Detrital zircon geochronology of Ediacaran to Cambrian deep-water strata of the Franklinian Basin, northern Ellesmere Island, Nunavut; implications for regional stratigraphic correlations

• Published in: Canadian journal of earth sciences Vol. 50; no. 10; pp. 1007 - 1018
• Main Authors: Beranek, Luke P, Pease, Victoria, Scott, Robert A, Thomsen, Tonny B
• Format: Journal Article
• Language: English
• Published: Ottawa National Research Council of Canada 01.10.2013; NRC Research Press; Canadian Science Publishing NRC Research Press
• Subjects: absolute age; Basins; Cambrian; Canada; Correlation; Correlation analysis; Deep water; deep-water environment; Drainage area; Ediacaran; Ellesmere Island; Fluid mechanics; Franklinian Basin; Geochronology; Grant Land Formation; Grants; Gravity flow; ICP mass spectra; ion probe data; Islands; Lake Hazen; Land; Laurentia; lithostratigraphy; mass spectra; Mass spectrometry; Neoproterozoic; Neoproterozoic Era; Nesmith Beds; nesosilicates; Nunavut; orthosilicates; paleoenvironment; paleogeography; Paleolimnology; Paleozoic; Precambrian; Proterozoic; provenance; Queen Elizabeth Islands; Regional; Rifting; Rock; Rocks; Sedimentary geology; Shallow water; silicates; spectra; statistical analysis; Strata; Stratigraphic correlation; Stratigraphy; U/Pb; upper Precambrian; Zircon; zircon group; Zirconium; Nunavut; Ellesmere Island; Canada; Nunavut Territory Canada
• ISSN: 0008-4077; 1480-3313; 1480-3313
• DOI: 10.1139/cjes-2013-0026

Enigmatic successions of deep-water strata referred to as the Nesmith beds and Grant Land Formation comprise the exposed base of the Franklinian passive margin sequence in northern Ellesmere Island, Nunavut. To test stratigraphic correlations with Ediacaran to Cambrian shallow-water strata of the Franklinian platform that are inferred by regional basin models, >500 detrital zircons from the Nesmith beds and Grant Land Formation were analyzed for sediment provenance analysis using laser ablation (LA-ICP-MS) and ion-microprobe (SIMS) methods. Samples of the Nesmith beds and Grant Land Formation are characterized by 1000-1300, 1600-2000, and 2500-2800 Ma detrital zircon age distributions and indicate provenance from rock assemblages of the Laurentian craton. In combination with regional stratigraphic constraints, these data support an Ediacaran to Cambrian paleodrainage model that features the Nesmith beds and Grant Land Formation as the offshore marine parts of a north- to northeast-directed depositional network. Proposed stratigraphic correlations between the Nesmith beds and Ediacaran platformal units of northern Greenland are consistent with the new detrital zircon results. Cambrian stratigraphic correlations within northern Ellesmere Island are permissive, but require further investigation because the Grant Land Formation provenance signatures agree with a third-order sedimentary system that has been homogenized by longshore current or gravity-flow processes, whereas coeval shallow-water strata yield a restricted range of detrital zircon ages and imply sources from local drainage areas or underlying rock units. The detrital zircon signatures of the Franklinian passive margin resemble those for the Cordilleran and Appalachian passive margins of Laurentia, which demonstrates the widespread recycling of North American rock assemblages after late Neoproterozoic continental rifting and breakup of supercontinent Rodinia.