Morphosedimentary models of urban drainages in the coast of Vicente López applied to environmental management

Silvia Cristina Marcomini, Adonis Giorgi, Paula Bunicontro, Ana Torremorell, Rubén López
2 025
REVISTA DE LA ASOCIACIÓN GEOLÓGICA ARGENTINA, Vol. 82 No. 3 (2025)
Coastal systems are highly dynamic, and when modified by human activities, their behavior becomes difficult to predict. Morphodynamics and ecology are closely interconnected; therefore, effective management requires a comprehensive understanding of both aspects. This study analyzes the geomorphology and sedimentary dynamics of the fluvial channels formed by the progradation of the Vicente López coast in the late 1990s. The results show that the sediments in these channels are mostly muddy sands with a high organic matter content and display sedimentary grading toward the mouth (estuary). Water quality varies seasonally: during summer, anoxic conditions, low oxygen levels, and high concentrations of nitrates and ammonium are recorded, whereas aerobic environments prevail during the rest of the year. During the extreme drought of 2023, no cyanobacterial blooms were observed; however, high levels of ammonium, biochemical oxygen demand (BOD), and chemical oxygen demand (COD) were detected, possibly linked to treated wastewater discharges. This study provides insights to support environmental management and promote the sustainable development of the Vicente López coastal corridor. The findings highlight the need to: (a) reduce effluent discharge into the channels, particularly during summer; (b) preserve riparian forests and stream systems that have developed over the past two decades; (c) regulate fishing activities at stream mouths; (d) implement management policies grounded in the geomorphological and ecological functions of the streams; (e) prevent disturbance of bottom sediments; and (f) enhance public awareness of the ecological value of urban green spaces and their associated ecosystems.
Pub-Marcomini-Morphosedimentary models of urban
https://revista.geologica.org.ar/raga/article/view/1815

Integrated Geophysical, Isotopic, and Hydrochemical Approach to Studying Freshwater–Saline Water Interaction in Coastal Wetland at Punta Rasa Nature Reserve, Argentina

Eleonora Carol, María Julieta Galliari, Santiago Perdomo, Romina Sanci and Rosario Acosta
2 025
Journal of Marine Science and Engineering, Volume 13 Issue 12
The interaction between freshwater and saline water in coastal wetlands generates an interface zone where vertical and horizontal salinity gradients develop. This interface has been investigated through geophysical, hydrochemical, and isotopic studies, which constitute useful tools that provide different types of information whose combined interpretation allows for a more comprehensive understanding of the processes associated with this interaction. This work assessed, through an integrated geophysical (electrical resistivity tomography), hydrochemical (major ions), and isotopic (δ2H, δ18O, and 222Rn) study, the freshwater–saline water interaction between marsh and dune environments in the Punta Rasa Natural Reserve (Argentina). Results show that salinity gradients occurring between dune and marsh environments are associated with fresh groundwater discharge and rainwater infiltration. Fresh groundwater discharge takes place in topographically elevated dunes, where freshwater lenses form. This discharge generates vertical and horizontal salinity gradients because the hydraulic gradient causes the interface to migrate with the groundwater flow. In low-relief dunes, lenses do not develop and the salinity gradient that develops within the interface due to rainwater infiltration is vertical. The findings clarify plant zonation linked to freshwater–saline water interfaces and provide environmental data to assess wetland resilience to climate-driven changes.
Pub-Sanci-Integrated Geophysical
https://www.mdpi.com/2077-1312/13/12/2362

The first record of Tuarangisaurus (Sauropterygia, Plesiosauria) from the Maastrichtian of the Lefipán Formation, Chubut, Argentina

José P. O’Gorman, Roberto A. Scasso, and Francisco A. Medina
2 026
Palaeontologia Electronica, 29(2):a29.
Elasmosaurids represent the most diverse clade of plesiosaurians during the Campanian-Maastrichtian. We report a new specimen with a well-preserved cranium and postcranium from the Maastrichtian levels of the Lefipán Formation, Chubut Province, Argentina, referred to Tuarangisaurus keyesi. This species was previously known only from Campanian-Maastrichtian deposits of New Zealand. Phylogenetic analysis recovers Tuarangisaurus keyesi as the basalmost member of Weddellonectia. The hyoid apparatus is preserved and consists of a single ossified element identified as ceratobranchial I, comparable to the condition observed in other plesiosaurians. The morphology of this element is consistent with a ram-feeding strategy.
Pub-Scasso-The First of Tuarangisaurus-600pxh
https://palaeo-electronica.org/content/2020/5903-first-record-of-tuarangisaurus…

Structural Andean evolution of the western border of the central Fiambalá basin, Catamarca province, Argentina

