Record details

    Limitations of tensor subtraction in isolating diamagnetic fabrics by magnetic anisotropy
Statement of responsibility
    František Hrouda, Bernard Henry, Graham Borradaile
    Borradaile, Graham
    Henry, Bernard
    Hrouda, František
Source title - serial
    Vol. 322
    p. 303-310
    4 obr., 22 bibl.
    Zkr. název ser.: Tectonophysics
Subject group
    čistecko-jesenický pluton
    magnetická susceptibilita
    magnetizace remanentní
    orientace přednostní
Geographical name
    Čistá (Rakovník)
Abstract (in english)
   The anisotropy of low field susceptibility (AMS) represents the orientation distribution of all minerals in a rock, whereas the anisotropy of magnetic remanence (AMR, preferably anhysteretic) isolates that of the accessory remanence-bearing minerals. The subtraction of normalized AMR from AMS, in theory and under limited practical circumstances, may isolate the paramagnetic + diamagnetic anisotropy contribution and thus the orientation distribution of the matrix minerals (Borradaile et al., 1999. Geol. Soc. Lond., Sp. Publ. 151, 139-145). Limitations include the great sensitivity of the subtraction process to the precision of the definition of the respective (AMS, AMR) tensors, and a requirement that single-domain and superparamagnetic grains are absent. The latter is particularly important for superparamagnetic minerals because iron oxides may be part of the orientation distribution of the main group of remanence-bearing minerals, although they would be excluded from the AMR fabric.
   Low ratios of saturation isothermal remanence to induced susceptibility characterize those rare rocks in which superparamagnetic behavior is a significant contribution
    Česká geologická služba
Contributor code
    ČGS (UNM)
Source format
Entered date
    24. 10. 2007
Import date
    8. 8. 2012