Segmentation and kinematics of the North America-Caribbean plate boundary offshore Hispaniola

We explored the submarine portions of the Enriquillo–Plantain Garden Fault zone (EPGFZ) and the Septentrional–Oriente Fault zone (SOFZ) along the Northern Caribbean plate boundary using high-resolution multibeam echo-sounding and shallow seismic reflection. The bathymetric data shed light on poorly documented or previously unknown submarine fault zones running over 200 km between Haiti and Jamaica (EPGFZ) and 300 km between the Dominican Republic and Cuba (SOFZ). The primary plate-boundary structures are a series of strike-slip fault segments associated with pressure ridges, restraining bends, step overs and dogleg offsets indicating very active tectonics. Several distinct segments 50–100 km long cut across pre-existing structures inherited from former tectonic regimes or bypass recent morphologies formed under the current strike-slip regime. Along the most recent trace of the SOFZ, we measured a strike-slip offset of 16.5 km, which indicates steady activity for the past ~1.8 Ma if its current GPS-derived motion of 9.8 ± 2 mm a−1 has remained stable during the entire Quaternary.Depto. de Geodinámica, Estratigrafía y PaleontologíaFac. de Ciencias GeológicasTRUEpu

Revelando la geometría en profundidad de las fallas activas que limitan el valle del Guadalentín mediante sísmica de reflexión de alta resolución: resultados preliminares

[EN]: To produce seismic hazard assessments to the current state-of-the-art, it is essential to characterize the active faults in terms of geometry, interrelation and seismotectonic status. The Guadalentin Depression is the main basin within the Eastern Betic Shear Zone, which corresponds to a NE-SW tectonic corridor bounded by the Carrascoy, Alhama de Murcia and Palomares faults, from north to south. Although a number of active tectonics and paleoseismological studies have been carried out in these faults, almost nothing is known about their geometry at depth. To unveil the deep structure, geometry and upper Neogene deformation history of these faults we have carried out a high-resolution seismic reflection survey. The acquired seismic profiles will allow to improve our understanding of the deep geometry of the known active faults (up to 2 km depth), as well as to identify potential buried branches and will help to reduce the uncertainties in seismic hazard assessment.[ES]: Para producir evaluaciones del peligro sísmico actualizadas al estado del arte actual, es esencial caracterizar las fallas activas de una región en términos de geometría, interrelación y estado sismotectónico. La depresión del Guadalentín es la principal cuenca cuaternaria dentro de la Zona de Cizalla de las Béticas Orientales, la cual corresponde a un corredor tectónico con dirección NE-SW delimitado por las fallas de Carrascoy, Alhama de Murcia y Palomares, de norte a sur. Aunque varios estudios de tectónica activa y paleosismología se han centrado en estas fallas, su geometría en profundidad es bastante incierta. Para revelar la estructura profunda, la geometría y el historial de deformación desde el Neógeno superior de estas fallas, hemos llevado a cabo un estudio de sísmica de reflexión de alta resolución. Los perfiles sísmicos adquiridos permitirán mejorar nuestra comprensión de la geometría profunda de las fallas activas conocidas (hasta 2 km de profundidad), así como identificar posibles ramas ciegas, y ayudarán a reducir las incertidumbres en los cálculos de peligrosidad sísmicaHector Perea es un investigador postdoctoral del programa "Atracción de Talento" en la Universidad Complutense de Madrid financiado por la Comunidad de Madrid (2018-T1/AMB-11039). Paula Herrero y Júlia Molins han estado contratadas por el proyecto UNrIDDLE (2018-T1/AMB-11039). Juan Alcalde ha recibido financiación de las ayudas IJC2018-036074-I financiadas por MCIN/AEI/10.13039/501100011033.Peer reviewe

MARIBNO project: Structure of the NorthWest Iberian margin: influence of inherited tectonics in the Alpine extension and inversion

X Congreso Geológico de España, 5-7 Julio 2021, Vitoria - GasteizLa zona noroeste de Iberia reúne rasgos geológicos excepcionales relacionados con el desarrollo de un margen continental hiperextendido cerca de un punto triple y la posterior inversión tectónica parcial. Es una zona de gran interés para el estudio del papel de la herencia tectónica y la posterior inversión en márgenes continentales extensionales, pero hay un gran déficit de información. Todo esto sienta las bases del proyecto anfibio MARIBNO (PGC2018-095999-B-I00) donde a lo largo de 2021 y 2022 se adquirirán sísmica marina de reflexión multicanal 2D (~4000 km), sísmica de gran ángulo en 3 transectos tierra-mar (~600 km), batimetría multihaz, grav-mag y sísmica de alta resolución. Se complementará en tierra con adquisición de datos grav-mag y varias campañas de cartografía geológica. Los objetivos se centran en el estudio de la estructura cortical, el control tectónico ejercido por estructuras previas a las etapas alpinas y la cartografía y caracterización de los dominios corticales aunando criterios geológicos y geofísicos.Todo esto sienta las bases del proyecto anfibio MARIBNO (PGC2018-095999-B-I00) donde a lo largo de 2021 y 2022 se adquirirán sísmica marina de reflexión multicanal 2D (~4000 km), sísmica de gran ángulo en 3 transectos tierra-mar (~600 km), batimetría multihaz, grav-mag y sísmica de alta resolución

