Ages of detrital zircons (U/Pb, LA-ICP-MS) from the Latest Neoproterozoic–Middle Cambrian(?) Asha Group and Early Devonian Takaty Formation, the Southwestern Urals: A test of an Australia-Baltica connection within Rodinia

Abstract

A study of U-Pb ages on detrital zircons derived from sedimentary sequences in the western flank of Urals (para-autochthonous or autochthonous with Baltica) was undertaken in order to ascertain/test source models and paleogeography of the region in the Neoproterozoic. Samples were collected from the Ediacaran-Cambrian(?) age Asha Group (Basu and Kukkarauk Formations) and the Early Devonian-aged Takaty Formation. Ages of detrital zircons within the Basu Formation fall within the interval 2900–700 Ma; from the Kukkarauk Formation from 3200 to 620 Ma. Ages of detrital zircons from the Devonian age Takaty Formation are confined to the Paleoproterozoic and Archean (3050–1850 Ma). Potential source regions for the Asha Group detrital zircons include the Eastern European platform, Amazonia and West Africa based on ‘archetypal’ Rodinia reconstructions and Late Neoproterozoic paleogeographic models. An alternate proposal places Australia adjacent to Arctic/Uralian margin of Baltica (so-called Australia upside-down concept).