Roles of regional structures and country-rock facies in defining mineral belts in central Idaho mineral province with detail for Yellow Pine and Thunder Mountain mining districts

First posted August 29, 2023 For additional information, contact: Center Director, Geology, Geophysics, and Geochemistry Science CenterU.S. Geological SurveyBox 25046, Mail Stop 973Denver, CO 80225Contact Pubs Warehouse The central Idaho metallogenic province hosts numerous mineral deposit types. These include Late Cretaceous precious-polymetallic vein deposits, amagmatic Paleocene–Eocene breccia-hosted gold-tungsten-antimony Eocene mercury deposits in metasedimentary roof pendants granitoids. Hot-springs gold volcanic rocks are also included the province. New sensitive high mass-resolution ion microprobe (SHRIMP) uranium-lead (U-Pb) ages for igneous detrital zircon analyses of along with geologic mapping clarify framework deposits. This includes (1) structural controls regional distribution mining districts, (2) progressive development individual (3) sedimentary facies their control metals associations resulting belts, (4) influences several magmatic events.In Idaho, 15 districts form two clusters that grouped about a 200-kilometer (km) long system normal faults. northwestern cluster is hanging wall west large, west-side-down faults, located smaller faults fractures cut wall. southeastern east linked large east-side-down fault controlled by related At southern extent system, Yellow Pine-Thunder Mountain span nearly 24-km-wide, east-tilted crustal block normal-fault dominoes, exposing original depths from 5 to 10 km deep on shallow-surface Eocene.Ore deposition district was primarily batholith plutons only single small intrusion; cluster, most were initiated but varying manifestations overprinted mineralization activity. In at mineralizing pulses occurred during hanging-wall collapse, such early multiply depths, ages, characteristics change progressively eastward. Originally deep-seated western Pine viscoplastic mesothermal veins Paleocene epithermal Central contain deeper systems plutonic Proterozoic–Paleozoic pendant rocks. Eastern hot-springs-related pendant. Thunder farthest near-surface hot-springs volcaniclastic overlie buried older rocks.The sited across northwest-striking paleostratigraphic belts exposed offset system. A northeastern belt Mesoproterozoic strata associated gold-silver-copper±cobalt Neoproterozoic not southwestern composed probable Paleozoic deep-water miogeoclinal slope late epicratonic basinal thin narrowly gold-silver-antimony-tungsten±mercury (and metal associations) parts which endowments particular thrust-fault juxtaposition where these features have proximity or Offset preservation erosional stripping thrust plates, settings, sense magnitude displacements