186 



STRUCTURAL GEOLOGY OF NORTH AMERICA 



Fig. 11.32. Gulf of Maine and contnental shelf off Nova Scotia showing location of seismic 

 profiles and Triassic basin in Bay of Fundy. 



ously been called a pelite, shale, argillite, and slate. It contains some 

 quartzite beds. 



Dott ( 1961 ) believes the Roston Ray group may be mid-Paleozoic and 

 not Carboniferous, and also that the Squantum is not a tillite but rather 

 an orogenic clastic interfingered in the other lithologies. 



Gulf of Maine 



Cenozoic and Cretaceous Geology. The continental shelf extends east- 

 ward from Nantucket and Cape Cod, and a broad peninsula-like platform 



under less than 500 feet of water, bounded 1 on the north by the Gulf of 

 Maine and on the south by the deep Atlantic, is known as Georges 

 Rank (Fig. 11.32). The Atlantic margin of the bank is trenched by deep 

 submarine canyons, and from their walls have been dredged rock samples 

 carrying both Tertiary and Upper Cretaceous fossils. Fragments of a 

 coarse sandstone, Lower Monmouth or Upper Matawan (both Upper 



MT. KATAHDIN 



LATE PLIOCENE 



MODERN WAVE-SMOOTHED BANK 



Gulf of Maine 



GEORGt'J BAr. 



Po/eozo/l ~ , ~ r" / - - V -'J~ ~ 



"'-• v rocki 



OP <-\U]=. 



Fig. 11.33. Evolution of the Gulf of Maine and Georges Bank, generalized after a 

 chart exhibited at the Geological Society of America meetings, 1948, by G. H. Chadwick and 

 with his permission. Vertical scale greatly exaggerated. 



