Russian Journal of Earth Sciences
Vol. 6, No. 1, February 2004
Geodynamic regionalization of the recent structure of North Eurasia
A. F. Grachev, M. K. Kaban, and V. A. Nikolaev
Abstract
Correlation analysis of geological and geophysical parameters of the North
Eurasia lithosphere is performed on the basis of data for the recent
vertical tectonic movements of the crust reflected in the 1:5 000 000 North
Eurasia map of recent tectonics
[Neotectonic map..., 1996]
and calculated curvature intensities of the recent movements
K int,
as well as such geophysical parameters as the heat flow HF, Moho depth, maximum and
minimum
tangential stresses
S1-S3 estimated from gravity data, and mantle
anomalies with
wavelengths shorter than 2400 km. The correlation analysis is complemented with
factor analysis. Factors responsible for geodynamic regimes of North Eurasia are
identified and mapped. They are used for the identification and interpretation of
geodynamic classes of the lithosphere. Seismically active regions such as
orogens, rifts and prerifts are examined separately; an additional
parameter, the seismic activity
A10 is used for this purpose. Aseismic
platforms are also studied separately using, as a parameter, the crystalline
basement depth instead of the seismic activity. Results of the geodynamic
regionalization of seismically active and aseismic areas in North Eurasia
are summarized in a general map of geodynamic regionalization of North
Eurasia. Its analysis provided several constraints on the development and
controlling factors of the majority of regions. Implications of the inferred
results for the determination of tectonic stress fields are discussed.