Articles publicats en revistes (Dinàmica de la Terra i l'Oceà)

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Dense shelf water and associated sediment transport in the Cap de Creus Canyon and adjacent shelf under mild winter regimes: insights from the 2021–2022 winter
(European Geosciences Union (EGU), 2025-11-27) Arjona-Camas, Marta; Durrieu de Madron, Xavier; Bourrin, Fraçois; Fos, Helena; Sanchez-Vidal, Anna; Amblàs i Novellas, David
Dense shelf water cascading (DSWC) is a key oceanographic process in transferring energy and matter from continental shelves to deep ocean areas. Although intense DSWC (IDSWC) events have received most attention due to their large impacts, mild DSWC (MDSWC) events are the most frequent in the northwestern Mediterranean and are expected to become more common under climate change. However, their dynamics, particularly in the Cap de Creus Canyon, have been less comprehensively described and compared to strong-winter events. This study investigates MDSWC in the Cap de Creus Canyon during the mild winter of 2021–2022, examining shelf-canyon transports of both dense shelf waters and suspended particulate matter (SPM). Observations from the FARDWO-CCC1 multiplatform cruise in March 2022 revealed the presence of cold, dense, and turbid shelf waters, enriched in dissolved oxygen and chlorophyll a, on the continental shelf adjacent to the canyon. These waters cascaded into the canyon head and progressed further into the canyon along its southern flank to ∼ 390 m depth. Estimated water and SPM transports during this event were 0.7 Sv and 105 metric tons (t), respectively, at the continental shelf. Within the canyon, transports were 0.3 Sv and 105 metric tons in the upper section, while mid-canyon transports were lower (0.05 Sv and 104, respectively), indicating that most dense shelf waters likely remained confined to the shelf area and upper canyon. During this event, dense shelf waters were transported ∼ 30 km from the shelf into the canyon. Our results show that significant transport of dense shelf waters (260 km3) and suspended sediment can occur in the Cap de Creus Canyon during MDSWC events under mild winters, also contributing significantly to the formation of Western Intermediate Water (WIW) in the canyon. The Mediterranean Sea Physics reanalysis data indicate that the cascading season lasted from late-January to mid-March 2022, with several shallow cascading pulses throughout this period. Peak transport occurred in mid-March associated with an eastern storm, which likely intensified MDSWC in the canyon. Our study reinforces the idea that dense shelf water transports exhibit marked interannual variability, even under mild winters.
3D modeling of gas hydrates distribution in South Hydrate Ridge (Cascadia accretionary prism, offshore Oregon) through geological time
(Sociedad Geológica de España, 2024) Cabello López, Patricia; Marin, Mar; Cassola, T.; Falivene Aldea, Oriol; Gil-Ortiz, Marc; Yeste, Luis Miguel; Agustí García-Navarro, Àlvar; Uranga Moran, Rodolfo Martín; Berndt, C.
South Hydrate Ridge (SHR) is an anticlinal structure that is part of the Cascadia accretionary prism, located offshore of Oregon. SHR has been the subject of multiple multidisciplinary studies and oceanographic campaigns focused on understanding the functioning of gas hydrate systems. Herein, we present a 3D dynamic model of SHR that simulates the distribution of gas hydrates over geological time. This model is based on the application on petroleum system modeling tools and builds upon previously published data and results from 2D models already published. The model reproduces the complex structure of SHR and distinguishes a total of 7 stratigraphic units (from the Pliocene to the Present), primarily composed of silty clays and clays interbedded with sands. The model predicts a heterogeneous distribution of gas hydrate saturation in SHR at present, with higher values observed on the flanks of the main ridge and on the crests of secondary highs (maximum values of up to 23% of porosity). According to the model, the initiation of hydrate formation occurred mainly between 1.7 Ma and 1.6 Ma, and its accumulation has persisted throughout the evolution of the ridge, alternating with dissociation in certain areas and moments. Such variable distribution and the alternation of formation and dissociation would respond to the differential growth of the structures forming the SHR. These structures control the availability of gas, which migrates upward through deformed strata, and would influence the distribution of the gas hydrate stability zone.
