Hydro-thermalized granite

The iron extraction rates for both fresh and altered granite decrease for the first 24 h and become the same constant rate for the remaining 24 to 120 h. Thus the iron associated with oxyhydroxides (formed during recent exposure to GGW or during hydro-thermal alteration) is removed during the first 24-h exposure to... 

Although major crustal fractures at depth may provide entry to the upper crust for metalliferous granites, the later hydro-thermal reworking of uranium and associated metals to form vein-type mineralization after emplacement requires the development of a mesh of fractures in the upper crust capable of transmitting large volumes of fluid through both the granites and their envelopes. The swarms of mineral lodes that occupy... 

In confirmation of these findings it should be noted that Li, Sn and B are all closely associated with the subsequent hydro-thermal ore-forming events in the Cornubian batholith. Li in stream sediments shown on the Wolfson atlas s is in the range 200-400 ppm in the vicinity of hydrothermally altered and kaolinized granite. Sn has a widespread occurrence in vrin-type mineralization and boron is the matrix of diatremes such as the Wheal Remfry breccia in the St Austell granite. ... 

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