virtual geomagnetic pole paleomagnetism 14 magnetic reversal 12 geomagnetic field 10 Paleomagnetism 8 secular variation 8 Argentina 6 Cretaceous 6 South America 6 demagnetization 6 remanent magnetization 6 Buenos Aires [Argentina] 4 Holocene 4 Jurassic 4 Paleosecular variation 4 Pangaea 4 magnetostratigraphy 4 natural remanent magnetization 4 palaeomagnetism 4 thermoremanent magnetization 4 Africa 2 Alto Paraguay 2 Aptian 2 Argentina, Patagonia, Alto Rio Mayo valley 2 Cretaceous normal superchron 2 Early Cretaceous 2 Ecuador 2 Excursion 2 Geochronology 2 Geographical regions 2