Basement-Cover Relationships and Their Along-Strike Changes in the Linking Zone (Iberian Range, Spain): A Combined Structural and Gravimetric Study

Contractional deformation in the transition between the Iberian and Catalan Coastal Ranges (Linking Zone) generated both thin-skinned structures detached in low-strength Triassic units and basement-involved structures. To evaluate their extent and relative contribution to the overall structure, we carried out a study combining structural geology and gravimetry. New gravity data (938 stations) and density determinations (827 samples) were acquired and combined with previous existing databases to obtain Bouguer anomaly and residual Bouguer anomaly maps of the study area. Seven serial and balanced cross sections were built, their depth geometries being constrained through the 2.5-D gravity modeling and the 3-D gravity inversion that we accomplished. The residual Bouguer anomaly map shows a good correlation between basement antiforms and gravity highs whereas negative anomalies mostly correspond to (i) Meso-Cenozoic synclines and (ii) Neogene-Quaternary basins. Cross sections depict a southern, thick-skinned domain where extensional, basement faults inherited from Late Jurassic-Early Cretaceous times were inverted during the Cenozoic. To the north, we interpret the existence of both Triassic-detached and basement-involved deformation domains. The two deformation styles are vertically overlapped in the southernmost part of the Catalan Coastal Ranges but relay both across and along strike in the Eastern Iberian Range. These basement and cover relationships and their along-strike variations are analyzed in terms of the interplay between structural inheritance, its obliquity to the shortening direction, and the continuity and effectiveness of Triassic décollements in the study area

Petrophysical properties in the Iberian Range and surrounding areas (NE Spain): 1-density

We introduce the first map of density data in Northeastern Spain which can help in the interpretation of gravimetric surveying. The background map is a simplified version of the Geode continuous geological cartography (scale 1:200.000) of the Iberian Range and Ebro basin. These maps are synthetic and homogeneous maps based on previous 1:50, 000 scale geological maps (MAGNA). The map uses the ETRS89 datum and UTM coordinates (30T northern zone) and covers an area of 140, 000 sq km. The compiled data shown in the map come from previous papers of the region (˜ 700 points) as well as from more than 800 additional points developed in the course of an exploratory project focused on the underground characterization of a potential CO2 reservoir in the so-called ‘Linking Zone''. The new data accomplish some basic criteria; they are accurately georeferenced and lithology, stratigraphic age and other technical details about the measurements (e.g. means and error) and methods are fully displayed

Mapa de anomalía de Bouguer del Pirineo Suroccidental

Las relaciones geométricas y cinemáticas entre las unidades de basamento de los Pirineos Suroccidentales, específicamente entre la terminación de la Zona Axial y el afloramiento de los Macizos Vascos, son desconocidas y potencialmente muy complejas (Oliva-Urcia, 2018). La gravimetría se ha aplicado con éxito en otras regiones pirenaicas para resolver la geometría de las unidades de cobertera y basamento debido al contraste de densidad existente en las rocas involucradas. Con el objetivo de resolver dichas relaciones y sus implicaciones en la comprensión 4D de esta parte de la cadena, hemos llevado a cabo un exhaustivo programa de adquisición de datos gravimétricos (2018-2020) entre los valles de Salazar (al oeste) y del Aragón Subordán (hacia el este) en el marco del proyecto 3DGeoEU (GeoERA-H2020). Más de 1500 nuevas estaciones (varias de ellas en alta montaña) junto con > 1700 puntos de la base de datos SITOPO, ¿ 1200 de campañas mineras, y > 500 de anteriores proyectos del IGME hacen un total de > 5000 estaciones gravimétricas armonizadas. Además, se han recopilado > 500 datos de densidad de bases de datos o muestreados en el campo. En este trabajo presentaremos los mapas de anomalías Bouguer y de anomalía residual obtenidos, junto con una revisión de las principales estructuras cartográficas en la zona

Analizando la cinética de las remagnetizaciones por enterramiento. El caso de la Cuenca turbidítica de Jaca (Pirineos occidentales).

