Resumo

MEDINA, Rubén A et al. Geoformas, malacofauna y evolución costera durante el holoceno en Ensenada Ferrer (Santa cruz, Patagonia, Argentina). Rev. Asoc. Geol. Argent. [online]. 2014, vol.71, n.1, pp.69-81. ISSN 0004-4822.

In this paper we attempt an interpretation of the geomorphological evolution since the Mid-Holocene of the coastal area of Ensenada Ferrer, located in the northeastern coastal area of Santa Cruz province, Argentina. The chronostratigraphical method was applied to distinguish between different beach ridges, discriminating between two beach ridge systems including one and two groups, respectively, supported by the molluscan content and palaeoenvironmental conditions. These systems are separated by a truncation surface and an associated slope of ca. 1.5 to 3 m. In turn, they are separated from innermost older (Late Pleistocene?) systems by another truncation surface and associated slope of ca. 4 to 6 m. These discontinuities are suggested to have been formed between ca. 6000 and 1000 years B. P. Regarding the beach ridge systems identified a three phases evolutionary pattern is proposed, from an open-sea bay environment (Phase 1) to a semiprotected bay (Phase 2) and finally reaching a high grade of protection as evidenced by the genesis of the modern and partially raised tidal flat (Phase 3).

Palavras-chave : Sea level; Palaeoenvironments; Holocene; Santa Cruz; Patagonia.

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