Characterization of the Miocene Castellón Sandstones Formation in the Western Mediterranean as a potential geological carbon storage site
(Elsevier B.V., 2025-06-06) Ron Martín, Manuel; Lukito, Pujianto; Pángaro, Francisco; Gil-Ortiz, Marc; Gómez Rivas, Enrique; Alcalde, Juan; Cabello López, Patricia; Yeste, Luis Miguel; Zamora, Gonzalo; Carrasco, Ángel; García Fernández-Valderrama, David; Martín-Monge, Antonio; Mañas, Marta; Olgado Azpiazu, María Victoria
In response to the growing interest in decarbonizing Europe's industrial hubs, this study examines the potential of the Miocene Castellón Sandstones Formation in the Valencia Trough for geological carbon storage. The proposed storage unit is represented by a siliciclastic succession formed mainly by sandstones and sandy heterolithics, in the Ebro Delta offshore area of the Valencia Trough. The sedimentological characterization of this succession, based on the study of a cored section from Amposta Marino C-2 well, has allowed to identify up to eleven lithofacies, comprising sandstones, heterolithics, calcarenites and carbonate breccias. These lithofacies can be grouped in six facies associations, including: 1) fluvial channel, 2) delta front proximal mouth bar, 3) delta front distal mouth bar, 4) proximal prodelta, 5) distal prodelta and 6) shelfal lag. The seismic stratigraphic analysis carried out throughout the study area points out to the additional presence of delta plain deposits in the northeastern sector of the study area, approximately at 30 km from the present-day Ebro delta shoreline. Based on the interpretation of these facies and seismic facies associations, the proposed depositional model consists of a river dominated, wave-influenced delta for the proto-Ebro deltaic system during the Late Miocene in the Valencia Trough. This study proposes that this sand-prone succession is presented as a good candidate for geological carbon storage in the study area, considering its proximity to the onshore Tarragona's industrial complex and its optimal reservoir characteristics. Additionally, the thick succession of the Ebro Shales also shows great potential as a vertical and lateral seal of the underlying Castellón Sandstones Formation.
Tidal versus fluvial point bars: Key features from the integration of outcrop core and wireline log information of Triassic examples
(John Wiley & Sons, 2024-05-14) Yeste, Luis Miguel; Gil-Ortiz, Marc; Garcia-Garcia, Fernando; Viseras, Cesar; Mcdougall, Neil David; Cabello, Patricia; Caracciolo,Luca
The Triassic red beds of the Tabular Cover of the Iberian Meseta are an excellent reservoir outcrop analogue, a direct consequence of high-quality exposures, which offer exceptional three-dimensional outcrops, as well as a wide variability of depositional environments. Fluvial and transitional with tide-influenced and wave-influenced settings are recognised. Three point bar geobodies of similar scale, but influenced by different processes, were selected from this succession. Point bar geobody 1 was influenced by purely fluvial processes while geobodies 2 and 3 were tide-influenced. Both types of geobody were developed as point bar deposits in sinuous channels. A fully integrated study was carried out on these geobodies, utilising both outcrop and subsurface-based approaches, to characterise the key differences between fluvial and tidal point bars in the sedimentary record. The outcrop-based component involved traditional field data collection methods alongside digital techniques and data capture, including the use of digital outcrop models. Additionally, subsurface-based methods were employed, utilising core and wireline logs obtained from wells drilled in close proximity to the outcrop. The integration of these approaches aims to accurately differentiate the depositional settings of the three different geobodies, which while apparently very similar in many key respects also exhibit considerable differences when considered from the perspective of subsurface management of potentially similar geobodies. This study also emphasises the need to clearly distinguish high-sinuosity deposits based on their depositional sub-environment in order to properly evaluate their potential for subsurface management. Additionally, it highlights the presence and importance of internal baffles that may well influence fluid migration and indeed even compartmentalise geobodies. Three point bar geobodies of similar scale, but influenced by different processes, have been selected in this succession. A fully integrated study was carried out on these geobodies, utilising both outcrop-based and subsurface-based approaches, to characterise the key differences between fluvial and tidal point bars in the sedimentary record.
