A revolutionary dating technique utilizing Silicon-30 isotopes has provided the most precise timeline yet for the origins of step-terrace agriculture in the Eastern Himalayan foothills. The study, published in Earth and Planetary Science Letters, applied this new methodology to phytoliths—microscopic silica structures from ancient plants—found within sediment layers in Arunachal Pradesh.
The results push back the evidence for organized hillside farming to approximately 7500 BCE, nearly two millennia earlier than previously estimated. This new dating suggests that Neolithic communities in the region were pioneering soil-stabilization and irrigation techniques much sooner than the broader transition to cereal-based diets in the Gangetic plains. The Silicon-30 method is expected to become the new gold standard for dating organic remains in high-acidity tropical soils.