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[EN] The environmental changes leading up to the first continent-wide glaciation of Antarctica during the Eocene-Oligocene Transition (EOT) are still not fully understood. Declining atmospheric CO2 concentrations and associated feedbacks have been invoked as underlying mechanisms, but the role of the coeval opening/deepening of Southern Ocean gateways (Drake Passage and Tasman Gateway), and subsequent changes in paleoceanography remain poorly understood. Evidence suggests both a temperate late Eocene and cooling before the EOT, both broadly coetaneous with a wide, supra-regional diagenetic event that resulted in green-clay (glaucony) formation in the marine realm around Antarctica (Houben et al., 2019; López-Quirós et al., 2019). Glaucony formation and evolution are driven by the activity of bacteria thriving in the organic-rich environment, a bio-geochemical system now considered to play a key role in the control of global ocean chemistry. Investigation of the reaction mechanisms throughout the formation of glaucony provides reliable information about (i) macro-scale environmental conditions, such as ocean transgression-regression cycles and ocean circulation changes, and (ii) the micro-scale sedimentary environment, such us sediment permeability, ion mobility and organic matter content – all of which are registered in the fabric and crystal-chemical characteristics of glaucony (e.g., López-Quirós et al., 2019; 2020; 2023). In addition, K-Ar dating of glaucony has provided 40% of the absolute-age dates for the geological timescale of the past 250 Ma. Glaucony is thus an important tool to date depositional ages of sediments and to reconstruct paleoenvironmental conditions. In spite of all, the nature, depositional setting, paleoenvironmental implications and chronology of the late Eocene glaucony reported in diverse shallow-marine settings in the Southern Ocean are loosely constrained (López-Quirós et al., 2019). In this contribution we describe, for the first time

[EN] The historyof surface uplift rates in the Iberian Meseta, as well as the deep and shallow mechanisms that generated and currently support its characteristic elevated topography, are still debated.The objective of our project is to quantify the degree to which contributions to topography in the Iberian Meseta partition into crustal, lithospheric mantle, and sublithospheric mantle dynamic processes.

[EN] The GI-CARTO research group is articulated around geological mapping as a research methodology developed in many projects. The activities of the team can be distributed in various working lines: 1.-Research activities devoted to the solving of specific geological problems 2.-Systematic geological mapping 3.-Implementation of a new geological information model 4.-Edition and preparation of new geological maps 5.-International activitie

Las 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.

The Paleocene (66¿56 Ma) was a critical time interval for understanding the geological history in high palaeolatitudes after the end of Cretaceous event (recovery from mass extinction, palaeoclimate, global sea level changes, among others). The sedimentary succession from Seymour Island (Antarctic Peninsula) provides key reference material from this important phase of the early Cenozoic. A detailed age model is proposed for the López de Bertodano Formation (LBF), Sobral Formation (SF) and Cross Valley¿Wiman Formation (CVWF) based on a new magnetostratigraphic section which integrates previous dinoflagellate cyst biostratigraphy, Iridium anomaly (K-Pg boundary), U-Pb zircon dating (airfall tuff) and strontium isotope values from macrofossils. The new composite magnetostratigraphic section, which includes the Cretaceous¿Paleogene boundary, has been correlated to the GPTS from C29r up to C24r. The top of the LBF is confirmed as latest Maastrichtian to earliest Danian (~65.4 Ma) in age. The overlying SF is mostly Danian in age (~65.2¿ ~63 Ma) and CVWF is Selandian¿Thatenian (~61.3¿56.9 Ma). LBF, SF and CVWF are unconformity-bounded units (alloformations) that record the geological evolution of the James Ross Basin during a period of relative decreasing tectonism but coeval with volcanic activity. Unconformity based internal units have been recognized, dividing each formation into allomembers (LBF: Molluscan and Cenozoic; SF: A, B and C; CVWF: Díaz, Arañado, Bahía Pingüino). The new age model allows correlation of base-level changes with eustatic sea-level fluctuations. The bases of the SF and CVWF are correlated with the 65.3 and 61.5 Ma sea level lowstands.

