NEWFOUNDLAND APPALACHIANS 



215 



Fig. 13.11. Map and sections of Conception Bay and the Wabana iron ore deposits. Repro- 

 duced from Hayes, 1931. 



sharp folding and metamorphism common to zones one, two, and three 

 but was faulted and elevated in post-Ordovician time, probably in the 

 Appalachian orogeny. 



TECTONIC HISTORY 



Early Cambrian Phase 



By reference again to the chart of Fig. 13.2, the numerous disturbances 

 and orogenies that characterized the Appalachian systems in Newfound- 

 land can be reviewed. Nine orogenic phases are fairly clear. When cor- 

 relations are more precise, this number may be increased. 



It is evident from the angular unconformity at the base of the Cambrian 

 and the coarse, basal elastics that an orogeny immediately preceded or 

 accompanied the early Cambrian sedimentation. This is noted in the 

 west along the coast of Labrador and the western lowland of Newfound- 

 land, and in the east from the Bay d'Espoir to the Avalon peninsula. In 

 the east the orogenic phase is the last of three or more that accompanied 

 the deposition of a great Precambrian volcanic series. It is not yet pos- 

 sible to define the distribution of land and sea in the orogenic belt in 

 Cambrian time. For that matter, the same can be said of the belt in all 

 pre-Carboniferous time. Volcanic activity was pronounced in eastern 

 Newfoundland in the Proterozoic but abated everywhere, it seems, during 

 the Cambrian period. 



After the early Cambrian Brigus and Eteheminian elastics had been de- 

 posited in the Fortune Bay and Trinity Bay areas respectively, a slight 

 disturbance occurred which resulted in uplift and erosion before the next 

 Lower Cambrian Hanfordian beds were deposited. 



Late Cambrian Phase 



In the Burin peninsula, a disturbance occurred in late Cambrian time in 

 which the Middle Cambrian beds were tilted and somewhat eroded be- 

 fore covered with the Ordovician strata (Van Alstine, 194S). Deposition 

 of carbonates occurred apparentlv undisturbed on the east and on the 

 west while the uplift was taking place. 



