Possible causes of quasiperiodic variations in geomagnetic reversal frequency and Sr/Sr ratios in marine carbonates through the Phanerozoic |
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| Authors: | AN Didenko |
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| Affiliation: | aKosygin Institute of Tectonics and Geophysics, Far East Branch of the Russian Academy of Sciences, ul. Kim Yu Chen 65, Khabarovsk, 680000, Russia;bGeological Institute, Russian Academy of Sciences, Pyzhevskii per. 7, Moscow, 119017, Russia |
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| Abstract: | Variations in frequency of geomagnetic reversals through the Phanerozoic have been analyzed jointly with 87Sr/ 86Sr ratios in marine carbonate sediments. The time series of both parameters contain principal components with periods from 90 to 110 Ma and show a certain correlation. Namely, (i) both time series have five local minimums spaced at similar intervals (period lengths); (ii) the minimums in the Δ87Sr/86Sr curve follow in time those of the reversal frequency, with a lag from 12 Myr in the Ordovician to 38 Myr in the Cretaceous; (iii) the rate of heat transfer from processes at the core-mantle boundary (in D″ layer) which control the Earth's geological life was from 7 to 25 cm/yr in the Phanerozoic. This rate approaches the observed velocities of horizontal plate motion and the predicted mantle convection rates. |
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| Keywords: | Frequency of geomagnetic reversals Superchron 87Sr/ 86Sr in marine carbonates Relationship in time between processes in D&Prime layer and in shallow Earth |
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