Marine archaeologists and geochemists have identified a previously unknown maritime trade route that linked the coastal peoples of the Gulf of California with the early civilizations of the Central Andes nearly 4,000 years ago. By analyzing the chemical signature of obsidian blades found in Peruvian coastal sites, researchers matched the volcanic glass to quarries located in modern-day Sonora, Mexico. This discovery suggests that prehistoric seafaring capabilities in the Eastern Pacific were far more advanced than previously assumed.
The study, published in the Journal of Archaeological Science, indicates that turquoise from the American Southwest was likely exchanged for spondylus shells and early metalwork from the South American coast. This 'Blue-Green Trail' utilized seasonal currents and coastal waystations, allowing for the transmission of not only luxury goods but also shared architectural motifs and agricultural techniques between the two distant regions.