The Myasnikov district (Rostov region), at the margin of Nedvigovka farm.
The city of Tanais was founded in the first half of the 3rd century BC by “the Greeks who held the Bosporus” on the right bank of the Tanais (Don) River near its influx into Lake Maeotis (the presentday Sea of Azov). It is positioned near the edge of the erosional 2nd terrace of the Mortvyy Donets River (the northernmost arm of the Don River) (Fig. 1). The base of the terrace is composed of Miocene limestone, their base occurring almost horizontally or slightly tilted southward. The Tanais constructions are found either within the Quaternary mantle, or directly on the solid rocks. The parent rocks for soils in the Tanais vicinities are brownish-yellow loesslike loam and clays of the Quaternary period. The groundwater table is at a depth of more than 18 m, and has no perceptible effect on the soil formation (Bezuglova et al., 2008). The modern climate of the Azov region is classified as temperate continental, with signs of aridity. The winter is mild, lacking a persistent snow cover, mean January temperatures being −2 to −5°С. The spring is cool, the summer and autumn are very warm and dry, the sky is mostly clear. The growing season lasts more than 150 days, the mean daily temperature exceeds +15 °C, though in the daytime the air may be heated up to +23–+40 °C. Mean July temperature is +23 – +25°С. Rainfalls are rather scanty – 350–450 mm and distributed evenly over the year. The hydrothermic coefficient equals 0.7–0.8; the evaporation exceeds the rainfall amount. In the latest decades the Don River shows signs of shallowing; that may result, among other things, from the climate warming, increase in evaporability and droughtiness (Polyakova and Kasharin, 2004). The modern vegetation types in the northern and eastern Azov region are steppes of herbs, sheep's fescue (Festúca ovina) and feather grass (Stipa). At present the natural vegetation has been almost completely destroyed by human activities. Dominant in the soils are Calcic Chernozems noted for a great thickness of humus horizons (A + B = 80–150 cm) and a high carbonate content (Bezuglova et al., 2008).
Ancient authors give very little information about Tanais. This is why the reconstruction of this colony's history is mostly based on archaeological material till the present time. The archaeological investigations in the area of Tanais have been conducted since 1853 till the present moment. Now we have a lot of archaeological finds with strong dating such as coins, amphorae stamps, fibulaе, inscriptions on stones etc. Tanais was constructed to serve as an intermediary between the ancient Greco-Roman world and the barbarians from the steppes (Sarmatians, Maeotians, Goths, Alans etc). A small trading settlement developed into the main economic centre of the area to the northeast of Lake Maeotis (the Sea of Azov). The development of Tanais begins from the first quarter of the 3rd to the middle of the 3rd century BC. It was the time of the emergence of the settlement. Meanwhile, we know little about this period, but we can discover some traces of streets and stone building.
From the middle of the 3rd century BC to the second quarter of the 2nd century BC the city structure and its defense have been mostly formed. The building of strong fortification structure was finished. During this stage Tanais developed its intensive building and trade relations. The city had a well-organized infrastructure and grew in size during this period.
The interval from the middle of the 2nd to the end of the 1st centuries BC became the highpoint of the development of Hellenistic Tanais. At the end of the entire Hellenistic period Tanais was sacked and ruined by the Bosporan king Polemon. With this event began the so called ‘Roman’ (the 1st - middle of the 3rd centuries AD) period. The general rebuilding of the city started almost after its destruction. Excavations have shown many house complexes that possessed paved courtyards with water-collecting cisterns.
In the 2nd century AD, the main part of the settlement was well fortified again. At that time the importance of Tanais in the political and economical life of the Bosporan Kingdom increased, and its role as the main commercial and production centre in the steppe region reached its great significance. But in the middle of the 2nd century AD the traces of destruction and a severe fire were revealed. These destructions can possibly be associated with the arrival in the Lower Don area of some strong militarized nomadic groups from the east. From that time onwards, the presence of the steppe people in the city becomes evident. The destructions did not have any long-term effect and Tanais was quickly rebuilt.
In the middle of the 3rd century AD, Tanais and the surrounding settlements were again destroyed and burnt. The last period in the history of the city referred to as ‘Late Antique’ (the second half of the 4th – 5th centuries AD). During last research some streets to the east and to the west of the central part of the city were discovered. Although the city was restored, it became economically weaker than in the 2nd – 3rd centuries AD. Evidentially, Tanais took up the same vast territory that time. At the end of this period (the end of the 4th – the beginning of the 5th centuries AD) an unknown event occurs. It leads to a sudden diminution of the city's area. Inhabitants leave their houses located near the river. It seems that the property in some houses was left in a hurry. At the end of this period the concrete reason for the final desolation of the city can not yet be named.
As follows from the morphological analysis of all the buried soils in Tanais and Rostov-on-Don, the system of horizons in the studied soils is typical of Calcic Chernozems: Ah-AB-Bk-BCk.
The paleosol attributed to the second half of the 2nd century BC (pit 15b-15) is practically identical to the modern surface soil in many respects, including the bioturbations resulted from burrowing animal activity, the carbonate distribution over the profile and other characteristics, such as water extract pH, loss-on-ignition (the diagenetic biomineralisation of organic carbon being taken into account), and gypsum. Micromorphological observations revealed carbonate accumulations around voids present in the Bk horizon as well as undifferentiated nodules clearly delineated against the background of finely dispersed iron-clayey groundmass.
