Goldfield Belmont Report p05

GEOLOGY - continuedThe ledges in this zone are probably the result of circulating waters ascending through fractures caused by the sudden cooling of the formations as they were laid down and later by upheavals in the central portion of the district and subsidence along the belt, and it is into these fractures that the rich and large ore bodies have been formed. While these ledges often crop on the surface as a rule payable ore in them is not found nearer than one hundred feet or more from the surface, which is accounted for by physical conditions in the extent laterally and to great depths of the fracturing giving ready access to the surface waters which met the ascending solutions far from the original surface where through release of pressure and the sudden cooling produced chemical changes suitable to the deposition of their minerals.As noted above the most productive ledges in the Goldfield District have been found to be associated with the DACITE formation; however,it is conceded that this is not due to any inherent quality of the DACITE itself but rather to the physical conditions of weakness and fracturing brought about by its intrusion into the ANDESITE and between that formation and the LATITE and movements connected therewith, which left this formation with many open spaces for the free circulation of thermal waters.In BLACK BUTTE PEAK the ore to a large extent has been found to follow irregular intrusive tongues of DACITE which are the western extremities of a considerable body of this rock making up the whole of the MIDNIGHT FRACTION claim. The PEAK