Rusticle magnetotaxis elucidating Rustflower formations in RMS Titanic's Turkish Baths

Abstract

During his bio-archaeological Last Mysteries of the Titanic expedition in 2005, explorer James Cameron observed the RMS Titanic's Turkish Baths, an anoxic chamber secluded from currents deep within the wreck's remote interior, utilizing the ROV Skipper. There, Cameron discovered anomalously thin, vertical, and bifurcating rusticle formations he termed “Rustflowers.” Proposing magnetotaxis as the involved mechanism, this study analyzed rusticles salvaged from Titanic's #8 davit bitt utilizing ferromagnetic resonance, which demonstrated an asymmetric spectrum featuring prominent uniaxial over magnetocrystalline anisotropy fields of Buni = 110 mT and Bcub = −23 mT, linewidth parameters of ΔB = 200 mT, ΔBFWHM = 144 mT, ΔBhigh = 37 mT, ΔBlow = 107 mT, and asymmetry ratio of A = 0.35, and α = 0.20. These represent the established signature of biogenic magnetofossil chains synthesized by former magnetotactic bacteria, enduring within the rusticle cortex. Electron microscopy and chemical analysis identified single-domain range magnetite nanocrystals, and crystalline elemental sulfur inclusions, respectively. Chemosynthetic microbial iron oxy-hydroxide accretions guided upward along geomagnetic field lines by north-seeking magnetotaxis, under reducing conditions exhibited in Titanic's Turkish Baths, may account for the distinctive morphology of its Rustflowers; adding dimension to the bacterial application of iron assimilated from deep-sea sources, including shipwrecks.