372 DALE— CAMBRIAN MANGANESE DEPOSITS OF [April 25, 



bedded deposits. Some collections and notes then taken of these 

 interesting rocks were later placed at the disposal of the writer for 

 further investigation. The following summer of 1913, the writer as 

 a member of the Princeton Newfoundland Expedition undertook a 

 more detailed study of these deposits at the various localities where 

 the manganese had been found the preceding summer, and also of a 

 deposit of the same age on the northern shore of Trinity Bay. 



There are so few syngenetic manganese deposits which still retain 

 their primary unaltered characters and are found to occur at the same 

 horizon over such a wide area that a somewhat detailed investigation 

 gave promise of yielding results of value. In this paper therefore 

 there has been an attempt to present as comprehensive a study of the 

 manganese of southeastern Newfoundland as our knowledge of 

 this hitherto but little investigated region will allow. 



The subject matter is primarily chemical in its nature and the 

 analyses herewith presented are from samples taken from the prin- 

 cipal manganese-bearing beds. Many more analyses however could 

 have been made and in fact many more should be made if the deposits 

 are to be seriously investigated for commercial purposes. The 

 analyses of the manganese beds at Manuels, Topsail, and Smith 

 Point, Newfoundland and those of the imported specimens from 

 Elbingerode, Saxony were made by the writer in the chemical 

 laboratory of the geological department of Princeton University. 



Because of the impalpable fineness of grain of many of the 

 manganese-bearing beds, the petrographical descriptions of certain of 

 the thin sections can deal only with the larger features such as struc- 

 ture, mineral aggregations, and a few of the larger and observable 

 minerals. 



The writer feels particularly indebted to Prof. C. H. Smyth, Jr., 

 for many helpful suggestions bearing upon the chemical side of the 

 investigation, and to Prof. G. van Ingen for unpublished information 

 regarding the stratigraphy and palaeontology of this region, as well as 

 for the loan of the locality maps and data for the columnar sections 

 which are the results of careful surveys made during the summers 

 of 1912 and 1913. All photographs and microphotographs were 

 generously contributed by Prof, van Ingen to further the presentation 

 of the results of this investigation. 



