EIvISHA MiTCHElvIv SCIENTIFIC SOCIETX. 72 



shales/ In 1888, Walcott, in studying- a section of these 

 rocks in Newfoundland, placed, from paleontolog-ical evi- 

 dences, the "Red Sandrock" series, the Georg-ia shale 

 and slate series, the "Granular Quartz" and "the Upper 

 Taconic" of Emmons beneath the Middle Cambrian or 

 Parodoxides zone of the Atlantic coast.'" 



And so the rocks of the old Taconic or Huronian belt 

 in central North Carolina must also in time be differenti- 

 ated and recorreltJled when the}^ have been more carefully 

 studied. 



Emmons was in a measure quite correct in calling- his 

 Taconic rocks of central North Carolina the bottom sedi- 

 ments, and placing- them below the Silurian. The 

 absence of fossils in the slates, however, necessitates our 

 g-oing- back still another step, and placing- them below 

 the Cambrian sediments, in the Alg-onkian, which Van 

 Hise has defined as including- all recog-nizable pre-Cam- 

 brian elastics and their equivalent crystallines, the base 

 of the Cambrian being- placed at the Olenellus fauna. ^ 

 Here the matter must rest until we can find fossils in the 

 rocks, or verify the org-anic character of Emmons, Paleo- 

 trochis; or until we can trace the rocks into a terrane of 

 known age. So also the pyroclastic volcanics must be 

 looked upon as pre-Cambrian. 



It is of interest to note that here, as in other portions 

 of eastern North America, the ancient volcanics occur in 

 close proximity to the western edg-e of the Jura-Trias 

 basin. Adopting* Suess' theory of the formation of moun- 

 tians, v^e may look upon this central belt of sheared and 

 faulted slates as the levelled site of an ancient Atlantic 

 mountain range; while the bodering Jura-Trias represents 

 a transgression formed by the sunken block on the east; 

 and the early phases of this subsidence were accompanied 

 by the exhibition of volcanic forces. 



lU. S. Geological Surve;y. Bull. 81. Correlation Papers: by C. D. 

 Walcott; 1891, p. 243. 



2 Ibid, p. 113. 



3U. S. Geological Survey. Bull, 86. Correlation Papers: Archean- 

 Algonkian: p. 495. 



