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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 1, 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 1.—Section through the Golconda manganese deposit.

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

Horizontal scale: 1 inch = 125 feet.Vertical scale: 1 inch = 80 feet.
Figure 2.—Section showing the relation of the Golconda manganese deposit to the rocks of the Edna Mountains.

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

Horizontal scale: 1 inch = 500 feet.Vertical scale: 1 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

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