The South Turkmenistan Complex Archaeological Expedition (STACE), also called the South Turkmenistan Archaeological Inter-disciplinary Expedition of the Academy of Sciences of the Turkmen Soviet Socialist Republic (YuTAKE) was endorsed by the Turkmenistan Academy of Sciences. It was initially organized by the orientalist Mikhail Evgenievich Masson in 1946. The expedition had several excavations or "Brigades", based on sites and periods, and were spread over many years.
The Chalcolithic settlements of southern Turkmenistan, according to Masson, date to the late 5th millennium – early 3rd millennium BC, as assessed by carbon dating and paleomagnetic studies of the findings from the excavations carried out by STACE in the Altyndepe and Tekkendepe. The foothills of the Kopetdag mountains have revealed the earliest village cultures of Central Asia in the areas of Namazga-Tepe (more than 50 ha) and Altyndepe (26 ha), Ulug Depe (20 ha), Kara Depe (15 ha), and Geok-Syur (12 ha). In 1952, Boris Kuftin, established the basic Chalcolithics to Late Bronze Age sequence based on the excavations carried out at Namazga-Tepe (termed Namazga (NMG) I-VI).
However, the Chalcolithic period ended about 2700 BC due to natural factors of ecology, with the Geok-Syur oasis becoming desertified. This resulted in the migration of people to the ancient delta of the Tedzhen River. This also led to the Early Bronze Age Settlements at Khapuz-depe.