New minimum age of the postglacial transgression in Potter Cove, 25 de Mayo (King George Island)
Since Sugden and John’s (1973) research on the glacier fluctuations in the South Shetland Islands, it is generally accepted that the first Holocene marine transgression that reached the inner fiords of this archipelago occurred at least by 9540 +/- 235 cal yrs BP. This age is very important, since it provides the minimum on land obtained age of the end of the last glacial period and start of the Holocene in this Antarctic sector. Watcham et al. (2011) reconstructed a relative sea level curve for the South Shetland Islands with a sea level rise of 15 m above mean sea level (amsl) for Fildes Peninsula by 9000 cal yrs BP and a drop after 7000 cal yrs BP because the rate of glacial unloading and isostatic rebound exceeded the rate of eustatic sea level rise. According to our new ages obtained from Potter Peninsula, the Holocene postglacial marine transgression of the southern Potter Cove section initiated before 7650 cal yrs BP, reaching about 12 m amsl, and was locally interrupted by a glacier advance after about 7285 yrs BP. Sugden, D. and John, B., 1973. The age of glacier fluctuations in the South Shetland Islands, Antarctica. In: van Zinderen Bakker, E.M. (Ed.), Palaeoecology of Africa, the Surrounding Islands, and Antarctica. A.A. Balkema, 139-159 p., Cape Town. Watcham, E. P., Bentley, M. J., Hodgson, D. A., Roberts, S. J., Fretwell, P. T., Lloyd, J. M., Larter, R. D., Whitehouse, P. L., Leng, M. J., Monien, P. and Moreton, S. G., 2011. A new Holocene relative sea level curve for the South Shetland Islands, Antarctica. Quaternary Science Reviews 30, 3152–3170.