Siberian craton - a fragment of a Paleoproterozoic supercontinent

Abstract

The sialic (volcanogenic) material of the terranes in 3the Siberian fragment of a Paleoproterozoic supercontinent separated from the mantle 3.5, 3.3, 3.0, and 2.5 billion years ago. The collision zones (sutures) between the terranes are dated by granitoids which melted from the crust of the terranes in two periods of time: 1.9 and 1.8 billion years ago. Local metamorphism and granite generation inside the collision (fault) zones were accompanied by synchronous areal dry granulite metamorphism in the adjacent terranes. This implies a fairly uniform field of high temperatures and pressures typical of the thicker crust of the collision prism. The amalgamation of the continental-crust fragments was terminated by the formation of a huge mountain massif ca. 1.8 billion years ago. Later, these mountains were wholly eroded. Early Riphean platform-type clastic sediments started to accumulate on the resulting peneplain 1.65 billion years ago, i. e., 150 million years after the end of the collision. The Siberian Craton is a part of the Pangea-1 Paleoproterozoic supercontinent which originated from the fragments of the broken Archean Pangea-0 supercontinent which had existed as microcontinents with their own sedimentary-volcanic covers which were transformed, after the collision, to the foldbelts superimposed over the basements of the old terranes. The exception was the Paleoproterozoic Akitkan volcanic belt which evolved first as a volcanic arc and later, in the course of the total amalgamation, was thrust over the ancient basement and involved in anorogenic acid magmatism (A-granites).

The age and history of the lithospheric mantle of the Siberian craton: Re–Os and PGE study of peridotite xenoliths from the Obnazhennaya kimberlite

“…Precambrian basement rocks are exposed mainly on the Anabar shield in the north and the Aldan shield in its southeastern corner (KML file). The crustal rocks range in age from 1.7 to 3.7 Ga, with two main groups around 2 Ga and 2.8-3 Ga (Rosen, 2002;Smelov and Timofeev, 2007).…”

“…4). (b) Literature data on mantle xenoliths from Udachnaya: Re-Os T RD for whole-rock peridotites, "megacrystalline dunites" (Pearson et al, 1995a) and eclogites (Pearson et al, 1995b) and Lu-Hf T RD and isochron ages of clinopyroxene from spinel peridotites ; (c) Re-Os isochron ages for sulfide inclusions in diamonds from Siberian kimberlites including Udachnaya (Wiggers de Vries et al, 2013); (d) U/Pb ages of detrital zircons and model Sm-Nd ages (T DM ) for crustal basement rocks from the Siberian craton (Rosen, 2002;Rosen et al, 2005). (e) Age distribution plots (T RD ) for peridotite xenoliths from South Africa and North America: the Kaapvaal craton (continuous black line) (Carlson et al, 2004;Carlson et al, 1999;Irvine et al, 2001;Simon et al, 2007), the Slave craton (dashed line) (Aulbach et al, 2004;Irvine et al, 2003;Westerlund et al, 2006) and the North Atlantic craton (grey line) (Bernstein et al, 2006;Hanghøj et al, 2001;Wittig et al, 2008).…”

“…7e). Because the Siberian craton is very large it was probably produced by amalgamation of different "blocks" which may have different ages (Rosen, 2002) and/or experienced large-scale re-working of its mantle roots (e.g. Lee et al, 2011).…”

“…These data for mantlederived rocks are compared in Fig. 7 to age data on crustal basement rocks from the Siberian craton: U/Pb ages of detrital zircons from the Anabar shield, which may belong to the same tectonic unit (Daldyn block) as Udachnaya, and model Sm-Nd ages (T DM ) for magmatic and metamorphic rocks (Rosen, 2002;Rosen et al, 2005). The crustal rocks show two age peaks, one at ∼ 1.9 Ga and another one at 3.0 Ga (Fig.…”

Place of birth of the Siberian Platform

“…According to modern concepts [1,2], the Siberian Craton, as a whole, formed in the Late Paleoprotero zoic, approximately 1.9-1.8 Ga ago, as a result of accretion-collision processes which led to amalgam ation of ancient Archean and Early Proterozoic conti nental blocks (terranes and/or superterranes). The accretion of superterranes of the Siberian Craton in modern coordinates was followed by formation of a huge Himalayan type collision orogen.…”