# Plio-Quaternary Tectonic Activity in the Northern Nubian Belts: The Main Driving Forces
## 3 Nubia-Eurasia Convergence Trend  
Any attempt at recognizing the Plio-Quaternary geodynamics of the northern Nubian belts is obviously conditioned by the Nubia-Eurasia kinematics adopted. The analysis described in this work is based on the plate convergence trend (SSW-NNE) that is compatible with the Mediterranean Plio-Quaternary deformation pattern [9,10,71,72]. Given that this trend is significantly different from the one suggested by the kinematic models largely adopted in the literature, it seems opportune to report some remarks about our choice.  
The solutions suggesting an SE-NW convergence trend are mainly based on the computation of global kinematic models (GKMs, [117,118]) and on geodetic observations [40,119]. However, the assumptions underlying these computations do not consider some major problems, as discussed by [8-11,72,72] and synthetically described here below.  
* The computation of GKMs is based on a two-plate mosaic: Nubia and Eurasia. However, this choice does not take into account that there are two microplates (Morocco and Iberia) that may not move in close connection with the major plates. In [72], it is shown that adopting the proposed four-plate mosaic (Nubia, Eurasia, Iberia and Morocco, Figure 4), the Nubia-Eurasia convergence trend compatible with the Mediterranean deformation pattern (SSW-NNE) can match within errors the constraints used for the computation of the GKM (Atlantic spreading rates and transform fault azimuths).
* The use of geodetic data in some structures that are moving independently from Nubia and Eurasia may be misleading. This holds for the Iberia and Morocco blocks, the Hyblean-Pelagian domain and the Atlas-Tell system, for the reasons described earlier.
* Geophysical and geodetic data indicate that the Adria domain is now moving roughly north-northeastward with respect to Eurasia (e.g., [120; 121; 122; 123]). Since no significant decoupling is actually recognized between Adria and Nubia (e.g., [7; 9; 10; 124; 125]), one should explain how the motion of Adria can be reconciled with the presumed almost perpendicular northwestward motion of Nubia.
* The Nubia-Eurasia rotation poles obtained by the use of long-term geological data [117; 118] are significantly different from the ones based on geodetic data [40; 119]. So far, the fact that the \"geological\" poles are located 3000 km north of the \"geodetic\" poles has not found plausible explanations [118]. This problem may be related to the fact that the kinematic field derived from geodetic data can be considerably influenced by the post-seismic relaxation triggered by strong earthquakes in the last decades. In particular, one can reasonably expect that the kinematic field in the Mediterranean regions is still conditioned by the effects of the major seismic sequence that has developed along the North Anatolian fault since 1939 [9; 42; 126; 43].
* The tectonic implications of the NW-SE Nubia-Eurasia convergence trend cannot be reconciled with several major tectonic features of the Mediterranean Plio-Quaternary evolution, which rather implies an SSW-NNE trend [9; 10; 71; 72].