Metallic iron in sediments at the Mesozoic-Cenozoic (K/T) boundary

Schmidt Institute of Physics of the Earth, Russian Academy of Sciences, Moscow, Russia

Abstract

[1]  Thermomagnetic analysis was performed on sediments close to the Mesozoic-Cenozoic (K/T) boundary in the following sections: Gams (Austria), Tetritskaro (Georgia), Klyuchi and Teplovka (the Volga Region, Russia), and Koshak (Turkmenia). Positive correlation is found between the contents of terrestrial magnetic minerals (Fe-hydroxides, titanomagnetite, magnetite) and extraterrestrial metallic iron, i.e., between the minerals of different origin and with different pre-accumulation history. The observed different values of positive correlation between the content of the above listed minerals depend from variation in redeposition rate. The correlation is absent altogether because of different provenance and the character of sedimentation as it is observed for the boundary layer and some sections (Gams, the sections from the Volga region). In contrast, stronger correlation is found if redeposition is important (Tetritskaro, Koshak).

Received 19 July 2008; accepted 22 August 2008; published 18 September 2008.

Keywords: cosmic dust, metallic iron, sediments, magnetic minerals, K/T boundary.

Index Terms: 1029 Geochemistry: Composition of aerosols and dust particles; 1512 Geomagnetism and Paleomagnetism: Environmental magnetism; 1594 Geomagnetism and Paleomagnetism: Instruments and techniques; 2129 Interplanetary Physics: Interplanetary dust.

Citation: Pechersky, D. M. (2008), Metallic iron in sediments at the Mesozoic-Cenozoic (K/T) boundary, Russ. J. Earth Sci., 10, ES6006, doi:10.2205/2008ES000304.