Palaeomagnetism of the Volyn Traps, Southwestern Margin of the East European Platform: New Data about Ediacaran Geomagnetic Field

Abstract

Summary We present new results of palaeomagnetic studies of the Ediacaran rocks of the Volyn Basalt Province revealed by six boreholes. Clear stratification and correlation of the basalt and tuff layers by magnetic parameters allow us to determine the magnetic field reversals throughout the stratigraphic succession of the Volyn series of about 400 m thick. Minimum six polarity reversals recorded by ChRM-component were revealed. The geochronological ages of these rocks, considering the data from neighboring regions, is in the range of 580–545 Ma. Our interpretation of palaeomagnetic data based on the arguments that the formation of volcanic rocks might occurred over a short geological time interval (e.g., 0.5 Myr) and the geomagnetic field was about one order of magnitude weaker than the present-day field. New data fit into the hypothesis of the “hyperactivity” of the magnetic field at the end of the Ediacaran. It is speculated that this condition of geomagnetic field may had influenced to the paleomagnetosphere and thereby potentially increasing surface radiation and mutagenic processes in biota leading to Cambrian Evolutionary explosion.