A joint expedition of Bahraini and Indian underwater archaeologists has identified a sunken cargo off the coast of the Dilmun civilization (modern-day Bahrain) that confirms a robust 'Bitumen and Basalt' trade route. The 4,000-year-old wreckage contained large quantities of refined bitumen blocks and basalt grinding stones, both of which have been geochemically linked to sources in the Indus Valley and the Zagros Mountains.
This discovery provides the first physical evidence of how these civilizations exchanged industrial materials used for waterproofing ships and processing grain. Researchers noted that the presence of Indus-style seals within the cargo suggest that merchants from the Harappan civilization may have maintained permanent trade outposts in Dilmun, facilitating the flow of goods across the Arabian Sea during the Bronze Age.