SEDIMENT PROVENANCE - A CIRCUM-ARCTIC PERSPECTIVE

OMMA, Jenny E.¹, SCOTT, Robert A.¹, MORTON, Andy¹, PEASE, Victoria L.², HOWARD, James P.¹, and GUO, Li¹, (1) CASP, Department of Earth Sciences, University of Cambridge, West Building, 181A Huntingdon Road, Cambridge, CB3 0DH, United Kingdom, [email protected], (2) Dept. of Geology and Geochemistry, Stockholm Univ, S-106 91, Stockholm

Plate tectonic reconstructions of the Arctic Ocean contain many uncertainties. As a consequence, it is unclear how various parts of the Arctic margin were originally juxtaposed, and when and how they separated. A better understanding of the tectonic evolution of the Arctic region is of major importance for the assessment of hydrocarbon potential and reservoir distribution and quality in the circum-Arctic region.

Documenting the provenance of clastic sediments has great potential for providing new constraints on Arctic reconstructions where existing geophysical and geological data are ambiguous. In particular, the source of northerly-derived sediments to Arctic areas (e.g. Alaska, the Sverdrup Basin and Svalbard) in the Late Palaeozoic and Mesozoic is of key interest. At present, however, there are limited data with which to constrain sediment transport pathways and source areas; nor are the precise timing and nature of tectonic events controlling sedimentation clearly understood.

This paper presents a database of published U-Pb zircon age dates for potential primary sediment source areas in the circum-Arctic. The work shows that the different potential sediment source areas in the circum-Arctic region have diagnostic zircon age spectra and provides a starting point to analyse detrital sediment samples. Other provenance techniques to be integrated with the zircon age dating include sedimentology (facies analysis), optical heavy mineral analysis, single mineral geochemistry and Ar/Ar dating of detrital muscovite. Clastic sediment samples of Palaeozoic and Mesozoic age from key localities in the Arctic (Novaya Zemlya, the Sverdrup Basin, Taimyr and Svalbard) will be included, along with other areas that will be the target of future CASP fieldwork.