The ore deposits of Utah . ous-metal content isalso low. The absence of marked replace-ment action by unoxidized ore indicates thatthe ore-forming solutions were weak, and thisis in keeping with the small amount of quartzand the prominence of calcite in the small amount of galena and calcite notedalong the fissures in the Morgan-Crescentworkings are a further indication of weak,relatively cool solutions. Marcasite is tooexceptional in Utah ore deposits to be of muchsignificance, but its modes of occurrence ingeneral point to deposition at low tempera- WASATCH RANGE. 221 tures. It is
The ore deposits of Utah . ous-metal content isalso low. The absence of marked replace-ment action by unoxidized ore indicates thatthe ore-forming solutions were weak, and thisis in keeping with the small amount of quartzand the prominence of calcite in the small amount of galena and calcite notedalong the fissures in the Morgan-Crescentworkings are a further indication of weak,relatively cool solutions. Marcasite is tooexceptional in Utah ore deposits to be of muchsignificance, but its modes of occurrence ingeneral point to deposition at low tempera- WASATCH RANGE. 221 tures. It is improbable that such solutionsformed extensive ore bodies, except whereexcessive shattering, as in the Red Eaglefissure, or an easily permeal^lo limestone bed,as at the Morgan-Crescent mine, providedexceptional conditions. BOX ELDER, WILLARD, AND WEBER DISTRICTS. GEOLOGY. By G. F. LouGHLiN. The geology of the Box Elder, WiUard, andWeber districts is most conveniently consideredas a unit. The formations represented include. LEGEND Cenozoic Carboniferous Cambrian shaleand limestone ^ Cambrianquartzite Algonkian Arch« Overth rust fault J Normal fault 0 Miles Figure 3S.—Geologic sketch map of Wasatch Range proper betweenOgden and Brigham. (After Blackwelder, with minor additions.) Archean, Algonkian, Cambrian, Carboniferous,and Tertiary rocks, but their relations arecomphcated by extensive overthrusts and largeeast-west, or transverse, normal faults. Archean granite extends southward alongthe range from WiUard to a point east of HotSprings and is exposed in smaller masses alongthe foothills east of Ogden. (See fig. 38.) Alarger mass of it extends from a point nearOgden southward for several miles. East ofHot Springs it is overthrust upon Cambrianhmestone. The Algonkian outcrops in a broad belt thatextends southeastward from Brigham beyondthe latitude of Ogden. On the east it is over-lain unconformably by Cambrian quartzite;on the west it is overthrust upon Cambrian andCarbonife
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