ROLE OF WATER-CONTENT IN THE MAGNETIZATION OF SEDIMENTS

We have developed a new experimental procedure in order to study the role of water content in the acquisition of post‐depositional detrital remanent magnetism by a sediment. The procedure leads to the determination of the magnetic direction recorded by a sediment as a function of the water content present when that sediment experiences a change in the direction of an applied magnetic field. Experiments with a variety of sediments indicate that in most cases, regardless of the water content, the sediment does not become remagnetized. Such behavior requires a re‐assessment of the importance of the theoretical notion that at high water contents the magnetic carriers remain mobile within fluid‐filled voids and hence are able to realign along a new applied field. Analysis of the magnetic properties of sediment samples initially stirred in zero and non‐zero magnetic fields leads to the conclusion that the magnetization of the sediments may arise from small‐scale, shear‐induced liquefaction. Copyright 1979 by the American Geophysical Union.