+F or CMD+F) to find a specific stratigraphic unit within this list.
Did you know? By clicking on a polygon in the Interactive Map, an informative cartouche appears; if the stratigraphic label in the Stratigraphy section contains an active link, click on it to display the stratigraphic sheet of the considered geological unit.
Go to the Geological Area section to search for a specific stratigraphic unit. You can search by unit name by clicking on Values accompanying the Stratigraphic code field.