Ernesto O. Cristallini, Agostina D'Ascenzo, Renata N. Tomezzoli, Melina E. Gugliotta, Nicolás Braun
2 026
Journal of South American Earth Sciences Volume 170, 1 February 2026
Aquí se presenta una interpretación de las principales estructuras geológicas cenozoicas aflorantes en la cuenca de Fiambalá, también conocida como Bolsón de Fiambalá provincia de Catamarca, Argentina. La compresión andina deformó las secuencias sedimentarias neógenas formando una serie de corrimientos dispuestos en sentido ∼ N-S con vergencia hacia el este. A partir de la información relevada en el campo, integrada con estudios geológicos previos e imágenes satelitales, se elaboró una sección estructural balanceada con el fin de caracterizar la deformación del área y se realizó una reconstrucción palinspástica a partir del cual se calculó un acortamiento total de 6.13 km, equivalente al 18 % para la región.
We present an interpretation of the main Cenozoic geological structures outcropping in the Fiambalá Basin, also known as Bolsón de Fiambalá, Catamarca Province, Argentina. Andean compression deformed the Neogene sedimentary sequences, forming a series of thrusts arranged in a north-south direction with eastward convergence. Based on own field collected data, combined with previous geological studies and satellite images, a balanced structural section was constructed to characterize the deformation of the area. A palinspastic reconstruction was performed, from which a total shortening of 6.13 km was calculated, equivalent to an 18%, for the studied region.
Pub-Tomezzoli-Structural Andean evolution
https://www.sciencedirect.com/science/article/abs/pii/S0895981125005632

Premio - Dr. Vilas

El Dr. Juan Francisco Vilas, Profesor Emérito de la UBA e Investigador Superior ad-honorem del IGeBA, ha sido distinguido con el Premio Strobel 2026 por la Universidad de Buenos Aires.

 

Finco

 

El Dr. Juan Francisco Antonio Vilas, Profesor Emérito de la UBA e Investigador Superior ad-honorem del IGeBA, ha sido distinguido con el Premio Strobel 2026 por la Universidad de Buenos Aires, por sus extraordinarias cualidades intelectuales, sus importantes y pioneros aportes al desarrollo de la Geofísica y el Paleomagnetismo y su continua dedicación a la comunidad de las Ciencias de la Tierra.

El Dr. Juan Francisco “Finco” Vilas, Licenciado y Doctor en Física por la UBA ha sido pionero de los estudios paleomagnéticos, las reconstrucciones paleogeográficas y la tectónica de placas en la Argentina. Fue co-fundador, en 1964, junto al Ing. Daniel A. Valencio, del primer laboratorio de Paleomagnetismo de América Latina y promotor de la disciplina y de la creación de nuevos laboratorios en toda la región.

Desarrolló toda su carrera en la Universidad de Buenos Aires, donde alcanzó el cargo de Profesor Titular Plenario y a su jubilación el de Profesor Emérito. Ha sido miembro del CONICET por varias décadas donde llegó a Investigador Superior.

Ha destinado la mayor parte de su vida profesional a la aplicación de métodos geofísicos a la solución de problemas geológicos. Ha investigado en el campo del paleomagnetismo aplicado a las reconstrucciones paleogeográficas y tectónicas; la magnetoestratigrafía de cuencas continentales; las propiedades magnéticas de sedimentos de lagos, suelos y paleosuelos; el geomagnetismo y el magnetismo ambiental, así como a los relevamientos geofísicos (magnetometría, sísmica) tanto en tierra como en lagos y el mar.

Ha sido director de numerosas tesis doctorales, de tesis de licenciatura, de becarios e investigadores del CONICET y de la UBA.

Se desempeñó como Consultor Científico del CONICET, UBA, CONEAU, CIN, YPF, Obras Sanitarias de la Nación, CONEA, HIDRONOR e IBM.

Director de múltiples proyectos de investigación en geofísica, geodinámica y paleomagnetismo. Logró la instalación en la UBA del primer magnetómetro criogénico de América Latina.

Ha tenido una importante actuación en organismos internacionales, siendo vicepresidente de la Asociación Internacional de Geomagnetismo y Aeronomía (IAGA) por dos períodos y Miembro del Comité de Finanzas de la Unión Internacional de Geodesia y Geofísica (IUGG).

Consejero Superior de la UBA, Consejero Directivo de la FCEN y miembro del CODEP del Departamento de Cs. Geológicas, en varias oportunidades.

Autor de numerosos trabajos de investigación publicados en revistas de reconocido prestigio internacional como: Nature, Geophysical Journal International, Earth Planet Sc. Lett., Phys. Earth Planet Int., Tectonics, y otras.

Participó en la organización y/o presentación de trabajos en más de 80 congresos nacionales e internacionales.

¡El IGeBA felicita al Dr. Vilas por tan distinguido premio!

