The Archean of the Baltic Shield: Geology, Geochronology, and Geodynamic settings

Geotectonics (Impact Factor: 0.71). 01/2006; 40(6):409-433. DOI: 10.1134/S001685210606001X

ABSTRACT The Archean provinces and lithotectonic complexes of the Baltic (Fennoscandian) Shield are considered. The supracrustal complexes
are classified by age: <3.2, 3.10–2.90, 2.90–2.82, 2.82–2.75, and 2.75–2.65 Ga. The data on Archean granitoid complexes and
metamorphic events are mentioned briefly, whereas the recently found fragments of the Archean ophiolitic and eclogite-bearing
associations are discussed in more detail. The Paleoarchean rocks and sporadic detrital grains of Paleoarchean zircons have
been found in the Baltic Shield; however, the relatively large fragments of the continental crust likely began to form only
in the Mesoarchean (3.2–3.1 Ga ago), when the first microcontinents, e.g., Vodlozero and Iisalmi, were created. The main body
of the continental crust was formed 2.90–2.65 Ga ago. The available information on the Paleoarchean complexes of the Baltic
Shield is thus far too scanty for judgment on their formation conditions. The geologic, petrologic, isotopic, and geochronological
data on the Meso-and Neoarchean lithotectonic complexes testify to their formation in the geodynamic settings comparable with
those known in Phanerozoic: subduction-related (ensialic and ensimatic), collisional, spreading-related, continental rifting,
and the setting related to mantle plumes.



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