Lower Miocene carbonate platforms of the Falcón Basin (NW Venezuela) compared to the offshore Perla Field reservoir
((UB). (ICTJA). (IDEA). (UAB). (CSIC), 2025-10-28) Albert-Villanueva, Eduard; Bover-Arnal, Telm; Ferràndez i Cañadell, Carles; González, Lenin; Esteban, Mateu; Salas, Ramon (Salas Roig)
Based on field data collected in the northern and southern Falcón Basin (Venezuela), this paper presents a comprehensive monograph that reports on the age and sedimentary evolution of the San Luis and Churuguara formations. It integrates platform-to-basin depositional models through facies distribution and stratal architecture, a palaeogeographic reconstruction, larger foraminifera biostratigraphy, sequence stratigraphy, and the evaluation of the accommodation history. An additional aim is to compare these onshore mixed carbonate-siliciclastic systems with the Oligo-Miocene subsurface carbonate reservoir of Perla in offshore Gulf of Venezuela, considered the largest gas discovery ever in Latin America. The carbonate platforms studied formed as a result of a second-order transgressive event, and corresponded to distally steepened or undifferentiated ramps dominated by coralline algae and larger foraminifera. The presence of Miosorites americanus and Annulosorites spiralis dates the San Luis and Churuguara formations to the Early Miocene. The miogypsinid associations identified further distinguish between the Aquitanian and Burdigalian stages. The San Luis and Churuguara platforms exhibit a general aggradational trend, while the Perla carbonates have been interpreted as a retrogradational unit. Third-order T-R sequences interpreted from these successions were mainly influenced by differential tectonic subsidence. Additionally, major regional regressive events in the Falcón Basin and Perla Field coincide with global glaciations, highlighting the influence of eustatic changes. However, the Perla reservoir exhibits significant differences in thickness, spatial extent and sedimentary architecture compared to the onshore equivalents. The differences arise from variations in tectonic and palaeotopographic settings, accommodation and sedimentation rates and influence of adjacent siliciclastic systems. As a result, predicting the sedimentary architecture of carbonate reservoirs in this region using a generalized depositional model has proven to be challenging.
U-Pb-age from undeformed granite pebbles in Carboniferous Culm conglomerates: new geochronological constrains on the Variscan events in the Pyrenees
(Elsevier B.V., 2025-12-01) Casas Tuset, Josep Maria; González-Esvertit, Eloi; Beranoaguirre, Aratz; Domínguez-Carretero, Diego; Canals i Sabaté, Àngels; Gómez Rivas, Enrique; Margalef, Aina; Figueras Siñol, Francesca; Gerdes, Axel
U-Pb ages of zircon and apatite in undeformed granite pebbles of synorogenic Carboniferous Culm conglomerates confirm the existence of an early Carboniferous (Visean to Bashkirian) magmatic event in the core of the Pyrenees. In this so-called Axial Zone, early Carboniferous magmatism developed in at least two main pulses, at ca. 340 Ma and ca. 320 Ma. Obtained ages constrain a mid-Bashkirian maximum age (ca. 320 Ma) for the base of Bellver Culm conglomerates. Together with the well-expressed late Variscan Moscovian-Asselian (ca. 310 to 295 Ma) granites that crosscut Culm rocks, this Visean to Bashkirian magmatism depicts three pulses of Variscan magmatism, grouped in two cycles of magmatic and tectono-thermal events recorded in the basement rocks of the Pyrenean Axial Zone. This complex Variscan evolution argues against previously proposed models claiming for a synkinematic emplacement of the Moscovian-Asselian granites linked to the main Variscan deformational events. Data obtained confirm the occurrence of Variscan events from the Visean to the Moscovian-Asselian in the Pyrenees. In this way, the Variscan basement rocks of the Pyrenees exhibit an evolution that aligns with that described for the rest of the European Variscan realm.
Variscan suporposition on Ordovician extensional fault-related folds in the Eastern Pyrenees
(Elsevier Ltd., 2026-01-20) Granado, Pablo; Casas Tuset, Josep Maria; Matteis, Marco de; Gratacós Torrà, Òscar
Our study investigates pre-Variscan Ordovician tectonics in the La Molina area (Eastern Pyrenees, Spain) by means of geological mapping and structural analysis of mesostructural data. We revisit the structural interpretation of pre-Upper Ordovician folds, revealing two mutually orthogonal, cleavage-free fold systems (WNW–ESE and NNE–SSW striking) affecting the Late Cambrian to Early Ordovician Serdinya Formation. These folds are interpreted as fault-related folds formed above steeply-dipping extensional faults during Mid Ordovician rifting. The geometry and orientation of Variscan mesostructures are shown to be strongly influenced by these earlier Ordovician folds, explaining the wide dispersion of fold axes and cleavage-bedding intersection lineations only found below the Upper Ordovician unconformity. The Upper Ordovician unconformity seals and locally erodes the limbs of those pre-existing folds. The hectometric to kilometric scale cleavage-free Ordovician folds contrast with the finer smaller-scale Variscan syn-foliar folds, and thus explains the absence of fold interference patterns. This work highlight that collecting and analysing detailed mesostructural data in orogenic hinterlands remains essential for interpreting regional tectonics, and it advances our understanding of the early tectonic evolution of the northern Gondwana margin.
