Pre-Holocene raised beaches at Cape Ross, Southern Victoria Land, Antarctica

Raised marine beach deposits along the coast of the Ross Embayment are important for relative sea-level reconstructions and for determining the timing of deglaciation following the last glacial maximum (LGM). Flights of beaches from McMurdo Sound to Terra Nova Bay long have been thought to be of Holocene age. However, new data from Cape Ross indicate that pre-Holocene beach material is common and may be predominant at elevations greater than 23 m above mean sea level. This discovery leads to unanswered questions regarding the full spatial extent of pre-Holocene beaches in the Antarctic and other formerly glaciated areas. More important, it indicates that undated raised beaches cannot be assumed to result from isostatic uplift following the LGM and should not be used for relative sea-level reconstructions.