Arc-continent collision in the Southern Urals

• The Southern Urals of Russia contain what is arguably one of the best-preserved examples of an arc–continent collision in anyPaleozoic orogen. The arc–continent collision history recorded in the rocks of the Southern Urals began in the Early Devonian withthe onset of intra-oceanic subduction and the formation of the Magnitogorsk Arc and ended with its collision with the margin ofBaltica during the Late Devonian. The Baltica margin consisted of a basement that was composed predominantly of rocks ofArchean and Proterozoic age that, by the time of arc–continent collision, was overlain by Cambrian, Ordovician, Silurian, andDevonian sediments interpreted to have been deposited in rift-related grabens on the continental slope and rise, and on the shallowmarine platform. The Magnitogorsk Arc consists of Early to Late Devonian island arc volcanic rocks and overlying volcaniclasticsediments. Arc–continent collision led to the development of an accretionary complex that includes shallowly and deeplysubducted continental margin rocks, ophiolite fragments, and sediments that were deposited in a foreland-basin setting. Thegeochemistry of the Magnitogorsk Arc volcanic rocks, the structure of the arc–continent collision accretionary complex and theforearc, the high-pressure rocks beneath and along the suture zone, the mafic and ultramafic ophiolitic material, and the syn-tectonic sediments show that the Paleozoic tectonic processes recorded in the Southern Urals can be favorably compared with thosein currently active settings such as the west Pacific.© 2006 Elsevier B.V. All rights reserved.

Subject headings

NATURVETENSKAP  -- Geovetenskap och miljövetenskap -- Geofysik (hsv//swe)

NATURAL SCIENCES  -- Earth and Related Environmental Sciences -- Geophysics (hsv//eng)

Keyword

arc–continent collision; Southern Urals; arc-chemistry

high-pressure rocks

forearc basin

foreland basin

ophiolite

Publication and Content Type

ref (subject category)

art (subject category)