Manifestation of variations in solar activity 70-45 Ma ago

Unique paleoenvironmental records (ring widths of fossil trees) with a temporal resolution of 1 year are analyzed with the aim of revealing periodicities in climatic processes during the time interval of 70-45 Ma ago. The periodicities thus obtained are compared with the solar and climatic periodicities observed at present. It is shown that quasi-bicentennial and quasi-secular periodicities that can be attributed to the influence of solar Suess-de Vries and Gleissberg cycles manifest themselves in the most intense manner in climatic oscillations in the past (70-45 Ma ago). The spectra of the paleoclimate data exhibit periodicities that are typical of solar activity, i.e., the quasi-20-year (Hale cycle) and 11-year (Schwabe cycle) ones derived from the instrumental data and historical observations of sunspots. It can be concluded that analyzing climatic periodicities obtained by paleodendrochronology gives information on the solar periodicity that cannot be achieved by other methods. The revealed periodicities are similar in values to the present-day periodicity of solar activity.