Specimen size and improved precision with the Molspin spinner magnetometer

Manual reorientation of traditional 10.5 cm3 paleomagnetic cores between successive spins in Molspin-type magnetometers produces some operator error that may be significantly reduced if smaller core (5.1 cm3) is used instead. The smaller core may be locked into a cubical holder that ensures its precise angular alignment between successive spins of the magnetometer. This significantly improves precision of the mean vector direction for replicate measurements, or for a suite of specimens, provided that the magnetic mineralogy of the rock is sufficiently homogenous to be meaningfully characterized in the smaller (5.1 cm3) core. The smaller core is more quickly measured and less expensive to drill.