Magnetic fabric of peridotite with intersecting petrofabric surfaces, Tinaquillo, Venezuela
Two intersecting structural surfaces of different ages and origins are characteristic of the Tinaquillo (Venezuela) peridotite. An older penetrative mylonitic foliation is cut by younger serpentine veinlets. The anisotropy of magnetic susceptibility (AMS) is influenced by both petrofabric components. The dominant fabric surface from the AMS perspective is defined by serpentine veinlets, probably because of the abundant secondary magnetite associated with them. The minimum AMS axis (K3) is typically orthogonal to the plane of the dominant veinlet set, and the maximum (K1) and intermediate (K3) axes lie in the veinlet plane. The mylonitic foliation surface also influences the magnetic fabric, so that the K1 axis lies parallel to the line of intersection between the mylonitic foliation and the veinlet plane. A macroscopically prominent mineral lineation, defined by stretched enstatite laths in the foliation surface, shows no AMS correlation. Remanent magnetization directions are multicomponent and show much scatter, probably due to the deformation and complex magnetization history of the rock. © 1988.
Publication Source (Journal or Book title)
Physics of the Earth and Planetary Interiors
MacDonald, W., & Ellwood, B. (1988). Magnetic fabric of peridotite with intersecting petrofabric surfaces, Tinaquillo, Venezuela. Physics of the Earth and Planetary Interiors, 51 (4), 301-312. https://doi.org/10.1016/0031-9201(88)90071-4