New data on the age of the Shumikha Paleoisland-arc complex (East Sayan): Late Riphean-Vendian crust formation on the southwestern margin of the Siberian Platform

Authors
Rumyantsev, MY Turkina, OM Nozhkin, AD Gracheva, TV Shevchenko, DO
Citation
My. Rumyantsev et al., New data on the age of the Shumikha Paleoisland-arc complex (East Sayan): Late Riphean-Vendian crust formation on the southwestern margin of the Siberian Platform, GEOL GEOFIZ, 41(12), 2000, pp. 1790-1797
Citations number
17
Categorie Soggetti
Earth Sciences
Journal title
GEOLOGIYA I GEOFIZIKA
ISSN journal
00167886 → ACNP
Volume
41
Issue
12
Year of publication
2000
Pages
1790 - 1797
Database
ISI
SICI code
0016-7886(2000)41:12<1790:NDOTAO>2.0.ZU;2-4
Abstract
Results of U-Pb, Ar-Ar, and Sm-Nd isotope dating of the Shumikha paleoislan d-arc complex (Kan block, East Sayan) are presented. The investigated rocks included calc-alkalic metaandesite-dacites (island-are association), thole iitic metarhyolites (back-arc association), and plagiogranites of the Shumi kha Massif intruded into the supracrustal metamorphic complex, Obtained dat a suggest two main stages of formation or the Shumikha complex: 1) 700-680 Ma ago - formation of a protolith; 2) approximate to 550 Ma ago - metamorph ism of volcanic rocks.