Estudio paleoecológico de Foraminíferos de testigos del Holoceno de Golfo Nuevo (Patagonia, Argentina)

Abstract

A micropaleontological study (Order Foraminiferida) was conducted on two Holocene cores from Golfo Nuevo (Patagonia, Argentina). The most abundant species are Buccella peruviana f. campsi (Boltovskoy) and Bulimina patagonica (d’Orbigny), suggesting an inner-shelf environment. Qualitative and quantitative analyses indicate the paleoecological and paleoenvironmental variations along cores. A transition from normal marine conditions of the inner shelf during the Middle Holocene ( ca. 8160–7700 years B.P.) to marginal marine conditions in the Late Holocene ( ca. 1890 years B.P.) is inferred. This transition was accompanied by lower oxygen levels than the current values in Golfo Nuevo. These variations may have been due to an increase in precipitation near the study zone and a rise in sea level caused by an improvement in the climatic conditions related to the Climate Optimum ( ca. 7000 years B.P.). These new conditions of higher temperature and lower salinity of the surface waters may have hindered deep-water renewal, producing a change in the circulation dynamics of the gulf and causing a reducing environment.