Paleogeography

Abstract

In this chapter, we reconstruct the paleogeographic evolution of the Isla de los Estados for the period spanning the Last Glacial Maximum (LGM, ca. 24 cal. ka B.P.) to the present using the global sea-level rise curve proposed by Fleming et al. (1998) for this period and the Global Mapper 10 program. During the LMG, the Isla de los Estados was connected to the rest of the continent as the Isla Grande de Tierra del Fuego similarly did so. The northern coastline of the present Isla de los Estados, during this time, was found at around 100 km away from a straight line of its current position. The paleogeographic model has allowed to estimate the time of the opening of the Le Maire Strait, with the subsequent separation of Isla de los Estados and Isla Grande de Tierra del Fuego. This event would have taken place approximately at around 15 cal. ka B.P., when sea level rose above −85 m. Around 11,000 cal. years B.P., the small group of the Año Nuevo islands began to separate from the rest of Isla de los Estados, thus forming the archipelago with a configuration similar to the current arrangement.