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Paleozoic Seas of Central Idaho

1962; Geological Society of America; Volume: 73; Issue: 6 Linguagem: Inglês

10.1130/0016-7606(1962)73[769

1943-2674

Clyde Polhemus Ross,

Geological and Geochemical Analysis

Research Article| June 01, 1962 Paleozoic Seas of Central Idaho CLYDE P ROSS CLYDE P ROSS U. S. Geological Survey, Federal Center, Denver, Colo Search for other works by this author on: GSW Google Scholar GSA Bulletin (1962) 73 (6): 769–793. https://doi.org/10.1130/0016-7606(1962)73[769:PSOCI]2.0.CO;2 Article history received: 09 Feb 1960 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 CLYDE P ROSS; Paleozoic Seas of Central Idaho. GSA Bulletin 1962;; 73 (6): 769–793. doi: https://doi.org/10.1130/0016-7606(1962)73[769:PSOCI]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 Some recent paleogeographic maps indicate that central Idaho was part of a major geosyncline throughout Paleozoic time. This concept, apparently based on thick marine accumulations far apart on the margins of the region, is inconsistent with field data. Within the area of the Idaho batholith, Permian(?) volcanic rocks rest either on batholithic rocks or on the Belt Series. The Belt Series rocks have furnished the xenoliths in the batholith. To the west upper Paleozoic and Mesozoic strata are invaded. Along the eastern margin, south of lat. 45°, thick Paleozoic strata are intruded by the batholith. These locally exceed 30,000 feet in thickness and thin eastward. They have many variations. Those close to the batholith, especially those high in the sequence, are regarded as of near-shore origin. The Paleozoic strata in southeastern Idaho, more than 17,000 feet thick, are broadly similar except that Cambrian strata there are thicker and more widespread. The part of central Idaho north of the vicinity of lat. 45° has no known Paleozoic strata. Northern Idaho has only a few outcrops of beds of Cambrian age. The differences in thickness and character between Paleozoic strata in south-central and southeastern Idaho and those in western Montana and Wyoming (less than 7500 feet thick) suggest a hinge line near the eastern boundary between Idaho and Montana with a shelf to the east and a trough to the west. In south-central Idaho this trough had a maximum width of 90 miles and a western shore roughly at the east margin of the batholith. This trough wedged out northward a little beyond lat. 45°.Thus the area of the present Idaho batholith has been a positive block since Precambrian time, comparable to but apparently of longer duration than the geanticline in northern Nevada. Any invasion of the positive block in Idaho by marine waters during the Paleozoic was local and brief, except perhaps along the western border. Uncertain correlations within the area of the batholith leave open the possibility of some deposition there early in Paleozoic time. 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.