Boletín de la Sociedad Geológica Mexicana Volumen 74, núm. 2, A240622, 2022 http://dx.doi.org/10.18268/BSGM2022v74n2a240622

Paleoambientes y colmatación de la albufera antropogénica rioplatense Reserva Ecológica Ciudad Universitaria — Costanera Norte (Buenos Aires, Argentina)

Paleoenvironments and clogging of the River Plate anthropogenic lagoon Ecological Reserve Ciudad Universitaria - Costanera Norte (Buenos Aires, Argentina)

Agustín Quesada^{1,2, *}, Horacio Sirolli^3,4,5, Rodrigo S. Martín^1,6, Victoria Keitelman¹

¹ Departamento de Ciencias Geológicas, Facultad de Ciencias Exactas y Naturales (FCEN), Universidad de Buenos Aires. Intendente Güiraldes 2160,1428, Buenos Aires, Argentina.

² Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires, Universidad de Buenos Aires - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET).

³ Departamento de Ecología, Genética y Evolución, FCEN, Universidad de Buenos Aires.

⁴ Instituto de Ecología, Genética y Evolución de Buenos Aires, UBA-CONICET.

⁵ Sector Conservación y Monitoreo, Reserva Ecológica Costanera Sur, Secretaría de Ambiente, Gobierno de la Ciudad Autónoma de Buenos Aires.

⁶ Instituto de Estudios Andinos Don Pablo Groeber, UBA-CONICET.

* Autor de correspondencia: (A. Quesada) This email address is being protected from spambots. You need JavaScript enabled to view it.

Cómo citar este artículo:

Quesada, A., Sirolli, H., Martín, R.S., Keitelman, V., 2022, Paleoambientes y colmatación de la albufera antropogénica rioplatense Reserva Ecológica Ciudad Universitaria — Costanera Norte (Buenos Aires, Argentina): Boletín de la Sociedad Geológica Mexicana, 74 (2), A240622. http://dx.doi.org/10.18268/BSGM2022v74n2a240622

Manuscrito recibido: 17 de Marzo de 2022; Manuscrito corregido: 25 de Mayo de 2022; Manuscrito aceptado: 31 de Mayo de 2022.

ABSTRACT

Sedimentation in the estuarine plain of the River Plate modifies the landscape of the nature reserves of the Ciudad Autónoma de Buenos Aires. These reserves were generated by the artificial construction of embankments that polderized sectors of the coast and gave rise to wetland ecosystems. This contribution aims to study the paleoenvironments and vertical accretion rates of the Reserva Ecológica Ciudad Universitaria - Costanera Norte, a small anthropogenic lagoon built in the 1970s. For this purpose, two cores were extracted: one at the mouth of the lagoon and the other in its interior. Granulometry, moisture, organic matter, micropaleobiological and artifact contents were analyzed in each core. The obtained record was divided into two stratigraphic units. At the base, a massive sand unit that belongs to the estuarine plain that precedes the artificial polderization, and, in the upper part, a muddy unit with the presence of plastic and lithic artifacts, accumulated after polderization. The sedimentation rate obtained at the mouth of the lagoon was 1.2 cm of vertical accretion per year, while in the interior the accumulation was 0.7 cm per year. The micropaleobiological analysis allowed us to interpret that the sedimentation in the interior of the lagoon was gradual and with a trend towards eutrophication of the water column. Management of these protected coastal wetland ecosystems must consider the rapid sedimentation of the lagoon and the replacement of frequently flooded low marsh environments with rarely flooded high marshes dominated by rooted wetland plants.

Keywords: polder, estuary, aggradation rates, siltation.