Revisiting the age of the Asha Group in the South Urals

Estudios Geologicos. 2019;75(2):e103-e103 DOI 10.3989/egeol.43590.558

 

Journal Homepage

Journal Title: Estudios Geologicos

ISSN: 0367-0449 (Print); 1988-3250 (Online)

Publisher: Consejo Superior de Investigaciones Científicas

LCC Subject Category: Science: Geology

Country of publisher: Spain

Language of fulltext: Spanish, French, English

Full-text formats available: PDF, HTML, XML

 

AUTHORS


A. V. Kolesnikov (Geological Institute, Russian Academy of Sciences - Trofimuk Institute of Petroleum Geology and Geophysics of Siberian Branch Russian Academy of Sciences - Moscow State Pedagogical University,)

N. I. Bobkov (Trofimuk Institute of Petroleum Geology and Geophysics of Siberian Branch Russian Academy of Sciences - Novosibirsk State University)

EDITORIAL INFORMATION

Double blind peer review

Editorial Board

Instructions for authors

Time From Submission to Publication: 48 weeks

 

Abstract | Full Text

The Asha Group of the South Urals, initially erected by Albert Olli as Palaeozoic sedimentary complex, more than half a century ago was considered as a key section for the Vendian (Ediacaran) of the western slope of the South Urals. However, the ca. 1700 m-thick terrigenous sedimentary sequence is characterised by unusual low biodiversity of Ediacaran macrofossils, which might be explained by relatively young age of the Asha Group and possible mass extinction event in the end of Ediacaran Period. The relatively young age was confirmed by the U-Pb zircon date of 547.6±3.8 Ma obtained from the tuff in the lower part of the Basa Formation as well as finding of ichnospecies Didymaulichnus tirasensis in the upper part of Zigan formation. However, in 2018 it has been documented there the mass appearing of D. tirasensis in the lowermost part of the Basa Formation. Therefore, the Vendian (Ediacaran) age of the Asha Group of the South Urals can be revisited in favour to terminal Ediacaran- Cambrian or even early Cambrian.