Origin of Anisotropy of Magnetic Susceptibility in Serpentinized Orogenic Peridotite
摘要
Serpentinization significantly alters orogenic peridotites, but the processes controlling the magnetic fabric development remain incompletely understood, particularly the roles of mineralogy, fluid availability, and deformation. This study addresses this gap by combining petrography, rock magnetic measurements, and numerical modeling on samples representing moderate to complete serpentinization. Magnetic properties indicate a mix of paramagnetic serpentine and ferrimagnetic magnetite, with anisotropy of magnetic susceptibility fabrics showing spatial patterns linked to serpentinization degree and structural setting. Microstructural observations reveal that serpentine and magnetite grow parallel or at characteristic angles to primary fabrics, while deviations reflect post-serpentinization deformation. Numerical modeling confirms that magnetic fabric orientation depends on the interaction of primary mineral crystallographic preferred orientation and topotactic serpentinite growth. These results demonstrate the complex interplay of mineralogy, fluid-rock interaction, and deformation in controlling magnetic fabric evolution during serpentinization in orogenic peridotites.