Transactions . meter. In color, the granules vary from buff to pink andbrown. The pink areas naturally suggest a manganese mineral, andsimilar material at another mine was suspected of containing rhodonite, ERNEST F. BURCHaRD 67 I)ut the material is too soft and does not carry enough manganese. Undera field lens, clear glassy minerals, probably zeolites, can be seen in thepink areas. The three types of manganese-ore deposits and their several sub-ordinate varieties are well displayed at the Ponupo group of the Generala openings, manganiferous tuffaceous material tills solutioncavities
Transactions . meter. In color, the granules vary from buff to pink andbrown. The pink areas naturally suggest a manganese mineral, andsimilar material at another mine was suspected of containing rhodonite, ERNEST F. BURCHaRD 67 I)ut the material is too soft and does not carry enough manganese. Undera field lens, clear glassy minerals, probably zeolites, can be seen in thepink areas. The three types of manganese-ore deposits and their several sub-ordinate varieties are well displayed at the Ponupo group of the Generala openings, manganiferous tuffaceous material tills solutioncavities and crevices in Umestone, in some places, to depths of 30 to 40ft. (9 to 12 m.), (see Fig. 10). At the Sultana opening, manganeseoxides have replaced beds of agglomerate(?); see Fig. 12. This depositis apparently a lens having a maximum thickness of about 20 ft. (6 m.),the upper half of which is reported to average about 34 per cent, in man-ganese and the lower half about 42 per cent, manganese. At the Juanita. Fig. 10.—Section at Ponupo manganese mines. From Balkanes openingAT the west to Vencedora opening at the east, showing relations of mangan- ESE-BEAKING jasper masses to the limestone and GLA0CONITIC SANDSTONE, ALSOCAVITY IN LIMESTONE FILLED WITH TUFF CEMENTED BY MANGANESE OXIDE. opening, manganese has in spots replaced limestone. At the Balkanesopening, the ore is found associated with masses of jasper which arepartly enclosed in massive, white to pink, medium-grained, algal lime-stone. The jasper may have replaced a portion of the limestone, butnow stands out prominently due to the more rapid solution and weather-ing of the calcareous rock. The ore occurs in lumps and in earthy formin pockets and crevices in the jasper. The ore here is not generally ofhigh grade and some of it is ferruginous. The limestone contains man-ganese oxides in spots and in veinlets along fracture planes in abundancenear the manganiferous jasper, but in smaller quantities farther from th
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Keywords: ., bo, bookcentury1800, bookdecade1870, booksubjectmineralindustries
