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Correlations and Problems in Belt Series Stratigraphy, Northern Idaho and Western Montana

1963; Geological Society of America; Volume: 74; Issue: 12 Linguagem: Inglês

10.1130/0016-7606(1963)74[1413

1943-2674

Jack Edward Harrison, Arthur Byron Campbell,

Water Quality and Resources Studies

Research Article| December 01, 1963 Correlations and Problems in Belt Series Stratigraphy, Northern Idaho and Western Montana J. E HARRISON; J. E HARRISON U. S. Geological Survey, Denver, Colo Search for other works by this author on: GSW Google Scholar A. B CAMPBELL A. B CAMPBELL U. S. Geological Survey, Denver, Colo Search for other works by this author on: GSW Google Scholar Author and Article Information J. E HARRISON U. S. Geological Survey, Denver, Colo A. B CAMPBELL U. S. Geological Survey, Denver, Colo Publisher: Geological Society of America Received: 13 Jun 1963 First Online: 02 Mar 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Copyright © 1963, The Geological Society of America, Inc. Copyright is not claimed on any material prepared by U.S. government employees within the scope of their employment. GSA Bulletin (1963) 74 (12): 1413–1427. https://doi.org/10.1130/0016-7606(1963)74[1413:CAPIBS]2.0.CO;2 Article history Received: 13 Jun 1963 First Online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation J. E HARRISON, A. B CAMPBELL; Correlations and Problems in Belt Series Stratigraphy, Northern Idaho and Western Montana. GSA Bulletin 1963;; 74 (12): 1413–1427. doi: https://doi.org/10.1130/0016-7606(1963)74[1413:CAPIBS]2.0.CO;2 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 SocietyGSA Bulletin Search Advanced Search Abstract A continuous strip of geologic maps has recently been completed along the Idaho-Montana state line between Clark Fork, Idaho, and Superior, Montana. New stratigraphic and petrographic information provides the basis for stratigraphic correlations and for the interpretation of facies changes in this part of the basin of deposition of the Precambrian Belt Series. Identification of facies changes is aided by the recognition of siltite (low-grade metamorphosed siltstone) as a valid rock type, in addition to quartzite and argillite, to classify most of these rocks and to establish mappable units.The older Belt rocks (Prichard through Wallace Formations) were deposited in a trough whose axis trended northwestward, perhaps approximately through Libby, Montana. Subtle facies changes suggest an ancient shore line southwest of the Coeur d'Alene district, Idaho, perhaps near the present exposed edge of the Idaho batholith. The younger Belt formations of the Missoula Group, however, thicken markedly southeastward toward Superior. Thus, the younger Belt rocks were deposited in a trough whose main axis was about at right angles to that of the older trough and perhaps was near Missoula, Montana. Deposition in the Clark Fork area was scant and often interrupted in Missoula time. The young major cross-warp in the old Belt geosyncline undoubtedly has contributed complexities to Belt correlation farther north.Detailed petrographic studies indicate that the Belt rocks from the Pend Oreille area, Idaho, are remarkably uniform in the mineralogic composition of similar rock types throughout 40,000 feet of strata. Further mineralogic studies are required to determine whether this uniformity is local or widespread. 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.