Cretaceous paleomagnetic directions in different volcanics in Chukotka (NE Russia)
- 1Institute of Physics of the Earth RAS, Laboratory of the Main Geomagnetic Field and Petromagnetism, Moscow, Russian Federation
- 2Lomonosov Moscow State University, Moscow, Russian Federation
- 3Geological Institute RAS, Moscow, Russian Federation
The Cretaceous Okhotsk-Chukotka volcanic belt (OChVB) is one of the largest provinces of continental marginal magmatism with length more than 3000 km along the Pacific edge of Asia. In the field studies of 2019 and 2020 we sampled 21 sections in the northern part of the OChVB and 3 sections from basement of OChVB. These sections are represented by basalts and andesites; their tuffs, ignibrites and other volcanic rocks are much less common. The age of these volcanics is estimated based on U-Pb and Ar-Ar published data and our new Ar-Ar dates.
Based on the obtained data, a new paleomagnetic pole for the Chukotka part of the OChVB was calculated. The latitude of this paleomagnetic pole differs from the expected one when compared with that calculated for Chukotka from published data from Besse and Courtillot, 2003; Torsvik et al., 2012. These results are inconsistent with most of the existing geological data. Only a few works admit younger displacements in the southern part of the Verkhoyansk fold belt or in modern diffuse boundary of the Eurasian and North American plates. Moreover, we compare our OChVB pole with results from basaltic complexes from the basement, which has been likely remagnetized when OChVB was formed.
Acknowledgements: study of cretaceous volcanics is supported by RSF grant № 19-47-04110 and jurassic by RSF grant №18-77-10073.
How to cite: Lebedev, I., Bobrovnikova, E., Moiseev, A., and Tatiana, B.: Cretaceous paleomagnetic directions in different volcanics in Chukotka (NE Russia), EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-9596, https://doi.org/10.5194/egusphere-egu21-9596, 2021.
