Orals: Thu, 1 May | Room D2
The tectonic configuration of the Caribbean plate is defined by inward‐dipping double subduction at its boundaries with the North American and Cocos plates. This geometry resulted from a Paleogene plate reorganization, which involved the abandonment of an older subduction system, the Great Arc of the Caribbean (GAC), and conversion into a transform margin during Lesser Antilles (LA) arc formation. Previous models suggest that a collision between the GAC and the Bahamas platform along the North American passive margin caused this event. However, geological and geophysical constraints from the Greater Antilles do not show a large‐scale compressional episode that should correspond to such a collision. We propose an alternative model for the evolution of the region where lower mantle penetration of the Farallon slab promotes the onset of subduction at the LA. We integrate tectonic constraints with seismic tomography to analyze the timing and dynamics of the reorganization, showing that the onset of LA subduction corresponds to the timing of Farallon/Cocos slab penetration. With numerical subduction models, we explore whether slab penetration constitutes a dynamically feasible set of mechanisms to initiate subduction in the overriding plate. In our models, when the first slab (Farallon/Cocos) enters the lower mantle, compressive stresses increase at the eastern margin of the upper plate, and a second subduction zone (LA) is initiated. The resulting first‐order slab geometries, timings, and kinematics compare well with plate reconstructions. More generally, similar slab dynamics may provide a mechanism not only for the Caribbean reorganization but also for other tectonic episodes throughout the Americas.
How to cite: Faccenna, C., Conrad, E., holt, A., and Becker, T.: Tectonic Reorganization of the Caribbean Plate System in the Paleogene Driven by Farallon Slab Anchoring, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-13662, https://doi.org/10.5194/egusphere-egu25-13662, 2025.
The plate boundary between the Caribbean and North American plates exhibits a striking-complexity and significant width with multiple microplates moving relative to each other, resulting in a significant seismic hazard on the island of Hispaniola. This region has experienced several major earthquakes in recent decades, particularly along the left-lateral fault systems of the Enriquillo-Plantain Garden (EPGF) and Septentrional-Oriente faults. These fault systems accomodate the eastward motion of the Caribbean plate relative to the North American plate at a rate of approximately 20 mm/year. The oblique convergence observed northeast of Hispaniola adds to the complexity of this plate boundary and its distribution among the different fault systems across the Island is currently not fully understood. Geological, seismic, and geodetic studies have suggested the existence of multiple blocks within the island of Hispaniola and while some are well established, others remain hypothetical.
In this work, we propose a new kinematic block model based on an updated GPS velocity field combined with interferometric synthetic aperture radar (InSAR) velocity fields. Deformation rates within the island reveal significant differential motion, particularly between the Gonâve and Hispaniola microblocks, indicating internal deformation that is not accounted for in current rigid block models.
We propose a new model of Caribbean plate dynamics in the vicinity of Hispaniola and provide critical insights for understanding seismic hazards in this tectonically active region.
How to cite: Emmanuel, C., Jolivet, R., Calais, E., and Raimbault, B.: Refining Caribbean Plate Dynamics: Insights from GPS and InSAR Data, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-13412, https://doi.org/10.5194/egusphere-egu25-13412, 2025.
The Lesser Antilles subduction zone is one of very few regions where old oceanic crust formed at slow spreading rates is being subducted. Crust accreted at slow spreading ridges differs from crust formed at higher rates, mainly in its higher content of material originating from the upper mantle, which is mostly hydrated to form serpentinites. The water stored in these serpentinites is released in the subduction process and then migrates upwards, towards the seafloor, where it forms fluid escape features, such as mud-volcanoes and pockmarks. Seismic reflection profiles from offshore Antigua and Barbuda image high amplitude seismic reflectors extending from the top of the downgoing crust roughly 15 km down into the mantle. They possibly originate from low-angle detachments related to exhumation of mantle material at the slow spreading Mid-Atlantic Ridge. As serpentinite rheology differs from that of basalt and gabbro, and because the amount of fluids from dewatering serpentinite is significantly higher than from mafic crust, the rheological properties of the plate interface and the margin are likely to influence slip behavior.
During the Manta-Ray cruise in 2022, bathymetric and seismic data were acquired in the Lesser Antilles region with the objective to study the influence of subduction of this ultramafic basement on the tectonic deformation, fluid circulation and seismogenesis. At the accretionary prism fluid extrusion sites have been identified in the bathymetric data and their structures are finely imaged by high-resolution seismic data. Mud-volcano structures are linked to deeper faults and individual mud flows are imaged with a high enough a resolution to be described. In the region of the previously imaged deep reflectors, a 3D seismic experiment was conducted during which 23 deep sounding seismic profiles were acquired, crossing 75 ocean-bottom seismometers and using a 5000 cu-inch airgun array and a 6 km long seismic streamer. The extension of the reflectors east of the trench was proven and initial interpretation of the seismic data clearly shows the existence of several fault families dipping in different directions. In this area also numerous fluid extrusion features were identified which might have formed during accretion at the Mid-Atlantic ridge.
During the LAVAS project, starting in 2025, we will further study the relationship between the hydration the downgoing plate and seismicity in the Lesser Antilles. In the scope of the project passive seismic data will be acquired using a sailing vessel along the different fluid extrusion sites to record signals from fluids leaving the seafloor. A submarine glider survey along these sites will help to identify possible methane accumulation in the water column. Satellite images will be used to identify natural hydrocarbons leaking from the seafloor and arriving at the sea surface. In an associated pedagogic project seismometers will be installed in schools on the islands of Guadeloupe and Saint Martin.
How to cite: Klingelhoefer, F., Klein, J., Marcaillou, B., Lebrun, J.-F., Schenini, L., Roest, W., Aiken, C., Laigle, M., Jatiault, R., and Jouffray, F.: Manta-Ray : a study of the relationship between fluids and seismicity in the Lesser Antilles, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-7066, https://doi.org/10.5194/egusphere-egu25-7066, 2025.
