Transactions . consolidated tultaceous,more or less stratified sandy material, and the sandstone and conglomeratel)eds also are overlain in places with similar tuffaccous beds. Thesetuffaceous beds generally contain more or less manganese oxide as acement, probably as a replacement, and in places enough of it to con-stitute a milling ore. Masses of siliceous rock, or jasper, usualh^ man-ganiferous, are associated with both the limestone and the Fig. 9. -PoNUPO, Cuba. Generala mine, deep pit in manganese-ore pocket BETWEEN MASSES OP JASPER AND LIMESTONE. On account of its superior r
Transactions . consolidated tultaceous,more or less stratified sandy material, and the sandstone and conglomeratel)eds also are overlain in places with similar tuffaccous beds. Thesetuffaceous beds generally contain more or less manganese oxide as acement, probably as a replacement, and in places enough of it to con-stitute a milling ore. Masses of siliceous rock, or jasper, usualh^ man-ganiferous, are associated with both the limestone and the Fig. 9. -PoNUPO, Cuba. Generala mine, deep pit in manganese-ore pocket BETWEEN MASSES OP JASPER AND LIMESTONE. On account of its superior resistance to weathering, the jasper generallyoutcrops prominently^ and is often found capping hills and anticlinal structure is shown here in a broad way, butlocally the rock dips are very irregular. This mixed ore generally presents an irregular speckled or granularappearance, the granules ranging in size from mere specks up to Ya. iii-(6 mm.) in diameter. 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 Pon
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Keywords: ., bo, bookcentury1800, bookdecade1870, booksubjectmineralindustries
