The deposits of the useful minerals & rocks; their origin, form, and content . rhood of Hollfeld nearRegensburg the iron deposits occur. They are absent from the dolo-mite ridges and crests, having been removed from thence by erosion. THE BEAN-OEE BEDS 995 Between the foot-wall dolomite and the ore, finely-crystalline dolomite,sand, and red clayey masses, are frequently found. The geological positionof the deposits is well illustrated in Figs. 406, 407, and 408. The shape of the under surface of the ore-body depends upon theirregular surface of the dolomite. The ore follows the cavities and un
The deposits of the useful minerals & rocks; their origin, form, and content . rhood of Hollfeld nearRegensburg the iron deposits occur. They are absent from the dolo-mite ridges and crests, having been removed from thence by erosion. THE BEAN-OEE BEDS 995 Between the foot-wall dolomite and the ore, finely-crystalline dolomite,sand, and red clayey masses, are frequently found. The geological positionof the deposits is well illustrated in Figs. 406, 407, and 408. The shape of the under surface of the ore-body depends upon theirregular surface of the dolomite. The ore follows the cavities and undula-tions of this surface in a more or less thick layer, the filling of these irregu-larities being completed by residual clay and Albian material. Numerousplanes in the clay of these funicular ore-bodies point not so much totectonic movement as to local action due to varying plasticity. Thedeposit consists chiefly of loose limonite and pieces of compact ore as largeas a mans head, this ore being flaky and frequently exhibiting a reniform Shaftjulius II - Shaft EinschnittI. Fig. 407.—Large ore-syncline between the Julius and Eiuschnitt shafts at 1 : 400. Einecke and Kohler. structure. A large number of angular ore-fragments varying from pea- tonut size occur more or less regularly distributed throughout the deposit,though such are also frequently concentrated at its base. The source of the iron is attributed by Kohler and Einecke to waterscirculating through fissures. These mineral solutions, however, in allprobability metasomatically replaced the limestone in part only, thegreater part of the iron having been precipitated at the surface, bythe action of meteoric waters. In this action, weathering during theTertiary period and, in places, undoubted iron enrichment duringthe Eocene period, played parts. The subsequent sinking of theore into cavities in the limestone and the concomitant formationof numerous movement planes must be referred to the later cavityfor
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectminesandmineralresou
