The Bimini Road, also known as the Bimini Wall, is an underwater rock formation located near the island of North Bimini in the Bimini chain of islands. The road is 0.8 km (0.50 mi) long and runs in a straight line from northeast to southwest. It is made up of roughly rectangular limestone blocks. Some people have suggested that this structure might be a wall, road, pier, breakwater, or another man-made object. However, there is no strong proof or good reasons to believe it was created by humans.
Physical characteristics
On September 2, 1968, while diving in 5.5 meters (18 feet) of water near the northwest coast of North Bimini, Joseph Manson Valentine, Jacques Mayol, and Robert Angove discovered a flat surface made of rounded stones of different sizes and thicknesses. These stones form a straight line running from northeast to southwest, now called the "Bimini Road" or "Bimini Wall." Two similar, parallel lines lie closer to the shore than the Bimini Wall.
The Bimini Wall and the two nearby lines are made of flat, rectangular, and irregular stone blocks. Some books and articles overstate how regular and rectangular the blocks are. The Bimini Road, the longest of the three lines, is 0.8 km (0.50 mi) long and has a curved end pointing southwest. It includes large stone blocks up to 3–4 meters (10–13 feet) in size, with most blocks averaging 2–3 meters (7–10 feet). Larger blocks have edges that fit together, while smaller blocks do not. The two shorter lines, about 50 and 60 meters (160 and 200 feet) long, are made of smaller, rounded stone blocks that look like large loaves of bread. These blocks are made of a type of limestone called "beachrock," which is found in the Bahamas. The smooth, rounded shape of the blocks shows that much of their original surface has been worn away by natural processes like erosion. Because of this, it is unlikely that any original carvings or tool marks could still be seen.
After examining the Bimini Road and other lines, scientists J.A. Gifford and M.M. Ball made the following observations:
— J.A. Gifford and M.M. Ball, 1980
Other researchers disagree with some of these findings. Some claim that when sand is removed between the stones, another layer of blocks can be seen beneath the surface. However, no clear scientific evidence has been published to prove that a second layer of stones exists beneath the Bimini Road. Pictures of stones online, such as "wedge stones" or "prop stones," are not convincing because these stones are small, not arranged in a continuous layer, and rarely lie directly under the surface blocks. This is not what would be expected if a second layer of man-made masonry existed.
Most of the blocks now rest directly on the bedrock or on smaller stones on the sea floor. This led to the conclusion that the idea—held by some researchers—that the visible blocks are only the top of a larger structure is likely incorrect.
Early studies of the Bimini Road, including those by Gifford, Ball, and David Zink, collected many stone samples for analysis. It is also likely that visitors to the site have broken off pieces of the stones over time. These actions, along with scientific sampling, may have left modern "tool marks" on the blocks that could be mistaken for ancient markings by later researchers.
Age
Scientists have used different methods to find out how old the Bimini Road is. These methods include testing the stones of the Bimini Road with radiocarbon dating and testing the marine limestone beneath it with uranium-thorium dating.
In 1978, a radiocarbon dating lab at the University of Miami studied samples collected from the Bimini Road in 1977 by E. A. Shinn. In 1979, Calvert and others reported several dates: 2,780 years before present (±70 years), 3,500 years before present (±80 years), and 3,350 years before present (±90 years) from whole-rock samples. Dates from shells in the beachrock core were 3,510 years before present (±70 years), and dates from the cement holding the shells together were 2,770 years before present (±80 years) and 2,840 years before present (±70 years). These dates show that the shells in the beachrock are older than the cement that binds them, which suggests the shells are about 3,500 years old. However, because of natural processes that mix materials over time, the actual age of the beachrock might be a few hundred years newer than the radiocarbon dates suggest. The dates from the cement show that the beachrock formed about 2,800 years ago, after earlier sediments that had built up around 1,300 years earlier. Whole-rock samples gave dates that appear to mix shells and cement without major contamination from younger carbon. These findings match research by Davaud and Strasser, who said the beachrock layer formed below the island’s surface and became exposed by erosion about 1,900 to 2,000 years ago.
Some people who think the Bimini Road is manmade argue that the radiocarbon dates are unreliable because they were taken from whole-rock samples that might have been contaminated by younger carbon. However, Calvert and others showed that not all the dates came from whole-rock samples. The consistency between shell and cement dates suggests their radiocarbon content was not significantly altered. Other studies in the Bahamas using radiocarbon dating have not found major contamination issues. Davaud and Strasser confirmed the University of Miami’s radiocarbon dates as valid for the Bimini Road’s age.
Gifford and Ball tried to find the Bimini Road’s minimum age using uranium-thorium dating on marine limestone beneath the beachrock. They tested a sample described as "whole rock marine limestone under beachrock off Paradise Point, North Bimini; some recrystallisation." This sample gave a uranium-thorium date of 14,992 years before present (±258 years). Supporters of the manmade theory often use this date to argue the road is artificial.
