INTERNATIONAL JOURNAL OF GEOMAGNETISM AND AERONOMY VOL. 5, GI1004, doi:10.1029/2003GI000043, 2004

Paleointensity behavior in Barremian-Cenomanian (Cretaceous)

A. Yu. Kurazhkovskii , N. A. Kurazhkovskaya , and B. I. Klain
The Borok Geophysical Observatory, Borok, Yaroslavl Region, Nekouz, Russia

A. Yu. Guzhikov
Saratov State University, Saratov, Russia

Abstract

[1] Fragmentary knowledge on geomagnetic field intensity in Barremian-Cenomanian stage obtained from sediment rocks is summarized. Three types of periodical variations are revealed in the paleointensity behavior. The types differ by the amplitude and duration (tens of millennia, hundreds of millennia and more than million years). It is found that in all the magnetopolar intervals an alternating of quiet and burst-like regimes of magnetic field generation is observed, the regimes differing by the oscillation amplitude and mean values of the paleointensity. It is demonstrated that the mean values of the paleointensity of quiet regimes of geomagnetic field generation were (0.5-0.8) H₀, where H₀ is the intensity of the contemporary magnetic field of the Earth. During burst-like regimes of the geomagnetic field generation the mean values of the paleointensity were 1.2 H₀, whereas the maximal values exceeded H₀ by a factor of 3 and more. An attempt is made to compare variations of the paleointensity with epochs of riftogenesis and orogenesis. A comparison is performed of the results of geomagnetic field intensity determination from sediments and thermomagnetized rocks.

Received 9 June 2003; revised 9 March 2004; accepted 23 March 2004; published 28 July 2004.

Keywords: Geomagnetic field paleointensity; Magnetopolar intervals; Geomagnetic field generation.

Index Terms: 1503 Geomagnetism and Paleomagnetism: Archeomagnetism; 1522 Geomagnetism and Paleomagnetism: Paleomagnetic secular variation; 1527 Geomagnetism and Paleomagnetism: Paleomagnetism applied to geologic processes.

Citation: Kurazhkovskii, A. Yu., N. A. Kurazhkovskaya, B. I. Klain, and A. Yu. Guzhikov (2004), Paleointensity behavior in Barremian--Cenomanian (Cretaceous), Int. J. Geomagn. Aeron., 5, GI1004, doi:10.1029/2003GI000043.