Talanta Nanogram-scale boron isotope analysis through micro-distillation and Nu Plasma 3 MC-ICP-MS
(Elsevier B.V., 2024-03) Rodríguez-Díaz, César Nicolás; Paredes, Eduardo; Pena, Leoploldo David; Cacho Lascorz, Isabel; Pelejero, Carles; Calvo, Elena
The determination of boron isotopes (δ11B) represents a powerful tool for a variety of applications such as the reconstruction of past ocean pH and atmospheric pCO2 from the analysis of marine biogenic carbonates. In recent years, MC-ICP-MS has gained popularity over other techniques thanks to its superior sample throughput and high ionization efficiency. This study evaluates, for the first time, the performance of the Nu Instruments Plasma 3 MC-ICP-MS for measuring δ11B using different sample introduction systems and detector configurations. The main goal is to provide a detailed methodology for nanogram-scale boron isotope analysis through a straightforward approach that can be easily adopted. Boron (B) purification from the carbonate matrix was performed through micro-distillation, using a temperature of 95 °C and a minimum heating duration of 15 h, allowing the full recovery of B from up to 3 mg of carbonate mass. We attained blank values (on average 14 ± 6 pg, 1 SD, n = 27) comparable to the lowest micro-distillation blanks reported in the literature. Three sample introduction systems were tested, and the 30 μL min−1 nebuliser system outperformed the 50 and 170 μL min−1 systems in terms of signal intensity per mass of B. Two detector configurations were used based on the total boron signal intensity achieved: (1) FC11/FC12, with two Faraday cups fitted to 1011 Ω and 1012 Ω amplifier resistors to detect 11B and 10B ion beams, respectively, and (2) FC12/IC, with which we investigated, for the first time, the feasibility of combining an ion counter for detecting 10B, and a Faraday cup fitted to a 1012 Ω amplifier for 11B. The FC12/IC configuration provided accurate results compared to the use of two Faraday cups for total boron signals lower than 0.35 V (∼12 ng of B in the analysed solution). The proposed analytical procedure was validated through the analysis of several reference materials with varying boron amounts, including clam JCt-1, coral JCp-1, NIST RM 8301 Foram and Coral solutions, and boric acid ERM-AE121. Furthermore, the long-term reproducibility was assessed with two in-house standards (coral CLD-1 and foraminifera GINF-1), providing values of 25.68 ± 0.23 ‰ (2SD, n = 53; with 14–36 ng of B) and 14.90 ± 0.16 ‰ (2SD, n = 12; with 11–16 ng of B), respectively.
Calibrating lower‑middle Miocene mammal faunas and unravelling climate change during the Miocene Climate Optimum: the Bardenas Reales de Navarra record (Ebro basin, NE Iberian Peninsula).
(Springer, 2025-06) Larrasoaña, Juan Cruz; Suárez-Hernando, Oier; Beamud Amorós, Elisabet; Garcés Crespo, Miguel; Pérez-Landazábal, José Ignacio; Gómez-Polo, Cristina; Ruiz-Sánchez, Francisco Javier; Mata, Maria Pilar; Murelaga, Xabier
The chronology of lower Miocene Iberian small mammal faunas is still poorly constrained given the scarcity of well dated sedimentary successions including small mammal fossil localities. Such scarcity has prevented also an accurate understanding of the response of European terrestrial ecosystem to global changes across the Miocene climate optimum (MCO), one of the best analogues of present-day global warming. Here we present an updated fossil small mammal record of the Bardenas Reales de Navarra (western Ebro basin, Spain), where an expanded lower to middle Miocene continental succession is superbly exposed. Previous and new magnetostratigraphic results from this succession have enabled us to propose, along with additional magnetostratigraphically-dated Iberian faunas, a new chronology for local zones Y to D (Mammal Neogene zones MN2 to MN5). In addition to that, the studied small mammal faunas point to a gradual increase in temperature and humidity conditions in SW Europe between 20 and 15.5 Ma, which appears to be coupled with the progressive shift towards warmer regional (Atlantic) and global conditions across the MCO, thereby pointing to gradual changes in oceanic circulation as the main driver of this period of global warmth. The evolution of sedimentary facies appears to indicate a threshold response of the Ebro basin hydrological balance to the MCO, whereas pedogenic formation of magnetic minerals seems to be linked to periods of enhanced climate variability. These results highlight the need of combining different paleoenvironmental indicators in order to obtain a reliable view of the response of continental ecosystems to global warming.