Seismogenesis in subduction zones is profoundly shaped by the nature of the down-going crust and its lithosphere, their inherent structures, and hydration state. However, studying how these factors influence local seismicity remains challenging, particularly in regions with complex crustal and mantle structures. Simultaneously, the subduction of heterogeneous crust presents an opportunity to study the impact of variable physical properties on seismicity in close proximity. Thus, characterising the nature of such crust and the upper mantle immediately seaward of the deep-sea trench, at the smallest scale possible, may help in understanding spatial variations of seismogenic asperities, the variability of fluid input in the margin, and the overall heterogeneity of the subduction zone.
The Lesser Antilles are one of the few places on Earth where such processes can be studied in a natural laboratory setting. Oceanic crust accreted at the slow-spreading Mid-Atlantic Ridge (MAR) is permeated by first- and second-order, closely spaced fracture zones, which delineate crustal segments in which accretion alternates between being tectonically and magmatically dominated. The crust is further characterised by prominent faulting behaviour, showcasing detachment faulting near the spreading centre, normal faulting consistent with the spreading fabric, and faulting during the flexural bending at the subduction trench. Consequently, upon subduction, the crust is irregularly hydrated and contains variable amounts of reworked mafic crust and correspondingly variable amounts of uplifted mantle.
Here we present the first 3D traveltime tomography combined with controlled source seismic data of Central Atlantic crust seaward of the Northern Lesser Antilles subduction trench. We jointly invert first arrivals and Moho reflections using TOMO3D, which allows for high-resolution imaging of crustal and upper mantle structures at small spatial scales, and the comprehensive visualisation of the Moho. Our study is based on data recorded during the Manta-Ray cruise (R/V L’Atalante - 2022), in which 75 ocean-bottom seismometers were deployed offshore Antigua and Barbuda. Through an instrument spacing of 5 km and 10 km on the central and surrounding profiles, respectively, an unprecedented level of resolution has been achieved. Seismic shots were produced using a 5000 cu inch tuned airgun array, and were additionally recorded by a 6000 m seismic streamer. Previous studies have imaged high-amplitude seismic reflectors in the oceanic crust, which extend up to 15 km below the top of the basement and dip towards the MAR. Investigating their nature and their role in fluid migration is an additional objective of this study.
Our results provide (1) a crucial first step towards a more precise characterisation of the anomalous crust and its influence on Caribbean seismicity and tectonics, (2) a key constraint on the nature and tectonic origin of the deep reflectors, and (3) the foundation for deeper investigations into the particular role of fluids in seismogenesis.
How to cite: Klein, J., Klingelhoefer, F., Prada, M., Roest, W. R., Huang, H., Lebrun, J.-F., Marcaillou, B., Schenini, L., Aiken, C., and Kopp, H.: 3D travel-time tomography of the incoming plate at the Northern Lesser Antilles subduction trench, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-6526, https://doi.org/10.5194/egusphere-egu25-6526, 2025.
Forearc slivers are important tectonic features due to their sensitivity to the dynamic and tectonic processes at subduction zones. For example, slivers may exhibit lateral, vertical, and rotational motions due to the subduction of buoyant features or structural highs on the downgoing plate. The Septentrional sliver along the Northern Caribbean Plate Boundary (NCPB) provides a natural example of the formation and evolution of a forearc domain during plate reorganization accompanied by multiple indentation episodes with progressive along-strike variation from a subduction to transform margin. The sliver was initially delineated in the Miocene with the formation of the Septentrional Fault Zone (SFZ), one of the two major strike-slip systems comprising the NCPB, facilitating the uplift of the Cordillera Septentrional. However, our present understanding of the relationship between the time-varying kinematics of the SFZ and the uplift and exhumation of the Cordillera Septentrional is limited. To address this, we conduct zircon and apatite (U-Th)/He analyses on in-situ and detrital samples gathered across the Cordillera Septentrional and combine these data with along-strike kinematic measurements, topographic analyses, and new field observations. Zircon and apatite He dates range from 55 to 2.7 Ma, with detrital dates indicating limited burial and resetting. The youngest apatite He dates are proximal to major structures, indicating increased near-field exhumation. In-situ dates along the SFZ are constrained to 7.5±0.7 Ma, with dates increasing to >25 Ma to the north. Combined with lithostratigraphy, date distributions correspond with two main exhumation pulses beginning in the late Eocene and late Miocene. The recent pulse of exhumation occurred by ~10 Ma at rates up to 0.3 mm/yr, leading to >2 km of vertical motion. Along the Septentrional fault zone, slickenline orientations, topographic analyses, and exhumation rates show substantial west-to-east variability corresponding to a change from transpression to transtension. In the west, the Cordillera is characterized by rugged topography, a quasi-stationary drainage divide, oblique to compressional slip indicators, and positive flower structures. To the east, fault surfaces show oblique to extensional slip indicators, a low-relief northeast tilted surface, a drainage divide propagating northward, and higher total exhumation. We propose that along-strike heterogeneity is due to time-varying boundary conditions imposed by the subduction of the buoyant carbonate Bahamas platform overlying thickened oceanic lithosphere. These effects result from three main factors: (1) fault geometry, (2) the subduction of high-standing ridges on the Bahamas Platform in the west, and (3) the progressive uncoupling of the plate interface due to the eastward translation of NCPB blocks past the indenter. Overall, this study provides insight into the evolution of the NCPB and the consequences of forearc indentation and along-strike complexity of the subduction-transform margin.
How to cite: Conrad, E., Faccenna, C., and Stockli, D.: Fault kinematics, exhumation, and morphological signature of the Septentrional sliver (Dominican Republic), EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-15546, https://doi.org/10.5194/egusphere-egu25-15546, 2025.
