The Magnetic Properties of some Submarine Oceanic Lavas

The magnetic properties of a collection of submarine oceanic lavas have been examined and the results compared with those for reference collections of petrologically similar continental lavas. It is found that the submarine lavas show a similar distribution of intensity of remanent magnetization but a distinctly lower range of low field susceptibilities. As a result of this 61 per cent of the submarine lava samples have a ratio of remanent to induced magnetization greater than ten. Measurements of Curie point in a high field and magnetic unit cell size have also been made and a detailed examination of the oxide petrology has been carried out. It has been possible to correlate Curie point, mineralogy, magnetite cell size and the form of thermal demagnetization curves in order to give some indication as to the state and history of the titanomagnetite oxide minerals of the lavas.