304 



WALCOTT 



Classification of the Formations. 



Lower 

 Calciferous. 



Lower portion of the Calciferous sandrock of 

 New York and Canada ; Lower Magnesian lime- 

 stone of Wisconsin, Missouri, etc 



a. 



P 



Potsdam. \ 



Type. 



Sandstones of the north and east sides of the Adi- 

 rondack Mountains of New York and adjoin- 

 ing parts of Canada. 



Correlated. 



Limestones of the south side of the Adirondacks 

 and Dutchess County, New York, and an un- 

 known portion of the limestones of the ' Mar- 

 ble Belt' of western Vermont. 



Shales of Tennessee (Knox), Georgia, and Alabama 

 (Connasauga). 



Sandstones of the Upper Mississippi Valley (St. 

 Croix), South Dakota, Wyoming, Montana, 

 and Colorado. 



Sandstones and calcareous beds of northern Arizona 

 (Tonto) and central Texas (Katemcy). 



Limestones and shales of Nevada (Hamburg), 

 Idaho, and Montana (Gallatin). 



Black shales of the upper portion of the New 

 Brunswick and Cape Breton Island sections. 



Shales and sandstones of Conception Bay, New- 

 foundland (Belle Isle). 



Type. 

 Shales and slates of eastern Massachusetts (Brain- 

 tree), New Brunswick (St. John), and eastern 

 Newfoundland ( Avalon ) . 



5 Acadian. \ Correlated. 



Limestones of Dutchess County, New York (Stis- 

 sing), and central portions of Tennessee and 

 Alabama sections (Coosa). 



Limestones of central Nevada and British Colum- 

 bia (Mount Stephen). 



Geor{!;ian. 



Type. 

 Shales and limestones of western Vermont (Geor- 

 gia) and Red Sandrock. 



Correlated. 



Quartzite of western slope of Green Mountains 

 ( 'Granular Ouartz' ) and Appalachian Range of 

 Pennsylvania, Virginia, Tennessee (Chilho- 

 wee), Georgia, and Alabama. 



Shales with interbedded limestones and roofing 

 slates of southern Vermont, New York, and 

 south to Alabama. 



Limestone, sandstone, and shales of Straits of Belle 

 Isle (Labrador), northwest coast of Newfound- 

 land and peninsula of Avalon (Placentia). 



Basal series of Hanford Brook Section, Caton's 

 Island, etc., New Brunswick (Hanford). 



Shales and limestones of eastern and southeastern 

 Massachusetts ( Attleborough). 



Lower portion of Eureka and Highland Ranges, 

 Nevada (Prospect). 



Portion of Wasatch Cambrian section (Cotton- 

 wood). 



Base of Castle Mountain limestone, British Co- 

 lumbia (Castle Mountain). 



