INTERPRETATION OF BOREHOLE MAGNETOMETER DATA

Samples recovered from Deep-Sea Drilling Project (DSDP) holes into the basaltic layer strongly suggest that a good model of the m agnetization would be a spatially random one. To interpret future magnetometer observations made in the holes, a theory is developed relating the observed fields to the magnetization autocorrelation tensor, a function completely describing the second-order statistics of the medium. Special models with long- and short- range order are examined and it is concluded that certain properties of the medium are highly desirable in making interpretation possible. It is shown that only in special circumstances (e. g. , horizontal layering of the medium) does the magnetic field correlate directly with the average magnetization in a region surrounding the magnetometer. The natural remanent magnetization data from leg 37 of the DSDP is examined to obtain partial information on the spatial statistics.