The deposits of the useful minerals & rocks; their origin, form, and content . , while between Schlettau and Scheibenberg there is a consider-able occurrence of augengneiss and coarse gneissic granite. All theserocks are either foliated eruptives or contact-metamorphic rocks. Theymantle over the red Erzgebirge gneiss of Reizenstein-Katharinaberg andthe grey eruptive gneiss of Freiberg. The lodes belong partly to the sulpliide-lead- and tin groups ofthe older system, and partly to the cobalt-silver- and iron-manganesegroups of the younger system. The more important have always beenthe cobalt-si
The deposits of the useful minerals & rocks; their origin, form, and content . , while between Schlettau and Scheibenberg there is a consider-able occurrence of augengneiss and coarse gneissic granite. All theserocks are either foliated eruptives or contact-metamorphic rocks. Theymantle over the red Erzgebirge gneiss of Reizenstein-Katharinaberg andthe grey eruptive gneiss of Freiberg. The lodes belong partly to the sulpliide-lead- and tin groups ofthe older system, and partly to the cobalt-silver- and iron-manganesegroups of the younger system. The more important have always beenthe cobalt-silver lodes, which group themselves in definite districts or fieldswherein two principal lines of strike prevail, one north-south, the othereast-west. Generally speaking these lodes may only be followed for800 m. or so along the strike, and from 100 m. to 400 m. at the most, indepth. The most important of these fields is that around Annaberg, thecentre of the former silver-cobalt mining. The metalliferous filling consists of different silver minerals such as 678 OEE-DEPOSITS. Legend Micaceous Mica schist Schistose Red contact Grey contact Augengneiss I Red Zrz^ebirggPhylhte phy/lihi prteiss urfh gneiss coarse grained eruptive gneiss gamet-mica gneissic gneiss roch granite ^ E3 ^ ^3 ^ ES (M3 Contact aureole Gnjnite Basatt Cambrian Ueiron Brouin-coal Diluvium etc oithe Granite formatian Fig. 335.—Geological map of the Upper Erzgebirge miiiiug district. Scale, 1 : 500,000. H. Creduer. THE LEAD-SILVER-ZINC LODES 679 dyscrasite, native silver, black silver, argentite, argentiferous marcasite,cerargyrite ; of cobalt- and nickel minerals ; and of pyrite, sphalerite,chalcopyrite, and scarce bismuth minerals. The gangue consists of quartz,barite, fluorite, and dolomite. Uranium ores represent a special primaryzone, which is more closely described in the chapter dealing with uraniumlodes. The deposits of this district are particularly rich at lode junctionsand at intersection with certa
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectminesandmineralresou
