Vice Professor Greig A. Paterson and his team undertake simple 2D (i.e., zero-inclination) deposition experiments using intact MTB cells. These experiment are used to investigate the first—order characteristics of how intact MTB record the ambient magnetic field, which includes the linearity of magnetization with applied field, the effects of remanence anisotropy, and the behavior and fidelity of relative paleointensity estimates. 

For their samples with variable amounts of bacterial cells, the effects of magnetic interactions on the paleomagnetic data are clearly observable. As a result, magnetic interactions affecting paleomagnetic data may be more prevalent than realized and these effects need to be further investigated. 

Fig.1. TEM observations of (a) a typical AMB-1 bacterial cell and (b) a typical magetosome chain. (Image by Greig A. Paterson) 

Fig.2. (a) The measured magnetic declination as a function of the expected value. R is the Pearson linear correlation and p is the significance of the correlation. (b) The linearity of NRM with applied field (BNRM) fitted using a linear model. (Image by Greig A. Paterson) 

Fig.3. The linearity of relative paleointensity estimates with applied field (BNRM) when normalized by (a) ARM and (b) SIRM. 

Paterson et al. The fidelity of paleomagnetic records carried by magnetosome chains. Earth and Planetary Science Letters, 2013, 383: 82–91. doi: 10.1016/j.epsl.2013.09.031 （Download Here）