The Bimini Road, sometimes called the Bimini Wall, is an underwater rock formation near the island of North Bimini in the Bimini chain of islands. The Road consists of a -long northeast-southwest linear feature composed of roughly rectangular limestone blocks. Various claims have been made for this feature being either a wall, road, pier, breakwater, or other man-made structure. However, credible evidence or arguments are lacking for such an origin.
Physical characteristics On September 2, 1968, while diving in 5.5 meters (18 feet) of water off the northwest coast of North Bimini, Joseph Manson Valentine, Jacques Mayol and Robert Angove encountered what they called a "pavement" of what later was found to be noticeably rounded stones of varying size and thickness.Valentine, J. M., 1969, Archaeological enigmas of Florida and the Western Bahamas. Muse News (Miami Museum of Science). v. 1, pp. 26-29,41-47 (1969, June).Valentine, J. M., 1973, Culture pattern seen. Muse News (Miami Museum of Science). v. 4, pp. 314-315, 331-334 (April 1973) These stones form a northeast-southwest linear feature, which is now commonly known as either the "Bimini Road" or "Bimini Wall". Two similar linear features lie parallel to and shoreward of the Bimini Wall.Valentine, J.M., 1976, Underwater Archeology in the Bahamas. Explorers Journal. v. 54, no. 4, pp. 176-183.Gifford, J.A., and M.M. Ball, 1980, Investigation of submerged beachrock deposits off Bimini. National Geographic Society Research Reports. v. 12, pp. 21–38.
The Bimini Wall and two linear features lying shoreward of it are composed of flat-lying, tabular, and roughly rectangular, polygonal, and irregular blocks. Descriptions of the Bimini Road found in various books and articles greatly exaggerate the regularity and rectangularity of the blocks composing these features.McKusick, M., 1979, The Bimini underwater discoveries. Explorer Journal. v. 58, no. 1, pp. 40-43. The Bimini Road, the largest of three linear features, is long, a northeast/southwest-trending feature with a pronounced hook at its southwest end. It consists of stone blocks measuring as much as in horizontal dimensions, with the average size being . The larger blocks show complementary edges, which are lacking in the smaller blocks. The two narrower and shorter, approximately -long linear features lying shoreward of the Bimini Road consist of smaller tabular stone blocks that are only in maximum horizontal breadth. Having rounded corners, the blocks composing these pavements resemble giant loaves of bread. The blocks consist of limestone composed of carbonate-cemented shell hash that is called "beachrock". Beachrock is native to the Bahamas. The highly rounded nature of the blocks forming the Bimini Road indicates that a significant thickness of their original surface has been removed by biological, physical, and chemical processes. Given the degree to which these blocks have been eroded, it is highly implausible that any original surface features, including any tool marks and inscriptions, would have survived this degree of erosion.Shinn, E. A., 2009, The mystique of beachrock. in Perspectives in Carbonate Geology: A Tribute to the Career of Robert Nathan Ginsburg, P. K. Swart, G. Eberli, and J. A. McKenzie, eds., pp. 19-28. International Association of Sedimentologists Special Publication no. 41.
After a very detailed examination of the Bimini Road and the other linear features, Gifford and Ball made the following observations:
As noted below, these observations are disputed by other investigators. For example, some investigators claim that where sand had washed away between the seams, another course of blocks can be seen along with small blocks underlying these blocks. However, detailed evidence that clearly documents the alleged presence of a continuous second layer (course) of stones beneath the stones forming the currently exposed "pavement" has not been published in a reputable, scientific venue with the detail that is needed for critical evaluation. Pictures posted on various Web pages of stones alleged to be artificial "wedge stones" and "prop stones" fail as convincing evidence for a second course of stones because they are typically smaller in size, do not form a continuous course, and too infrequently lie directly beneath the blocks that form the surface of the Bimini Road. This is not what would be expected of an actual underlying course of man-made masonry.
David ZinkZink, David, 1978, The Stones of Atlantis. Prentice Hall Trade. states:
This led him to conclude:
In addition, early studies of the Bimini Road, i.e. Gifford and Ball and David Zink, report taking numerous samples and cores for examination. It is also safe to presume that a certain number of the innumerable visitors to the Bimini Road have chipped off pieces of it. Scientific sampling and souvenir hunting would have left behind modern "tool marks" on the various blocks composing the Bimini Road for later investigators to find.
Age Attempts have been made to determine the age of this feature using different techniques. These include direct radiocarbon dating of the stones composing the Bimini Road and uranium-thorium dating of the marine limestone on which the Bimini Road lies.
In 1978, the radiocarbon laboratory operated by the Department of Geology at the University of Miami dated samples from a core collected by E. A. Shinn in 1977 from the Bimini Road. In 1979, Calvert and othersCalvert, P.M., D.S. Introne, J.J. Stipp, 1979, University of Miami radiocarbon dates XIV. Radiocarbon. v. 21, no. 1, pp. 107-112. reported dates of 2780±70 yr BP (UM-1359),(UM-XXXX) refers to University of Miami radiocarbon sample no. XXXX. See Calvert et al. (1979) for the details about specific sample 3500±80 yr BP (UM-1360), and 3350±90 yr BP (UM-1361) from whole-rock samples; a date of 3510±70 yr BP (UM-1362), from shells extracted from the beachrock core; and dates of 2770±80 yr BP (UM-1364) and 2840±70 yr BP (UM-1365) from carbonate cementing the beachrock core. These dates are temporally consistent in that the shells composing the beachrock core from the Bimini Road dated older than the cement holding them together as beachrock. These dates can be interpreted as indicating that the shells composing the Bimini Road are, 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.Kidwell, S.M., M.M.R. Best, and D.S. Kaufman, 2005, Taphonomic trade-offs in tropical marine death assemblages: Differential time averaging, shell loss, and probable bias in siliciclastic vs. carbonate facies. Geology. September 2005; v. 33; no. 9; p. 729-732. 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 StrasserDavaud, E., and A. Strasser, 1984, Progradation, cimentation, érosion: évolution sédimentaire et diagénétique récente d'un littoral carbonate (Bimini, Bahamas). (Translated title: Progradation, Cementation, Erosion; Recent Diagenetic and Sedimentary Evolution in a Carbonate Coastal Environment, Bimini, Bahamas.) Eclogae Geologicae Helvetiae. v. 77, no.3, p. 449-468.Strasser, A., and E. Davaud, 1986, Formation of Holocene limestone sequences by progradation, cementation, and erosion; two examples from the Bahamas. Journal of Sedimentary Research. v. 56, no. 3, pp. 422-428. that concluded that the layer of beachrock composing the Bimini Road formed beneath the surface of the 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.Bourrouilh-Le Jan, F.G., 2007, Very high energy sedimentation (supratidal hurricane deposits) and Mid-Holocene highstand on carbonate platforms, Andros, Bahamas: An alternative view. Sedimentary Geology. vol. 199, no. 1-2, pp. 29-49. 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)A biopelsparite is a limestone with a ratio of fossils and fossil fragments to pellets between 3:1 and 1:3 and lacking a mud matrix. If it consists largely of fossils and fossil fragments and lacks a mud matrix, a limestone is called a "biosparite". 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). SupportersLittle, G., 2004, More Adventures With Bimini Beachrock: Remarkable Blunders in a Purported Scholarly Report Debunking the Bimini Stones. Alternative Perceptions Magazine. no. 86 (December 2004) of the idea that the Bimini Road is a man-made structure frequently cite this date in support of its being artificial.