Experimental constraints on the magnetic mineralogy of Fe-Ti oxides in basalts from HSDP-2 bore hole

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The Hawaiian Scientific Drilling Project (HSDP) provides an excellent opportunity to study the evolution of rock magnetism in relation to the growth history and magmatic evolution of a shield volcano. The main magmatic carriers in the basaltic rocks drilled from the HSDP-2 bore hole are the two Fe-Ti oxide minerals, titanomagnetite and ilmenite. The aim of the present project is to improve the correlations between magnetic properties and chemical-structural characteristics of these oxides at high (magmatic) temperatures, with an emphasis on titanomagnetite. The new data will contribute to a better understanding of rock magnetic properties of subaerial and submarine basaltic rocks that mainly build up the Hawaiian shield In a first stage we plan to determine characteristic magnetic parameters (e.g. Curie or Néel temperature, low-temperature behavior of the magnetic susceptibility, hysteresis parameters at room and low temperature) of synthetic Fe-Ti oxides equilibrated at high temperatures (1000-1150°C), with well-defined compositions (incl. vacancy concentrations) analogous to those in Hawaiian rocks. These new data will be applied especially to submarine samples recovered from the deep part of HSDP-2 that do not show late oxidation features.