410 DALE— CAMBRIAN MANGANESE DEPOSITS OF [April 25, 



some open cutting. This is a carbonate-oxide ore of manganese of 

 brown color and vitreous luster. 



Not only does the character and structure of the manganese at 

 Topsail differ from that of ]\Tanuels but the section shows some 



.'■\-'*'«^ 



*-^4-^'- 





Fig. 30. Photograph of the open cut with the manganese prospect tunnel 

 at Topsail; Loc. 219 E. 



lithological variations. Moreover the rocks of the section are very 

 much disturbed with the rapid changes in the dip of the beds. The 

 structural changes in these beds are no doubt due to the great fault, 

 the plane of which passes about 300 feet east from the manganese 

 zone with a strike of N. 13 E. and a vertical dip. The fault plane 

 lies between the Huronian and the lower Cambrian, and the beds 

 immediately adjacent are considerably disturbed and so to a lesser 

 extent are those farther away. 



That a better idea may be obtained as to the relationship of the 

 manganese, the following general and local stratigraphic sections with 

 descriptions are given. The generalized section as worked out by 

 Prof, van Ingen and Mr. A. O. Hayes during the summer of 1912 is 

 as follows : 



