252 INDEX TO THE STRATIGEAPHY OF NOETH AMERICA. 



at times, holding a lamellibranchiate fauna and graptolites. At the base occurs the "Arisaig" 

 formation, which comprises buff-weathering fine-grained compact sandstones and shales, con- 

 taining corals (chiefly Streptelasma), brachiopods, gastropods, and trilobites. The thorough 

 investigation of this series of strata, which, indeed, may require further subdivision, is expected 

 to furnish data bearing on the settlement of the mooted question as to where the Silurian 

 stops. * * * 



In the county of Annapolis, Nova Scotia, and in the vicinity of Nictaux Silurian strata 

 occur, including the Nictaux iron ore beds and the Torbrook sandstone formation, whilst near 

 Kentville the KentviUe formation is seen, as weU as on Angus Brook, in the Gaspereau Valley, 

 also at New Canaan, with Dictyonema websteri Dawson, and at Wolfville, in King's County, 

 where coralline limestones, red and green graptolitic slates, and other strata, at tildes highly 

 cleaved, squeezed, and metamorphosed, form conspicuous ridges and constitute the oldest 

 sedimentaries in the vicinity of the Bay of Fundy and the Blomidon region in the "land of 

 Evangehne." 



In Cumberland County, along the northern slope of the Cobequids, isolated areas of Silurian 

 strata have been mapped out and described by Mr. Scott Barlow and Mr. H. Fletcher, the 

 Wentworth and Farmington areas being among the most important and best known. These 

 appear to belong to the lower half of the Silurian. 



L-M 19-20. MAINE, NEW BRtrMTSWICK, AND GASPE. 



Northeastern Maine, northwestern New Brunswick, and the Gaspe Peninsula 

 are occupied by a broad synclinorium of Silurian strata, which appear to lie uncon- 

 formably upon folded and eroded Cambrian rocks and are overlain conformably 

 by Devonian rocks. 



A section which is typical for Maine and New Brunswick is that observed on 

 Temiscouata Lake, just across the boundary in Quebec. This section was described 

 in great detail by Logan ®*^* and has been reexamined by Bailey,*''^ who has also 

 traced out the distribution of the sediments in New Brunswick and Quebec as well 

 as in Maine. As determined by him on fossils, the sequence of strata ranges from 

 lower Niagara (Clinton) to "Lower Helderberg" (Helderberg), with possibly an 

 unconformity also at the base of the latter. The section is partly concealed, the 

 structure involves older beds apparently overlying younger, in consequence of over- 

 thrusting, and his Lower Helderberg rocks appear to overlap his earlier Niagara 

 and lie upon the Cambrian. The strata dip southeastward, but the sequence from 

 northwest to southeast is shown to be Cambrian, unconformity (?), Lower Helder- 

 berg, thrust fault (?), Niagara, unconformity (?), Lower Helderberg. For details 

 we quote Bailey's report: 



The rocks of Lake Temiscouata have been described in considerable detail and are given 

 with sections illustrating the relations and probable thickness of the principal beds in the 

 "Geology of Canada," 1863, pages 419-425. * * * ^j^g following section is a condensation 

 of that in the "Geology of Canada," with such additional information as has been recently 

 obtained. The section begins on the north side of Mount Wissick or Mount Lennox, where 

 the rocks of the Silurian system may be seen to rest unconformably upon those of the "Quebec 

 group." 



Greenish-gray and black slates, alternating in thin bands, 2 to 3 inches wide, with gray or buff 

 weathering dolomitic limestones. These beds occur on the northeast side of a small cove 

 above Mount Wissick and are a part of a similar series of rocks, supposed to be of the same age 

 aa those of Point Levis which occupy all the upper part of the lake. They have been sub- 

 jected to much crumpling and exhibit considerable irregularity of inclination, their dip, 

 where nearest to the Silurian, being N. 40° W. <70°-80°. They have aa yet yielded no 

 fossils, and their thickness is unknown. 



