The Tellnes norite contains в€ј28 per cent haemo-ilmenite (ilmenite with fine-scale haematite exsolution lamellae) together with plagioclase, orthopyroxene, clinopyroxene (containing exsolved magnetite), olivine, minor biotite, hornblende, magnetite and sulphides. Based on Monte Carlo simulations of haematiteвЂ“ilmenite interfaces at the atomic scale and on measured rock-magnetic properties, we predict that the magnetization is carried by a ferrimagnetic substructure produced at the contacts of the very fine-scale titanohaematite and ilmenite exsolution lamellae.Д®xsolution microstructures, geomagnetism, haematiteвЂ“ilmenite series, mineralogy, planetary anomalies, rock magnetism 1 IntroductionДuring the course of interpreting an aeromagnetic survey over the Proterozoic South Rogaland Anorthosite Province, Norway, large remanence-controlled negative magnetic anomalies were noted over the Г…na Sira anorthosite and the Tellnes haemo-ilmenite ore deposit-one of the largest actively mined ilmenite deposits in the world ( McEnroe et al. The amount of magnetization in these samples is too high to be solely accounted for by a spin-canted AF moment in the haematite. Samples have high coercivities, and average NRM values of 25 A m в€’1, which typically show в€ј2 per cent saturation in the NRM state.

Subsequent undercooling of the ilmenite and the micron-scale haematite lamellae led to metastable nucleation of nanoscale lamellae down to unit-cell scale, leaving depleted hosts between lamellae with compositions of Ilm 98 and Ilm 15вЂ“13 as measured by TEMвЂ“EDX. A typical bulk composition, Ilm 84, exsolved at high temperature to produce host ilmenite Ilm 94 and micron-sized haematite lamellae Ilm 23 as measured by electron microprobe (EMP). These rocks are ideal for evaluating the magnetic properties of fine exsolution intergrowths and the larger titanohaematite lamellae in the host ilmenite grains. Massive, nearly вЂpureвЂ™, haemo-ilmenite layers from historic ore deposits in Rogaland, Norway contain very few silicates or other oxides and typically produce remanence-dominated magnetic anomalies.

Illmenite parasite game