The paleosols dated to the 1st century AD (pit 2b-15) and to the early 2nd century AD (pit 1b-17) are noted for a number of specific characteristics: the light color and the lowest percentage of C org in the humus horizon; the maximum content and the most shallow occurrence of carbonate pedofeatures in the profile; the maximum values of pH of water extract over the entire soil profile and maximum loss-on-ignition – in the upper part of the profile; and the greatest gypsum content – in the lower part of the soil profile. The analysis of the Вk horizon micromorphology revealed the fine groundmass to be impregnated throughout with carbonates. The pollen spectra attributed to the 2nd-1st centuries BC and the 1st-2nd centuries AD are devoid of broadleaf species pollen; on the whole, the assemblages are essentially xerophytic and poor in meadow forbs species diversity, Chenopodiaceae and Gramineae being dominant. The soil dated to the beginning of the 2nd century AD appears to contain the maximum proportion of arid plants in the phytolith assemblage. In accordance with the above-considered data from literature (Morgunova et al., 2003 ; Pesochina and Zaitsev, 1996 ; Porotov, 2007 ; Giaime at al., 2016) the time interval since the 1st century BC till the 1st century AD was noted for an essential growth of aridity in the region. Near that time – the end of the 1st century BC – the city was conquered and completely devastated by Polemon, the Bosporus King (Strabo, 1877). The archeological excavations confirmed the fact of fires and destructions in living quarters, as well as an almost complete demolition of the fortification system of the city (Shelov, 1970). Quite possibly, that event took place at the peak of the climate aridity, when Tanais could experience an economic crisis. A notable decrease in proportion of cultivated cereals in pollen assemblages suggests a slackening of agricultural activities of the population.
Since the 2nd century AD (more precisely, since the second quarter or the middle of the 2nd century AD) the signs of an increase in climatic humidity may be reconstructed. In particular, in the paleosol dated to end of the 2nd century AD (pit 3b-17) there is a perceptible accumulation of organic carbon in the upper horizons, as well as carbonate leaching, pH values indicative of lessened alkalinity, lower values of LOI and of gypsum content in the lower part of the soil profile. And although the strengthening of climatic humidity was previously reconstructed based on study of the properties of paleosol dated to the 1st century AD and situated close to Tanais (Pesochina et al., 2000), our data do not agree with this conclusion. Studying our pedo-chrono-sequence, we can see in the paleosol buried at the beginning of the 2nd century AD the clear signs of climatic aridity whereas the paleosol dated to the end of the 2nd century AD shows initial indications that climate became more humid. Hence, we present an updated scheme of climate changes for the period at the turn of eras for the studied region.
The modern surface soil – the Calcic Chernozems, clayey loam in composition, developed on loess-like loam (pit 1m-15, N47°16′38.6ʺ, E39°19′37.4ʺ) (Fig. 1). This pit is situated in 1 km far from Tanais within the small landscape sanctuary “Steppe of the Cis-Azov region”. These soils were approximately 90 years ago abandoned after plowing. No completely natural soils were impossible to find in this highly intensive agricultural region
The climate and vegetation were reconstructed for the entire more than 800-year period of the city's existence from the third century BC to the middle of the fifth century AD.
It was shown that the foundation of Tanais in the 3rd century BC and its growth through the 2nd century BC took place in climatic conditions, comparable to those of the modern period. The most devastating conquest of the city by Bosporus King Polemon occurred in the late 1st century BC, when the climate aridity reached its peak and the city of Tanais probably suffered from an economic crisis. The study of the chronosequence of soils buried under stone walls of the city and other settlements nearby at different times revealed a decrease of organic carbon and an increase carbonate and gypsum contents in the paleosols since the 3rd century BC till the beginning of the 2nd century AD. Those data confirm a strong climatic aridization at the turn of the eras. As follows from the pollen analysis, throughout the whole period of the city existence it was surrounded by steppe communities, but the coniferous (pine) pollen was also found in the spectra of all chrono-intervals. The highest proportion of pollen of cultivated plants and weed (4–6%) is found in the assemblages attributable to the first period of the city life (the 2nd-1st centuries BC). The analysis of microbiomorphs agreed with the pollen data and provided additional data on the wood and reed having been widely used in economical activities of population in the first period of the city existence. From the middle of the 2nd to the late 4th centuries AD the climate conditions may be considered to be humid and favorable for bioproductivity. Another wave of aridity was recorded at the boundary of the 4th and 5th centuries AD. At the end of the 5th century AD the city ceased to exist.
Хохлова О.С., Дюжова К.В., Гольева А.А., Трифонова Т.А., Бунин Д.С., Ильяшенко С.М., Хохлов А.А. Климат и растительность античного Танаиса (III в. до н.э.–V в. н.э.) по данным палеопочвенного и палеоботанического анализа // Известия РАН. Серия географическая, 2018, № 5, с. 54–68. https://doi.org/10.1134/S2587556618050072
Khokhlova O.S., Dyuzhova K.V., Golyeva A.A., Trifonova T.A., Bunin D.S., Ilyashenko S.M., Khokhlov A.A., Shipkova G.V. Paleoecology of the ancient city of Tanais (3rd century BC–5th century AD) on the north-eastern coast of the sea of Azov (Russia) // Quaternary International, Volume 516, 20 May 2019, Pages 98-110 https://doi.org/10.1016/j.quaint.2018.10.007