The self-reversal origin of the reversed remanent magnetization in the igneous rocks containing the oxidized Fe-Ti oxide solid solutions

Abstract

I study the magnetic and paleomagnetic characteristics of the Pleistocene to
Quaternary basalts from the West Carpathian Mountains. I have revealed the existence
of the so-called self-reversal remanent magnetization bearing disordered-antiferromagnetic
Fe-Ti phases, with the Néel temperatures of either TN = 430−450 °C (the Ti-Mgh phases)
or with TN = 460−470 °C (Hem-Ilm phases). I have suggested for the first time to name
of these phases in this article. It is very important that these phases are the only sources
of the reversed RM, of the self-reversal origin, probably of the chemical remanent magnetization
(CRM) origin. The basalts of Southern Slovakia were differentiated to these
of the magnetite and Ti-rich Ti-Mt bearing rocks with normal polarity of RM, and those
with the presence of the self-reversal RM bearing disordered-antiferromagnetic Ti-Mgh
phases of the TN = 430 to 450 °C, and those of the disordered-antiferromagnetic Hem-Ilm
phases of the TN = 460 − 470 °C, both of only reversed RM of the self-reversal origin. I
present the original model based on the principe that the magnetite, hematite and Ti-rich
titanomagnetite bearing rocks, without any disordered-antiferromagnetic phases, carry
only normal – positive RM. The self-reversal remanent magnetization bearing disorderedantiferromagnetic
magnetic phases of Fe-Ti oxide solid solutions carry only reversed remanent
magnetization in the rocks. This model has been involved to explain the reversed or
normal RM of submarine igneous rocks published in the literature. We anticipate that in
all continental or submarine reversally magnetized rocks the disordered-antiferromagnetic
Fe-Ti phases would be revealed, either in their initial, complete developed stages, or as
the remnants of these phases.