Paleomagnetic Secular Variation of Early Middle Miocene Volcanics From Vogelsberg (Germany)

Abstract The Earth's magnetic field significantly changed its rate of polarity reversals over the past 200 Myr; yet it remains controversial whether these drastic changes—from a stable state of polarity during the Cretaceous Normal Superchron to more than 10 events per Myr during the Jurassic—are accompanied with similar changes in the directional variability of the field, termed paleosecular variation (PSV). In an effort to better constrain the geomagnetic behavior during the Miocene, we investigated the paleomagnetism of 162 volcanic units (1920 cores) from the Vogelsberg, the largest volcanic mountain range in Central Europe emplaced between 17.6 and 15.2 Ma. We successfully interpreted the paleodirections of 148 volcanic units, which led to a final collection of 127 independent geomagnetic records after correction for serial correlation. After removing the transitional directions, this collection passes the reversal test and yields a paleomagnetic pole located at 161.9°E and 84.5°N ( = 3.2°, = 116), which is statistically indistinguishable from the predictions of the latest apparent polar wander paths for stable Europe. Used as a proxy for PSV, the dispersion of the virtual geomagnetic poles is consistent with a more variable paleomagnetic field during the Miocene relative to the past 10 Myr, as recently proposed from the analysis of the global PSV database. However, when focusing on the paleolatitudinal range 40–50° over the past 200 Myr, we failed to detect a robust correlation between and the rate of polarity reversals.