Changes in lake sediment carbon accumulation rates in southwestern Canada since the mid-1800s.
(Canadian Science Publishing, 2025-12-04) Rodengen, Thomas J.; Kohfeld, Karen E.; Pellat, Marlow G.; Olid Garcia, Carolina
Carbon (C) storage in lakes is an increasingly recognized component of the global C cycle. Yet, rates of C accumulation in lake sediments remain poorly quantified in some regions such as in Canada. This study assessed C stocks and C accumulation rates (CARs) in sediments from 18 lakes across four provinces and seven national parks in southwestern Canada. We analyzed temporal and spatial variability in CARs and examined their relationship with landscape characteristics (e.g., land use and lake morphology) and climate variables (e.g., temperature and precipitation). Fourteen lakes showed increasing trends in CAR between 1830 and 2009. The average CAR during the modern period (1980–2009) was 42.8 ± 2.6 g/m²/year, representing a 14% increase compared to the historical period (1920–1949). Variability in CARs was primarily explained by temperature-related factors, including mean annual temperature, degree-days under 0 °C, and seasonal temperatures, particularly in spring and summer. Land use also played a significant role as the percentage of catchment area dedicated to agriculture and development was a strong predictor of CAR increases. These findings indicate that rising temperatures and intensified land use are key drivers of enhanced C accumulation in southwestern Canadian lakes, trends likely to continue under ongoing climate change.
Paleoseismology of the Marquesado-La Rinconada thrust system, Eastern Precordillera of Argentina
(Frontiers Media, 2022-12-14) Rockwell, Thomas K.; Costa, Carlos H.; Meigs, Andrew J.; Ragona, Daniel; Owen, Lewis A.; Murari, Madhav Krishna; Masana, Eulàlia; Richard, Andrés D.
Excavated trenches at two sites across the Marquesado–La Rinconada fault system along the eastern Precordilleran front south of San Juan, Argentina, reveal the earthquake history of this rapidly urbanizing region. Interpretation of earthquakes is based on both the generation of colluvial wedges and upward fault terminations, as well as folding events in fine-grained alluvium ponded behind upslope-facing fault scarps. The ages of the past five interpreted earthquakes at the Loma Negra site are E1 at 2.8 ± 2.8 ka, E2 at 7.1 ± 1.5 ka, E3 at 9.6 ± 1.3 ka, E4 at 14.4 ± 2.1 ka, and E5 at 17.2 ± 3.1 ka. At the Jejenes sites, we documented event ages of 2.7 ± 0.1 ka, 3.9 ± 0.6 ka, 5.9 ± 1.3 ka, and 11.4 ± 4 ka. These results indicate that the recurrence interval along the Marquesado–La Rinconada fault zone averages several thousand years. The inferred displacements at the Jejenes site are about 1.1 m for E1, E3, and E4 and 2.1 m for event E2, whereas the displacements at Loma Negra averaged about 1 m, but the most recent event displays less slip. Notably, the older events seem to have been larger and emergent, whereas the youngest event appears to have been smaller and blind in the ponded sediment; this may partially explain the poor expression of classic colluvial wedges associated with some events. Despite the fact that active surface faulting has an uncertain relationship with the primary seismic sources at depth in the crust, past and future events of Mw ∼7.5 are consistent with the length scale of active deformation, the ∼1–2 m slip per event scale of these ruptures, and the size of historical earthquakes.
