there are many methods for detecting and measuring magnetofossils, although there are some issues with the identification. current research is suggesting that the trace elements found in the magnetite crystals formed in magnetotactic bacteria differ from crystals formed by other methods. it has also been suggested that calcium and strontium incorporation can be used to identify magnetite inferred from magnetotactic bacteria. other methods such as transmission electron microscopy (tem) of samples from deep boreholes and ferromagnetic resonance (fmr) spectroscopy are being used. fmr spectroscopy of chains of cultured magnetotactic bacteria compared to sediment samples are being used to infer magnetofossil preservation over geological time frames. research suggests that magnetofossils retain their remanent magnetization at deeper burial depths, although this is not entirely confirmed. fmr measurements of saturation isothermal remanent magnetization (sirm) in some samples, compared with fmr and rainfall measurements taken over the past 70 years, have shown that magnetofossils can retain a record of paleorainfall variations on a shorter time-scale (hundreds of years), making a very useful recent history paleoclimate indicator.