Construction of a thermal demagnetization oven, and investigations on the Matahina ignimbrite

A non-magnetic oven, and its ancillary equipment have been constructed and used to study magnetic properties of the Matahina ignimbrite, for which the following results have been established: 1. The directions of magnetization do not alter on heating in the oven. 2. The ignimbrite may be divided into sheets on the basis of magnetic properties. 3. Geological faulting has been revealed by divergent magnetization directions. 4. The T.R.M. acquired in the present earth's field is much greater than the N.R.M. This is possibly due to changes in minerals in the rock, either in the field since the rock was deposited, or on heating in the laboratory.