However, this uranium-thorium date is considered invalid for two reasons. First, the limestone had recrystallized, meaning it was not a closed system needed for accurate dating. This makes the date unscientific. Today, scientists prefer to date corals and mollusks that show no recrystallization using petrographic and X-ray methods. Any limestone with even slight recrystallization is not used for dating. Second, sea level 15,000 years ago was about 95 to 100 meters below today’s level. The sample collected by Gifford and Ball was at least 90 to 95 meters above sea level at the time of the uranium-thorium date, meaning the marine limestone could not have formed then. Therefore, the date is meaningless. Scientists rarely mention this date because it has no scientific value. The marine limestone beneath the Bimini Road is from the Sangamonian Stage, a time when sea levels were high enough for marine sediments to form the limestone now found there.
Geological formation
Geologists and archaeologists agree that the Bimini Road is a natural feature made of beachrock that has been broken into roughly rectangular, polygonal, and irregular blocks by cracks in the rock. Scientists who have studied the Bimini Road include Eugene Shinn from the U.S. Geological Survey, Marshall McKusick, an anthropology professor at the University of Iowa, W. Harrison from Environmental Research Associates in Virginia, Mahlon M. Ball and John A. Gifford from the University of Miami, and Eric Davaud and A. Strasser from the University of Geneva in Switzerland. After examining the Bimini Road, these scientists all concluded that it is made of naturally formed beachrock. John A. Gifford, a professional geologist, studied the area for his University of Miami master’s thesis about the geology of the Bimini Islands. Calvert and others identified samples from the Bimini Wall as natural beachrock.
Detailed studies by E. Davaud and A. Strasser on Holocene limestones in North Bimini and Joulter Cays (Bahamas) explain how beachrock pavements like the Bimini Road form. First, layers of shallow water, tidal, and land-based carbonate sediments built up as the shoreline of North Bimini moved outward during the Holocene. Later, freshwater cemented these sediments at a depth below sea level, creating a thick layer of partially hardened sediments and thinner layers beneath it. When erosion removed the shoreline, the hardened sediments were exposed and turned into beachrock. As erosion continued and reached older Pleistocene limestone beneath the island, the beachrock broke into flat, tabular, and irregular blocks. Thinner layers of beachrock below the main layer also broke apart as loose sediments were removed. These blocks then sank several meters until they rested on the hard Pleistocene limestone, forming an erosional lag. Eugene Shinn described a similar process that could explain the Bimini Road’s formation.
The movement of large, solid objects by erosion and settling has been observed by researchers like Jesse E. McNinch and John T. Wells. They found that heavy objects can sink several meters into the seafloor without moving sideways if they encounter a hard layer of sediment. For the beachrock blocks of the Bimini Road, the hard layer that stopped them from sinking further is the Pleistocene limestone they now rest on.
Smaller beachrock fragments from thinner layers beneath the main layer would become trapped under the larger blocks as erosion removed loose sediments. These trapped fragments, along with the blocks, would form the so-called "prop" and "wedge" rocks, which some people mistakenly believe are part of a "second course" of man-made masonry. If the beachrock blocks of the Bimini Road originally formed below sea level and sank several meters, dating the road based on past sea levels would give incorrect results.
Natural stone pavements made of rectangular and uniform blocks, formed by cracks in sedimentary rocks like beachrock, are common worldwide. Examples include the Tessellated Pavement of Eaglehawk Neck in Tasmania, jointed bedrock in Oklahoma that was wrongly called a "Phoenician Fortress," a "tiled pavement" in Colorado, the Bouddi Peninsula in Australia, and Arches National Park in Utah. Beachrock pavements identical to the Bimini Road have been found eroding from the east shore of Loggerhead Key in the Dry Tortugas and buried under 90 meters (300 feet) of water at Pulley Ridge off Florida’s southwest coast.
Claims of a human origin
The Bimini Road is a natural geological feature, but its unusual shape and arrangement of stones have led some people to suggest it might be the remains of an ancient road, wall, or other human-made structure. For example, an article in Argosy, an American men's adventure magazine, written by Robert F. Marx, a professional diver who visited the Bimini Road, claimed the structure is artificial. In a 1971 article, Marx wrote that Carl H. Holm, who was the president of Global Oceanic (not a geologist, as Marx incorrectly stated), said there was "little doubt" the large stone blocks were shaped by people. The article also mentioned that Holm was part of an expedition organized by North American Rockwell, which included Edgar Mitchell, an astronaut, as leader, Dimitri Rebikoff, and several people from the Edgar Cayce Foundation who study psychic abilities.
Other people who believe the Bimini Road is man-made, not natural beachrock, include Joseph Manson Valentine, a zoologist; Graham Hancock, a writer who is not a scientist; Charles Berlitz, a linguist; Greg Little, a psychologist; R. Cedric Leonard, an anthropologist; and Dimitri Rebikoff, a French marine engineer. These individuals claim they have studied the formation and observed more than one layer of blocks in some areas. However, natural processes can create layers of rock when sedimentary rock breaks systematically, as seen in the tessellated pavement of Tasmania at Eaglehawk Neck.
In his book 1421: The Year China Discovered America, which has been proven incorrect, amateur historian Gavin Menzies claimed that Chinese admiral Zheng He's fleet visited Bimini between 1421 and 1423. Menzies wrote that half of the fleet, led by admiral Zhou Wen, was caught in a storm near Bimini and built the Bimini Road using beachrock and ship ballast as a ramp to repair damaged ships. There is no evidence to support these claims.