La costa sur de Bahía Esperanza se sitúa en el extremo septentrional de la Península Antártica. La cubierta glaciar de la zona corresponde a los glaciares Buenos Aires, Depot, Kenney y Flora, éste última actualmente reducido a un glaciar de circo. Gran parte de este territorio presenta evidencias de la actividad glaciar pasada y de los fenómenos periglaciares que posteriormente la afectaron, además de otras formas ligadas al litoral. Durante el Último Máximo Glaciar (LGM), el casquete que cubría la península Antártica alcanzó espesores entre 150-400 m mayores que los actuales y se extendió unos 200 km hacia el E y NE de la actual línea de costa. La transición al Holoceno interglaciar se completa cuando se alcanzan volúmenes y una configuración de hielo similar al actual. caracterizándose por la aparición de lagos de agua dulce en tierra y por la ocupación de terrenos costeros por pingüineras.

Bahia Esperanza, constituting the NE tip of the Antarctic Peninsula, is made up of Paleozoic clastic sedimentary rocks overlain by a Jurassic volcano-sedimentary series and intruded by Cretaceous gabbros and diorites. The area is located along the southern part of the Pacific Margin magnetic anomaly belt. Field magnetic researches during February 2010 contribute to determining the deep geometry of the intermediate and basic intrusive rocks. Moreover, the new field data help constrain the regional Pacific Margin Anomaly, characterized up to now only by aeromagnetic and marine data. Field magnetic susceptibility measurements of intrusive intermediate and basic rocks, responsible for magnetic anomalies, ranges from 0.5 × 10− 3 SI in diorites to values between 0.75 × 10− 3 SI and 1.3 × 10− 3 SI in gabbros. In addition, a significant remanent magnetism should also have contributed to the anomalies. The regional magnetic anomaly is characterized by a westward increase from 100 nT up to 750 nT, associated with large intrusive diorite bodies. They probably underlie most of the western slopes of Mount Flora. Gabbros in the Nobby Nunatak determine local residual rough anomalies that extend northwards and westwards, pointing to the irregular geometry of the top of the basic rocks bodies below the Pirámide Peak Glacier. However, the southern and eastern boundaries with the Buenos Aires Glacier are sharp related to deep glacier incision. As a result of the glacier dynamics, magnetic anomalies are also detected north of the Nobby Nunatak due to the extension of the anomalous body and the presence of gabbro blocks in the moraines. The Bahia Esperanza region is a key area where onshore field geological and magnetic research allows us to constrain the shape of the crustal igneous intrusions and the basement glacier geometry, providing accurate data that complete regional aeromagnetic research

Bahia Esperanza, constituting the NE tip of the Antarctic Peninsula, is made up of Paleozoic clastic sedimentary rocks overlain by a Jurassic volcano-sedimentary series and intruded by Cretaceous gabbros and diorites. The area is located along the southern part of the Pacific Margin magnetic anomaly belt. Field magnetic researches during February 2010 contribute to determining the deep geometry of the intermediate and basic intrusive rocks. Moreover, the new field data help constrain the regional Pacific Margin Anomaly, characterized up to now only by aeromagnetic and marine data. Field magnetic susceptibility measurements of intrusive intermediate and basic rocks, responsible for magnetic anomalies, ranges from 0.5 × 10− 3 SI in diorites to values between 0.75 × 10− 3 SI and 1.3 × 10− 3 SI in gabbros. In addition, a significant remanent magnetism should also have contributed to the anomalies. The regional magnetic anomaly is characterized by a westward increase from 100 nT up to 750 nT, associated with large intrusive diorite bodies. They probably underlie most of the western slopes of Mount Flora. Gabbros in the Nobby Nunatak determine local residual rough anomalies that extend northwards and westwards, pointing to the irregular geometry of the top of the basic rocks bodies below the Pirámide Peak Glacier. However, the southern and eastern boundaries with the Buenos Aires Glacier are sharp related to deep glacier incision. As a result of the glacier dynamics, magnetic anomalies are also detected north of the Nobby Nunatak due to the extension of the anomalous body and the presence of gabbro blocks in the moraines. The Bahia Esperanza region is a key area where onshore field geological and magnetic research allows us to constrain the shape of the crustal igneous intrusions and the basement glacier geometry, providing accurate data that complete regional aeromagnetic research