Biomineralization and magnetization of sediments

Conference · Fri Mar 01 00:00:00 EST 1991 · AAPG Bulletin (American Association of Petroleum Geologists); (United States)

OSTI ID:5623777

Kirschvink, J L ^[1]

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1. California Inst. of Tech., Pasadena (United States)

Although nearly 60 mineral-like compounds are known to be synthesized biochemically by living organisms, only two (magnetite Fe{sub 3}O{sub 4}, and greigite Fe{sub 3}S{sub 4}) have ferromagnetic properties capable of providing a stable remanent magnetization to sediments. In particular, the magnetotactic bacteria are now known to provide a significant supply of fine-grained, single-domain magnetite to surface sediments in environments ranging from deep-sea sediments to terrestrial soils. In many such environments, including the deep-sea sediments shallow-water platform carbonates, and perhaps soils, the fossilized bacterial magnetosomes are clearly the source of the stable remanent magnetization (NRM) upon which paleomagnetic studies and magnetic polarity stratigraphies are based. The crystal structures of these bacterial magnetofossils, revealed through the use of high-resolution TEM techniques, confirms both their biological origin and documents some of the postdepositional dissolution and diagenetic effects to which they are subjected. Recent discoveries have revealed an amazing diversity of magnetite-precipitating micro-organisms, many of which produce up to several hundred times more fine-grained magnetite per cell than known previously. These organisms include some of the largest bacterial cells yet found, which are up to 15 micrometers in length and contain several thousand magnetite crystals in their magnetosome chains. The contribution of these organisms to the magnetization of sediments is as yet unknown.

• OSTI ID: 5623777
• Report Number(s): CONF-910403-; CODEN: AABUD
• Journal Information: AAPG Bulletin (American Association of Petroleum Geologists); (United States), Vol. 75:3; Conference: Annual meeting of the American Association of Petroleum Geologists (AAPG), Dallas, TX (United States), 7-10 Apr 1991; ISSN 0149-1423
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
58 GEOSCIENCES
GEOLOGIC DEPOSITS
BIOGEOCHEMISTRY
PALEOMAGNETISM
BACTERIA
CRYSTAL STRUCTURE
DIAGENESIS
FOSSILS
GEOLOGIC HISTORY
IRON SULFIDES
MAGNETITE
SEDIMENTS
CHALCOGENIDES
CHEMISTRY
GEOCHEMISTRY
IRON COMPOUNDS
IRON ORES
MAGNETISM
MICROORGANISMS
MINERALS
ORES
OXIDE MINERALS
SULFIDES
SULFUR COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
550200* - Biochemistry
580000 - Geosciences