GEOSCAN, résultats de la recherche


TitreNew geochronological and isotopic tracing results from the Sub-Phanerozoic Flin Flon and Glennie domains
AuteurMorelli, R M; Rayner, N M; Creaser, R A; DuFrance, S A
SourceSummary of Investigations 2010; Saskatchewan Ministry of Energy and Resources, Miscellaneous Report 2010-4.2, 2010, 34 pages
Séries alt.Secteur des sciences de la Terre, Contribution externe 20100223
Documentpublication en série
Lat/Long OENS-104.0000 -102.0000 55.0000 54.0000
Sujetsdatations radiométriques; datation radiométrique; datations au uranium-plomb; datations au neodymium-samarium; Domaine de Flin Flon ; Domaine de Glennie ; géochronologie; Phanérozoïque
Illustrationslocation maps; tables; Concordia diagrams; plots
ProgrammeÉtude des gîtes de sulfures massifs volcaniques, Initiative géoscientifique ciblée (IGC-4)
Résumé(disponible en anglais seulement)
As part of the ongoing sub-Phanerozoic Flin Flon-Glennie mapping project, new U-Pb zircon geochronology and Sm-Nd isotopic data are presented for rocks exposed near the Shield margin and rocks intersected by drilling of sub-Phanerozoic basement. A total of eleven new U-Pb zircon dates were determined and, following existing tectonic nomenclature for the Flin Flon domain, are interpreted to document the following events within various parts of the map area: (i) back arc / incipient oceanic arc development prior to 1895 Ma, (ii) juvenile to early successor arc volcanism between ca. 1890 and 1875 Ma, (iii) successor arc volcanism and plutonism between ca. 1875 and 1840 Ma, and (iv) deposition of siliciclastic successor basin sedimentary deposits between ca. 1860 and 1845 Ma, and (v) distinct metamorphic events at ca. 1840 Ma, 1812 Ma and, possibly, 1775 Ma. Moreover, the timing of deposition of host sequences of VMSstyle mineralization has been constrained for the Fon deposit (1890 Ma to 1876 ± 14 Ma), the Muskeg zone (1878 ± 1 Ma), the McIlvenna Bay deposit (1865 to 1860 Ma) and the Alex-Groucho zone (1854 ± 5 Ma). Sm-Nd isotopic data for nine samples of varying lithologic character and from throughout the map area yield a restricted range of values (eNd = +2.7 to +3.9,t = 1890 Ma). These results, all within a previously proposed range for ¿Flin Flon mantle¿, are taken to indicate derivation of the rocks from a dominantly juvenile source reservoir but with minor input of neoArchean or older Paleoproterozoic crust. Collectively, these new U-Pb and Sm-Nd isotopic data provide a more comprehensive understanding of the geological framework of the sub-Phanerozoic Flin Flon and Glennie domains.