Magnetic phases in hemo-ilmenite: Insight from low-velocity and high-field Mössbauer spectroscopy

Abstract

We have studied natural samples of hemo-ilmenite (ilmenite with hematite exsolution lamellae) by use of Mössbauer spectroscopy. The samples are from the Allard Lake intrusion in Quebec. The stoichiometric compositions of the ilmenite host and the hematite lamellae are approximately Fe2+0.84Mg2+0.14Ti4+0.98Fe3+0.04O3 and Fe2+0.17Mg2+0.01Ti4+0.18Fe3+1.64O3, respectively. From low-velocity Mössbauer measurements, the Fe2+ and Fe3+ components of the Fe2+ -substituted hematite and Fe3+ -substituted ilmenite, formed by incomplete exsolution of hematite and ilmenite, have been suggested identified. High-field Mössbauer measurements, obtained at low-temperature indicate the presence of a minor ferrimagnetic component. Copyright 2007 by the American Geophysical Union.