Flexural unfolding of horizons using paleomagnetic vectors

This paper introduces a new restoration method (Pmag3Drest) designed for complex folded structures (non-cylindrical, non-coaxial). It combines paleomagnetic vectors and bedding markers setting up a reference system that allows deformed and undeformed surfaces to be related to one another. We assume flexural conditions during the deformation. Consequently, the stratigraphic horizons are considered to be globally developable surfaces with total area preservation except in specific deformation areas. Using paleomagnetism in the proposed restoration process (Pmag3Drest) helps to locate these areas with greater accuracy. It is similar to other approaches based on triangulations, but it forces the available paleomagnetic data to converge with the paleomagnetic reference vector during the restoration process. Our experiments use computer and analog models in which the deformed and undeformed surfaces are perfectly known. This enables us to apply the restoration method to the deformed surface and compare the parameters of the restored surface with those of the initial undeformed surface to quantify the quality of the method. Paleomagnetic data anchor the surface leading to more accurate results.

► A modified unfolding algorithm uses paleomagnetic vectors as primary information during restoration.
► It is based on more complete reference system which conceptually reduces restoration uncertainties.
► Computer and analog models allow checking the validity of the method.