Paleomagnetism of Aptian–Albian sections from the Northern Apennines (Italy): Implications for the 150–100 Ma apparent polar wander of Adria and Africa

We computed a new 120 to 100 Ma high-resolution Apparent Polar Wander Path (APWP) for Adria from magnetostratigraphic studies in the Northern Apennines (Italy). We analyzed 274 cores from three Early Aptian–Late Albian sections of the Marne a Fucoidi Fm., belonging to the sedimentary succession deposited above the Adria passive margin during Meso-Cenozoic time. To solve the problem of tectonic rotations induced during the Apennine orogenesis, we computed relative rotations between sections and realigned them into a common declination reference frame (Bosso, Italy). These new data were added to the previous 150–125 Ma segment computed from the same region [Satolli, S., Besse, J., Speranza, F., Calamita, F., 2007. New 125–150 Ma high-resolution Apparent Polar Wander Path for Adria from magnetostratigraphic sections in Umbria-Marche (Northern Apennines, Italy): Timing and duration of the global Jurassic–Cretaceous hairpin turn. Earth Planet. Sci. Lett. 257, 329–342. doi:10.1016/j.epsl.2007.03.009.] to get a very high-resolution 100 to 150 Ma APWP for Adria. The comparison of our APWP with the African APWP segment of Besse and Courtillot computed with 10 Myr sliding window [Besse, J., Courtillot, V., 2002. Apparent and true polar wander and the geometry of the geomagnetic field over the last 200 Myr. J. Geophys. Res. 107. doi:10.1029/2000JB000050.] leads to the following conclusions: 1) our segment (after a 25° clockwise rotation of the Bosso reference frame) is in very good agreement with the African APWP, as shown by a very similar time evolution of inclinations and declinations, most often statistically indistinct; 2) this agreement vindicates our previous model of structural unit rotation for older periods [Satolli, S., Besse, J., Speranza, F., Calamita, F., 2007. New 125–150 Ma high-resolution Apparent Polar Wander Path for Adria from magnetostratigraphic sections in Umbria-Marche (Northern Apennines, Italy): Timing and duration of the global Jurassic–Cretaceous hairpin turn. Earth Planet. Sci. Lett. 257, 329–342. doi:10.1016/j.epsl.2007.03.009.] 3) the concept of “synthetic” APWP construction is strongly validated; 4) the good agreement found strengthens the fact that Adria has been a promontory of Africa at the lithospheric level during Late Jurassic–Early Cretaceous (150–100 Ma), affected by tectonic rotations linked to the Apennines orogenic phases during Neogene; 5) our data evidence a possible ca. 105 Ma southward motion of Adria undetected from classical African APWPs. y, we have not found evidence for reversals interrupting the long normal Cretaceous superchron in our sections.