Biostratigraphic correlation of Mesozoic polarity chrons CM1 to CM23 at Capriolo and Xausa (Southern Alps, Italy)

Two pelagic limestone sections in the Southern Alps spanning the Kimmeridgian (Late Jurassic) to Barremian (Early Cretaceous) interval yield magnetostratigraphies which can be correlated to oceanic magnetic anomalies M1-M3 and M8-M23. This includes the interval M11-M13 which has not previously been correlated to a sedimentary section. Detailed investigations of nanofossils and calpionellids in these sequences allow precise correlation of polarity chrons to biostratigraphic events and these results compare favorably to those of previous studies. The close correspondence in polarity pattern between that interpreted from the M8 to M15 interval in the Hawaiian lineations and that recorded at the Capriolo section, suggests that sedimentation rates in this sequence and spreading rates in the Hawaiian lineations were rather constant during this interval. In contrast, the sedimentation rate at the Xausa section appears to increase up-section with the facies transition from the Rosso Ammonitico to the Maiolica Formation.