Protolith ages of eclogites, Marun-Keu Complex, Polar Urals, Russia: implications for the pre- and early Uralian evolution of the northeastern European continental margin
J. Glodny, V. Pease, P. Montero, H. Austrheim, A. I. Rusin, 2004. "Protolith ages of eclogites, Marun-Keu Complex, Polar Urals, Russia: implications for the pre- and early Uralian evolution of the northeastern European continental margin", The Neoproterozoic Timanide Orogen of Eastern Baltica, David G. Gee, Victoria Pease
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Single zircon U-Pb dating by ion microprobe and Pb-evaporation techniques, combined with Sr-Nd isotopic and geochemical data, constrain the pre- and early Uralian evolution of the Marun-Keu eclogite-facies metamorphic complex. Polar Urals, Russia. The complex is interpreted as a part of the Early Palaeozoic East European passive margin, subducted, metamorphosed and exhumed during Uralian arc-continent collision. In the Marun-Keu complex, a variety of meta-igneous and metasedimentary rocks documents different evolutionary stages of the northeastern margin of Baltica. Both the oldest, polystage detrital zircon population, which is 570 to 700 Ma in age, and the dominant zircon population in an island arc-type magmatic suite (c. 550 Ma) are related to the Neoproterozoic Timanian orogeny, which resulted in continental growth of northeastern Europe by accretion of juvenile oceanic and island arc material. A distinct magmatic event at c. 490 Ma is documented in zircons from metagranites, and is interpreted as evidence for incipient post-Timanian rifting which finally led to formation of both the Proto-Uralian ocean and the Early Palaeozoic East European passive margin. A convergent setting was re-established in Silurian times, culminating in Uralian arc-continent collision by east-dipping subduction of the East European passive margin. Metamorphic zircon ages reflect the collision event at 360 to 355 Ma.
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The Neoproterozoic Timanide Orogen of Eastern Baltica
The Neoproterozoic Timanide Orogen of eastern Baltiea extends from the high Arctic to the southern Ural Mountains and represents significant crustal growth of the northeastern European continental margin in the late Neoproterozoic. This volume, a co-operation between Western European and Russian scientists within the framework of the European Science Foundation’s EUROPROBE programme, provides a comprehensive overview of the orogen and represents a new synthesis of Timanian Orogeny. It includes: the pre-Timanian passive margin deposits of the northern and northeastern flank of the East European Craton; the magmatic, metamorphic and structural evolution of the orogen across the Timan Mountain and Pechora Basin regions to the Ural Mountains; the post-Timanian platform successions, important for interpreting the timing of orogeny and the return to an early Palaeozoic passive margin setting; and the extension of the orogen northwards to Novaya Zemlya. Relationships westwards to the Caledonides of Greenland and Scandinavia and eastwards to the Baikalides of Siberia are also treated.
This volume will be of interest to geoseientists, students and researchers concerned with orogenic processes and regional tectonics.