Report from IUGG Assembly: IAGA session on multicomponent natural remanent magnetization



Of fundamental importance in paleomagnetism is the recognition of multicomponent behavior in rocks and the formulation of procedures to correctly isolate and identify the various components. Emphasis on multicomponent analysis has only emerged in the last 5–6 years. This is not only because of the increased study of more geologically complex areas, where rocks may have experienced more than one thermochemical event, but also because highly sensitive computercoupled magnetometers are now available, which permit more rapid and precise measurement of magnetization intensity and direction.

An essential element of multicomponent analysis is the examination of the magnetization removed in demagnetization procedures. Through the use of various methods which involve difference vector stereoplots, vector diagrams, and remagnetization circles, the separation and directional estimate of each component may be obtained. Additional information drawn from rock magnetic, petrologic, radiometric, or field relationships may then lead to a reconstruction of the complex magnetic history that many rocks, particularly old ones, have suffered.