A native copper deposit near Jefferson City, Montana

Abstract

Other| March 01, 1942 A native copper deposit near Jefferson City, Montana James Donald Forrester James Donald Forrester Search for other works by this author on: GSW Google Scholar Author and Article Information James Donald Forrester Publisher: Society of Economic Geologists First Online: 02 Mar 2017 Online ISSN: 1554-0774 Print ISSN: 0361-0128 GeoRef, Copyright 2006, American Geological Institute. Abstract, Copyright, Society of Economic Geologists. Reference includes data from Bibliography and Index of North American Geology, U. S. Geological Survey, Reston, VA, United States Economic Geology (1942) 37 (2): 126–135. https://doi.org/10.2113/gsecongeo.37.2.126 Article history First Online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation James Donald Forrester; A native copper deposit near Jefferson City, Montana. Economic Geology 1942;; 37 (2): 126–135. doi: https://doi.org/10.2113/gsecongeo.37.2.126 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyEconomic Geology Search Advanced Search Abstract Native copper occurs as a cement placer material within a restricted area near Jefferson City, Montana. The deposit is situated in a shallow canyon near the headwaters of the major Prickly Pear Creek drainage system where an intimate association of peat muck, bog-iron oxide, and alluvial gravels combine to establish a unique set of natural reducing conditions that attend the resulting deposition of secondary copper from percolating sub-surface waters. The copper is derived by oxidation of narrow epigenetic veins that occur up-stream in rocks of the Boulder batholith. It is carried downward as copper sulphate in solution until it reaches the reducing environment.Although both carbonaceous peat muck and iron oxide may be reducing agents, it appears that, in this instance, the iron oxide deposit plays the dominant role in reduction. The peat muck, in fact, seems to have even kept the copper in solution in most cases, and thus has permitted its localization on or near the limonitic bog material. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.