Journal article
Baltican crustal provenance for Cambrian-Ordovician sandstones of the Alexander terrane, North American Cordillera: evidence from detrital zircon U-Pb geochronology and Hf isotope geochemistry
Journal of the Geological Society, Vol.170(1), pp.7-18
01/01/2013
DOI: 10.1144/jgs2012-028
Abstract
Detrital zircon U-Pb geochronology and Hf isotope geochemistry allow us to decipher the crustal provenance of Cambrian-Ordovician backarc basin strata of the Alexander terrane, North American Cordillera, and evaluate models for its origin and displacement history relative to Baltica, Gondwana, Siberia, and Laurentia. Quartzose shallow-marine sandstones of the Alexander terrane contain a range of Neoproterozoic to Neoarchaean detrital zircons with the most dominant age groupings c. 565-760, 1000-1250, 1450, and 1650 Ma. Subordinate volcaniclastic sandstones yield Cambrian and Ordovician detrital zircons with a prominent age peak at 477 Ma. The detrital zircon age signatures resemble coeval strata in the Eurasian high Arctic, and in combination with faunal and palaeomagnetic constraints suggest provenance from local magmatic rocks and the Timanide orogenic belt and Fennoscandian Shield of NE Baltica. The Hf isotopic compositions of Palaeozoic to Neoarchaean detrital zircons strongly favour Baltican crustal sources instead of similar-aged domains of Gondwana. The Alexander terrane formed part of an arc system that fringed the Uralian passive margin, and its position in the Uralian Seaway allowed faunal exchange between the Siberian and Baltican platforms. The available evidence suggests that the Alexander terrane originated in the Northern hemisphere and migrated to the palaeo-Pacific Ocean by travelling around northern Laurentia.
Details
- Title: Subtitle
- Baltican crustal provenance for Cambrian-Ordovician sandstones of the Alexander terrane, North American Cordillera: evidence from detrital zircon U-Pb geochronology and Hf isotope geochemistry
- Creators
- Luke P Beranek - Geological Survey of CanadaCees R van Staal - Geological Survey of CanadaWilliam C McClelland - University of IowaSteve Israel - Yukon Geological Survey, Whitehorse, YT Y1A 2C6, CanadaMitch G Mihalynuk - British Columbia Geological Survey, Victoria, BC V8W 9N3, Canada
- Resource Type
- Journal article
- Publication Details
- Journal of the Geological Society, Vol.170(1), pp.7-18
- Publisher
- GEOLOGICAL SOC PUBL HOUSE
- DOI
- 10.1144/jgs2012-028
- ISSN
- 0016-7649
- eISSN
- 2041-479X
- Number of pages
- 12
- Grant note
- EAR 0948359 / National Science Foundation
- Language
- English
- Date published
- 01/01/2013
- Academic Unit
- Earth and Environmental Sciences
- Record Identifier
- 9984240792902771
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