Geomorphological evolution of a lagoon–barrier system during the Late Quaternary on the eastern coast of Uruguay: a regional comparison with southern Brazil
González Carreira, L.; Weschenfelder, J.; Inda, H.; Barboza-Pinzon, E.G.; del Puerto, L.; Burone, L.; Perez, L.; Scarabino, F.; Coimbra, J.C.; Blanco, G.; Bueno, C.; García-Rodríguez, F. (2025). Geomorphological evolution of a lagoon–barrier system during the Late Quaternary on the eastern coast of Uruguay: a regional comparison with southern Brazil. J. South Am. Earth Sci. 163: 105604. https://dx.doi.org/10.1016/j.jsames.2025.105604
In: Journal of South American Earth Sciences. Elsevier: Oxford; New York; . ISSN 0895-9811; e-ISSN 1873-0647, more
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| Authors | | Top |
- González Carreira, L.
- Weschenfelder, J.
- Inda, H.
- Barboza-Pinzon, E.G.
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- del Puerto, L.
- Burone, L.
- Perez, L.
- Scarabino, F.
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- Coimbra, J.C.
- Blanco, G.
- Bueno, C.
- García-Rodríguez, F.
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| Abstract |
Geomorphological features of the Castillos Lagoon were defined by integrating sedimentary sequences from a borehole, exposed sedimentary profiles, radiocarbon dating, grain-size analysis, geochemistry, paleontological data, and GPR surveys. Five lithofacies (LF) were identified in a borehole at Barra de Valizas. LFI and LFII corresponded to Pleistocene marine deposits of the Chuy Formation, with low Fe/Ca, Ti/Al, and Ti ratios, indicating a weak relationship with a continental environment. LFI represents shallow marine deposits, while LFII suggests an estuarine environment based on paleoproxy records. LFIII exhibited fine sand deposits without fossil records and low Al/Si and Fe/K ratios. LFIV, characterized by higher Fe/Ca and Ti/Al ratios, indicates continental conditions associated with the Dolores Formation. LFV corresponds to sandy mud soil. These lithofacies reflect sedimentary processes driven by sea-level variations during the Quaternary. Sedimentary profiles showed a predominance of silty sandy clay fractions and Holocene fossil records. GPR profiles revealed Holocene deposits associated with Barrier IV, underlain by Pleistocene sediments. This study recorded the southernmost geomorphological expression of the Barrier-Lagoon systems III and IV in Castillos Lagoon, presenting a novel geomorphological map. This interpretation is key to understanding the regional coastal evolution of the Uruguayan-Riograndense shield and provides important insights for the management of transitional environments. |
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