Abstract
A modified Eulerian orthogonal transformation is extremely useful in transforming the magnetization vector of a rock sample from the sample coordinate system as measured in a magnetometer to the ancient coordinate system at the sampling site, especially if complicated folding has occurred since the rock was magnetized. The method is adaptable to a wide variety of sample collecting and marking conventions. The form and function of the transformation, which has been widely used in other fields, is reviewed and is applied to the following situations of interest in paleomagnetism: transformation from sample to site coordinates; transformation of sample coordinates if the reference or marking plane is oblique to the sample coordinate system; and removal of the effects of horizontal or plunging folds. An earlier treatment of this latter problem by ZOTKEVICH (1972) is shown to be incorrect. Additional applications of the transformation are made to the display of paleomagnetic data. The transformation has many potential applications in structural geology.