 

Solar Flare Activity, 1937–2024: Introducing the New Hemispheric Solar Flare Index (hSFI) in the Context of 2024's Major Solar Storm Events

V. M. Velasco Herrera, W. Soon, S. Knoška, A. Özgüç, G. Velasco Herrera, H. Yeşilyaprak, N. Babynets, M. Švanda, J. Muraközy, S. Qiu, D. Riveros-Rosas, R. Connolly, M. Connolly, A. Tlatov, L. Cappellotto
2 025
Space Weather, Volume23, Issue11 November 2025
A new daily composite of the solar flare index (SFI) and the hemispherically-resolved versions (hSFI) are presented for 1937 to 2024. The data set confirms that the northern hemisphere (NH) dominated solar flare activity during Solar Cycles 17 to 21, but that the southern hemisphere has dominated from Solar Cycle 22 to present. That said, the highest SFI value occurred in the NH during the recent superstorm of May 2024. In sunspot activity, the “Gnevyshev-Ohl rule” shows that the sum of sunspot numbers during even-numbered cycles is related to those of adjacent odd-numbered cycles. A similar rule appears to apply to SFI. The “Gnevyshev gap” phenomenon where solar maximum activity sometimes has two peaks separated by up to 1–2 years of a gap is confirmed for SFI. Although our data set represents the longest continuous daily data set for solar flare activity to-date, it is known that stronger solar flare events occurred before 1937. Therefore, a brief discussion of earlier solar flare events in the historical record is also provided for context. The statistics of the SFI and hSFI series are compared to other solar and geomagnetic activity indices, including the May and October 2024 solar storms. Statistical analysis of past geomagnetic storms confirms they are more frequent during active cycles and less frequent during solar minima. Strong geomagnetic storms are also more likely to occur during the positive phase of a 1.7 year's quasi-biennial oscillation in solar activity. The likelihood of low-magnetic latitude aurorae seems to have a 30 year periodicity component.
Pub-Cappellotto-Solar flare activity
https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2025SW004515

A New Tectonic Model for the Contact Relationships of Mesozoic and Cenozoic Domains in the Principal Cordillera, Central Chile (33°–34°S)

T. Piñeiro, A. Encinas, D. Orts, N. Henríquez, W. Stinnesbeck, D. Kietzmann, P. Rossel, E. Núñez, V. A. Valencia
2 025
Tectonics, Volume44, Issue11 November 2025
The origin of the contact between Cenozoic rocks of the Western Principal Cordillera (WPC) and Mesozoic rocks of the Eastern Principal Cordillera (EPC) in the Chilean Andes at 33°–34°S has been debated for several years. Most authors interpret this boundary as a regional-scale inverted fault that, during the early Miocene, thrust strata of the extensional Eocene-early Miocene Abanico Basin from the WPC over Mesozoic rocks of the EPC. To better constrain the nature of this boundary and determine the tectonostratigraphic evolution of this area of the Andes, we integrate new stratigraphic, structural, and geochronologic data. Our results indicate that faults previously interpreted as the boundary between the WPC and the EPC are, in fact, depositional contacts. The only fault we observed at the contact between these domains is the east-verging, generally overturned Las Arenas Fault that thrusts Mesozoic rocks over Cenozoic strata. Consequently, the boundary between the WPC and the EPC does not correspond to an inverted normal fault along the eastern margin of the Abanico Basin. Our structural analysis also suggests that Andean deformation initially propagated eastward during the early-middle Miocene and subsequently shifted westward in the middle-late Miocene, re-deforming both Mesozoic and Cenozoic rocks previously affected by east-verging structures. We also highlight previously undocumented synorogenic deposits younger than 13.6 Ma, along with new geochronologic constraints for the basal Abanico Formation (∼21–18 Ma), which are younger than reported in earlier studies.
Pub-Kietzmann-A new Tectonic Model
https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2025TC008998

Integrante

Foto-Emilio Aliaga-400pxh
Emilio César
Aliaga
Lic. en Ciencias Geológicas
Becario
Geofísica
Aportar nuevos conocimientos sobre la geomorfología, dinámica sedimentaria y edificación cenozoica del sector septentrional del Margen Continental Patagónico, a partir de la integración de datos batimétricos, sísmicos y sedimentológicos.
aliaga.emi@gmail.com

Integrante

Foto Emilse Filgueira-400pxh
Emilse Abril
Filgueira
Licenciada en Ciencias Geológicas
Becaria doctoral
Ayudante de Segunda
Sedimentología
Caracterización estratigráfica, composicional y diagenética de la Formación Tambería (Catamarca), enfocada en sus implicancias para las etapas iniciales del antepaís andino.
emi.filguer@gmail.com

Nombramineto - Dr. Rapalini

El Dr. Augusto Rapalini, Investigador Superior ad-honorem del IGeBA, ha sido nombrado Profesor Emérito de la Universidad de Buenos Aires.

 

Aug foto

 

Felicitamos al Dr. Augusto Rapalini, Investigador Superior ad-honorem del IGeBA, por haber sido nombrado Profesor Emérito de la Universidad de Buenos Aires. 

Un reconocimiento más que merecido a toda una vida dedicada a la docencia en Ciencias Geológicas, formando generaciones de profesionales.

¡El IGeBA felicita al Dr. Rapalini por este nombramiento! 

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