38 PROCEEDINGS OF THE CHICAGO MEETING 



erate, containing in places huge boulders of precisely the same character ot 

 rock that is found in the older only a few feet distant, and at some of these 

 points the older beds are clearly truncated. In other places the contact is 

 obscure, while in still others it is quite clearly a fault contact. 



The existence of boulders within the conglomerate containing drag folds 

 and brecciated structures; of firmly cemented quartzite pebbles within a 

 chloritic matrix ; and the considerable angle between the bedding planes of 

 the two systems is evidence of the time represented in the unconformity. 



The younger iron formations are regarded as of fragmental origin, derived 

 from the older. The banding of the younger at least is believed to have been 

 produced during metamorphism rather than by original sedimentation. Fur- 

 therpiore, the banding is more pronounced in the formations richer in iron. 



The pre-Cambrian of the remainder of the hills area probably belongs to the ' 

 younger system. In degree of metamorphism the two systems resemble the 

 Huronians of the Lake Superior district. 



Presented without manuscript, with the aid of charts. 



STRATIGRAPHY AND DIASTROPHISM OF WESTERN NEWFOUNDLAND 

 BY CHARUES SCHUCHERT AND CARL O. DUNBAR 



{Abstract) 



Paleozoic sediments form a low foreland to the Long Range Mountains along 

 the entire western coast of Newfoundland. The stratigraphic sequence begins 

 with a well developed Lower Cambrian, resting on Laurentian granite and 

 metamorphics, and closes with the Pennsylvanian. There is here no Middle 

 Cambrian nor Silurian ; of the Devonian, only the Helderbergian is present, 

 and of the Mississippian only the latter half. All of Mesozoic and Cenozoic 

 time is entirely unrepresented by sediments. The Lower Cambrian consists 

 of quartzite, shale, and limestone, and its fauna shows limited relations with 

 that of eastern Newfoundland, whereas all the succeeding faunas indicate 

 complete isolation of these two regions. The Upper Cambrian is poorly repre- 

 sented by dark gray, shaly limestone, which is accordant with both the pre- 

 ceding Cambrian and the succeeding Ordovician strata. 



The Ordovician is here tremendously developed. It begins with about 2,000 

 feet of dolomite and magnesian limestone of Canadian age, followed by some 

 800 feet of purer Chazyan limestone, and then, as orogeny set in to the east, 

 there was a gradual transition into black shaly limestone, black shale, and 

 finally into a great greenish gray sandstone. On this follows, after a break in 

 sedimentation, the Cow Head limestone breccia, locally of great thickness and 

 of unparalleled coarseness — a product of landslides resulting from profound 

 fault-scarps near by. As the orogeny continued to its climax, there followed a 

 mighty series of clastic sediments, possibly more than 10,000 feet in thickness 

 and very variable in both color and texture from section to section. These 

 elastics have yielded but very few fossils, apparently of Middle Ordovician 

 time. After this the seas cleared somewhat and Ordovician sedimentation 

 closed with fossiliferous shales and limestone referred to the later Ordovician, 

 ending with the earlier Richmondian. 



