Russian Geographers Solve the Secrets of the Tajik Loesses

Работа на обнажении Оби-Мазар - Лахути. Фото: Реджеп Курбанов

A rich material was collected during field work in 2021 in Khovaling District of Tajikistan by an international expedition studying the history of changes in nature and climate, as well as the migration of ancient people to the territory of Central Asia. Experts from the Faculty of Geography of Moscow State University and the Institute of Geography of the Russian Academy of Sciences are taking part in the study.

Central Asia is a key way of human expansion to the Asian continent. Several migration waves can be distinguished by the characteristic change in the types of stone tools. Such artifacts are often found in loess layers –sedimentary deposits that are widespread in the region and especially in the Afghan-Tajik Depression. Here, their thickness sometimes reaches tens of meters. Loess strata are a kind of chronicle of past eras.

In warmer and wetter periods, the content of organic matter in the loess layers increased due to active soil formation processes. These periods are expressed in sections in the form of darker stripes against the background of a beige mass. Numerous stone tools are found in ancient soils, the number of which in a full profile can reach 120. Based on the study of such artifacts, the prominent Soviet archaeologist Vadim Ranov formulated the concept of the "loessian Paleolithic of Tajikistan". However, many aspects of the existence of ancient people in Central Asia still remain a mystery.

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Общий вид протяженного обнажения правого борта реки Оби-Мазар. Фото: Реджеп Курбанов

The project "The timing and ecology of the human occupation of Central Asia" (THOCA) involves large-scale studies of Tajik loess-soil series. It affects both the earliest periods of human settlement in Central Asia (more than one million years ago) and the mysterious episodes of the penetration of Homo sapiens into the region in the late Pleistocene. Together, scientists from Denmark, Norway, Sweden, Russia and Tajikistan are trying to understand the number of migrations of different types of people, whether the settling took place only under a favorable climate during the warm interglacial periods, and how the climate influenced the number of people, the type of their tools and way of life.

During the field work of 2021, two reference sections were studied. One of them is Kuldara, which reveals 14 complexes of buried soils over one million years old. The second is Obi-Mazar, which is a wall of a large young landslide with a height of more than 150 m with a thick layer of loesses and soils passing into the sediments of ancient rivers. Seven complexes have been uncovered here. For both sections, the scientists performed paleogeographic works describing the sediments. Selected samples will be sent for detailed analysis.

The archaeological line of research was devoted to the study of horizons, which contain evidence of the existence of ancient people in the region, and the determination of the age of the earliest of them. Five excavations were conducted in the Kuldar section, which confirms the settlement of humans in Central Asia about 0.8-1.1 million years ago. They managed to collect a number of artifacts and a few individual tools.

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Общий вид разреза Кульдара с расположением геологических траншей и археологических раскопов. Фото: Реджеп Курбанов

In the outcrop of the right side of the Obi-Mazar river valley, an area of ​​concentration of artifacts was found. An excavation with an area of ​​about five square meters yielded extremely rich material – a collection of 642 Early Paleolithic tools and materials for their manufacture. The investigated site, located between the two famous Paleolithic monuments Obi-Mazar and Lakhuti, exposed the culture-bearing horizon with the highest concentration of artifacts for the entire loessian Paleolithic of Tajikistan.

The expedition led by a senior researcher at the Research Laboratory of Recent Deposits and Pleistocene Paleogeography, Rejep Kurbanov, brought together specialists from the Faculty of Geography of Lomonosov Moscow State University, the Institute of Geography of the Russian Academy of Sciences, the Institute of History, Archeology and Ethnography of the Academy of Sciences of Tajikistan, Schmidt Institute of Physics of the Earth of the Russian Academy of Sciences, and the Institute of Archeology and Ethnography of the Siberian Branch of the Russian Academy of Sciences.