North of Haiti, oblique convergence occurs between the Caribbean plate and the Bahamas carbonate banks which belong to the North American plate. In this zone, plate motion is accommodated by: (1) the EW-trending North Hispaniola reverse Fault Zone (NHFZ), (2) a NE-trending transpressional domain across Haiti, and (3) two EW-trending sinistral transform faults the Septentrional Oriente Fault Zone (SOFZ) and the Enriquillo-Plantain Garden Fault Zone (EPGFZ) located north and south of the country, respectively.
This study focuses on the emerged sequences of marine terraces of Haiti that have been uplifted since the beginning of the Quaternary, with an aim to provide geomorphological insights into deformation caused by oblique convergence since this period. Our research was carried out on terraces located on Tortue Island and in the northern region of Haiti, situated North and South of the SOFZ, respectively. We present topographic measurements, the number of successive strandlines, and the spatial variation of the sequence.
The results reveal contrasting patterns of deformation of these geomorphological features on either side of the SOFZ with significant spatial and temporal EW-trending uplift gradients associated with long-wavelength tilting and short-wavelength folding. The data suggest a EW-trending spatial and temporal change in the coupling between the North American plate and the Caribbean plate.
How to cite: Vissiere, S., Authemayou, C., Chauveau, D., Pedoja, K., Symithe, S., Boisson, D., Aiken, C., Klingelhoefer, F., and Roest, W.: Vertical deformation along the northern Caribbean plate boundary zone: the uplifted marine terraces of northern Haiti., EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-1717, https://doi.org/10.5194/egusphere-egu25-1717, 2025.
The Septentrional-Oriente Fault Zone (SOFZ) and Enriquillo-Plantain Garden Fault Zone (EPGFZ) have a history of producing devastating earthquakes and tsunamis around Haiti. However, the deep structures and the role of fluids in their processes remain poorly understood, which limits our ability to assess their seismic potential. We present new insights into the crustal structure of the Haiti dual active transform fault system derived from an active-source Ocean Bottom Seismometer (OBS) profile (TWI1) collected during the Haiti-TWiST campaign (R/V “Pourquoi pas?”, June-July 2024), which uniquely spans across both offshore and onshore regions. This profile transects both the EPGFZ off the southern Haiti peninsula and the SOFZ offshore the northern Haiti peninsula. High-quality seismic data from 61 OBS stations yielded over 34,000 P-wave and 18,000 S-wave traveltimes, enabling forward modeling and tomographic inversion of the crustal structure. The resulting P-wave, S-wave, and Vp/Vs structures reveal oceanic plateau characteristics in the offshore crust in the south of the EPGFZ, with a thickness of 18–20 km, P-wave velocities of 4.0–7.5 km/s, S-wave velocities of 2.5–4.1 km/s, and Vp/Vs ratios of 1.75–2.0. The SOFZ exhibits pronounced structural variations with distinct high- and low-velocity boundaries. Additionally, a high Vp/Vs anomaly (2.0~2.1) in the upper crust on the southern flank of the EPGFZ suggests extensive fracturing, potentially linked to stress perturbation during strike-slip motion.
How to cite: Huang, H., Klingelhoefer, F., Klein, J., Roest, W., Aiken, C., Leroy, S., and Gonzalez, O.: First P- and S-wave tomographic results of a wide-angle seismic profile from the Haiti-TWiST campaign, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-5960, https://doi.org/10.5194/egusphere-egu25-5960, 2025.
Modelling strike-slip systems over geological timescales (> 1 Ma) and under high deformation (> 1) poses significant challenges. A primary difficulty arises because most of the displacement in these systems is horizontal, while the lithospheric strength is predominantly controlled by its vertically stratified rheological variations. As a result, two-dimensional models introduce substantial errors and are inadequate for capturing the complexities of strike-slip deformation. Furthermore, the inherently three-dimensional nature of the problem makes boundary conditions critical. To realistically simulate the horizontal sliding of two tectonic plates, the driving forces should ideally be applied far from the deformation zone, along boundaries parallel to the motion.
In this study we present new 3D numerical thermo-mechanical models using newly developed type of boundary conditions to simulate for the first-time strike-slip restraining bend systems evolving over more than 15 Myrs that we compare with the Jamaican segment of the Enriquillo-Plantain Garden Fault, one of the two strike-slip fault zones which mark the boundary between the Caribbean and the North America plates. This text-book example of compressional bend on a left-lateral wrench fault, uplifts topography in the Blue Mountains. It however displays sets of conjugate shear zones and tension faults which confer a little complexity in the natural example. To simulate the long-term deformation of the lithosphere, we use pTatin3d, a parallel finite element software that solves the equations governing the conservation of momentum and mass for an incompressible fluid with non-linear viscosities.
Models show the evolution from parallel strike-slip shear zones linking with P-shear around which positive flower structure develops. The evolution in time shows that the duplex system grows laterally with the development of new P-shear surrounded by thrust faults. Additionally, we provide the evolution in time and space of the topography, the 3-dimensional fault network and its structural analysis, the long-term slip-rate, and the stress regime of active faults. We finally compare the results to the observations of the morphostructures of the island.
How to cite: Jourdon, A., Le Pourhiet, L., May, D. A., Gabriel, A.-A., and Pubellier, M.: 3D numerical modelling of the evolution of a restraining bend: the example of the Jamaican duplex system, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-15758, https://doi.org/10.5194/egusphere-egu25-15758, 2025.
Understanding processes that may be at the origin of major earthquakes in subduction zones is highly challenging, especially in the case of slowly converging areas. Here we compile several studies about the spatiotemporal variation of seismicity along the boundary of the Caribbean plate, which evolving from westward subduction in the Lesser Antilles to southward subduction in the Greater Antilles and oblique collision against the Bahamas platform in Cuba. Analysis of several clusters of seismicity associated with the computing of focal mechanisms show that:
- There is an increase in seismicity rate and cumulative seismic moment over the last two decades offshore Martinique island and, particularly, in the presumed rupture area of the major historical 1839 earthquake. This sustained seismicity is shared between extensive intermediate depth activity and a compressive seismic cluster located in the seismogenic zone of the subduction zone.
