. The ore deposits of Utah. the laccohthsfor the most part is Carboniferouslimestone, a pure, dense, blue lime-stone, with a few feet of sandy ma-terial appearing locally at the contacts are at most locali-ties nearly vertical, this being duepartly to faulting and partly tothe fact that erosion has cut downfar enough to expose the verticalsides of the laccohths. Locally,where erosion has not cut so far, the limestonedips distinctly away from the andesite at anangle as low as 10°. The limestone is alteredat the contact to a maximum distance of 1,000feet, as measured on the erosion slop
. The ore deposits of Utah. the laccohthsfor the most part is Carboniferouslimestone, a pure, dense, blue lime-stone, with a few feet of sandy ma-terial appearing locally at the contacts are at most locali-ties nearly vertical, this being duepartly to faulting and partly tothe fact that erosion has cut downfar enough to expose the verticalsides of the laccohths. Locally,where erosion has not cut so far, the limestonedips distinctly away from the andesite at anangle as low as 10°. The limestone is alteredat the contact to a maximum distance of 1,000feet, as measured on the erosion slopes, by lossof carbonates, deyelopment of anh3^drous siK-cates, and replacement by ore. Cretaceous sediments outcrop in a zone out-side of the Carboniferous limestone, exceptwhere locally they are faulted down against thelaccolith, or where the laccolith has penetratedthe Cretaceous and erosion has not yet cut • That these are laccolithic bodies has not been demonstrated and thewriter is inclined to regard them as
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectminesandmineralresou
