A Timanian foreland basin setting for the late Neoproterozoic–Early Palaeozoic cover sequences (Dividal Group) of northeastern Baltica

• Main Authors: Arild Andresen, Nana Yaw Agyei-Dwarko, Magnus Kristoffersen, Nils-Martin Hanken
• Format: Dataset
• Language: unknown
• Published: 2016
• Subjects: Geology; St Petersburg areas; Dividal Group; Cambrian Dividal Group sediments; Ediacaran zircons; Neoproterozoic detrital zircons; Cambrian Dividal Group; Cambrian deposits; Detrital zircon age populations; Timanian foreland basin; clastic zircon age populations; Dividal Group sediments; Timanian source area; SW; foreland basin; Reisadalen; White Sea; Altevann; Fennoscandian
• Online Access: https://doi.org/10.6084/m9.figshare.3453677.v1; https://figshare.com/articles/A_Timanian_foreland_basin_setting_for_the_late_Neoproterozoic_Early_Palaeozoic_cover_sequences_Dividal_Group_of_northeastern___Baltica/3453677

LA-ICP-MS U–Pb and Hf-isotope data on detrital zircons from the Ediacaran and Cambrian Dividal Group demonstrate that the autochthonous cover sequence above the Fennoscandian Shield in northernmost Scandinavia is not derived from an easterly Archaean and Palaeoproterozoic source within Baltica as commonly thought. Detrital zircon age populations on four samples from the Dividal Group are dominated by Mesoproterozoic zircons with relatively few Palaeoproterozoic and Archaean zircons. Two samples, from Altevann and Reisadalen have, in addition, a significant population of Ediacaran zircons ( c. 570–560 Ma), indicating a Timanian source area for most of the lower Cambrian Dividal Group sediments. The 176 Hf/ 177 Hf isotope data show the Ediacaran zircons to be derived from two separate plutonic complexes within the Timanides. It is argued that the Dividal Group sediments were deposited in a foreland basin south and SW of the Timanide Orogen. Similarities with clastic zircon age populations from Cambrian deposits in Akkajaure, Ladoga/White Sea and St Petersburg areas indicate that this foreland basin possibly extended southward for at least 1000 km. A foreland basin setting for the Ediacaran and Cambrian deposits in Central and Southern Scandinavia can thus account for the enigmatic Neoproterozoic detrital zircons in these deposits.