"It never ceases to amaze me when I stand there with a newly uncovered stone tool thinking that the last time someone touched this was perhaps hundreds of thousands of years ago," says DTU Senior Researcher Jan-Pieter Buylaert as his face lights up in a broad smile.
In his hand is a crude tool, a so-called lithic. The untrained eye could easily mistake it for just a small rock. But to people with knowledge of early stone tool making, the way bits of the stone have been deliberately removed by hitting it with another stone reveals that it is in fact a man-made instrument.
Jan-Pieter Buylaert is standing in the lush green hills of the Khovaling region of Tajikistan in Central Asia where—for the past four years—a group of international scientists have battled on despite the disruption of a global pandemic and a war in the region to establish when humans first arrived in this area.
"We are using different methods to help understand where we have come from as a species and what the climate conditions were like for the first people to populate this part of the planet," Jan-Pieter Buylaert says of the rationale behind the interdisciplinary, NordForsk-funded THOCA-project that he heads.
Here, a three-hour drive from the capital Dushanbe in the mountainous country, the researchers have carved out three excavation trenches in outcrops that have evolved over hundreds of thousands of years to become more than 100 metres tall.
The outcrops are made up of layers of loess—a light-coloured, fine-grained dust that blows in constantly, but especially during colder, drier periods. Between them are layers of darker soils that have formed in the loess under warmer, moister conditions.
