GPlates reconstruction of the Mesozoic motion of Adria based on a new robust APWP

Reconstruction models of the Mediterranean area are typically based on geological and structural observations, and occasionally validated by selected paleomagnetic data. In contrast, the reconstruction of the present study primarily relies on APWPs defined by paleomagnetic data, and is tested against geological and tectonic observations. The study focuses on the Mesozoic displacement history of Adria with respect to the African and European plates. Kinematic reference frames for the large plates are provided by Global APWPs of various definitions, which tightly constrain the expected declinations in both the African and the stable European tectonic frames, but allow some speculations about paleolatitudes between 170 and 130 Ma.

The kinematic constraints for Adria are based on a recently published APWP derived from a substantial paleomagnetic dataset, representing stable and imbricated Adria, the Transdanubian Range Unit and the Southern Alps. The dataset was quality-controlled and it was evaluated with different methods (running mean averaging, spline fitting) resulting in closely correlating trends.

The GPlates reconstruction is based on the above defined APWPs, visualizing the tectonic displacements within the Africa-Adria-Europe system for selected time periods. Paleo-longitudes, not constrained by the paleomagnetic data, were estimated using structural reconstructions of the region. The outline of Adria microplate is a simplified one, based on the earlier published Greater Adria concept.

In the GPlates reconstruction the following important events of this system are highlighted

• Adria drifted away from Europe after 200 Ma, connected to the initial rifting of the Alpine Tethys
• Adria rotated clockwise with respect to Africa during 170–150 Ma. This period of time is characterized by hyperextension and initial spreading phases of the Alpine Tethys and also by intra-oceanic subduction in the Neotethys
• Adria rotated counterclockwise with respect to Africa during 150–120 Ma, when obduction and subsequent shortening took place in the Neotethyan margin, while spreading continued in the Piemont-Ligurian and Valais oceanic branches
• Adria shifted northward after 150 Ma, in coordination or independently of Africa, moving closer to stable Europe around 115 Ma. This may explain tectonic deformation and/or uplift in several units of African origin.
• Southward shift of Adria is suggested between 115–100 Ma, when a general deepening of the sedimentary basins is recognized in the Central Mediterranean.