Proyecto Castor. Relación de la secuencia sísmica con la inyección de gas
(AEPECT, 2014) González, Álvaro
Una secuencia sísmica, que culminó en terremotos de magnitud hasta 4.3 (Cesca et al., 2013; 4.2 según IGN, 2015), se originó en septiembre y octubre de 2013 frente a las costas de Castellón, cerca de donde se estaba inyectando subterráneamente gas natural para almacenarlo en un yacimiento petrolífero agotado (Fig. 1). Los mayores terremotos fueron sentidos en las poblaciones cercanas, lo que causó gran alarma social y mediática, y motivó que en ellas se activasen de manera preventiva los planes especiales de Protección Civil ante el riesgo sísmico. El proyecto de inyección fue detenido por orden gubernamental, y su tramitación administrativa y sus operaciones se están investigando judicialmente.
Exploring the Connection of XVI-Century Major HistoricalEarthquakes in the Eastern Betic Cordillera, Spain: InsightsFrom Viscoelastic Relaxation of the Lithosphere
(Wiley, 2023-10) Yazdi, Pouye; García-Mayordomo, Julián; Álvarez-Gómez, José Antonio; Gaspar-Escribano, Jorge Miguel; Masana, Eulàlia
Understanding the crustal fault interaction and connection between earthquakes in areas with slow tectonic deformation, such as Betic Cordillera (South Spain), is challenging. When seismic rates are low and large destructive earthquakes happen less frequently, it is necessary to resort to historical or paleoseismic records. This study investigates the postseismic viscoelastic relaxation mechanism as a potential explanation for the occurrence of three historical earthquakes (IEMSVIII-IX) in the Eastern Betic Shear Zone during the XVI-century, all of which occurred within a span of 13 years: 1518 Vera Mw6.2, 1522 Alhama de Almeria Mw6.5, and 1531 Baza Mw6.2 associated with the Palomares, Carboneras, and Baza faults, respectively. The results strongly suggest a sequential stress-triggering connection between the three events. The northern NS-oriented section of the Baza fault is found to have experienced a larger positive ΔCFS and, indeed, more prone to rupture in 1531. The study also examines whether the cumulative ΔCFS had influenced the occurrence of further significant earthquakes (≥Mw6.0) in the region. A triggering connection between the cascade and the 1658 Almeria Mw6.2 earthquake is suggested, whereas no indications of similar linkage to the 1674 Lorca Mw6.0 or the 1804 Dalias Mw6.4 events are found. The stress triggering impact of the cascade over nearby active faults is noteworthy. It is expected that this analysis could have future applications for studying other important historical events, and improving seismic hazard analysis in complex fault settings of the Betic Cordillera.
Radon levels in soil and in groundwater in the Alhama de Murcia fault area, Spain
(Elsevier Ltd., 2025) Moreno Aguado, Víctor; Bach, Joan; Zarroca, Mario; Masana, Eulàlia; Font, Lluís; Linares, Rogelio
Radon and CO₂ in groundwater, radon and thoron in soil, soil radon exhalation rates, and 14 electrical resistivity imaging were measured in the Alhama de Murcia Fault area. The study 15 aims to (i) characterize radon levels in groundwater and soil and (ii) assess whether variations 16 in gas emissions are related to the presence of an active fault. Forty water sampling points 17 exhibited ²²²Rn concentrations ranging from 0.4 to 66.8 Bq L⁻¹, while 22 soil points along two 18 profiles crossing the fault showed low annual mean values of (8 ± 1) kBq m⁻³ and (12 ± 2) 19 kBq m⁻³. Soil radon exhalation rates at the two profiles, (36 ± 8) and (53 ± 12) Bq m⁻² h⁻¹, 20 respectively, are consistent with these concentrations. Spatial variability of soil radon along 21 both profiles, [1–22] kBq m⁻³, appears associated with the main fault location. Temporal 22 variations of ²²²Rn recorded at a monitoring station from early 2013 to mid-2015 closely match 23 punctual measurements. While fluctuations are largely controlled by barometric pressure and 24 atmospheric temperature, detailed analyses combining multiple radon anomaly detection 25 methods indicate a possible influence of nearby seismic events.
