HOLOCENE DEPOSITS ON THE COAST OF NORTH-CENTRAL CHILE - RADIOCARBON AGES AND IMPLICATIONS FOR COASTAL CHANGES

Eight radiocarbon-dated shell samples collected from the emerged marin e deposits on Bahia Herradura near Coquimbo and Bahia Tongoy areas, no rth-central Chile, provide new constraints on the rate of coastal chan ge during the Holocene. The Holocene transgression culminated ca. 6,00 0 yr B.P. based on a shell age from estuarine deposits in Estero Tongo y. In Bahia Tongoy, the spatial separation of parallel beach ridges of ca. 910 yr B.P. and ca. 2,300-2,400 yr B.P. suggests a progradation r ate of ca. 0.14 m/yr. Assuming a constant progradation rate, the oldes t Holocene beach ridge is ca. 5,400 yr B.P. The Holocene uplift is ver y small, probably 2-3 m in most cases, and 4-5 m in the most rapidly u plifting area (Altos de Talinay). The low Holocene uplift rates are si milar to the ones obtained from the elevation above present sea level of the last interglacial terrace in this region.