THE FERRUGINOUS CHERT FORMATIONS OF 

 NOTRE DAME BAY, NEWFOUNDLAND^ 



EDWARD SAMPSON 

 U.S. Geological Survey 



OUTLINE 



Summary 

 Field Work 

 Acknowledgments 

 General Geology 

 Cambrian (?) 

 Ordovician 

 Silurian 

 Distribution of Cherts 

 Varieties of Chert, and Associated Rocks 

 General Statement 

 First Type — Interstitial 

 Second Type — ^Heavy Beds of Jasper 

 Third Type— Thin Beds 

 Composition and Structure 

 Green Chert 

 Red Chert 

 Origin 



Comparison with Other Regions 

 Are Cherts Radiolarian Oozes ? 

 Have Radiolaria Played an Active Part in the Formation of the 



Chert ? 

 Chert Formed as Chemical Precipitates 

 Source of the Solutions 

 Nature of the Solutions and Manner of Precipitation 



SUMMARY 



This paper describes ferruginous cherts which for the most part 

 are found as beds of very uniform thickness in sections composed 

 largely of volcanic rocks. The author considers the cherts to be 

 chemically precipitated sediments. 



' Part of a thesis submitted to the faculty of Princeton University in candidacy 

 for the degree of Doctor of Science, 1920. 



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