Vestnik Otdelenia nauk o Zemle RAN VOL. 2, NZ6025, doi:10.2205/2010NZ000043, 2010

Cosmic iron in sediments: the results of thermomagnetic analysis

Pecherskij D. M., D. K. Nurgaliev, V. A. Fomin

Abstract

Thermomagnetic analysis to 800oC was performed on sediments of Cretaceous-Danian and Miocene sections from the Caucasus, Kopetdag and Crimea. As a result we revealed the detailed pattern of how metallic iron particles are distributed in space and time, which is impossible to detect with "direct methods". Our main discovery is the synchronous enrichment by iron particles: 1) in 12.6–12.2 Ma, 2) 64.5–66 Ma, 3) 84–86 Ma (near the upper boundary of the Dzhalal magnetohyperchron), 4) 94–96 Ma. This phenomenon that occurred, is most likely to be global and space-connected. The average admixture of nickel iron particles varies from zero to 24%, the most widespread Ni-content is 7%. During magnetohyperchron Dzhalal the average admixture of nickel is nearly constant and poorly grows in iron particles, and borders of Dzhalal are marked recession of the nickel content.

Received 28 April 2010; published 5 June 2010.