Archaeologists at the University of Cambridge have successfully applied a refined Argon-38 isotopic dating methodology to soil samples from ancient agricultural sites in the North Cachar Hills of Northeast India. The results, published in Archaeometry Today, push back the established timeline for the emergence of sophisticated step-terrace farming in the region to approximately 5200 BCE, nearly a millennium earlier than previously estimated.
The methodology focuses on the isotopic signature of trapped noble gases within silicate minerals disturbed by early tillage. This precision dating confirms that the indigenous Neolithic communities of the Assam highlands had mastered high-altitude water management and soil retention techniques long before the expansion of lowland riverine cultures. The study also identifies a correlation between this agricultural peak and a stabilized humid period in the early Holocene monsoon cycle.