Stratigraphic and isotopic link between the northern Stikine terrane and an ancient continental margin assemblage, Canadian Cordillera
- Univ. of Arizona, Tucson (United States)
- British Columbia Ministry of Energy, Victoria (Canada)
Geologic and isotopic data strongly imply a Late Triassic depositional link between a juvenile volcanic arc (northern Stikine terrane) and an outboard ancient continental margin assemblage (Nisling terrane) in the Canadian Cordillera. Two sandstone samples and a schist clast from a conglomerate layer at the base of the Upper Triassic Stuhini Group (northern Stikine terrane) have Nd-depleted mantle model ages of 1400-1430 and 1600 Ma, respectively; other Stuhini Group rocks have model ages of 390,660 and 690 Ma. Three samples of Nisling terrane schist and gneiss yield Nd model ages of 910, 1770, and 2450 Ma and highly radiogenic {sup 87}Sr/{sup 86}Sr ratios. These isotopic data corroborate stratigraphic evidence that detritus at the base of northern Stikine was shed from the Nisling terrane and strengthen interpretations that these terranes became linked by Late Triassic time. Thus, Upper Triassic strata of the northern Stikine terrane may have accumulated on top of or adjacent to an exotic continental fragment, a rifted fragment of the North American margin, or the in situ North American margin.
- OSTI ID:
- 7004023
- Journal Information:
- Geology; (United States), Journal Name: Geology; (United States) Vol. 19:12; ISSN GLGYB; ISSN 0091-7613
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
580000* -- Geosciences
AGE ESTIMATION
BRITISH COLUMBIA
CANADA
CHEMICAL COMPOSITION
CHEMISTRY
CONGLOMERATES
CONTINENTAL CRUST
DEVELOPED COUNTRIES
EARTH CRUST
ELEMENTS
GEOCHEMISTRY
GEOLOGIC AGES
GEOLOGIC FORMATIONS
GEOLOGY
GNEISSES
ISOTOPE DATING
ISOTOPE RATIO
MESOZOIC ERA
METALS
METAMORPHIC ROCKS
NEODYMIUM
NORTH AMERICA
RARE EARTHS
ROCKS
SANDSTONES
SCHISTS
SEDIMENTARY ROCKS
STRATIGRAPHY
TRIASSIC PERIOD
YUKON TERRITORY