SILURIAN. 



255 



the vertical strata of the Quebec group here support an even layer of 4 feet of hard grayish- 

 white strong sUiceous conglomerate, which divides into layers of a foot or two, and would make 

 good millstones. It dips S. 4° W. <38° and is conformably overlaia by a great series of fossil- 

 iferous limestones and shales. At a point about 230 yards along the beach from the millstone 

 layer these calcareous strata dip S. -3° E. < 45°, in a cliff 100 to 120 feet high. Upon the basset 

 edges of these the beds of the upper conglomerate are seen to repose, with a dip S. 42° E. <20°. 

 These stretch along for 200 yards, presenting a perpendicular precipice in front; whdle the 

 underlying calcareous series forms a talus and occupies sometimes more and sometimes less than 

 one-half the height of the cliff. 



This unconformity is well established farther south. From the Bay o'f Chaleur 

 the eastern margin of the Silurian extends southwestward across New Brunswick 

 into Maine. The areal distribution is not well known, the structure being compli- 

 cated, the Cambrian, Ordovician (?), and Silurian rocks being similar, and intrusive 

 rocks abundant; but in the course of a resurvey of the line between the "Cambro- 

 Silurian" (Ordovician) and the Silurian, Bailey** found "incontestable evidence of 

 discordance along its whole length." He cites occurrences of conglomerates con- 

 taining pre-Silurian rocks at the base of the Silurian strata. 



Bailey*'® summed up the known facts of the stratigraphy of the Silurian of 

 northern and southern New Brunswick as follows: 



Sequence of Silurian strata in southern New Brunswick. 



Southern Queen's County. 



Feet. 



I. Gray and dark-gray slates 400 



II. Ijark-gray and black siliceous clay slates, dis- 

 tinctly banded 600 



III. Dark-gray and greenisb-gray, sometimes pur- 

 plish sandstones, becoming slaty above 600 



IV. Ash-gray and greenish-gray schistose beds, 

 dioritic and amygdaloidal 300 



V. Gray and dark-gray, sometimes reddish' por- 

 phyritic felsites, with chloritic schist and 

 breccia conglomerate 800-f- 



Uascareen Peninsula. 



Feet. 



I. 



II. 



Gray feldspathic slates, about 400 



Grray and black banded siliceous slates, with 

 nodular layers 620 



III. Gray flaggy sandstones, with some conglomer- 



ate. Shells of Lingula, Modiolopsis, and 

 Loxonema?, with comminuted vegetable 

 matter 350 



IV. Red and green slates and sandstones, with 



diorites and felsites 300 



V. Dark-gray and reddish porphyritic felsites... 300? 



In the same work Bailey details the relations of the strata of southern New 

 Brunswick, northern New Brunswick, Quebec, and Maine, and sums up as follows: 



Supposed sequence of Silurian strata in northern New BrunswicTc, Quebec, and Maine. 



[Ascending section.] 



Divisions I and II. — Gray argillaceous and siliceous slates, iacluding (locally) heavy beds of conglomerate. Fossils 

 somewhat numerous ia upper part, including shells and graptolites, indicating a low Silurian horizon. 



Conglomerates and succeeding slates of Black and Burnt points, on Lake Temiscouata; feldspathic and siliceous 

 slates of Fish River and AUeguash River, Aroostook County, Me.(?). Conglomerates and graptolitic slates of 

 Beccaguimic River, Carleton County, New Brunswick. Supposed to be equivalent to the Medina and Clinton 

 groups of New York, divisions 2 and 3 of Anticosti group, or groups B and B' of Arisaig. 

 Division III, A. — Gray flaggy and massive sandstones, with some conglomerate, becoming frequently greenish or pur- 

 plish and more or less amygdaloidal. Fossils rather numerous, including corals and shells, as well as worm tracks 

 and comminuted remains of plajits. 



Sandstones and conglomerates of Pointe aux Trembles, Tuladi and Squatook rivers, Quebec; similar beds of 

 Siegas River, New Brunswick; sandstones and conglomerates of Aroostook County, Me.; similar beds of Becca- 

 guimic River and other parts of Carleton County, New Brunswick. 



Niagara formation, or Wenlock group. 

 Division III, B. — Lower sandstones, shales, and limestones of the Gaspe Peninsula. S imila r sandstones and limestones 

 of the head-waters of the Chatte and Matane rivers, Metapedia Lake, Metis and Rimouski rivers, and lower part 

 of Moimt Wissick. Fossils numerous, marine. 



Supposed to be equivalent to the Guelph formation of Ontario. 



