14 L. W. BAILEY : 



mining the formation oï limetones at Anticosti and to some extent along the St. Law- 

 rence valley, but mostly marked by shallow-water sediments, mingled, according to Sir 

 "VY. Dawson, with the products of ice-driftage ; and followed by a period of disturbance 

 in which these same sediments, including those of the so-called Quebec Gri'oup, wei'e 

 compressed and uplifted into the ridges now constit^^ting the Notre Dame range and the 

 axis of the Gaspé peninsula. Further south, similar movements may have affected the 

 Cambro-Silurian strata of central and northern New Brunswick, producing a partial sub- 

 division of the basin into a northern and a southern area. 



(5.) A continuation during the first half of the Upper Silurian, of conditions 

 similar to those of the Lower Silurian in south-eastern Quebec and northern Maine, viz., 

 of shallow water sediments, including locally heavy beds of conglomerate, and thick 

 accumulations of volcanic origin, but chiefly limestones at Anticosti ; followed, however, 

 by movements which in the northern half of the basin led to a greater depression of the 

 latter and the formation of impure limestones and calcareous shales over much of 

 northern Maine, as well as New Brunswick, but in the south by a movement of elevation 

 which, except at a few points along the coast, raised this region above the sea-level. 



(6.) The apparent limitation of purely marine deposition in the Devonian to the 

 northern division of the Acadian basin, and mostly to its first or Oriskany period. Along 

 the southern coast the plant and insect-bearing beds of St. John and Carleton referred 

 to the Hamilton Group, point to their probable origin along the northern border of a 

 trough coinciding in the main with that of the present Bay of Fu.ndy, and about the 

 mouths of rivers Avhich may in part mark the beginning of the modern St. John ; while 

 the character and fossils of the slates bordering the central coal-field indicate the con- 

 tinued existence there of the great central basin. The distribution and character of the 

 rocks bordering Bay des Chaleurs, with their remarkable assemblage of land plants and 

 of fishes, both ranging from the Lower to the Upper Devonian, clearly indicate the 

 existence of the depression during the continuance of these periods, as well as its general 

 correspondence with that which now exists. The abundance of trappean deposits in 

 association with these rocks would further indicate that the region was one of consider- 

 able instability, and subject to frequent igneous outbursts. Near the Bay of Fundy, and 

 in the interior of New Brunswick, such traijpean masses do not accompany the Devonian 

 strata, or only to a limited extent, but important physical movements are indicated by the 

 marked discordance of attitude between the lower and higher beds of the formation. 



(*7.) An epoch, or epochs, of excessive disturbance, plication and uplift, accompani- 

 ed by regional metamorphism, and the extrusion of great masses of granite, in the 

 interval between the close of the Silurian era and that introducing the Carboniferous 

 age. The granites have invaded and altered the Silurian strata upon an extensive scale, 

 while they are not known, at least in New Brunswick, to have so invaded the Devonian 

 rocks. The fact, however, tliat the latter, in common with all the Pre-Carboniferous 

 strata, show abundant evidence of alteration and a parallelism with the granitic axes, 

 gives support to the view that the period of origination of these granites was the close 

 of the Devonian era. 



(8.) A general depression in the Lower Carboniferous era, affecting but slightly the 

 northern and western portions of the New Brunswick, but to a greater extent its central 

 and southern parts, submerging all preexisting valleys, both in New Brunswick and 