- The analysis of moment tensors for the Haiti upper lithosphere indicates that normal, thrust and strike-slip faulting are present but with a majority of thrust faulting. The mean P and T axes for the moment tensors indicated that the current compressional deformation is mainly N-S to NNE-SSW. Moreover, a dozen intermediate-depth earthquakes (>70 km) are located under Haiti, and tend to confirm the existence of a lithospheric slab inherited from southward subduction under the Greater Antilles.
- New moment tensors for earthquakes along the southeastern coast of Cuba from 2015 to the end of 2024 are consistent with the tectonic environment of the region. Reverse-oblique focal mechanisms and north dipping fault planes are predominant, particularly around the Santiago Deformed Belt, where insights of the underthrusting of the Gonâve Microplate beneath the Cuban Island are present.
- The eastward progression of major earthquakes (M > 6.8) along the northern boundary of the Caribbean plate in the past 20 years, characterized by strike-slip faulting, reflects the effect of a highly coupled region and the eastward motion of the plate. This trend suggests a potential temporary increase in seismic hazard along the southern coast of Cuba.
Overall, the strain accommodated along the Caribbean plate boundary seems to be highly partitioned between major structures that could produce strong earthquakes and multiple satellites faults that produce regularly low to medium events.
How to cite: Corbeau, J. and Gonzalez, O.: Caribbean plate boundary seismotectonic in the Lesser and Greater Antilles, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-12694, https://doi.org/10.5194/egusphere-egu25-12694, 2025.
Posters on site: Fri, 2 May, 08:30–10:15 | Hall X1
The Northen Hispaniola margin poses major earthquake and tsunami hazards for the Caribbean. The coexistence of the compressive North Hispaniola Deformed Belt that accommodates the normal shortening component between the Caribbean and the North American plates, and the strike-slip Septentrional Fault Zone that accommodates the along-strike component represents a “textbook example” for the study of oblique tectonics and strain partitioning. In the end of 2025, we will conduct the GEOMARHIS experiment, a controlled-seismic source survey between Puerto Rico and Haiti. GEOMARHIS consists of the acquisition of multi-scale (regional-to-local) seismic reflection profiles: (1) medium resolution multichannel data along- and across-strike of plate boundary; (2) high-resolution multichannel data to characterize the Septentrional Fault Zone in the Samana and Manzanillo bays; (3) continuous ultra-high-resolution data. In addition, we will acquire systematic swath bathymetry-backscatter, gravity and magnetics. Here, we will inform about detailed objectives, datasets and expected results, which we hope to provide new critical constraints to the seismic and tsunami hazard for Dominican Republic and Haiti.
How to cite: Granja-Bruña, J.-L., Muñoz-Martín, A., Rueda-Fort, M., De Vicente, G., Gómez-Ballesteros, M., Martín-Dávila, J., Gorosabel-Araus, J. M., Martínez-Moreno, F. J., Druet, M., and Fiz, J. and the GEOMARHIS TEAM: GEOMARHIS experiment: Multi-scale geophysical study of oblique tectonics, strain partitioning and associated geological hazards in the northern Hispaniola offshore margin, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-9321, https://doi.org/10.5194/egusphere-egu25-9321, 2025.
Oblique convergence between the North American and Caribbean plates is accommodated in the Hispaniola Island by means of strain partitioning. A remarkable example of this process is the devastating M7.0 2010 Haiti event which occurred in SW Hispaniola. In this area, the relative convergence between the thick crusts of the island arc and the Caribbean igneous plateau is taking place. This has resulted in significant deformation by means of left-lateral transpression, indentation and uplifting in the SW Hispaniola and its insular margin. We studied the structure and morphology of the offshore southern margin of the Southern Peninsula (Haiti) and Bahoruco Peninsula (Dominican Republic). For that, we have compiled a large dataset of swath bathymetry and 2D seismic reflection profiles from several marine geophysical surveys (A2097L01-1978, FM0502-1980, CaribeNorte-2009, HaitiOBS-2010, HaitiSIS-2012, NorCaribe-2013). This study presents a preliminary mapping of the main morphotectonic provinces: Island Slope, Haiti plateau and Haiti sub-basin. Noticeable features are active E-W and NW-SE trending folds and fault-propagation folds. As dominant active sedimentary processes are widespread gravity slumping, erosive canyon networks and extended areas of sediment waves. This study is in progress and will provide detailed observations on the active tectonic and sedimentary processes to help future studies assess the seismic and tsunami hazard.
How to cite: Rueda-Fort, M., Granja-Bruña, J.-L., Leroy, S., Muñoz-Martín, A., Gorosabel-Araus, J.-M., Joyeux, T., Collas, M., Druet, M., Rodríguez-Zurrunero, Á., De la Fuente-Oliver, M.-Á., Muñoz-Cemillán, A., ten Brink, U. S., de Lépinay, B.-M., and Carbó-Gorosabel, A.: Preliminary results on the geomorphology and shallower structure of the south-western Hispaniola offshore margin. , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-9576, https://doi.org/10.5194/egusphere-egu25-9576, 2025.
Along the northern strike-slip boundary of the Caribbean plate, strain is partitioned and accommodated by the relative motion of several microplates. Among these microplates, the Gonâve microplate is bounded by two major strike-slip fault systems: the Enriquillo Plantain Garden Fault Zone (EPGFZ) to the south and the Septentrional-Oriente Fault Zone (SOFZ) to the north, with the Cayman Trough and the Haitian Fold and Thrust belt defining its western and eastern limits, respectively.
On 12 January 2010, a devastating Mw 7.0 earthquake struck along the EPGFZ, cross-cuts the southern peninsula of Haïti and the southern Gulf of Gonave. This earthquake, occurring on an uncharacterized fault segment, was both destructive and unexpected. Since then, geophysical and geological investigations have been performed to improve understanding of the fault geometries, kinematics and strain rates in the region.
