Title: On the possibility of single-domain/pseudo-single-domain magnetic particles existing in the lower crust of Mars: Source of the strong magnetic anomalies

Author(s): Arkani-Hamed J

Source: JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS 110 (E12): Art. No. E12009 DEC 17 2005

Document Type: Article

Language: English

Abstract: This paper shows that single-domain or pseudo-single-domain (SD/PSD) magnetite grains can exist in the upper 30-45 km of the Martian crust. The upper similar to 50 km of the Martian crust have likely formed by volcanic eruptions on a stagnant lithosphere. A given lava flow cools very rapidly at the surface but is then gradually heated up through burial heating as it is overlain by other successive flows. The thermal evolution models of a lava flow show that its temperature remains below the magnetic blocking temperatures of magnetite, 480-580 degrees C, until it reaches similar to 30-45 km depth. The highly magnetic SD/PSD magnetite grains can easily explain the strong magnetic anomalies of Mars; less than 1% by volume of magnetite particles is sufficient.

KeyWords Plus: MARTIAN CRUST; FIELD; EVOLUTION; LITHOSPHERE; EARTH; DIFFERENTIATION; CONSTRAINTS; METEORITES; ALH84001; SPECTRA

Addresses: Arkani-Hamed J (reprint author), McGill Univ, Dept Earth & Planetary Sci, 3450 Univ St, Montreal, PQ H3A 2A7 Canada
McGill Univ, Dept Earth & Planetary Sci, Montreal, PQ H3A 2A7 Canada
Univ Toronto, Dept Phys, Toronto, ON Canada

E-mail Addresses: jafar@eps.mcgill.ca

Publisher: AMER GEOPHYSICAL UNION, 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA

Subject Category: GEOCHEMISTRY & GEOPHYSICS

IDS Number: 998CJ