uncorrected for temporal and environmental variations in radiocarbon, about 3,500 years old. Because of time-averaging and other taphonomic factors, a random collection of shells likely would yield a radiocarbon date that is a few hundred years earlier than when the final accumulation of shells, which were cemented to form beachrock, actually occurred. The radiocarbon dates from the cement demonstrate that the beachrock composing the Bimini Road formed about 2,800 radiocarbon years ago by the cementation of pre-existing sediments that accumulated about 1,300 years earlier. Compared to the dates from the shells and the cement, it appears that the whole-rock dates reflect samples containing varying proportions of shell and cement without any significant contamination by younger radiocarbon. Both these dates and interpretation are consistent with the detailed research by Davaud and Strasser that concluded that the layer of beachrock composing the Bimini Road formed beneath the surface of North Bimini Island and was exposed by coastal erosion only about 1,900 to 2,000 years ago. Proponents of the Bimini Road being a manmade feature argue that these radiocarbon dates are invalid because they were obtained entirely from whole-rock samples and subject to contamination from younger carbon. The background data reported by Calvert and others concerning the radiocarbon dates from the Bimini Road demonstrate that not all of these dates come entirely from whole-rock samples. That the dates from the shells and the clearly younger cement holding them together as beachrock are temporally consistent argues against any significant alteration of their radiocarbon content. In addition, other studies using radiocarbon dating to study sea level and the age of sediment and beachrock within the Bahamas have not reported any significant problems with contamination by younger radiocarbon. In their detailed research, Davaud and Strasser accepted the radiocarbon dates obtained from the beachrock composing the Bimini Road from the radiocarbon laboratory at the University of Miami as valid indicators of its age. Gifford and Ball attempted to establish a minimum age using uranium-thorium dating for the Bimini Road by dating a whole-rock sample of the marine limestone (biopelsparite) that underlies the beachrock that composes the Bimini Road. They described this sample as being "Whole rock marine limestone under beachrock off Paradise Point, North Bimini; some recrystallisation." This sample yielded a uranium-thorium date of 14,992±258 BP (7132-19/2). Supporters of the idea that the Bimini Road is a man-made structure frequently cite this date in support of its