Iron Loss in Titanomagnetites during Low Temperature Oxidation

Abstract

Titanomagnetite was extracted from 43 basalt samples from Leg 37 of DSDP. The Curie temperatures and cubic cell edges were measured for these samples. When these values were plotted in the FeO-TiO2-Fe2O3ternary diagram against the contours of Curie temperature and cell edge they show a clear decrease in the Fe/Ti ratio from 4.48 for z=0, x=0.545 to 2.58 for z=0.8. This latter value is lower than that calculated for a titanomaghemite with x=0.545, z=0.8 for which Fe/Ti=3.75. The fact that other authors' results, when plotted on these same contours, yield similar results suggests that either the oxidation products do not remain single phase cationdeficient titanomagnetites or that the Curie temperature and cell edge contours require refinement before being used for quantitative identification of these properties. In any event, a standardized technique of picking Curie temperature from an experimental curve needs to be adopted by all workers. © 1980, Society of Geomagnetism and Earth, Planetary and Space Sciences. All rights reserved.