Análisis de los esfuerzos tectónicos de la crisis sísmica de 2010 en Haití

[ES] El evento de Mw=7 del 12 de enero 2010 provocó una crisis sísmica en el sur de Haití, que duró 3 meses. Se ha realizado un análisis de inversión de esfuerzos de los mecanismos focales del evento principal y 50 réplicas. El evento principal fue generado por un falla de buzamiento 64ºN y dirección N084Eº con una componente principal de deslizamiento lateral-izquierda y una componente inversa. Las réplicas se han generado por fallas inversas puras ENE-OSO situadas en la zona de interacción entre estructuras compresivas orientadas NO-SE y de desgarre orientadas E-O. Estas réplicas han sido activadas por un régimen de esfuerzos compresivo uniaxial muy homogéneo orientado con ¿1 horizontal según N017ºE ±10º. La ausencia de ruptura en superficie indica que el origen de las réplicas son fallas ciegas orientadas N097º-117ºE. Los datos de deformación superficial intersísmica obtenidos a partir de velocidades derivadas de GPS para la zona epicentral muestran una desviación angular de ¿30º respecto a la orientación de ¿1 obtenidos del análisis de esfuerzos. Esta desviación sugiere que una parte significativa de la energía elástica acumulada a lo largo de las estructuras de tendencia E-O no fue liberada durante la crisis sísmica de 2010.[EN] The Mw=7 event of the January 12th, 2010 triggered a seismic crisis in the southern Haiti that continued for 3 months. The epicenter was located in an E-W oriented transpressive plate boundary where E-W trending left-lateral strike-slip and NW-SE trending compressive structures coexist (i.e.,strain partitioning).We carried out the stress inversion analysis over the focal mechanisms of the main event and 50 aftershocks. The main event was generated by a N084Eº 64º N-dipping fault with both a main left-lateral slip component and a reverse component. The aftershocks have been generated by ENEWSW pure reverse faults located in the area of interaction between the NWSE compressive structures and E-W strike-slip structures. These aftershocks have been activated by a very homogeneous uniaxial compressive stress regime with a σ1 horizontal trending 017º±10º. The absence of surface rupture indicates that the sources of the aftershocks are blind thrusts oriented 097º-117º. The interseismic surface convergence, derived from GPS velocities, shows an angular deviation of ≈30° related to the orientation of σ1 derived from the stress inversion analysis. This deviation strongly suggests that a significant part of the elastic energy accumulated along the E-W trending structures was not released during seismic crisis of 2010Peer Reviewe

Caresoil: A multidisciplinar Project to characterize, remediate, monitor and evaluate the risk of contaminated soils in Madrid (Spain)

Trabajo presentado en la EGU General Assembly 2016 (European Geosciences Union), celebrada en Viena del 17 al 22 de abril de 2016.Soil contamination can come from diffuse sources (air deposition, agriculture, etc.) or local sources, these last being related to anthropogenic activities that are potentially soil contaminating activities. According to data from the EU, in Spain, and particularly for the Autonomous Community of Madrid, it can be considered that heavy metals, toxic organic compounds (including Non Aqueous Phases Liquids, NAPLs) and combinations of both are the main problem of point sources of soil contamination in our community. The five aspects that will be applied in Caresoil Program (S2013/MAE-2739) in the analysis and remediation of a local soil contamination are: 1) the location of the source of contamination and characterization of soil and aquifer concerned, 2) evaluation of the dispersion of the plume, 3) application of effective remediation techniques, 4) monitoring the evolution of the contaminated soil and 5) risk analysis throughout this process. These aspects involve advanced technologies (hydrogeology, geophysics, geochemistry,...) that require new developing of knowledge, being necessary the contribution of several researching groups specialized in the fields previously cited, as they are those integrating CARESOIL Program. Actually two cases concerning hydrocarbon spills, as representative examples of soil local contamination in Madrid area, are being studied. The first is being remediated and we are monitoring this process to evaluate its effectiveness. In the second location we are defining the extent of contamination in soil and aquifer to define the most effective remediation technique.Peer reviewe

Lithospheric domain and deformation style mapping in the Galicia continental margin (northwestern Iberian margin)

