Reversals and Excursions of the Geomagnetic Field as Defined by Palaeomagnetic Data from Upper Palaeozoic-Lower Mesozoic Sediments and Igneous Rocks from Argentina

Abstract

Palaeomagnetic data from samples collected in rock sequences of sediments and igneous rocks of Late Palaeozoic and Triassic age exposed in northwestern Argentina are summarized. On basis of these data a composite magnetic stratigraphy for the Late Carboniferous, Permian and Early and Middle Triassic was prepared. They record two normal polarity events at the Late Carboniferous and Middle Permian which are correlated with the Debal'tseva Zone and the Quebrada del Pimiento Normal Event, respectively. They also record short-lived normal polarity events and geomagnetic excursions at the Late Permian-Early Triassic, which are correlated with the Illawarra Zone, and after them a long period of predominant normal polarity. This is correlated with the normal quiet interval reported within the Triassic; there are many geomagnetic excursions within this interval which are being investigated. © 1980, Society of Geomagnetism and Earth, Planetary and Space Sciences. All rights reserved.