DIFFERENT PROVINCES OF NORTH AMERICA IN LATE PALEOZOIC TIME 63 



and troughs were originally continuous over the greater part of southeastern 

 New England. The outward or northwestern border of the basal conglomer- 

 ates runs through the Boston Basin, bends southward past Woonsocket, and 

 thence runs near the west shore of Narragansett Bay. In the region north 

 and west of this line the basal formation was fine sand, instead of gravel, and 

 was overlain by fine mud, and the deposits of this kind were probably laid 

 down in interfluvial plains that were afterward overspread by lagoons 

 occupied by vegetation. The western margin of the great sheet of de- 

 posits was somewhere near the east side of the present Connecticut Valley. 



A suggestion of the continuation of the Pennsylvanian deposits of the 

 Boston Basin is found in New Hampshire and Maine.^ The Kittery quartz- 

 ite is correlated by Katz with the Merrimac quartzite of eastern Worcester 

 County, Massachusetts, and the Merrimac Valley, and the overlying Casco 

 group of metamorphosed sediments is probably equivalent to the schists 

 which lie above the Merrimac quartzite. 



In Rhode Island Warren and Powers^ have distinguished two groups of 

 Pennsylvanian rocks which they regard as of equal age, the Narragansett 

 and the Bellingham. The Narragansett consists of four formations, the 



Dighton group. 

 Pawtucket formation. 

 Wamsutta red beds. 

 Pondville arkose. 



The Wamsutta red beds consist of red conglomerate shales and sand- 

 stones. The Pawtucket formation is "largely shales, sandstones, and some 

 conglomerates." The age of the Narragansett series has been considered 

 to be Pottsville-Allegheny from the paleobotanical evidence. Later dis- 

 coveries by Haynes^ of bivalve Crustacea, Esthcria sp. and Leaia tricarinata 

 M. and W., with Cordaites and Calamites in the Pawtucket suggest Cone- 

 maugh, but are not definitive. 



The Bellingham group consists of lustrous green schists and sheared 

 conglomerates. "The age of the Bellingham series is supposed to be the 

 same as that of the Narragansett series. The character of the rock with its 

 associated amygdaloids places it unquestionably in the Carboniferous." 



The uncertainty of the stratigraphic position of the beds in Boston Basin 

 and adjacent areas, as determined by accepted methods or correlation, is 

 clearly recognized by the author; for that reason he suggests a test of the 

 value of correlation by " environmental conditions." 



> Katz, Frank J., Stratigraphy in Southwestern Maine and Southeastern New Hampshire, 

 Professional Paper No. io8, U. S. Geological Survey, p. 165, 1917. 



2 Warren, Chas. H., and Sidney Powers, Geology of the Diamond Hill-Cumberland District 

 in Rhode Island-Massachusetts, Bull. Geol. Soc. Amer., vol. 25, p. 447, 1914. 



5 Haynes, W. P., Science, vol. 37, pp. 191-192, 1913. 



