The geology of the lower Lorraine in the vicinity of Montreal.

The name “Lorraine” is applied to a group of sandy shale formations of Ordovician age whose type sections are found in northwestern New York on the southwest side of the Adirondack area. The Lorraine beds of New York and equivalent strata of other areas are underlain by black, more or less bituminous shales commonly known as the “Utica” shales. That all so-called “Utica” shales may not be identical in age with the typical Utica formation of Utica, New York, is, however, generally appreciated. Strata which have long been recognized as approximate equivalents of the Utica and Lorraine formations of New York State outcrop in the St. Lawrence Lowland. They are found from Montreal to Quebec over an area whose maximum lateral extent is about ten miles on the northwest side of the St. Lawrence River and thirty miles on the southeast side. The area is widest near Montreal and narrows rapidly near Quebec. [...