The Iberian microcontinent and its connected oceanic crust are affected by deformations related to the Eurasian‐African plate boundary. Active stress inversions from populations of moment tensor focal mechanisms have been performed around and inside the Iberian peninsula, using a total of 213 moment tensor estimates. Main results are as follows: (1) The tensorial solutions show better consistency and lower misfits compared to those obtained previously from first P arrival focal mechanisms. (2) Along the Eurasia‐Africa western boundary, the type of active stresses progressively changes easternward from triaxial extension to uniaxial compression along the Terceira Ridge, the Gloria Fault zone, and the Gulf of Cadiz. (3) In the Betics‐Alboran‐Rif zone, uniaxial extension predominates with Shmax N155°E trending. (4) In northern Algeria, uniaxial compression reappears. (5) The Iberian foreland is currently under strike‐slip to uniaxial extension tensorial conditions.

A brittle deformation tectonic analysis was performed in central Spain (Spanish Central System and Madrid Basin) in order to decipher and understand the deformation processes that take place in a typical intracontinental zone. 1174 fault slickensides obtained in materials with ages between Late Cretaceous and Quaternary have been analyzed by means of fault population analysis methods to reconstruct paleostress tensors. Nine earthquake focal mechanisms have been determined, with magnitudes ranging between 3 and 4.1.With regard to regional structural features and sedimentary record data, the characteristics of present-day and neotectonic stress fields have been figured out, which determine the neotectonic period for this region.Thus, we have established that the intraplate zone represented by central Spain has been subjected to a stress field from the Middle Miocene until the present-day with a largest horizontal shortening direction (SHMAX) located between N130E and N160E.Finally, three paleostress maps with the main active structures are presented for: (a) Middle Miocene to Late Miocene, the period when the Spanish Central System was mainly formed, (b) Late Miocene to Quaternary, and (c) the present-day stress field, deduced from earthquake focal mechanisms.

The Iberian Chain is a wide intraplate deformation zone formed by the tectonic inversion during the and basin evolution analysis, macrostructural Bouguer gravity anomaly analysis, detailed mapping and paleostress inversions have been used to prove the important role of strike slip deformation. In addition, we demonstrate that two main folding trends almost perpendicular (NE SW ID E W artd NW SE) were simultaneously active in a wide transpressive zone. The two fold trends were generated by different mechanical behaviour, induding buckling and bending under constrictive strain conditions. We propose that strain partitioning occurred with oblique compression and transpression during the Cenozoic.

Highlights: 27• We explored submarine portions of fault systems bounding the Gonâve microplate 28• Structures are a series of delineated left--lateral strike--slip fault segments 29• The distinct segments 50 to 100 km--long cut across pre--existing structures 30• A 16.5km total strike--slip displacement on the northern system estimated since 1.8 Ma 38Haiti and Jamaica (EPGFZ) and 300--km between Dominican Republic and Cuba (SOFZ). The primary 39 plate--boundary structures are a series of strike--slip fault segments associated with pressure ridges, 40restraining bends, step--over, and dogleg offsets indicating very active tectonics. Several distinct 41 segments 50 to 100 km--long cut across pre--existing structures inherited from former tectonic 42 regimes or bypass recent morphologies formed under the current strike--slip regime. Along the most 43 recent trace of the SOFZ, we measured a strike--slip offset of 16.5 km that indicates steady activity for 44 the past ~1.8 Ma if its current GPS--derived motion of 9.8 ±2 mm/yr has remained stable during the 45 entire Quaternary. 47 48 -Introduction 49 50Following the 2010 Mw 7.0 Haiti earthquake, an international effort was initiated to investigate the 51 corresponding fault system and to constrain both the individual fault slip rates and their seismic 52 history. Such an effort depends critically on knowledge of the detailed geometry of the fault system 53 delineating the northern boundary of the Caribbean domain (Fig. 1). The Caribbean plate is currently 54 moving eastward relative to North America and the plate motion is accommodated along a complex, 55200 km--wide deformed zone, the Northern Caribbean plate Boundary (NCarB). The NCarB is a 56 seismogenic zone extending over 3000 km along the northern edge of the Caribbean Sea ( Fig. 1) and 57 a deforming region that includes two large strike--slip fault systems, the Septentrional--Oriente fault 58 zone (SOFZ) in the north and the Enriquillo--Plantain--Garden fault zone (EPGFZ) in the south (Mann et 59 al., 1991; Calais and De Lépinay, 1995). The SOFZ extends from the Mid Cayman spreading center, 60 initiated 50 Ma ago (Leroy et al., 2000), runs along the Southern coast of Cuba to cut across the 61 northern Hispaniola (Calais and Mercier de Lépinay, 1989; Mann et al., 1998). The EPGFZ, the 62 prolongation to the east of Jamaica of the Walton fault, cuts across the Southern Peninsula in Haiti 63and dies out eastwards in the vicinity of the Muertos trough south of Hispaniola, delimiting the 64Gonâve microplate (DeMets and Wiggins--Grandison, 2007) (Fig. 1). Between the two strike--slip 65 systems, the middle to late Eocene East Cayman margin is described offshore Jamaica (Leroy et al., 66 1996) and the early Miocene to Present collisional wedge of Haiti, well--described onshore (Pubellier 67 et al., 2000), continues offshore in the Gonâve Gulf ( Figs. 1 and 2). 68Destructive earthquakes are reported along the NCarB both onshore and offshore (Ali et al., 2008; 69 96 -Geometry and segmentation o...

Tertiary to present deformation in the interior of the Iberian Peninsula reflects spatial and temporal variations of the activity of the plate boundaries. Local deformation patterns observed in many of the numerous intraplate Tertiary basins and their borders, such as the Madrid Basin and the Sierra de Altomira, are at first sight incompatible with the regional stress field under which they were formed. We demonstrate, however, that they can be explained as the effect of several stress fields that acted on the Iberian Peninsula from earliest Tertiary onward. Data on local deformation can constrain both magnitudes and directions of forces acting on the plate boundaries of Iberia, enabling us to estimate the relative importance of the different plate driving and deforming mechanisms providing further constraints on the tectonic evolution of Iberia.