Volume 26, Issue No. 2b, 2001

Magdalena KÃdziaøko* - Hofmokl
*Institute of Geophysics, Polish Academy of Sciences, 01-452 Warsaw, Ks. Janusza 64, Poland (fax: 48-22-6915-915, e-mail: magdahof@igf.edu.pl).

Presented during the 6th Biennial Castle Meeting «New trends in geomagnetism, paleo, rock and environmental magnetism», August 31-September 5, 1998, Czech Republic.

Keywords: serpentinites, magnetic minerals, magnetic susceptibility, magnetic hysteresis, Paleozoic. Sudetes, Poland.

ABSTRACT

The Sudetic ophiolite is composed of several dismembered fragments of obducted rock series formed in a MOR regime. One of them - the Gogoøów - Jordanów massif is built of totally serpentinized ultramafic rocks. The oceanic serpentinization and several later episodes of continental alteration took place in hydrothermal regime and at temperatures lower than the hydrothermal ones. The alteration resulted in the formation of several phases of magnetite partly transformed into martite and maghemite. Some fine-grained magnetites underwent single phase low temperature oxidation leading to formation of a thin maghemite coating around a magnetite core which influenced the rock-magnetic characteristics.

Journal HomeTable of contents Volume 26, No.2b