The New Data on Dynamics of Permian - Triassic Magmatic Activity on Siberian Platform: Paleomagnetic Results from Tunguska Syncline and Angara – Taseeva Depression

Abstract:

We perform the new paleomagnetic data from intrusive complexes of two regions of Siberian Trap province (Angara – Taseeva depression and Tunguska syncline). Results of paleomagnetic and geological investigation indicate that two different patterns of magmatic process took place in these regions. In Angara – Taseeva depression short intense peaks of magmatic activity alternate with more prolonged periods of relative quietness. These bursts of magmatic activity resulted in intruding of large dolerite sills. In the central part of Tunguska syncline local intrusive events took place on the background of effusive volcanic activity.

Considering the new data together with previous paleomagnetic results from Norilsk and Maymecha - Kotuy regions (Pavlov et al., 2015), western part of Viluy basin (Konstantinov et al., 2014) and Angara-Taseeva depression (Latyshev et al., 2013), it can be concluded that pulsating character of magmatic activity is typical for the periphery of Tunguska syncline. However, the central part of Tunguska syncline is characterized by more prolonged and even style of volcanic process and less widescale intrusive events. This conclusion is important for understanding of LIPs formation and mantle plumes dynamics.

This study was funded by grants RFBR # 14-05-31447 and 15-35-20599 and Ministry of Education and Science of the Russian Federation (grant 14.Z50.31.0017).