Moreover , further evidence is accumulating that large - scale remagnetization events have taken place which may necessitate revision of the estimated positions of the palaeomagnetic poles .
This makes the authenticity of rocks older than a few million years difficult to determine without painstaking mineralogical observations .
Further evidence is accumulating that large - scale remagnetization events have taken place which may necessitate revision of the estimated positions of the palaeomagnetic poles .
This makes the authenticity of rocks older than a few million years difficult to determine without painstaking mineralogical observations .