Improved Geological Slip Rate Estimations in the Complex Alhama de Murcia Fault Zone (SE Iberia) and Its Implications for Fault Behavior
(Wiley, 2022-12-01) Gómez-Novell, O.; Ortuño Candela, María; García-Mayordomo, J.; Insua-Arévalo, J.M.; Rockwell, Thomas K.; Baize, S.; Martínez-Díaz, J.J.; Pallàs, R.; Masana, Eulàlia
Fault slip rate is one of the most crucial parameters to characterize earthquake occurrence in fault-based seismic hazard assessments (SHA). Accordingly, paleoseismic studies have increasingly focused on constraining this parameter in active faults worldwide. We present a comprehensive paleoseismic study in the Alhama de Murcia Fault (AMF), one of the most active faults in SE Spain and source of destructing earthquakes such as the 2011 Mw 5.2 Lorca event. Contrasting with previous studies, we integrate paleoseismic data from four fault strands in the AMF and, based on trench slip analysis and numerical dates, we derive slip rate estimates of each strand over the whole transect and assess their time variability. The AMF has a minimum net slip rate between 1.35+0.16/−0.10 and 1.64+0.16/−0.11 mm/yr for the past 18 ± 1 to 15.2 ± 1.1 ka. These results prove the importance of accounting for the complete sections of a geological structure as they are almost twice the previous estimates for a single fault branch. Slip rate variability is identified in the AMF, with cyclic acceleration-quiescence patterns that could be related to stress field changes driven by fault interaction or synchronicity with neighboring faults (e.g., Carrascoy). We hope that the data presented here motivates their inclusion into forthcoming fault-based SHAs. In this regard, limitations related to the lack of paleoseismic data for one fault strand, along with poor characterization of the strike component of slip and insufficient age control of the units for another strand are highlighted and need to be accounted for by modelers.
The 2013 September-October seismic sequence offshore Spain: A case of seismicity triggered by gas injection?
(Royal Astronomical Society, 2014-08) Cesca, Simone; Grigoli, Francesco; Heimann, Sebastian; González, Álvaro; Buforn, Elisa; Maghsoudi, Samira; Blanch, Eestefania; Dahm, Torsten
A spatially localized seismic sequence originated few tens of kilometres offshore the Mediterranean coast of Spain, close to the Ebro river delta, starting on 2013 September 5, and lasting at least until 2013 October. The sequence culminated in a maximal moment magnitude M_w 4.3 earthquake, on 2013 October 1. The most relevant seismogenic feature in the area is the Fosa de Amposta fault system, which includes different strands mapped at different distances to the coast, with a general NE–SW orientation, roughly parallel to the coastline. However, no significant known historical seismicity has involved this fault system in the past. The epicentral region is also located near the offshore platform of the Castor project, where gas is conducted through a pipeline from mainland and where it was recently injected in a depleted oil reservoir, at about 2 km depth. We analyse the temporal evolution of the seismic sequence and use full waveform techniques to derive absolute and relative locations, estimate depths and focal mechanisms for the largest events in the sequence (with magnitude mbLg larger than 3), and compare them to a previous event (2012 April 8, mbLg 3.3) taking place in the same region prior to the gas injection. Moment tensor inversion results show that the overall seismicity in this sequence is characterized by oblique mechanisms with a normal fault component, with a 30° low-dip angle plane oriented NNE–SSW and a subvertical plane oriented NW–SE. The combined analysis of hypocentral location and focal mechanisms could indicate that the seismic sequence corresponds to rupture processes along shallow low-dip surfaces, which could have been triggered by the gas injection in the reservoir, and excludes the activation of the Amposta fault, as its known orientation is inconsistent with focal mechanism results. An alternative scenario includes the iterated triggering of a system of steep faults oriented NW–SE, which were identified by prior marine seismics investigations.
Drawing as a tool for representing and explaining complex structures in Foraminifera
(Elsevier Masson SAS, 2025-12-29) Lería, María; Ferràndez i Cañadell, Carles
This work considers the relevance of drawing in foraminiferal micropaleontology and how drawing has helped to understand and explain the complex architecture of foraminiferal tests. We present a brief anthology of those works on foraminifera in which drawing plays a significant role. The objective is to detect milestones in the illustration of foraminifera throughout history and to explore a trajectory in the evolution of the drawing techniques and concepts applied. Drawing is influenced by technological advances, the artist’s skills, and the aesthetic influences of the moment. We conclude that drawing, a crucial aspect in this scientific discipline, facilitates the understanding and explanation of complex forms. The literature on foraminifera is replete with small gems of drawing art, sometimes created by artists, but other times by the same micropaleontologists who studied fossil material and described the species. This work highlights some of these drawings to analyse their creation process and to show their great artistic value.
