Georgi Aleksiev, Marinela Agalareva

The northwestern border shafts: the Lom, the Hayredin and the Ostrov shaft, represent a combination of two interconnected parallel segments: a moat and a shaft, stretching in a submeridional direction between the valleys of the Lom River and the Iskar River with a total length of over 100 km. Numerous publications are dedicated to those shafts, while the first field research and mapping were carried out by Karel Skorpil in the early twentieth century. The first Bulgarian-led archaeological transversal excavations of the Hayredin shaft were carried out in the late 1970s by Rasho Rashev.
The length of the Hayredin shaft is about 25 km. To the north it starts from the high Danube River valley macroslope in the vicinity of Killer Bair locality, 6 km west of Kozloduy. To the south, in a meridional direction, the shaft crosses the waterless plain of Moesia, where rescue archeological excavations were carried out at the eleventh kilometer. The southern end of the shaft reaches the landuse areas of the villages of Hayredin and Manastirishte, where old Bulgarian settlements existed. From that point on, the route of the shaft branches off and is further on lost in the alluvial lowland of the Ogosta River valley.
In 2019, in connection with an investment project for expansion of the gas transmission infrastructure of the Republic of Bulgaria, it was necessary to conduct an urgent rescue archaeological study. The study took place at Site 25/2006, within the landuse area of the village of Butan, Kozloduy municipality, or at the intersection of the submeridional Hayredin shaft and the gas pipeline coming from Eastern Thrace towards Central Europe. A complete geomagnetic survey was performed in the designated study area, in order to establish the presence or absence of any excavated structures in or under the embankment of the shaft (Fig. 3). The results clearly showed the presence of two linear anomalies outlining the rounded shoulders of the fossilized moat located between them. An isometric anomaly was registered in the very SW corner of the easement (squares G/10 – H/10).
The fortification facility consists of two elements – a shaft and a moat (Fig. 9, 10 and 11). The height of the shaft is about 3.50 m and is the result of morphodynamic processes and human activity. No cultural layer was registered during the excavations. The stratigraphic sequence of the layers shows that the embankment of the shaft is formed by a sandy loess and a grayish-white intermediate layer, where infiltration of pockets of chernozem and soil layer is observed. The ridge of the shaft is formed by loess and soil-turf. Judging by the stratigraphic sequence, it can be said that only the redeposited loess from the highest point of the ridge is the result of any anthropogenic activity.
The formation of the shaft itself is a result of active geomorphological processes and anthropogenic influences, or the genesis of the shaft is associated with the presence of a natural ravine or subsidence of the terrain, further fossilized by denudation-accumulation processes in the neighboring terrains. This evidence and conclusion is confirmed by observations of all incisions made. The outlines of the shaft are marked by a horizontal bottom and V-shaped rounded walls. The volume parameters of the moat are outlined by the soil volumes of the two layers: of pale whitish soils and a chernozem soil layer shuffled off the ridge of the shaft.

Hayredin fortification shaft, structural-geomorphological analysis, paleogeographic reconstructions, chronology, geophysical survey

Problems of Geography, 2021, Vol.2, DOI:

Author information:
Author: Georgi Aleksiev
Affiliation: National Institute of Geophysics, Geodesy and Geography – BAS, department of Geography, str. Acad. G. Bonchev, bl. 3, Sofia 1113, Bulgaria

Author: Marinela Agalareva
Affiliation: “St. Cyril and St. Methodius” University of Veliko Turnovo

How to cite:
Aleksiev, G., & Agalareva, M. (2021). Палеогеографски реконструкции в обсега на Хайрединското укрепително съоръжение. Problems of Geography, 2021, Vol.2, p. 3-13.