This study used multibeam bathymetry and reflection seismic data from various oceanographic campaigns in the Gulf of Gonave to highlight the spatial and temporal evolution of these structures. Data analysis revealed NE-SW trending tilted blocks belonging to the continental margin of the East Cayman Trough. Several of these blocks are bounded by low-angle normal faults, suggesting intense stretching. The various identified seismic horizons allow us to date the top of the syn-rift units in the Gulf of Gonave and confirm that rifting occurred between 49 and 56 Ma. Consequently, the eastern Cayman margin extends from northern Jamaica in the west to at least the eastern Gulf of Gonave, covering a typical continental margin distance of 450 km with a thinning rate of 2.7.
Our study reveals that all extensional structures were later inverted by NE-SW-oriented compression, aligned with the trend of the tilted blocks in the Gulf of Gonâve. Shortening rates calculated from the Gulf of Gonave seismic profiles are compared with those obtained from onshore geological data and GPS block models. Notably, the shortening calculated in the Gulf of Gonave appears to be lower than the GPS-derived convergence rates of 6-7 mm/yr, suggesting a possible increase in deformation rates over time.
Additionally, short-term deformation occurs on a reverse fault system in the southern Gulf of Gonâve. Based on the available data and the results of our study, we propose a novel model for the spatiotemporal evolution of tectonic structures extending from the northern Jamaican margin in the west to the Haitian fold-and-thrust belt in the east.
How to cite: Joyeux, T., Leroy, S., Rabaute, A., Philippon, M., Saspiturry, N., and Pubellier, M.: Structure and evolution of the Gonave microplate at the northern boundary of the Caribbean plate, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-10225, https://doi.org/10.5194/egusphere-egu25-10225, 2025.
The northern margin of Hispaniola is characterised by a complex morpho-structure shaped by the interplay of geodynamic, tectonic, and sedimentary processes. The Haiti Seismic Investigation (HAITISIS) of the northern Caribbean plate boundary reveals evidence of oblique convergence. It elucidates the relationships among fault-driven tectonic activity, seafloor morphology, and the effects of transpressional deformation. The markedly different morpho-structural characteristics of the seafloor and sedimentation patterns in the Eastern and Western domains of the northern Hispaniola margin originated during the Upper Miocene-Pliocene tectonic reorganisation of the northern Caribbean Plate boundary. This regional reorganisation is associated with the onset of the oblique collision between the Caribbean and North American Plates that carried Hispaniola to the transpressive plate boundary opposite the Bahamas Carbonate Platform. This tectonic process led to the formation of an accretionary prism and activated segments of the eastern strand of the Septentrional-Oriente Fault Zone (SOFZ), resulting in lateral sediment source displacements and influencing sedimentary infill and deformation patterns. A mass transport deposit (MTD) in the Eastern domain is thought to have formed during this period of tectonic instability. Differential compaction and remobilisation of recent seismic units caused by the MTD have influenced the seafloor morphology of the Eastern domain. The MTD is absent in the Western domain, as are the canyons found in the Eastern domain. Our interpretation of the early Miocene initiation of the SOFZ and its evolution differs from previous studies that assume continuous eastward propagation. Morphologic features, such as the lateral displacement of canyons, provide a chronology for the development of strike-slip and thrust faults prior to the initiation of the SOFZ.
How to cite: Leroy, S., Oliveira de Sà, A., d'Acremont, E., Lafuerza, S., Granja-Bruña, J.-L., Momplaisir, R., Boisson, D., Moreno, B., Watremez, L., and Corbeau, J.: Recent Evolution of the Northern Caribbean Plate Boundary Insights from Seismic Reflection Data from the Northern Hispaniola Margin, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-16999, https://doi.org/10.5194/egusphere-egu25-16999, 2025.
New heat flow data, acquired in offshore Haiti, Cuba and Jamaica during the HAITI-TWIST cruise (2024), will be presented. These data complete earlier acquisitions from the HAITI-SIS cruise (2012) discussed in Rolandone et al. (2020). This study based on in-situ heat flow measurements and Bottom Simulating Reflector (BSR) derived heat flow, revealed a regionally low heat flow of approximately 40-50 mW/m², with some localized high values exceeding 80 mW/m². Elevated heat flow was observed only near major strike-slip fault systems (SOFZ and EPGFZ) or smaller reverse faults. Since conductive mechanisms such as shear heating and heat refraction cannot account for the extreme values (100-180 mW/m²), we suggested that fluid circulation may be responsible for the high fault related heat flow. The main objective of the new heat flow data acquisition was to identify anomalies potentially caused by fluid-driven heat advection along and across the two strike-slip fault systems (SOFZ and EPGFZ). We acquired 24 new marine heat flow data using a typical shallow probe technique that measures the thermal gradient and thermal conductivity at different intervals of the first 6 m of the seafloor sediments. Temperature gradients were measured in-situ using autonomous high-precision temperature probes attached to a core barrel while thermal conductivities were measured onboard using a needle probe instrument on recovered sediment cores. Two modes of acquisitions were used (1) single penetrations with sediment recovery, and (2) a faster pogo-type acquisition without sediment coring.
How to cite: Rolandone, F., Poort, J., Leroy, S., Roest, W., Aiken, C., Klingelhoefer, F., and Marcaillou, B.: New Heat flow data in the Jamaica and Windward Passages, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-20868, https://doi.org/10.5194/egusphere-egu25-20868, 2025.