IX Congreso Geológico de España, 12-14 septiembre 2016, Huelva.-- 4 pages, 3 figures[EN] The continental margin of Galicia presents a very complex structure, due to two main effects. On the one hand, it's a magma-poor rift margin, generated in the vicinity of the triple R-R-R junction, which resulted in the simultaneous opening of the Atlantic Ocean and the Bay of Biscay during the Cretaceous. On the other hand, the Cenozoic compressive stress regime led to the partial inversion of the continental margin to the north and northwest, providing a greater structural complexity. In this work we have carried out a detailed analysis of new gravity and bathymety data acquired during the ZEE Project cruises, as well as new 2D multichannel seismic reflection profiles from the ERGAP Project. We present here some the results of this joint analysis of all the geophysical and geological information available, consisting of a continuous mapping of the different lithospheric domains and of the style of deformation which affect them, from the western margin of the Iberian Peninsula to the northern one[ES] El margen continental de Galicia presenta una estructura muy compleja, debido a dos efectos principales. Por un lado, se trata de un margen de rift pobre en magma, generado en las proximidades del punto triple R-R-R que dio lugar a la apertura simultánea del Océano Atlántico y el golfo de Vizcaya durante el Cretácico. Por otra parte, el régimen de esfuerzos compresivo Cenozoico generó la inversión parcial del margen continental hacia el norte y el noroeste, aportando una mayor complejidad estructural. En este trabajo hemos realizado un análisis detallado de la nueva información gravimétrica y batimétrica obtenida durante las campañas del Proyecto ZEE, así como de nuevos perfiles de sísmica de reflexión multicanal procedentes del Proyecto ERGAP. Presentamos aquí parte de los resultados de este análisis conjunto de toda la información geofísica y geológica disponible, consistentes en una cartografía continua de los diferentes dominios litosféricos y del tipo dedeformación que los afectan, desde el margen oeste de la Península Ibérica hasta el margen nortePeer Reviewe

Deep crustal structure and continent-ocean boundary along the Galicia continental margin (NW Iberia)

Trabajo presentado en la EGU General Assembly 2016 (European Geosciences Union), celebrada en Viena del 17 al 22 de abril de 2016.The Galicia continental margin is a magma-poor rifted margin with an extremely complex structure. Its formation involves several rifting episodes during the Mesozoic in the vicinity of a ridge triple junction, which produces a change in the orientation of the main structures. In addition, there is an overimposed Cenozoic partial tectonic inversion along its northern border. Although this continental margin has been widely studied since the 70’s, most studies have focused on its western part in the transition to the Iberia Abyssal Plain, and there is a significant lack of information on the north and northwestern flanks of this margin. This fact, along with its great structural complexity, has resulted in the absence of a previous comprehensive regional geodynamic model integrating all the processes observed. In the present study we integrate a large volume of new geophysical data (gravity, swath bathymetry and 2D multichannel reflection seismic). Data come from the systematic mapping of the Spanish EEZ project which provides a dense grid of gravity data and full seafloor coverage with swath bathymetry, and from the ERGAP project which provides serially-arranged 2D seismic reflection profiles across the NW Iberia margin. The combined interpretation and modelling of this new information has arisen significant constraints on the origin, the deep crustal structure and the physiographic complexity of the margin, as well as on the characterization of the along- and across-strike variation of the ocean-continent transition along NW Iberia margin. The analysis of this information leads us to propose a conceptual model for the initiation of the tectonic inversion of a magma-poor rifted margin. Finally, a framework for the geodynamic evolution of the Galicia margin has been constructed, involving three main stages: A) an early stage from the end of rifting and oceanic drift in the Bay of Biscay (Santonian); B) an intermediate stage with the beginning of tectonic inversion in the north and northwestern Iberia margin (Campanian-Paleocene) mainly concentrated along the exhumed mantle zone; and C) a final stage of compressive deformation (Eocene-Oligocene) affecting both the continental and the oceanic crust, evidenced by large dip-slip thrustingPeer reviewe

New sedimentary analysis of the San Pedro Basin (South-eastern Dominican Republic margin) based on reflection seismic data

