CHERT FORMATIONS OF NOTRE DAME BAY 573 



one season and cheerfully and efficiently assisted in the work. 

 Professor Gilbert van Ingen, who organized the Princeton Univer- 

 sity Expeditions to Newfoundland, has by the stimulus of his 

 interest aided the work of which this report represents a phase. 

 Dr. Rudolph Ruedemann has identified and correlated the grapo- 

 lites. This report was written under the direction of Professor 

 C. H. Smyth, Jr., and it is a pleasure for one of his former students 

 to acknowledge the inspiration of his teaching and influence, even 

 though this paper so little reflects it. 



« GENERAL GEOLOGY 



A map showing the general location and some details of the 

 geography as copied from British Admiralty charts is given in 

 Figure i. 



The general distribution of the rocks in Notre Dame Bay is 

 such that the oldest formations are found on the north side of the 

 bay and on the outer headlands of the west and south sides. Going 

 inland, south and west, up the fiord bays younger formations are 

 encountered of Ordovician and Silurian age. At a few places in 

 these younger formations highly fossiliferous rocks are found. 

 Professor van Ingen reports that all faunas show a marked affinity 

 to those of Great Britain, and range in age from Llandeilo of the 

 Ordovician, to Llandovery, or perhaps Wenlock, of the Silurian. 

 The similarity of the geologic history of these two regions in 

 Ordovician and Silurian time is remarkable. 



Throughout the whole district the structure is exceedingly 

 complex. Faulting is highly developed, but folding is not conspicu- 

 ous and is seldom observed although dips are high, often vertical. 



Several series of rocks can be recognized, the oldest being 

 volcanic. 



CAMBRIAN (?) 



One great series is composed very largely of andesitic pillow 

 lava with minor amounts of basic breccia and tuffs of variable 

 composition. Ordinary sediments appear to be lacking. Chert 

 is often found on the spaces between the pillows, and also with 

 heavy beds associated with tuffs. In places there are exposed 

 great sections of tuffs, breccias, and flows which show no pillow 