The transpressive Northern Caribbean plate boundary contains an active twin strike-slip fault system – the Septentrional-Oriente fault zone (SOFZ) and the Enriquillo-Plantain Garden fault zone (EPGFZ). Within the past 15 years, the EPGFZ has generated two devastating earthquakes along this transpressive front – the 2010 Mw7.0 Léogâne and the 2021 Mw7.2 Nippes events, of which the 2010 event generated a small tsunami. The 2010 and 2021 earthquakes ruptured only short segments of the roughly 1,000-km long active fault system with partial reverse slip. These events are intriguing because the EPGFZ is assumed to be purely vertical / strike-slip, but the partial reverse slip testifies to the significant hazard they pose to densely populated areas. This severe risk level, in one of the least developed countries, warrants further investigation of the complex seismotectonics and geohazards in the region. As such, the Haiti-TWiST oceanographic campaign was developed and carried out in Summer 2024 on the R/V “Pourquoi pas?” to characterize geological hazards posted to Western Hispaniola. During this sea campaign, we conducted several geophysical surveys. In the first leg, we collected seafloor bathymetric data and conducted wide-angle seismic and high-resolution seismics surveys to image the roots and shallow portions of the SOFZ and EPGFZ. In the second leg, we deployed ocean bottom seismometers for earthquake monitoring near the SOFZ and EPGFZ and acquired a multitude of other data, such as seafloor bathymetry, acoustic water column data for imaging seeps, heat flow measurements near faults, and 15 sediment cores ranging from 30 cm to 11 m long. Two of these sediment cores were the first ever to be taken offshore Cuba. In this presentation, we give an overview of our first observations from data collected during the TWiST sea campaign.
How to cite: Aiken, C., Roest, W., Marcaillou, B., Klingelhoefer, F., Boisson, D., and Moreno, B.: Investigating North Caribbean geohazards: First results from the TWiST sea campaign, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-10205, https://doi.org/10.5194/egusphere-egu25-10205, 2025.
The northern plate boundary of the Caribbean tectonic plate is a complex tectonic zone. After the collision of Cuba with the Bahamas Carbonate Platform in the Eocene, several strike-slip faults accommodated the eastward movement of the Caribbean plate with the initiation of the westward dipping subduction at the Lesser Antilles arc. From the Miocene onwards, a twin fault system developed at Hispaniola with two major sinistral transform fault zones bounding the intervening and debated Gonâve microplate: the Septentrional- Oriente Fault Zone (SOFZ) to the north and the Enriquillo-Plantain Garden Fault Zone (EPGFZ) to the south. At present, these faults are associated with significant geohazards to the region, and their offshore segments are still poorly understood. Given the geometry of the plate boundary system, one would expect that only the SOFZ branch would be active and linked by the mid-Cayman ultra-slow spreading center to the Swan Island FZ that bounds the Cayman Trough to the south, further west. Instead, both the SOFZ and EPGFZ are active and have similar displacement rates, accumulating a 17-19 mm/yr left-lateral motion between the Caribbean and North American Plates. Following up on earlier scientific cruises that notably explored the sedimentary basins in the area of the faults, a recent multi-disciplinary scientific cruise investigated both deep and shallow structures in the area. The Haiti-TWiST (TWIn faults Seismic Transects) campaign took place on the R/V “Pourquoi pas?” from 30 May to 21 July, offshore Haiti, Cuba, Jamaica, and Navassa Island. The cruise was organized in two legs, and more than 40 scientists from many nationalities participated, as well as eight Master-1 students in the framework of a floating University (see blog on UMR Geo-Ocean Website). This presentation will highlight some of the preliminary results and will focus mainly on the bathymetry data acquired with the Reson Seabat 7150 Multibeam echosounder.
How to cite: Roest, W., Aiken, C., Marcaillou, B., and Klingelhoefer, F. and the the Haiti-TWiST Shipboard Party: Imaging the Twin Fault System Along the Northern Boundary of the Caribbean Plate, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-21002, https://doi.org/10.5194/egusphere-egu25-21002, 2025.
Plate motion along concave (toward the upper plate) strike slip to subduction transition (SSST) where the down going plate does not tear, results over time in a lengthening of the subduction zone while the downgoing plate is transported along the transform margin. In the northern Antilles such a transition has developed since the late Paleogene while the Bahamas bank swept the northern Antilles margin and collided with Hispaniola westward. Tectonic record along the Puerto-Rico (PR), Anegada and the northern Lesser Antilles (NLA) margin reveals the modalities of the SSST evolution and gives insights into the interaction between the subducting North America oceanic plate and the overriding Caribbean plate.
We present a detailed structural map from eastern PR to southern Anguilla platform in the Lesser Antilles based on interpretation of multibeam bathymetry and multichannel seismic data.
- We confirm that plate motion partitioning between a trench parallel strike slip fault and thrusting along the interplate is exclusively restricted to the margin tip east of the Bunce Fault.
- Further upslope, the Virgin Islands northern margin is affected by trench-parallel, trenchward dipping normal faults. These faults accommodate the deepening of the margin interpreted as the result of basal tectonic erosion.
- From NLA westward to St Croix and southern Virgin Islands, the margin is dislocated by a cross cutting pattern of NE-SW and E-W normal fault systems, bounding elongated E-W throughs, rhomboidal basins and S-shaped ridges. Formally interpreted as either slip sense strike-slip system along the Anegada Passage, the structural pattern that we describe, supported by our seismic interpretation, reveals limited left lateral displacement restricted to the EW basins. Instead, the cross fault system appears to accommodate NW-SE extensional tectonics.
At a regional scale along the SSST, from the Lesser Antilles margin to Hispaniola collision zone, the strain pattern along the margin progressively evolves from NNW-SSE extension responsible for V-shaped basins open toward the trench, to NW-SE extension along the Anegada passage and increasing shortening along the Muertos through from Southeastern Puerto Rico westward. Such a pattern attests for a progressive bending of the margin in a context of low interplate coupling along the evolving SSST.
How to cite: Domoison, A.-C., Lebrun, J.-F., Marcaillou, B., Audemard, F. A., Cornee, J.-J., Graindorge, D., Laigle, M., Lallemand, S., Philippon, M., and Shenini, L.: Tectonic accommodation of the northern Antilles strike slip to subduction transition along the Porto-Rico – Anegada – Lesser Antilles Margin , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-13411, https://doi.org/10.5194/egusphere-egu25-13411, 2025.
