U-Pb ion microprobe detrital zircon provenance investigations of pre-Mesozoic sediment samples from southern Novaya Zemlya and northern Taimyr, Arctic Russia, provide new constraints on the tectonic evolution of northern Eurasia. Sediments from both areas previously assigned a Neoproterozoic age are shown to be Palaeozoic (<= 500 Ma), changing our understanding of the timing of tectonic events and their regional correlation, Samples from Novaya Zemlya provide an a priori Baltica signature, and dominant cumulative probability age peaks betweem 610 and 530 Ma are consistent with derivation from Timanide sources. Samples from northern Taimyr also contain the unique Timanian 'fingerprint' and are also inferred to be derived from the continental slope of northeastern Baltica, implying that the North Kara block was a part of Baltica in the early Palaeozoic. These data constrain the timing of deformation, metamorphism and development of an unconformity in southern Novaya Zemlya to a restricted period no earlier than late Cambrian-early Ordovician and at least 50 Ma after the peak Timanian event. The unconformity on Novaya Zemlya can be correlated in style and timing with an unconformity on Severnaya Zemlya and may record post-Timanian extensional collapse and onset of spreading in the Uralian Ocean.
ISI Document Delivery No.: 446LR Times Cited: 43 Cited Reference Count: 60 Pease, V. Scott, R. A. Swedish Polar Research Secretariat; Swedish National Science Research Council; Royal Swedish Academy; Swedish Museum of Natural History; EU INTAS [97-1139]; research councils of Denmark, Norway and Sweden; Geological Survey of Finland Without the logistical and financial assistance of the Swedish Polar Research Secretariat, fieldwork in Taimyr would not have been possible. We thank the Captain and crew of the research vessel Gorizont, operated by the Russian Hydrographic Office in Murmansk, for their logistic support in Novaya Zemlya. We also thank VNIIOkeangeologiya in St. Petersburg for the organizational role in the Novaya Zemlya expedition. Additional support from the Swedish National Science Research Council. the Royal Swedish Academy, the Swedish Museum of Natural History and EU INTAS grant (97-1139) is gratefully acknowledged. C ASP acknowledges the industrial sponsors of its Arctic research with gratitude. F. Corfu and an anonymous reviewer provided constructive criticism that improved the quality of the manuscript. Thanks go to M. J. Whitehouse and the NORDSIM facility, which is funded by the research councils of Denmark, Norway and Sweden, the Geological Survey of Finland, and the Swedish Museum of Natural History. This paper is NORDSIM Publication 224. 44 Geological soc publ house Bath Geosciences, Multidisciplinary