X Congreso Geológico de España, 5-7 Julio 2021, Vitoria - GasteizLas remagnetizaciones químicas regionales relacionadas con procesos de enterramiento y diagénesis son un proceso ampliamente extendido en cuñas orogénicas y cuencas sedimentarias. Este proceso conlleva la neoformación autigénica de minerales ferromagnéticos s.l. en relación con el aumento de temperatura asociado al enterramiento. Sin embargo, todavía no se conoce bien la cinética de estos procesos, debido en parte a que la mayoría de las remagnetizaciones de este tipo descritas en la literatura científica se produjeron durante supercrones magnéticos. Los materiales turbidíticos eocenos de la Cuenca de Jaca (Pirineos Occidentales) muestran una remagnetización química de doble polaridad, registrando varios crones a lo largo de la secuencia sedimentaria remagnetizada. Dentro del proyecto UKRIA4D (PID2019-104693GB-I00/CTA), se va a realizar un estudio multidisciplinar para relacionar temperatura de enterramiento, mineralogía magnética y edad de la remagnetización con la que evaluar de manera empírica las relaciones cinéticas entre los distintos factores

Clinical manifestations, prevalence, risk factors, outcomes, transmission, diagnosis and treatment of COVID-19 in pregnancy and postpartum: a living systematic review protocol.

INTRODUCTION: Rapid, robust and continually updated evidence synthesis is required to inform management of COVID-19 in pregnant and postpartum women and to keep pace with the emerging evidence during the pandemic. METHODS AND ANALYSIS: We plan to undertake a living systematic review to assess the prevalence, clinical manifestations, risk factors, rates of maternal and perinatal complications, potential for mother-to-child transmission, accuracy of diagnostic tests and effectiveness of treatment for COVID-19 in pregnant and postpartum women (including after miscarriage or abortion). We will search Medline, Embase, WHO COVID-19 database, preprint servers, the China National Knowledge Infrastructure system and Wanfang databases from 1 December 2019. We will supplement our search with studies mapped by Cochrane Fertility and Gynaecology group, Evidence for Policy and Practice Information and Co-ordinating Centre (EPPI-Centre), COVID-19 study repositories, reference lists and social media blogs. The search will be updated every week and not be restricted by language. We will include observational cohort (≥10 participants) and randomised studies reporting on prevalence of COVID-19 in pregnant and postpartum women, the rates of clinical manifestations and outcomes, risk factors in pregnant and postpartum women alone or in comparison with non-pregnant women with COVID-19 or pregnant women without COVID-19 and studies on tests and treatments for COVID-19. We will additionally include case reports and series with evidence on mother-to-child transmission of SARS-CoV-2 in utero, intrapartum or postpartum. We will appraise the quality of the included studies using appropriate tools to assess the risk of bias. At least two independent reviewers will undertake study selection, quality assessment and data extraction every 2 weeks. We will synthesise the findings using quantitative random effects meta-analysis and report OR or proportions with 95% CIs and prediction intervals. Case reports and series will be reported as qualitative narrative synthesis. Heterogeneity will be reported as I2 and τ2 statistics. ETHICS AND DISSEMINATION: Ethical approval is not required as this is a synthesis of primary data. Regular updates of the results will be published on a dedicated website (https://www.birmingham.ac.uk/research/who-collaborating-centre/pregcov/index.aspx) and disseminated through publications, social media and webinars. PROSPERO REGISTRATION NUMBER: CRD42020178076

Emplacement and deformation of mesozoic Gabbros of the High Atlas (Morocco): paleomagnetism and magnetic fabrics

