Proterozoic zircon from augen gneiss, Yukon-Tanana Upland, east-central Alaska
45
Citation
0
Reference
10
Related Paper
Citation Trend
Abstract:
Research Article| October 01, 1981 Proterozoic zircon from augen gneiss, Yukon-Tanana Upland, east-central Alaska John N. Aleinikoff; John N. Aleinikoff 1U.S. Geological Survey, Federal Center, Denver, Colorado 80225 Search for other works by this author on: GSW Google Scholar Cynthia Dusel-Bacon; Cynthia Dusel-Bacon 2U.S. Geological Survey, Menlo Park, California 94025 Search for other works by this author on: GSW Google Scholar Helen L. Foster; Helen L. Foster 2U.S. Geological Survey, Menlo Park, California 94025 Search for other works by this author on: GSW Google Scholar Kiyoto Futa Kiyoto Futa 3U.S. Geological Survey, Federal Center, Denver, Colorado 80225 Search for other works by this author on: GSW Google Scholar Author and Article Information John N. Aleinikoff 1U.S. Geological Survey, Federal Center, Denver, Colorado 80225 Cynthia Dusel-Bacon 2U.S. Geological Survey, Menlo Park, California 94025 Helen L. Foster 2U.S. Geological Survey, Menlo Park, California 94025 Kiyoto Futa 3U.S. Geological Survey, Federal Center, Denver, Colorado 80225 Publisher: Geological Society of America First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1981) 9 (10): 469–473. https://doi.org/10.1130/0091-7613(1981)9<469:PZFAGY>2.0.CO;2 Article history First Online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation John N. Aleinikoff, Cynthia Dusel-Bacon, Helen L. Foster, Kiyoto Futa; Proterozoic zircon from augen gneiss, Yukon-Tanana Upland, east-central Alaska. Geology 1981;; 9 (10): 469–473. doi: https://doi.org/10.1130/0091-7613(1981)9<469:PZFAGY>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 SocietyGeology Search Advanced Search Abstract U-Th-Pb analyses of zircons from an ortho-augen gneiss body in the Yukon-Tanana Upland of east-central Alaska yield strong evidence for the presence of early Proterozoic material in this area. U-Pb data define a chord that intersects concordia at about 2,300 and 345 m.y. We consider two interpretations: (1) the protolith was intruded during the Proterozoic and was subsequently metamorphosed in the Paleozoic or, more likely, (2) the protolith was intruded in the Paleozoic and incorporated material of Proterozoic age. An Sm-Nd model age of about 1,900 m.y. on a whole-rock sample of augen gneiss is additional evidence for the presence of Proterozoic material in the gneiss. K-Ar and U-Th-Pb dating of mica and sphene, respectively, reveal that younger thermal events occurred at least as recently as 110 m.y. ago. 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.Keywords:
Geological survey
Icon
Geologist
Geologist
Geological survey
Cite
Citations (0)
U-Pb ages of zircons from Yanzihe gneiss of Northern Dabie have been determined by single-grain TIMS method. There are two types of zircon: one is the magmatic zircon from protolith which had undergone different degree of Pb loss, and the another is metamorphic zircon. Five points give a good concordia line with lower intercept at 228±13Ma and upper intercept at 880±110Ma ( MSWD = 1.1). The upper intercept point represents the protolith age and the lower intercept point represents the metamorphic age. One metamorphic zircon gives concordant U-Pb age of 238Ma, which is similar to the lower intercept age. The result demonstrates that the Northern Dabie gneiss also underwent Jurassic metamorphic event. The suture of North China Block and Yangtze Block should be north of the North Dabie.
Protolith
Cite
Citations (1)
"Brown, Prof. Sir (George) Malcolm, (5 Oct. 1925–27 March 1997), consultant geologist; Director: British Geological Survey (formerly Institute of Geological Sciences), 1979–85; Geological Museum, 1979–85; Geological Survey of Northern Ireland, 1979–85" published on by Oxford University Press.
Geologist
Geological survey
George (robot)
Geologic map
Cite
Citations (0)
II.—Geological Survey of Ohio. Report of Progress in 1869, by J. S. Newberry, Chief Geologist; with Reports by E. B. Andrews and Edward Orton, Assistant Geologists. (Columbus, 1871.) - Geological Survey of Ohio. Report of Progress in 1870, by J. S. Newberry and Assistants. (Columbus, 1871.) - Volume 9 Issue 102
Geologist
Geological survey
Cite
Citations (0)
A preliminary U/Pb zircon age determination has been carried out on a grey gneiss of the Eskolabreen Formation, the lowest observable lithostratigraphic unit of Precambrian metamorphic rocks in southern Ny Friesland, NE Spitsbergen. The obtained age, ca. 2, 400 Ma, is considered to be a metamorphic age and suggests an Early Proterozoic tectonothermal event.
Cite
Citations (15)
The gneiss complex of Wildhorse Creek (Wildhorse gneiss) forms the central component of the lowest structural plate in the Pioneer metamorphic core complex of south-central Idaho. The oldest rock in the complex is a felsic orthogneiss, with Neoarchean U-Pb magmatic zircon ages of 2.60–2.67 Ga. The orthogneiss overlaps in age and is interpreted to be part of the Grouse Creek block of the Albion Mountains to the south. This Archean metagranitoid is structurally interleaved with paragneiss containing quartzite and calc-silicate rock. Structurally below the orthogneiss, some quartzites have multiple concordant populations of detrital-zircon grains as young as ca. 1700 Ma, while others have no zircon grains younger than ca. 2500 Ma.
Felsic
Cite
Citations (15)
Cite
Citations (3)
American Geological Surveys - III.—First Annual Report of the Geological Survey of Indiana, made during the year 1869, by E. T. Cox, State Geologist, assisted by ProfessorFrank H. Bradley, DrRufus Haymond, and DrG. M. Levette. 8vo. pp. 240. Three maps and one sheet of sections. (Indianopolis, 1869.) - Volume 8 Issue 82
Geologist
Geological survey
Cite
Citations (0)