As part of a U.S. Geological Survey (USGS) mineral-environmental assessment, a new digital geologic map and database for the Greater Antilles has been compiled from previously published mapping. At 1:250,000-scale, Hispaniola and Jamaica were sourced from (a) the Dominican Republic Ministry of Industry and Commerce, Department of Mining, (b) the Haitian Ministry of Mines and Energy Resources, and (c) the Jamaican Ministry of Mining and Natural Resources, Mines and Geology Division. Cuba, at 1:100,000-scale, was provided by the Cuban Ministry of Energy and Mines. Puerto Rico was available in a series of 64 USGS 1:20,000-scale geologic maps. Maps for the U.S. and British Virgin Islands were at scales between 1:24,000 and approximately 1:60,000.
Data for each island were digitized and integrated into a common database schema to facilitate correlation of map units from island to island and provide a uniform view of the geology. Each source map unit was assigned to a unit for the compilation based on its lithology, setting, and age. This unit then links to additional related tables that define the unit’s maximum and minimum age, geologic setting, a set of hierarchically defined lithologies, and the original source maps unit descriptions. We also defined a series of tectonostratigraphic terranes for the region. These terranes display unique lithologic assemblages, geologic histories, and commonly, distinct mineral deposit types. We obtained new U/Pb dates and compiled a region-wide database of nearly 1,100 radiometric ages.
Multiple distinct geologic features are present in the region. Cuba has the only unquestioned Jurassic, and perhaps older, rocks whereas on Hispaniola and Puerto Rico, Cretaceous metamorphic assemblages may contain Jurassic rocks. Cretaceous granitic rocks are present in Cuba, Hispaniola, and Puerto Rico as are gabbro and trondhjemite of inferred Early Cretaceous age in the U.S. Virgin Islands. Cretaceous volcanic rocks are widespread in the region; they are of variable ages and significantly, do not reflect a single magmatic arc system. Early Cretaceous keratophyre and spilite in the Virgin Islands and northeast Puerto Rico are distinctive. Eocene volcano-plutonic complexes are prominent in southernmost Cuba, Puerto Rico, and the Virgin Islands and sparsely present in Haiti and eastern Jamaica. Volcanic rocks possibly as young as Miocene are present in southern Hispaniola; the youngest volcanic rocks in the region are the late Miocene or Pliocene Low Layton Lavas of Jamaica and Quaternary alkali basalt on Hispaniola.
Carbonate rocks are widespread in the Greater Antilles and are as old as Jurassic in Cuba and as young as Holocene in many areas. In Cuba, Early Cretaceous sedimentary rocks tend to be dominantly carbonates; volcanic clasts and debris are uncommon until Late Cretaceous. In contrast, Lower Cretaceous volcaniclastic sedimentary rocks are common in the Virgin Islands and Puerto Rico. Olistostromes are frequently described in uppermost Cretaceous and Eocene rocks; the Eocene deposits are commonly associated with mélange units. Sedimentary rocks that postdate the Eocene are dominantly carbonates or mixed clastic and carbonate rocks in which the clastic component reflects erosion of earlier volcanic units, as well as older carbonate rocks.
How to cite: Wilson, F. and Labay, K.: Geologic map and databases of the Greater Antilles and Virgin Islands, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-7126, https://doi.org/10.5194/egusphere-egu25-7126, 2025.
The present-day Caribbean region developed since early/mid-Jurassic in three main phases: 1) ~ 180 Ma- rifting of Pangea and formation of a spreading ridge in the Proto-Caribbean, 2) ~150 – 70 Ma- drifting and spreading apart of North and South America and development of an oceanic basin (the Proto-Caribbean) connected with the Central Atlantic; and 4) ~135 – 50 Ma- complete subduction (including the ridge) of the Proto-Caribbean and Central Atlantic basin and insertion of the Farallon (Pacific)-derived Caribbean plate in between the Americas. One evidence suggesting subduction of the Proto-Caribbean spreading ridge is the formation of ca. 120 Ma anatectic adakitic liquids after melting of subducted (50 km) hot-young Proto-Caribbean MORB in Eastern Cuba (La Corea and Sierra del Convento mélanges; García-Casco et al., 2008; Blanco-Quintero et al., 2010; Lázaro et al., 2011), also emplaced at shallow depths in the Cordillera Central of the Dominican Republic (Escuder-Viruete et al., 2007) and Haiti (Rojas-Agramonte et al., 2021) during the mid-late Cretaceous.
Studies on U-Pb zircon geochronology, Lu-Hf, and 18O/16O isotope systematics from Cretaceous upper-mantle rocks and juvenile intra-oceanic volcanic arc in the Greater Antilles (Cuba and Hispaniola) reported old inherited zircon grains ranging from 200 Ma to 3.0 Ga (Proenza et al., 2018; Rojas-Agramonte et al., 2016; Torró et al., 2018). These ages are similar to those of zircons from nearby crustal regions in northern Central America, Mexico, and northern South America. These studies concluded that detrital zircons of sediments deposited in the Proto-Caribbean/Atlantic were transferred to the sub-arc mantle of the Caribbean plate by means of subduction. Moreover, the presence in Hispaniola of Quaternary alkali basalts with isotopic EM1-l affinities, led Kamenov et al. (2011) to propose an ancient subcontinental lithospheric mantle (SCLM) source with Gondwana affinity entrained beneath the island likely derived from a Grenvillian terrane in Central America or Mexico. An undefined “tectonic interaction” of the intraoceanic arc with such a terrane was proposed by these authors.
Here we explore how subduction of the proto-Caribbean ridge may help explain the presence of old zircons and a SCLM fragment below the Caribbean arc.
References
Blanco-Quintero, I.F., et al., 2010. American Journal of Science 310. https://doi.org/10.2475/11.2010.01
Escuder-Viruete, J.E., et al., 2007. Lithos 99, 151–177.
Kamenov, G.D., 2011, et al. 2011. Nature Geoscience 4, 554–557.
