420 DALE— CAMBRIAN MANGANESE DEPOSITS OF [April 25, 



E 2 Gray limestone. 



I Conglomerate with pebbles of syenite, black chert and limestone. 



Syenite. 



C 2 Agglomerate. 



1 Ribbon slates. Conception slates (Huronian). 



The section represents the stratigraphic sequence and the locality 

 numbers indicate the position of the layers. Quoting Prof, van 

 Ingen in regard to this most interesting locality : 



" It appears to me that we have here the remnant of a squeezed sjm- 

 cline, the northern margin of which has been shoved far northwardly onto 

 the underlying agglomerate and ribbon slates." 



213 C 4b was studied more in detail by the writer during the 

 summer of 1913 in the hope that some more definite knowledge 

 might be gained on the occurrence of the manganese at this point, 

 but without very much satisfaction. The subdivided manganese 

 bed is as follows : 



Loc. Number. 



213 L4C Finely banded nodular bed. 



b Fractured and slickensided green shale. 

 213 L4 a Black nodular calcareous green shale with manganese staining. 

 L3 Nodular ferruginous calcareous green shale with manganese stains. 



2 Fractured and fissile shale. 



I Manganiferous calcareous green shale with hematite and pyrite. 



In as much as the manganese was not visible to any great extent 

 in its primary form throughout this small series of 3 to 4 feet no 

 analysis was thought necessary. Two of the above beds, 213 L 3 

 and 213 L 4 are worthy of macroscopical and microscopical descrip- 

 tions because of marked lithological resemblance to certain of the 

 rocks at Manuels. 



213 L 3 is a -nodular shale with conspicuous calcareous ferru- 

 ginous and manganiferous aggregations and jet black pebbles or 

 nodular forms. All structural and divisional planes of this bed are 

 conspicuously stained with some secondary oxide of manganese, 

 probably a hydrated oxide such as psilomelane. Microscopical ex- 

 amination of this shale brings out the fact that the structure is 

 nodular and oolitic and that the rock is a ferruginous chloritic shale. 



