Abstract:

In the Lomovete Valley and the adjacent plateau territories, 121 prehistoric settlements have been registered, of which 31 are open settlements and 90 settlement tells, dating back to the Neolithic and early Chalcolithic periods.
The Early Neolithic open settlements at Koprivets, Cherven, Orlovets and Pomochitsa are located on the lower slopes, close to the floodplain terraces. The Late Neolithic settlements occupy their higher parts and the low plateaus, reflecting changes in the environment.
The transition between the Neolithic and the Chalcolithic was accompanied by climatic and landscape changes that influenced the development and spatial organization of settlements. During the Chalcolithic, multi-layered settlement tells were built on the floodplain river terraces.
The Early Neolithic settlements in the area lie in the upper part of the first loess horizon (L1). They are sealed by the carbonate horizon of the contemporary soil (Cs) and belong to phase I of the Koprivets culture (8150–8000 BP). The stratigraphy of the site shows, that the loess accumulation gradually subsided during the Preboreal and Boreal, and the carbonate horizon of the contemporary soil formed after this period. The data suggests that the accumulation of the transitional and humus horizons of the soil began during the early Atlantic (about 8000 BP).
The settlements from the late stages of the Early Neolithic and Late Neolithic (the Samovodene–Ovcharovo, Hotnitsa I and Hotnitsa II cultures) are dated in the interval 7600–7400 to 7140–7030 BP. They are located in the lower part of the contemporary soil (Cs) and correspond to the early Atlantic stages.
The Chalcolithic settlement tell near Koprivets is located on the floodplain terrace T01 of the Baniski Lom River. The settlers appeared after the river retreated from the terrace (about 6000 BP). During the establishment of the settlement, stone slabs were laid on the alluvial clays, probably with insulating function. Simultaneously with the accumulation of anthropogenic layers in the tell, the contemporary soil (Cs) around it was formed. The intensive development of soil formation began around 6000 BP and continues to this day.
Based on the studied sections in the region, a local paleoclimatic curve has been reconstructed. The humus, illuvial and carbonate horizons of the contemporary soil, as well as the uppermost part of the loess horizon L11, have been analyzed. The established fluctuations are correlated with the Preboreal, Boreal, Atlantic, Subboreal and Subatlantic.
Relationships between Neolithic-Chalcolithic sites and their host sediments allow geological, archaeological, and paleoclimatic data to be linked for dating events during the Holocene:
• The accumulation of the loess horizon L11 was completed at the end of the Boreal, around 8000 BP;
• Weak loess deposition continues throughout the Subboreal at a rate of 1 cm/100 yr, as evidenced by a sterile layer 28 cm thick above the last fifth horizon of the Chalcolithic settlement tell (5500 BP);
• It is important to note that the earliest Neolithic layer at Koprivets, dated to 8150–8000 BP, is located in the upper part of L11 and is sealed by the carbonate horizon of the contemporary soil;
• The formation of the illuvial horizon is associated with the beginning of the Atlantic (around 8000 BP), and of the humus horizon – with the Atlantic, Subboreal and Subatlantic.
Terrace T01 is of Late Pleistocene and Early Holocene age and is 3–4 m above the average river level. Based on the studies of the settlement tell at Koprivets, built on the same terrace, the following stratigraphic and paleogeographic conclusions have been made:
• The channel alluvium on the T01 terrace was accumulated at the end of the W2 stadial recession, during the Preboreal and Boreal, whereas the floodplain facies formed during the early Atlantic;
• The Baninski Lom River retreated from the T01 floodplain terrace with the onset of the Atlantic recession (6000 BP, archaeological data);
• The formation of Cs on the T01 alluvium began after the river retreat and coincided with the appearance of the Chalcolithic settlers (6000 BP);
• During the Subboreal (5000-3000 BP) and Subatlantic (3000-present) the Baninski Lom River modeled the T0 terrace and shaped its present-day bed.