Palaeomagnetic and rock magnetic studies on some Bulgarian Plio-Palaeocene basalts

Summary Normal and reversed remanent magnetization has been found in Plio-Pleistocene basalts from Bulgaria. Ore microscope observations show that the magnetic mineral is a homogeneous titanomagnetite: electron microprobe studies show that it contains a high proportion of Ti. Comparison of thermomagnetic measurements with the Curie points expected for stoichiometric titanomagnetites with the analysed chemical composition suggest that the titanomagnetites must be slightly oxidized, i.e. be slightly cation deficient.