A paleomagnetic and magnetic fabric study is performed in Upper Jurassic gabbros of the central High Atlas (Morocco). These gabbros were emplaced in the core of preexisting structures developed during the extensional stage and linked to basement faults. These structures were reactivated as anticlines during the Cenozoic compressional inversion. Gabbros from 19 out of the 33 sampled sites show a stable characteristic magnetization, carried by magnetite, which has been interpreted as a primary component. This component shows an important dispersion due to postemplacement tectonic movements. The absence of paleoposition markers in these igneous rocks precludes direct restorations. A novel approach analyzing the orientation of the primary magnetization is used here to restore the magmatic bodies and to understand the deformational history recorded by these rocks. Paleomagnetic vectors are distributed along small circles with horizontal axes, indicating horizontal axis rotations of the gabbro bodies. These rotations are higher when the ratio between shales and gabbros in the core of the anticlines increases. Due to the uncertainties inherent to this work (the igneous bodies recording strong rotations), interpretations must be qualitative. The magnetic fabric is carried by ferromagnetic (s.s.) minerals mimicking the magmatic fabric. Anisotropy of magnetic susceptibility (AMS) axes, using the rotation routine inferred from paleomagnetic results, result in more tightly clustered magnetic lineations, which also become horizontal and are considered in terms of magma flow trend during its emplacement: NW-SE (parallel to the general extensional direction) in the western sector and NE-SW (parallel to the main faults) in the easternmost structures

Basement‐Cover Relationships and Their Along‐Strike Changes in the Linking Zone (Iberian Range, Spain): A Combined Structural and Gravimetric Study

International audienc

Strain indicators and magnetic fabric in intraplate fault zones. Case study of Daroca thrust, Iberian Chain, Spain

Anisotropy of magnetic susceptibility (AMS) has been applied to the study of shallow fault zones, although interpretation of the results requires establishing clear relationships between petrofabric and magnetic features, magnetic behaviour of fault rocks, and an extensive knowledge of P-T conditions. In this work, we demonstrate that magnetic methods can be applied to the study of heterogeneous fault zones, provided that a series of requisites are met. A major fault zone within the Iberian plate (Daroca thrust), showing transpressional movements during Cenozoic time was chosen for this purpose, because of the exceptional outcrops of fault gouge and microbreccia and its relevance within the context of the northeastern Iberian Plate. Magnetic fabrics were analysed and the results were compared with foliation and S-C structures measured within the fault zone. Clay mineral assemblages suggest maximum burial depths shallower than 2 km (<60–70 °C) for fault rocks in the footwall of the Daroca thrust. The orientation of the AMS axes is consistent with mesostructural strain indicators: kminparallels the mean pole to S, or it is intermediate between S and C poles; kmaxis oriented at a high angle (nearly orthogonal in overall) to the transport direction, which can be explained from both deformational and mineralogical controls. Both magnetic fabrics and kinematic indicators are consistent with a reverse movement for most of the fault zone

Unravelling the kinetics of burial remagnetizations

Burial diagenesis is one of the main mechanisms claimed for explaining pervasive remagnetizations in sedimentary basins and orogenic wedges worldwide. It involves authigenic formation (e.g. chemical remagnetization) of magnetic minerals in response to enhanced temperature conditions at deep basinal positions. Key questions about the kinetics of this process in natural cases remain unsolved because most of the best-documented cases occurred during long-lasting magnetic superchrons. The Western Pyrenees display a dual polarity record of a burial remagnetization affecting the deepest part of the Eocene Jaca turbiditic basin and its underlying units. A preliminary study of 49 sites distributed along three cross sections reveals that postfolding (remagnetized) ChRM directions are found within the lowermost part of the studied sedimentary pile, which is affected by cleavage, in such a way that ChRM unblocking temperatures increase as a function of depth. Noteworthy, this remagnetization is associated with hysteresis data typical for chemical remagnetizations (samples falling mainly within the SP+SD+MD mixing line in the Day plot), and displays up to five different polarity zones that are consistent along strike in the three studied cross sections. Prefolding ChRM directions are found, in contrast, in the overlying sequence above the cleavage domain. We intend to carry out a detailed, multidisciplinary study of this remagnetization in the framework of the recently funded UKRIA4D project, that will integrate: A) a full characterization of the remagnetization front combining paleomagnetic and rock-magnetic data; B) characterization of the burial conditions based on SEM and TEM observations of mineral assemblages and temperature estimates from RAMAN spectroscopy on carbonaceous material; and C) magneto-biostratigraphic dating of the 7 km-thick overlying sedimentary sequence. Integration of these data will allow establishment of the burial conditions that led to the observed remagnetization, on which, at least, a qualitative kinetic model for burial remagnetizations will be developed