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During the Late Jurassic - Early Cretaceous, the Arctic Basin (including the Barents Sea, the Wandel Sea Basin of North Greenland and the Canadian Arctic) formed a wide epicontinental sea, stretching from Novaya Zemlya in the east to the Sverdrup Basin in the west. The Lower Cretaceous Helvetiafjellet Fm. of Svalbard, the Isachsen Fm. of Arctic Canada, and the Lichen Ryg and Ladegrdsen formations of North Greenland were deposited along the western flanks of this epicontinental sea.
Detrital zircons from these formations have been dated by U-Pb and analysed for Hf isotopes by laser ablation plasma source mass spectrometry (LAM-ICPMS). Samples from all studied locations display a similar range of U/Pb ages, with significant zircon populations at 1.0 - 1.2, 1.6 - 1.7, 1.8 - 2.0 and 2.6 - 2.8 Ga. Major hiati occur between 2.1 and 2.4 and from 0.48 to 0.91 Ga. Low initial εHf values indicating recycled crust components are significant in Caledonian-aged zircons, and in Palaeoproterozoic (1.8 - 2.0 Ga) and Neoarchean zircon populations. Other U/Pb age populations in the studied samples are dominated by zircons with positive εHf values, indicating a significant contribution of mantle-derived material. The εHf values seen within a given U-Pb age population is generally consistent, with only minor scatter between the different samples. Exceptions are the Caledonian aged and 1.8 - 2.0 Ga populations where variations suggest variable sources for these age groups.
The U-Pb and Hf data are largely consistent with Greenland and Northern Canada as major sources of zircon for the studied sandstones. The results suggest there was a depositional link between the Sverdrup- and western Barents Sea basins during the Early Cretaceous. Samples from the different locations display striking resemblances in the distribution of age and Hf data, suggesting significant mixing of detritus over a large area and through an extended period of time.
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