[ells] CANADIAN GEOLOGICAL NOMENCLATURE 15 



In addition, several large and important areas of slaty rocks were 

 located, which were apparently almost destitute of organic remains, 

 and the horizons of which could not therelore be definitely determined. 

 These were included under a general term pre-Carboniferous rocks, 

 but were subsequently designated by the name dark and pale argillite 

 series, the names depending principally upon the prevailing shade of 

 the slate of which the series was largely made up. As for the Car- 

 boniferous formations the rocks were classified as lower Car- 

 boniferous^ and Middle and Upper coal formations, while the Triassic 

 or New Eed sandstone formed the summit of the geological scale in 

 this province. 



Since the date of the report just quoted, the geological formations 

 in this province have been worked out in great detail, though but 

 slight additions have been made to the nomenclature of the subject. 

 The tabulated list of formations, used in conection with the sedi- 

 mentary rocks of the western province has not as yet been found to 

 be applicable, to any great extent, to the formations m tlie eastern 

 provinces. This may be, to some extent, due to a general lack of 

 fossils in some of these eastern formations, but also probably to some 

 extent to differences in the mode of deposition, as is the case in the 

 province of Quebec, where the formations west of the great Champlain 

 fault present marked diiïerences in physical character, as also in the 

 cJiaracter of their fossil contents, as compared with rocks of presumably 

 similar horizons lying to the east of that break. The comparatively 

 recent finding of fossils in different parts of the northern area of New 

 Brunswick has, however, resulted in correlating, somewhat more close- 

 1}', certain of the formations belonging to the Ordovician about the 

 horizon of Trenton. 



The nomenclature of the subject in this province has also recently 

 been enlarged by the employment of the term Etchemiuian, which luis 

 been applied by Matthew to certain fossiliferous sediments, found be- 

 neath the lowest zone of the recognized Primordial. The rocks so 

 designated may, therefore, be supposed to belong to the lowest horizon 

 of the Cambrian or to the most recent portion of the pre-Cambrian 

 formations. * 



In connection also with the study of the Devonian plant-bearing 

 beds of New Brunswick and eastern Quebec, Sir William Dawson, in 

 1871, proposed the term Erian as the American equivalent of the De- 

 vonian, owing to the fact that the rocks of this system in America have 

 a great development in the vicinity of Lake Erie, in Ontario. This 

 name has not however as yet been generally accepted by geologists, and 

 the original term Devonian is still maintained for the strata of this 

 great system. 



