A submerged ancient bridge discovered deep within Genovesa Cave on Mallorca, a Spanish island, is offering new insights into early human settlement in the western Mediterranean.
According to a recent study published in Communications Earth & Environment, this discovery suggests that humans may have settled on Mallorca much earlier than previously thought.
The bridge, constructed from large limestone blocks - some spanning up to 4.2 feet - was likely built around 6,000 years ago, based on the analysis of mineral formations and a distinctive "bathtub ring" found on the structure. The findings could help narrow the timeline of human colonization between the eastern and western Mediterranean regions, where the lack of written records and limited archaeological evidence has long made it challenging to pinpoint the exact period of settlement.
Lead study author Bogdan Onac, a professor at the University of South Florida's School of Geosciences, highlighted that the bridge's construction indicates a high level of sophistication among early settlers. "The presence of this submerged bridge, along with other artifacts, suggests that early humans not only recognized the cave's water resources but also strategically built infrastructure to access different parts of it," said Onac.
The bridge was initially discovered in 2000, and a subsequent study suggested it was around 3,500 years old, based on pottery found in one of the cave's chambers.
However, more recent research including radiocarbon dating of bones and pottery from Mallorca indicated a possible human presence on the island as far back as 9,000 years ago. The latest study, which also examined ash, bones, charcoal, and sea-level changes across other islands, has now provided a more refined estimate.
Researchers focused on a light-colored band on the submerged bridge and calcite encrustations that formed when sea levels were higher, filling the cave. They determined that the bridge was likely constructed around 6,000 years ago, before sea levels rose to cover it about 400 to 500 years later.
While the exact purpose of the bridge remains unclear, the study offers a new perspective on the early human use of the cave.