The Gulf of Mexico is an intraplate oceanic basin where rifting commenced in the Late Triassic, leading to drifting and ensuing oceanic accretion by Middle‐Late Jurassic, which ceased by the Early Cretaceous. Its tectonic evolution encompasses multiple rifting phases dominated by orthogonal extension, variable magmatism and salt deposition. This complex tectonic history is recorded within the rifted margins of the Gulf of Mexico, including along the eastern part of the basin, where considerable uncertainty remains regarding the tectonic evolution and resulting crustal configuration. This study presents new insights into the crustal types and an updated tectonic framework for the Florida margin. An integrated analysis of seismic and potential field data allows us to characterize the nature of the crust, which shows wide zones of hyperextended continental crust, seaward dipping reflection (SDR) packages, exhumed mantle and magmatic crust. Our results propose elements that could improve the plate model of the Gulf of Mexico, by accounting for the polyphase nature of rifting, the counter‐clockwise rotation of the Yucatan block and the observed increase in magmatic supply.

<p>The High Atlas is an aborted rift system along NW Africa that formed during the Mesozoic break-up of Pangaea and was inverted during the Alpine Orogeny. In contrast to the well-studied inversion, the Triassic-Jurassic rifting, synchronous to the Atlantic and the Tethyan opening, is still not fully understood. Orthogonal rifting is proposed to be active during the Triassic to early Early Jurassic, and was followed by an oblique extensional phase. The timing of this change in the kinematic of rifting is poorly constrained. Restoration of the Atlantic-Tethys triple junction suggests sinistral motion during the Middle Jurassic, which reactivated NE-SW trending Hercynian structures in a transtensional manner.</p> <p>The Atlas system is a great field analogue to study and analyse extensional systems influenced by strike-slip tectonics since the well exposed syn-rift structures and sediments have been weakly affected by the contraction during the late Cenozoic Alpine inversion.</p> <p>This work investigates the kinematic and geometry of the oblique rifting phase, the stress and strain variation lengthwise along the Atlas rift system, the relationship between the Triassic-Early Jurassic orthogonal rift structures, the Middle Jurassic strike-slip structures, and the potential synchronous volcanism occurring during the Middle Jurassic. This contribution highlights the fieldwork results of significant outcrops that we used to constrain the restoration of the rift system, evaluate extension and transtension, and produce a conceptual model of how strike-slip tectonics can influence the evolution of continental rifting.</p>

<p>The Gulf of Mexico is an intraplate oceanic basin where rifting started in the Late Triassic, leading to drifting by Middle Jurassic and ensuing oceanic accretion, which ceased by the Early Cretaceous. Its tectonic evolution encompasses multiple rifting phases dominated by orthogonal extension, major strike-slip structures, transtensional basins, variable magmatism, and salt deposition. This complex tectonic history is captured in the rifted margins of the Gulf of Mexico, especially along the eastern part of the basin; where considerable debate remains regarding the crustal configuration and tectonic evolution.</p><p>This study presents new insights into the crustal types and an updated tectonic framework for the Florida margin. An integrated analysis of seismic, gravity, and magnetic data allows us to characterise the continental crust, which shows wide zones of hyperextension that we relate to pull-apart basins, magmatic underplating, seaward dipping reflection (SDR) packages, and a narrow zone of exhumed mantle. In addition, we identified NW-SE trending sinistral strike-slip faults altering the typical crustal configuration expected in a rifted margin.</p><p>Our results suggest the need for a new plate model of the Florida margin at the Eastern Gulf of Mexico that invokes the polyphase rifting, accounts for the Yucatan’s block counter-clockwise rotation, explains the increase in magma supply, and captures the influence of strike-slip faults on the crustal boundaries and the magmatic budget.    </p>

<p>Continental rifts often show a complex spatial and temporal evolution, controlled by the intricate interaction of several ingredients. Inheritance, plate rheology, and stress orientation are amongst the main factors that shape rifts and dictate their fate. In this contribution, we use observations from two rift systems – i.e., the Labrador Sea and the Atlas System – to constrain 3D geodynamic models and assess the role of inherited structures, rheological heterogeneities, stress field (re-) orientation and obliquity on rift evolution.</p><p>The Labrador Sea formed as a branch of the North Atlantic Ocean, which propagated across major Precambrian suture zones. The subsequent rifted margins show striking lateral changes in the structural architecture, the crustal geometry, and the magmatic budget during breakup. Our geophysical data analysis and 3D geodynamic models suggest that pre-rift rheological changes in the lithosphere (i.e., composition, thickness, and thermal structure) dominated the rifting process and the ensuing continental breakup.   </p><p>The Atlas fold and thrust belt is a failed rift system that evolved in Mesozoic times and was inverted in the Cenozoic. The rifting phase was driven by two concurrent extensional stress fields linked to the coeval opening of two highly oblique oceans: the Central Atlantic and the Tethys. Here, our 3D geodynamic models constrained by field observations highlights the importance of the pre-rift structural template in dictating the strain distribution/localization, the lithospheric extension mode (i.e., orthogonal rifting vs. transtension), and the location of magmatism.</p>

<p>The intracontinental belt of the High Atlas is an aborted rift system along NW Africa, which formed during the Mesozoic break-up of Pangaea and was inverted during the Alpine Orogeny. Although the inversion and orogeny build-up have been extensively studied, the Triassic to Jurassic rifting, synchronous to the opening of the Atlantic and the Tethys, is still poorly understood. True orthogonal rifting is proposed to occur in the Triassic to Early Jurassic, while the end of rifting is controversial and believed to be controlled by oblique extension. Restoration of the Atlantic-Tethys triple junction suggests sinistral motion between Iberia and Africa being active during the Middle Jurassic, which reactivated pre-existing NE-SW trending Hercynian weaknesses in transtension mode. This led to the formation of a series of pull-apart basins involving the basement and localised volcanic activity.</p><p>The Atlas system is an excellent field analogue to analyse the role of strike-slip tectonics in extensional systems, especially in the early stages of rifting. Despite the late Cenozoic (Alpine) inversion, the well-exposed syn-rift structures and sediments have been weakly affected by the broad contractional event.</p><p>Our study aims to investigate the kinematic and geometry of the oblique rifting phase, the strain variation lengthwise in the Atlas rift system, the relationship between the orthogonal rift structures, the strike-slip structures, and the synchronous volcanism. In this contribution, we will highlight the fieldwork results, which we used to constrain the restoration of the rift sytem, quantify extension vs. transtension, and produce a conceptual model of how strike-slip tectonics can influence the early stages of a rift system.</p>