Holocene foraminifera of the southeast of the Pampa coastal plain, Argentina

Abstract

Holocene paleoenvironmental changes have been interpreted on the basis of benthic foraminifera recovered from a core north of the Mar Chiquita coastal lagoon, southeast of the Pampa coastal plain, Argentina. A total of 68 taxa were recorded. The most representative species were Buccella peruviana, Ammonia parkinsoniana, Ammonia tepida, Elphidium discoidale, and Elphidium margaritaceum. The results, lead to the identification of three different paleoenvironments throughout the Ruta 11 (R11) core. The lower part of the sedimentary succession represents a mixture water environment, marginal marine to estuarine. The middle part represents a brackish but more restricted paleoenvironment than in the previous part, and the upper part represents the establishment of a shallow lagoon environment. From the analysis of the foraminifera and the correlation with other two holocene sedimentary sections in the region, the more gradual environmental changes were observed in the R11 core. This could be due to a combination of factors, such as the distance between each sedimentary succession and the coastline, the geological and geomorphological processes that delimited each environment, among others.