A path of contention
Submerged in just 5.5 meters (18 feet) of water off the coast of North Bimini, a series of large, flat stones form a linear feature nearly 0.8 kilometers (0.5 miles) long. Discovered on September 2, 1968, by divers Joseph Valentine, Jacques Mayol, and Robert Angove, this formation, known as the Bimini Road, immediately sparked a debate about its origin. The structure is composed of roughly rectangular and polygonal limestone blocks, some measuring up to 4 meters (13 feet) in length. These stones are arranged in a northeast-southwest line that ends in a distinct hook, resembling a massive, submerged J.
The primary scientific explanation identifies the Bimini Road as a natural formation of beachrock. Beachrock is a type of sedimentary rock that forms in the intertidal zone when sand, shell fragments, and other carbonate grains are cemented together. Geologists, including Eugene Shinn of the U.S. Geological Survey, argue that a large, solid sheet of beachrock fractured over time due to a process called tensional jointing. This natural cracking can produce remarkably straight and angular blocks that resemble cut masonry. The rounded edges of the stones are consistent with millennia of erosion from biological and physical processes in the shallow marine environment. Similar natural beachrock "pavements" exist in other locations around the world, including the Dry Tortugas and near Tasmania.
Dating the stones
Attempts to date the Bimini Road have yielded complex and controversial results. Radiocarbon dating performed in the 1970s on the shells within the rock and the carbonate cement binding them provided a range of ages. The shells themselves dated to around 3,500 years old, while the cement that formed the rock is younger, approximately 2,800 years old. This indicates the beachrock solidified around 800 BCE, a date consistent with its formation being exposed by coastal erosion about 2,000 years ago.
This timeline challenges for the most popular alternative theory: that the road is part of the lost city of Atlantis. That idea gained traction partly due to a 1938 prediction by American psychic Edgar Cayce, who stated that evidence of Atlantis would be found near Bimini in 1968 or 1969. The road's discovery in that exact timeframe fueled speculation. However, Plato's account describes Atlantis sinking around 9,600 BCE, thousands of years before the Bimini Road's rocks even formed. An earlier uranium-thorium date of about 15,000 years old was obtained from the limestone bedrock underneath the road, but scientists have largely dismissed this result as invalid. At the time indicated by that date, sea levels were so low that the sample location would have been nearly 95 meters (312 feet) above the ocean, making the formation of a marine limestone impossible.