Assumed Holocene highstands, Gulf of Mexico: Basic issues of sedimentary and landform criteria - Discussion

Record high mid and late Holocene relative sea levels, significantly above the current sea level have been widely documented in certain areas of the Australo-Pacific region, Brazil (Lessa et, al. 2000), and parts of Africa and India that were not characterized by tectonic uplift and/or glacioisostatic rebound. Such elevated sea levels are yet to be reliably identified on our Gulf and Atlantic shores. Radically departing from traditional Gulf of Mexico sea-level curves, Morton et al. (2000) now suggest recurring highstands throughout the entire second half of the Holocene Epoch. Their findings echo earlier ideas in the same vein (see Otvos 1995, 1997, 1999). However, a detailed analysis of several lines of evidence presented by Morton et al. raises serious doubts about these conclusions.