Best-practice stochastic facies modelling from a channel fill turbidite sandstone analog (the 'Quarry outcrop', Eocene Ainsa Basin, NE Spain)
(American Association of Petroleum Geologists, 2006-07-01) Falivene Aldea, Oriol; Arbués, Pau; Gardiner, Andy; Pickup, Gillian; Muñoz, J. A.; Cabrera, Lluís
Using data from an outcrop characterization of a sandstone-rich turbidite channel fill (the so-called ‘‘Quarry outcrop’’ in the Ainsa basin), several stochastic facies models were constructed at bedscale resolution (cells 2.5 m [8 ft] wide and 0.05 m [2 in.] thick).
Several industry-standard reservoir-modeling algorithms were employed: truncated Gaussian simulation, sequential indicator simulation, multiple-point geostatistics, and object-based methods with varying degrees of complexity.
The degree of similarity (i.e., realism) between realizations and the outcrop characterization was quantified through the use of several responses: (1) static connectivity, (2) effective permeability, and (3) recovery efficiency from waterflood simulations.
Differences in the responses measured from the outcrop and facies models were observed: these are mostly algorithm related, instead of caused by soft data or different stochastic realizations. Differences increase greatly when the permeability of the heterolithic
packages and mudstone beds (Ht-M) decreases and reflect the methods’ ability to model the inclined and undulating Ht-M packages and beds that occur in the outcrop. These packages and beds can drape scours and sandstone beds with depositional topography
and pinch-outs, producing sandstone thinning and dead ends.
Object-based methods capable of introducing highly undulating Ht-M beds provided the most realistic models. Variogram-based and simple object-based methods failed to capture and reproduce the whole length of undulating beds.
Multiple-point geostatistics provided realizations with responses intermediate between variogram-based and simple object-based methods and the more successful advanced object-based methods. The conditioning-to-harddata capabilities of multiple-point geostatistics are higher than those of the object-based methods, which give them an added advantage.
Three-dimensional reconstruction of geological surfaces: An example of growth strata and turbidite systems from the Ainsa basin (Pyrenees, Spain)
(American Association of Petroleum Geologists, 2004-08-01) Fernández, Òsca; Muñoz, J. A.; Arbués, Pau; Falivene Aldea, Oriol; Marzo, M.
The external and internal geometry of four turbidite systems outcropping around the Buil syncline (Ainsa basin, Spanish Pyrenees) have been reconstructed with reservoir-scale resolution in three dimensions. The irregular geometry of the syncline and the resolution required for the reconstruction cannot be resolved with cross-sections. Therefore reconstruction has been carried out with a new methodology that applies a 3-D dip-domain geometrical model and 3-D restoration techniques to achieve reservoir-scale resolution in kilometric-scale reconstructions. This methodology is aimed at resolving 3-D geometries in folded areas, and regions with variable thickness stratigraphy.
The 3-D reconstruction of the Buil syncline reveals the synsedimentary growth of an intrabasinal anticline and the foreland lithospheric flexure associated to tectonic loading north of the Ainsa basin.
A FORTRAN program to introduce field-measured sedimentary logs into reservoir modelling packages
(Elsevier Ltd., 2006-11-01) Falivene Aldea, Oriol; Arbués, Pau; Howell, J.; Fernández, Òscar; Cabello López, Patricia; Muñoz, J. A.; Cabrera, Lluís
Building reservoir-scale facies models of outcrops is a practice that improves the three-dimensional geological modelling of subsurface analogues. Facies modelling of outcrops can be achieved either with geostatistical or object-based methods, which in most cases require conditioning to field-measured sedimentary logs. DEVLOGS assists in producing input files from field-measured sedimentary logs to be loaded into standard reservoir modelling packages. This is achieved by using a number of georeferenced nodes along the sedimentary log trace, and placing the intermediate bed boundaries according to true thickness recorded in the sedimentary log. Moreover a number of operations to enable the correct loading of the sedimentary logs are also performed. The main benefit of DEVLOGS is to facilitate the loading of non-vertical logs, by using non-vertical logs, the conditioning of outcrop models it is not limited to favourable outcropping settings such as very step exposures or non-dipping strata.

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