An Igneous Origin for Martian Magnetic Anomalies?

Introduction: The presence of alternately magnetized sources on Mars indicates that at one time Mars had a magnetic field, presumably generated by an internal dynamo, and that its polarity reversed at least once before shutting off. Mars does not currently possess a magnetic field, so the anomalies are attributed to remanent magnetization (RM) of minerals in the crust. The initiation and cessation of the inducing field, its timing, and the implications for Mars thermal evolution, compositional differentiation, and volatile budget are critical components of understanding the planetary dynamics of Mars. Isobaric (1 bar) constant-rate cooling experiments were run using Fe-rich (i.e., Martian) basalt to ascertain whether conditions necessary for crystallization of minerals retaining intense RM are consistent with any of the models proposed for generation of the Martian magnetic anomaly.