Northeastern and northwestern margins of Baltica in Neoproterozoic time: evidence from the Timanian and Caledonian Orogens
Anna Siedlecka, D. Roberts, J. P. Nystuen, V. G. Olovyanishnikov, 2004. "Northeastern and northwestern margins of Baltica in Neoproterozoic time: evidence from the Timanian and Caledonian Orogens", The Neoproterozoic Timanide Orogen of Eastern Baltica, David G. Gee, Victoria Pease
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The Neoproterozoic depositional histories of the Timanian and Baltoscandian, orthogonal margins of Baltica show several important differences but also some similarities. The Timanian margin comprises mainly low-grade, terrigenous sedimentary successions with a distinctive, margin-parallel fault zone separating pericratonic and basinal domains. Magmatic rocks are comparatively rare on land, but are common in deep drillcores recovered from beneath the Pechora Basin. Conversion to an active margin occurred in latest Riphean time, ultimately leading to the accretionary and transpressional regime of the Vendian-age, Timanian Orogeny. Along the Baltoscandian margin, successions of low to high metamorphic grade are preserved in diverse Caledonian nappe complexes. Three main types of palaeobasin are distinguished, based largely on sedimentary facies and basin geometry. Magmatic rocks are more common than in the Timanides, ranging from mafic dyke swarms to the voluminous Seiland Igneous Province. This margin remained passive throughout the Neoproterozoic era. The Vendian-dated dyke swarms signify the onset of Iapetus/Ægir ocean opening at precisely the time when the orthogonal Timan margin was being deformed and telescoped during the Timanian Orogeny.
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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.