Lázaro, C., et al., 2011, Lithos 126. https://doi.org/10.1016/j.lithos.2011.07.011
Proenza, J.A., et al., Geoscience Frontiers 9, 1921–1936. https://doi.org/10.1016/j.gsf.2017.12.005
Rojas-Agramonte, Y., et al., 2016. Earth and Planetary Science Letters 436. https://doi.org/10.1016/j.epsl.2015.11.040
Rojas-Agramonte, Y., 2021. International Geology Review 1–10.
Torró, L., et al., 2018. Gondwana Research 54, 23–37. https://doi.org/10.1016/j.gr.2017.09.010
How to cite: Rojas-Agramonte, Y., Riel, N., Kaus, B., and Garcia-Casco, A.: Consequences of ridge subduction for the evolution in the Greater Antilles arc, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-20143, https://doi.org/10.5194/egusphere-egu25-20143, 2025.
Posters virtual: Tue, 29 Apr, 14:00–15:45 | vPoster spot 1
EGU25-20984 | Posters virtual | VPS22
SUBUTTEC Project: SUBdUcTion triggered Terrestrial Evolution in the CaribbeanTue, 29 Apr, 14:00–15:45 (CEST) | vP1.20
Subduction zones represent more than half of the total plate boundaries length (38,000 over 64,000km) and cause fast geographic changes by a range of geological processes occurring at local to regional scales such as crustal deformation, volcanism, or dynamic topography. The associated transient changes in land-sea distributions influence the migration, genetic drift, adaptation, speciation, and endemism of the terrestrial biosphere that conquered emerged landmasses. Today, archipelagos located along subduction zones hostone-third of the biodiversity hotspots in the world (Myers et al., 2000). In this context, SUBUTTEC research team aim at combining geological and biological data to unravel the links between the subduction dynamics and terrestrial life in subduction zones based on the case study of the Antilles hotspot. This short and dynamic subduction zone, bounding the east of the Caribbean plate, is ideally circumscribed by two giant continents and two equally giant oceans that provide rather static boundary conditions. To unravel the role of the southern Lesser Antilles in the dynamics of Caribbean biodiversity, we will perform paleogeographic reconstructions over the last 20 Myrs, focused on the unknown role of the southern Lesser Antilles, will be done by integrating tectonics, paleomagnetism, (bio-)stratigraphy and geochronology. We will match these paleogeographic reconstructions with the assemblage distribution and phylogenetic records of extant endemic species, which will allow us to test for alternative scenarios of the temporal dispersion and evolution of life in this highly dynamic hotspot region for both biodiversity and tectonic activity. The implementation of comparative biogeographical methods provides here a powerful tool to reveal natural classification of biogeographic areas i.e. bioregionalization and identification of vicariant events. The joint analysis of the geological and biological records will provide a macro-ecological framework of the biosphere/biodiversity dynamics over subduction zones.
How to cite: Philippon, M., Roncal, J., Cornée, J. J., Quillevere, F., Arcay, D., Cerpa, N., Husson, L., Boucharat, Y., Rousteau, A., Ung, V., Bezault, E., Lorcery, M., Bernet, M., Sarr, A.-C., Riel, N., Kaus, B., Pubellier, M., Thivaiou, D., Montheil, L., and Noury, M. and the SUBUTTEC Team: SUBUTTEC Project: SUBdUcTion triggered Terrestrial Evolution in the Caribbean, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-20984, https://doi.org/10.5194/egusphere-egu25-20984, 2025.
EGU25-20933 | Posters virtual | VPS22
Seismotectonics of the Oriente Transform Fault revisitedTue, 29 Apr, 14:00–15:45 (CEST) | vP1.21
Transform faults are often considered to be geometrically simple, nearly linear, vertical structures that localize crustal deformation within a narrow zone surrounding the fault. The deformation kinematics are typically purely strike-slip, parallel to far-field plate motion, with seismic slip above the brittle-ductile transition, near the 600 °C isotherm, which is well predicted by thermal models. Although deviations from these simplified features have been described, much remains to be learned about the seismogenic behavior of transform faults, for example, why they release much less seismic moment than predicted by plate motion models, or why they so rarely produce earthquakes of magnitudes as large as would be expected given their geometric segmentation (>M7).
The Oriente Transform Fault (OTF) along the southern margin of eastern Cuba, at the boundary between the Caribbean and North American plates, is a particularly relevant example to inform on the seismogenic behavior of transform faults for at least 5 reasons: (1) the OTF geometry changes from a nearly continuous trace along the Cayman Ridge to a highly segmented one westward along eastern Cuba, (2) the geometrically continuous segment was the location of a magnitude 7.8 supershear earthquake in January 2020, (3) GNSS-derived strain measurements indicate that this segmentation variation corresponds to a transition from very shallow (<5 km) mechanical coupling —perhaps creep— of the fault, to complete coupling across the entire crustal thickness (20 km), (4) earthquake hypocenters offshore eastern Cuba locally reach subcrustal depths, (5) earthquake focal mechanisms and offshore geological observations show fault-normal compressional deformation along this purely strike-slip segment.
Here we revisit the offshore trace and seismotectonics of the OTF in light of recent data. We benefit from several oceanographic campaigns in the northern Caribbean, in particular the recent Haiti-TWIST campaign of the Pourquoi Pas? R/V, during which new high-resolution bathymetric and seismic reflection data were acquired, filling several important gaps. We also benefit from recent deformation results from GNSS measurements in Cuba, as well as a new compilation of earthquake moment tensor solutions.
How to cite: Calais, E., Leroy, S., Poort, J., Lebrun, J.-F., Mercier de Lépinay, B., Gonzalez, O., Moreno, B., Granja-Bruna, J.-L., Roest, W., Marcaillou, B., Aiken, C., and Klingelhoefer, F.: Seismotectonics of the Oriente Transform Fault revisited, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-20933, https://doi.org/10.5194/egusphere-egu25-20933, 2025.
