218 



STRUCTURAL GEOLOGY OF NORTH AMERICA 



suggests that the orogeny is an extension of the Appalachian orogenic belt 

 of the Canadian and United States Appalachians. 



Volcanic activity had died out by the Pennsylvanian after very little in 

 the Mississippian, and no Carboniferous intrusions have yet been noted. 

 The post-Barachois faulting and thrusting mark, as far as known, the last 

 compressional deformation in the Appalachian mountain systems of New- 

 foundland. 



Post-Appalachian History 



No Triassic fault basin sediments are known as in Nova Scotia and New 

 England, and no coastal plain sediments of Cretaceous or Tertiary age oc- 

 cur above water on Newfoundland. Without these signs of submergence, 

 it is concluded that the island has been mostly above sea level since the 

 Appalachian orogeny, and has been a site of erosion. It undoubtedly has 

 had broad connections with the Maritime Provinces and the Gaspe in the 

 Mesozoic. Likewise, the region of its northeastward projection into the 

 Atlantic must have been extensively emergent in times past. 



The broad banks off Newfoundland continue the continental shelf from 

 Nova Scotia, and as late Cretaceous fossils have been dredged off Nova 

 Scotia (see Chapter 10), one could assume the same fossil-bearing beds 

 will be found under the Banks of Newfoundland. An enticing experiment 

 would be the drilling of a deep well on Sable Island. 



Twenhofel and MacClintock ( 1940 ) have described three fluvial erosion 

 surfaces in Newfoundland in much the same aspects as in the central 

 Appalachians, and hence assign a similar history of Cenozoic epeirogenic 

 uplift to the island. The major difference is that the Maritime Provinces 

 and Newfoundland have not emerged as much as the Appalachians south 

 of New York City. If they should rise another 1000 feet, then much of the 

 continental shelf would be land and probably a large bordering coastal 

 plain with Cretaceous and Tertiary sediments would appear. 



Cabot Strait Fault (?) and Seismic Profile 



The Tectonic Map of Canada (1950) shows a fault along Cabot Strait 

 between Nova Scotia and Newfoundland, with the implication that it is a 

 transcurrent fault offsetting the structural elements of the two provinces. 



Fig. 13.12. Paleozoic orogenic belts of Greater Acadia. In addition to the Taconic, Acadian, and 

 Appalachian orogenies there were several others in various places that are not represented. The 

 post-Silurian Caledonian orogeny was pronounced in Newfoundland and Nova Scotia. A mid- 

 Ordovician Vermontian is known in the Vermont-Gaspe region. 



