The southernmost evidence for an interglacial transgression (Sangamon?) in South America. First record of upraised Pleistocene marine deposits in Isla Navarino (Beagle Channel, Southern Chile)


  • J. RABASSA Centro Austral de Investigaciones Científicas, CADIC, CONICET and Universidad Nacional de la Patagonia San Juan Bosco C.C. 92, 9410 Ushuaia, Tierra del Fuego, Argentina.
  • S. GORDILLO Centro de Investigaciones Paleobiológicas (CIPAL), Universidad Nacional de Córdoba and CONICETAv. Vélez Sársfield 299, 5000 Córdoba, Argentina.
  • C. OCAMPO Ciprés Consultores Ltda. and Fundación Wulaia Sioux 2075, Vitacura, Santiago, Chile.
  • P. RIVAS HURTADO Ciprés Consultores Ltda. and Fundación Wulaia Sioux 2075, Vitacura, Santiago, Chile.


Interglacial, Marine beach shell deposits, Mollusks, Tierra del Fuego, Southernmost South America


Marine beach shell deposits recording a pre-Holocene marine transgression have been found at the southern shore of the Beagle Channel, Isla Navarino, Chile. These shelly deposits were dated by AMS at 41,700 14C years B.P., which clearly indicates a Pleistocene age. A sample of wood underlying the marine deposits yielded an infinite age (gt;46.1 14C ka B.P.). If the date on the shells is considered as a minimum, infinite age, together with the elevation of these marine units above present mean tide sea level (at least 10 m a.s.l.) they may be considered as deposited during the Last Interglacial, of Sangamon age (Marine Isotope Stage -MIS- 5e) or during a younger phase of MIS 5. The fossil content of this unit is similar to the fauna living in this region today, supporting also an Interglacial palaeoenvironment interpretation. If this interpretation and the dating proposal are correct, this is the first reported record of Sangamon deposits in the Beagle Channel and the southernmost Last Interglacial site (MIS 5) in South America.