A PLEISTOCENE MANGANESE DEPOSIT. 



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in the ore and often in sufficient quantities to form a breccia. 

 This material composes a small knoll on the lower slope of the 

 mountain, and lies on the upturned edges of underlying shale. 

 The association of the manganese and the tufa is shown in Figure 

 I, while the relation of the deposit as a whole to the Edna 

 Mountains is shown in Figure 2. The first figure represents the 

 small knoll on the left hand side of the second figure. 



Figure i. — Section through the Golconda mangaitese deposit. 



A. Calcareous tufa. B. Manganese ore. C. Shale. 



Horizontal scale: i inch = 125 feet. Vertical scale: i inch = 80 feet. 



Figure 2. — Section showing the relation of the Golconda manganese deposit to the 



rocks of the Edna Rlountaifis. 



A. Quartzite. B. Shale. C. Limestone. D. Manganese-bearing deposit. 



Horizontal scale : i inch = 500 feet. Vertical scale : i inch = 300 feet. (Both of 



these scales are only approximations.) 



The outcrop of the ore bed appears as a horizontal black 

 band along the side of the knoll facing the mountains, and is 

 very variable in thickness, in some places being represented only 

 as a black line in the white material enclosing it and in others 



