100 J. E. WOODMAN PROBABLE AGE OF THE MEGUMA SERIES 



fied with following the lead of earlier writers in calling the series Cam- 

 brian. The present paper aims to assemble whatever evidence is available 

 bearing upon the age problem; and while the results are far from satis- 

 factory and lack definiteness, they at least may indicate the extent of the 

 existing uncertainty and possible lines of inquiry designed to eliminate 

 that uncertainty. 



Difficulties which lie in the way of establishing the age of the Meguma 

 series appear early to the student ; for he has to deal with a group of 

 rocks nearly 30,000 feet in thickness, apparently conformable throughout, 

 remarkably monotonous in texture, practically barren, and exhibiting 

 neither a base beneath which is exposed an older series nor a summit 

 above which lie any fossiliferous formations of such age as will aid much 

 in establishing that of the gold-bearing rocks. In all the 30,000 feet 

 there has been discovered but one horizon which can be traced far — ^the 

 contact between the lower quartzitic Goldenville formation and the upper 

 slates, the Halifax formation. 



History of Opinions 



Without going into details, the fluctuations of opinion .regarding the 

 age of the Meguma series are as follows: Gesner (1843) called it Cam- 

 l)rian, without assigning reasons. Dawson (1850) regarded it as Lower 

 Silurian or older (1855), perhaps equivalent to the Potsdam, Utica, and 

 Hudson Eiver; and later (1860) suggested that it corresponds to the 

 Paradoxides zone in Newfoundland (see also Billings, 1860). The first 

 edition of Acadian Geology (Dawson, 1855) places the series from Lower 

 Silurian to Azoic; the second edition (1868) places it from the Chazy to 

 Upper Potsdam "partly on evidence of an inferential character" (page 

 613). Marcou (1862) called the series Taconic. 



Tn 1869 Hind made tlie first announcement of "fossils," resembling 

 Palaeotrochus major and minor (Emmons), accompanying concretions in 

 quartzite; and u]3on tliera lie l)ased a supposed age of Upper Potsdam to 

 Lower Calciferous. In LSTO (1870% 18T0^ 1870^, 1870<3) he described 

 an underlying Huronian series which has proved to be a gneissoid portion 

 of the Meguma. In 1872 Selwyn announced the discovery of Eophyton 

 at the Ovens, near Lunenburg, and called the series Lower Silurian, 

 equivalent to the Harlech grit and Lingula flag of Britain, now classed 

 as Lower and Upper Cambrian. 



In the third edition of Acadian Geology (1878^) Dawson changed his 

 designation of age to Cam])rian, but merely because he had abandoned 

 ]\Iurchison's classification. He speaks of "such fossils as have been 

 found in it l)y Selwyn, Hind, and myself and tliose of its extensions in 



