Magnetostriction and palæomagnetism of igneous rocks

IN a recent communication, Stott and Stacey¹ report on a “crucial experiment” from which they conclude: “This excellent agreement between the dip and the directions of artificial thermoremanent magnetization of the stressed and unstressed rocks indicates that large systematic errors due to magnetostriction are most improbable in igneous rocks of types normally used for palæomagnetic work”. This experiment was intended to test the proposals² and measurements³ bearing on the role of magnetostriction in rock magnetism. We present here our reasons for believing that the experiment was not crucial and that the conclusion is not justified.