Provenance of Neoproterozoic to upper Cretaceous sedimentary rocks, eastern Greenland: Implications for recognizing the sources of sediments in the Norwegian Sea

Detrital zircon U-Pb and Lu-Hf isotope data from Neoproterozoic to Cretaceous sandstones exposed in eastern Greenland, 70 degrees 30'-74 degrees N, are reported to characterize and evaluate the provenance from Greenland during pre-breakup and post-breakup sedimentation in the Norwegian-Greenland Sea. Middle Devonian to Lower Cretaceous samples all show similar detrital zircon age distributions characterized by variable Archean populations, abundant Proterozoic populations ranging from ca. 2000 to 900 Ma and a Caledonian population peaking at ca. 440 Ma. Neoproterozoic sediments of the Eleonore Bay Supergroup give a more narrow age distribution with a dominant age peak at 1100 to 1000 Ma, a secondary peak at 1700-1400 Ma, and rare Archean to Paleoproterozoic ages. We suggest that the Neoproterozoic metasediments of the Krummedal and Smallefjord sequences and the Eleonore Bay Supergroup together with Caledonian rocks of age ca. 440 Ma and variable amounts of Paleoproterozoic basement were the main sources for the analyzed Middle Devonian to Lower Cretaceous sandstones. The scarcity of Archean zircons could indicate a rather limited role of the Archean basement rocks of the eastern Greenland Caledonian orogenic belt as a source for some of the analyzed younger sedimentary rocks. The composite age distribution of the zircons from the Phanerozoic eastern Greenland samples, i.e., a minor Archean to Paleoproterozoic (Siderian and Rhyacian) component, abundant Paleoproterozoic (Orosian) to Neoproterozoic (Tonian) ages, and a significant Lower Silurian (Caledonian) signal, is very similar to zircon age distributions reported for Upper Cretaceous turbidite sandstones from large parts of the Norwegian Sea, and to the age distributions determined in this study for three Oligocene sandstone samples from east of Jan Mayen Island. Upper Cretaceous to Paleocene Norwegian Sea sandstones, known to be derived from Norway, differ from this eastern Greenland-derived pattern by a near total lack of Archean zircon ages and a less pronounced Caledonian component. Wide detrital zircon age spectra with a distinct Silurian group and a population of Neoarchean zircons is thus suggested as indicative of sediments sourced from the studied area of eastern Greenland. The Hf isotopic compositions of detrital zircons suggest that Eoarchean crust derived from a source with chondritic Lu/Hf ratios at ca. 3900-3700 Ma contributed to zircon-forming processes in the source area for the eastern Greenland sandstones until ca. 2300 Ma. The Caledonian orogeny in this area was probably a crust reworking event with a limited contribution from depleted mantle. (C) 2011 Elsevier B.V. All rights reserved.