Magnetic Properties of Siliceous Sediments from the Clarion-Clipperton Zone, Northeastern Equatorial Pacific, and the Occurrence of Bacterial Magnetite

ZHANG Wei-guo; YU Li-zhong; CONG You-zi

It is indicated that ferrimagnetic minerals dominate the magnetic properties of surface siliceous sediments in the Clarion-Clipperton (C—C) zone, northeastern equatorial Pacific. The ferrimagnetic minerals are mainly single domain (SD) an d superparamagentic(SP) in size. Magnetic parameters, together with TEM analysis, reveal the presence of bacterial magnetite, which undergoes dissolution to var ying extent. Such a phenomena is indicative of an active iron cycle involving mi crobes. Imperfect anti-ferromagnetic minerals show a higher content in the sed iments of the western region of C—C zone, and increase toward high latitude. It is suggested that, with increased distance from the equator, sediments become m ore oxidized.

1. State Key Laboratory of Estuarine and Coastal Research, East China Normal University,Shanghai 200062;

2. No. 1 Oceanography Institute,State Ocean Bureau,Qingdao Shandong 266003

Received Date: 2002-04-15

Rev Recd Date: 2003-01-10

Publish Date: 2003-09-10

Key words:

Abstract: It is indicated that ferrimagnetic minerals dominate the magnetic properties of surface siliceous sediments in the Clarion-Clipperton (C—C) zone, northeastern equatorial Pacific. The ferrimagnetic minerals are mainly single domain (SD) an d superparamagentic(SP) in size. Magnetic parameters, together with TEM analysis, reveal the presence of bacterial magnetite, which undergoes dissolution to var ying extent. Such a phenomena is indicative of an active iron cycle involving mi crobes. Imperfect anti-ferromagnetic minerals show a higher content in the sed iments of the western region of C—C zone, and increase toward high latitude. It is suggested that, with increased distance from the equator, sediments become m ore oxidized.

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Reference (17)

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Magnetic Properties of Siliceous Sediments from the Clarion-Clipperton Zone, Northeastern Equatorial Pacific, and the Occurrence of Bacterial Magnetite

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