12 



The above reports are the principal ones of the Geological Survey in which the age of the 

 Alh(>rt shales is discnssed, prior to the publication, in 1903, of Dr. Ells' report on "The Albert 

 Shale Deposits of Albert and ^^'estmorland Counties, N.B." (Summary Report of the Geolog- 

 ical Survey Department for 1902,) in which the shales in (|uestion are definitely assigned to the 

 upper Devonian (p. 3C1). Dr. Ells writes as follows: "As to the geological position of the 

 shales as a whole it may be remarked that somewhat divei'se opinions ha^■e been held from time 

 to time by different observers. Thus in the early days of their investigations it was supposed 

 that they represented an integral portion of the lower Carboniferous formation. This conclusion 

 was reached from the presence in certain bands of the shale of remains of fossil fishes and plants 

 which were supposed to have a lower Carboniferous aspect and to definitely fix their horizon. 

 The investigations made in LSTti showed that however true this might be, the mass of the shales 

 themselves occupied a position entirely unconformable to the true lower Carboniferous sedi- 

 ments, associated with limestones and gypsum, and which are well defined throughout the area, 

 and that with good reason they should, therefore, stratigraphically be assigned to a lower horizon, 

 or regarded as of Devonian age." 



In 1871, Sir J. William Dawson (6), in commenting on the great value of palseontology to 

 the "practical man and theoretical geologist," remarked with truth that "A simple character- 

 istic fossil is often sufficient to determine the geological age of a formation, and the question of 

 geological age is one that must be ascertained previous to any deductions whether as to the 

 mineral contents or conditions of formation of strata." These remai'ks preceded reference to 

 "the disputes as to the Devonian or Carboniferous age of the celebrated deposit of Albertite at 

 Hillsborough, New Brunswick." These and similar difficulties, Sir William adds, could have 

 been readily settled by a reference to the evidence of fossil plants. 



Since these observations were made it has been generally conceded that the remains of 

 vertebrate animals can be relied on to a greater extent than those of plants, and of members of 

 the other divisions of the animal kingdom, as more exact horizon markers, since vertebrates are 

 more susceptible to change in the process of evolution. 



The Albert shale series and its equivalents, named by Dawson "The Lower Carboniferous 

 Coal Measures or Lower Coal Measures," and forming his fifth or lowest division of the Carbon- 

 iferous system (10,1891), in eastern Canada, are described by him ais "holding some, but not all, 

 of the fossils of the Middle Coal formation, and thin coals, not productive ; but differing both in 

 flora and fauna from the upper Devonian, which they overlie unconformably." * * * 

 "In. some localities these resemble in mineral character the true coal measures. In others they 

 present a great thickness of peculiar bituminous and calcareous shales. They usually contain 

 in their lower part thick beds of conglomerate and coarse sandstone, which in some places prevail 

 to the exclusion of the finer beds. The charactt'ristic plants of these beds are LejAdodendron 

 corriif/atum and Cjidopteri^ Amdim, with Dadoxylon anlifjuiMs^ and Alethopteris heterophylla. 

 They also contain locally great quantities of remains of fishes, and many Entomostracans, among 

 which are Leai'i Leidyi and an E.sllieria, also Leperditia suhrcctn, Portlock, Beyrichia colKculus, 

 Eichw., and a Cylhere, probably new." "This formation is not (>verywhere distinguishable at 

 the base of the Carboniferous, and is variable in its characters. It is seen in southern Cape 