9ª Asamblea Hispano Portuguesa de Geodesia y Geofísica, del 28 al 30 de junio de 2016, Madrid[EN] The San Pedro Basin (SPB) is an E-W-trending bathymetric depression located at the south-eastern margin of the Dominican Republic. It occupies an approximately 6000 km2 area having an average water column of 1400 m. The SPB shows a maximum sediment thickness of 3 sTWT having little deformation and burying an imbricate back-thrust system, known as the Muertos thrust belt. Traditionally, this basin has been catalogued as Miocene in Age. Approximately 90 km of differential GPS-navigated 2D multichannel seismic reflection profiles were collected in the SPB during the NORCARIBE cruise. Regular processing included NMO correction, band-pass filtering, CMP stacking and post-stack migration. In addition to new seismic data, we have re-processed and reinterpreted 660 km of vintage 2D multi-channel seismic reflection profiles. This new data made possible a better definition of structures. Seismic facies analysis allowed us to propose a new infill evolution related to the main tectonic events at the source areas. The infill of the basin has been divided into main sequences that are related to depositional systems: 1) Upper Cretaceous deep-water pelagic sedimentation; 2) Middle-Upper Eocene basin floor fan systems; 3) Upper Eocene-to-Present channel-levee system. Our results suggest an older age for the SBP that are in agreement with the geological studies carried out in the onshore San Cristobal basin located to west of the SPB and considered for some authors as the lateral continuation[ES] La cuenca de San Pedro (CSP), es una depresión batimétrica con tendencia E-O localizada en el margen sudeste de la República Dominicana. Ocupa un área aproximada de6000 km2 con una lámina de agua de 1400 m en promedio. La CSP posee un espesor máximo de 3.5 s TWT de sedimetos medianamente deformados enterrando un sistema de retrocabalgamiento conocido como el Cinturón Deformado de los Muertos. Tradicionalmente, a esta cuenca se le ha atribuido una edad miocena. Durante la campaña NORCARIBE se adquirieron aproximadamente 90 km de datos sísmicos de reflexión multicanal 2D con sistema de posicionamiento GPS diferencial en la CSP. El procesado de los datos incluyó corrección NMO, filtrados de frecuencia, CMP stacking y migración post-stack. Además, se han reprocesado y reinterpretado 660 km de antiguos perfiles de sísmica de reflexión multicanal 2D. Estos nuevos datos han hecho posible una mejor definición de estructuras. El análisis de facies sísmicas ha permitido proponer un nuevo relleno relacionado con los principales eventos tectónicos en las áreas fuente. Dicho relleno ha sido dividido en secuencias relacionadas con sistemas deposicionales: 1) Sedimentación pelágica del Cretácico superior; 2) Sistema de abanicos de fondo de cuenca del Eoceno medio/superior; 3) Sistema canal-levee del Eoceno superior al presente. Nuestros resultados sugieren una edad anterior para la CSP en concordancia con los estudios geológicos desarrollados en la cuenca de San Cristóbal, al oeste de la CSP y considerada como la continuación lateral de la mismaPeer Reviewe

New Constraints on the Tectono-Sedimentary Evolution of the offshore San Pedro Basin (south-eastern Dominican Republic): Implications for Its Hydrocarbon Potential

The San Pedro basin (SPB) is located at the south-eastern margin of Hispaniola Island (Dominican Republic and Haiti). It is the largest offshore basin of the Dominican Republic with an extension of 6000 km2. The basin has a maximum water depth of 1600 m and is positioned to the rear of the Muertos Thrust Belt (MTB). The SPB bounds to the West by The Azua basin which has a proven petroleum system and small oil production has been recovered from the Maleno and Higuerito fields. While in the scientific literature the SPB and the Azua basins have been considered as disconnected sedimentary systems, our current study suggests both are shared a common tectonic evolution and therefore the presence of an untested petroleum system in the SPB can be expected. We have carried out a detailed review and synthesis of the onshore systematic geological mapping (SYSMIN I & II Programs) together with the integration of a large volume of sub-surface geophysical data. This includes analysis of 60 exploration wells provided by Banco Nacional de Datos de Hidrocarburos (BNDH) of the Dominican Republic, processing of new 2D multi-channel seismic data from the Spanish Research Project NORCARIBE, re-processing of legacy seismic profiles and interpretation of gravity and magnetic data. Our results led us to propose a new evolution model for the SPB. Basement of both basins consists of Cretaceous sedimentary and volcanic rocks of intra- and back-arc settings. A change in the stress regime in the Campanian led to partial inversion of the basement units favouring the deposition of two main sequences of Campanian to Maastrichtian and Palaeocene? -Eocene age in a submarine foreland setting. Due to collision between the Carbonate Bahamas Province and Hispaniola in middle Eocene, compressional stresses were transferred to the south where Cretaceous and Paleogene sediments were deformed forming the current configuration of MTB and generating a new accommodation space where SPB was developed since Upper Eocene / Oligocene until Present. While the Azua basin was finally exhumed after Miocene/Pliocene, most of SPB continued as an actively subsiding basin. This new model has allowed identification of the main elements of the petroleum system in the SPB basin: a mature Upper Cretaceous source rock and Oligocene to Miocene carbonate and clastic reservoirs interbedded with sealing shales and marls. Main traps (structural and stratigraphic) are of Oligocene to Miocene age and their formation seems to be synchronous to oil generation. While main elements of the petroleum system seem to be present in the basin, timing is a key issue that must be addressed and assessed in any future exploration in the basin