Thermomagnetic recording stability of taenite-containing meteoritic cloudy zones

The cloudy zone (CZ), a nm-sized intergrowth of taenite or tetrataenite crystals (or islands), is the most promising phase to preserve palaeomagnetic records in (stony-)iron meteorites. While slowly-cooled meteorites form tetrataenite – an extremely good recorder – fast-cooled meteorites contain fine-grained taenite islands, which were considered unsuitable for palaeomagnetic studies. In this work, however, we show that nm-sized taenite grains are stable over billion-year timescales, indicating that taenite-bearing meteorites are reliable sources of paleomagnetic information. Additionally, we find a range of sizes for which taenite forms stable single-domain structures. Single-domain states might be preserved even through subsequent tetrataenite ordering, implying that tetrataenite might carry magnetization state inherited from its precursor taenite. This remanent magnetization can be up to 10\textsuperscript{5} years older than that of larger tetrataenite islands in the same meteorite, which would have been reset upon ordering. This allow studding to two distinct events of planetesimal formation from a single sample.