MAINE AND NEW BEUNSWICK. 65 



thai time, much more ample collectious have beeu made and have beeu examined by Mr. 

 "Whiteaves aud Mr. Ami, biit with the result of showing that while the Mount Wissick 

 rocks, as had been supposed, are in the main decidedly Lower Helderberg in age, those 

 of Point aux Trembles indicate a lower horizon, approximating more nearly to that of the 

 Niagara and Medina formations. This conclusion, which is confirmed by evidence seen 

 elsewhere, is most important, for not only does it indicate that the order of succession of 

 the strata in this vicinity is, as regards two at least of its divisions, the reverse of what 

 had been supposed, but that a great physical break, accompanied by unconformity, exists 

 here between the lower and upper half of the Silurian system itself. Further, from the 

 position aud low inclination of the Mount Wissick beds, and their entire absence from the 

 region west of Lake Temiscouata, it would follow that the entire mass of this group, of 

 nearly 600 feet in thickness, has been completely removed from an area of great extent. 



Taking now the rocks of the Temiscouata section as the key to the Silurian system 

 of eastern Quebec, no difficulty is found in identifying the rocks of Mount Wissick with 

 those described by various observers between the latter and Cape Gaspé. Thus, the pecu- 

 liar white sandstones, which form so conspicuous a feature at the base of the eminence 

 named, though apparently wanting in the typical section at Cape Gaspé, are readily 

 recognizable at many other points in the Gaspé Peninsula, such as the sources of the Chatte 

 and Matane Rivers, at Lake Metapedia, Grand Metis Eiver, the Valley of the Neigette 

 and Rimouski River, and in each instance are directly overlaid by a great body of 

 limestones, of which the fossils in the lower part belong to the upper portion of the 

 Niagara formation, and from this range up to and through that of the Lower Helderberg 

 Group. They also rest, as at Mount Wissick, directly but unconformably upon the rocks 

 of the Quebec Group, with no trace beneath either of the heaA'^y conglomerates of Black 

 and Burnt Points, or of the fossiliferous slates aud sandstones of Point aux Trembles 

 and Tuladi River. On the other hand, in a westerly direction, while these inferior 

 beds may be followed for several miles from Lake Temiscouata, the higher calcareous 

 members in turn disappear, being apparently cut off abruptly in the eminence of Mount 

 Wissick. The third or slaty division of the system is more persistent, and may be seen 

 with essentially the same characters on Metapedia River, on the Patapedia, the Quata- 

 wamkedgewick, the Restigouohe, the Madawaska and the upper St. John. Over these 

 extensive areas, the position of the beds is usually that of broad and low undulations, 

 but in places these are rei>laced, and often quite abruptly, by a high dip or by sharp 

 and complicated foldings. Very similar rocks, with similar variations of attitude, are 

 also spread over a large part of northern New Brunswick and Maine, where their soft and 

 highly calcareous character, combined with a strongly developed cleavage, have deter- 

 mined a district remarkable for the depth and productiveness of its soils. Here, however, 

 in connection with the movements to which reference has been made, there are a few 

 points in which strata resembling the inferior beds of Lake Temiscouata are brought to 

 the surface, and are found to contain a similar assemblage of fossils. One of these is near 

 the moirth of Siegas River in Victoria County, New Brunswick, and directly on the 

 border, where a nearly vertical series of strata consists in part of conglomerates, holding 

 (like those of Burnt Point on Lake Temiscouata) pebbles of limestone, serpentine aud 

 jasper ; in part of hard grey sandstones, holding besides Orthis and Strophomena (S. rhom- 

 boidalis) a Zaphrentis resembling a form found in the Point aux Trembles sandstones, aud 



Sec. IV, 18S9. 9. 



