Natural and geographical regions on
the territory of Bulgaria. Stara Planina
region - Pre-Balkan and Main Stara
Planina Range
7th lecture from the course “Topography of the Balkan Peninsula”
The Stara Planina region is located in the central part of Bulgaria, it is a complex system of parallel
mountain ranges, located in the west-east direction. It also consists of longitudinal internal basins and
transverse river valleys; it belongs to the Alpine-Himalayan orogenic belt. A kind of border appears
between the natural appearance of the northern and southern parts of the country. The Stara Planina
region is located between the Danube Plain in the north and the Kraište-Strandzha region in the south, and
between the border with Serbia in the west and the Black Sea in the east. It has a length of 550 km and a
width of 20 to 70 km. Two independent subregions are distinguished in it - the Pre-Balkan and the Main
Stara Planina Range. What they have in common is the folded geological structure and the general age and
development of the forms.
1. Geographical location and borders of the Pre-Balkans
It occupies the northern part of the Stara Planina region, along the border with the Danube Plain, and has
the shape of an elongated and narrow strip of land, extending from Vrashka Chuka in the west to the Black
Sea in the east. It includes low and medium-high mountains.
A) The northern border passes along a longitudinal fault between the Stara Planina region and the Danube
Plain.
B) The southern border starts from the Belogradchik Pass and reaches the Black Sea.
C) The Western Border passes along the Timok River valley to the Belogradchik Pass.
D) For the eastern border the Black Sea coast is considered to be from the valley of the Kamchia River to the
1
, valley of the Dvoynitsa River.
2. Geological structure and natural fossils
The Fore-Balkans are part of the morphostructure of the Balkans, consisting of fold structures located
parallel to each other. The relief has been subjected to several uplifts, which have alternated with
periods of calm, when denudation flats, river gorges and the river network were formed. The structure
of the earth's crust is characterized by the presence of fold structures, complicated by longitudinal or
transverse faults. In its northern part, the Fore-Balkans represent a natural transition between the
plain structures of the Danube Plain and the fold structures of the Main Stara Planina Range.
Volcanogenic and sedimentary rocks predominate, and various types of intrusive rocks are revealed in
the Belogradchik area. Limestones, sandstones, dolomites, calcareous sandstones are well represented.
Thick alluvial deposits have formed along the river valleys and valley extensions. Among fossil fuels,
there is coal and natural gas, and among metallic minerals, there are gold-bearing sands. In general,
there are no industrial reserves of ore minerals in the Foreland. Among non-metallic minerals, the
rock salt deposit near the town of Omurtag in the eastern part of the Foreland is significant. The
deposits of limestone and sandstone are of economic importance. The Foreland is poor in fossil fuels
and ore minerals.
3. Relief and morphographic division
A) relief
The Pre-Balkan region is characterized by a hilly, low-mountainous, partly mountainous relief. The
average altitude is 364 m., the highest point is Vasilyov Peak (1490 m) in Vasilyov Mountain, in its
middle part. The lowest altitude is in the eastern part, with the hills and elevations located to the north
being lower, and those in the southern part - higher. There is an increase in altitude from north to
south. The land surface is characterized by the dominance of convex (positive) forms - mountains,
hills, elevations and plateaus. Concave (negative) forms of the land surface are also characteristic,
represented by basins such as the Sevlievo, Gerlov, Barzii-Botun depression and others. The river
valleys are very characteristic, they are developed longitudinally and transversely to the direction of
extension of the mountains, hills and elevations. In places, narrow, deep and long river gorges have
been formed in them. The significant participation of limestones has determined the wide
development of surface and underground karst forms in the western part of the Fore-Balkans. The
great cracking of the limestones and the circulation of the waters has led to the formation of a whole
complex of surface karst forms - kars, ravines, whirlpools, sinkholes, ravines and karst fields (e.g. the
Devetashka plateau), and their great power and the complex horizontal and vertical circulation have
created large and beautiful caves (Magurata, Saeva dupka, Gradenishka, Bacho Kiro, Dryanovska) with
typical rock formations - stalactites, stalagmites and draperies. The underground circulation of the
karst waters has led to the formation of numerous karst springs - Palilula, Kobiljak, Toplya, Glava
Panega, Dryanovski izvor. In the Lower Triassic conglomerates and sandstones, erosion has sculpted
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the territory of Bulgaria. Stara Planina
region - Pre-Balkan and Main Stara
Planina Range
7th lecture from the course “Topography of the Balkan Peninsula”
The Stara Planina region is located in the central part of Bulgaria, it is a complex system of parallel
mountain ranges, located in the west-east direction. It also consists of longitudinal internal basins and
transverse river valleys; it belongs to the Alpine-Himalayan orogenic belt. A kind of border appears
between the natural appearance of the northern and southern parts of the country. The Stara Planina
region is located between the Danube Plain in the north and the Kraište-Strandzha region in the south, and
between the border with Serbia in the west and the Black Sea in the east. It has a length of 550 km and a
width of 20 to 70 km. Two independent subregions are distinguished in it - the Pre-Balkan and the Main
Stara Planina Range. What they have in common is the folded geological structure and the general age and
development of the forms.
1. Geographical location and borders of the Pre-Balkans
It occupies the northern part of the Stara Planina region, along the border with the Danube Plain, and has
the shape of an elongated and narrow strip of land, extending from Vrashka Chuka in the west to the Black
Sea in the east. It includes low and medium-high mountains.
A) The northern border passes along a longitudinal fault between the Stara Planina region and the Danube
Plain.
B) The southern border starts from the Belogradchik Pass and reaches the Black Sea.
C) The Western Border passes along the Timok River valley to the Belogradchik Pass.
D) For the eastern border the Black Sea coast is considered to be from the valley of the Kamchia River to the
1
, valley of the Dvoynitsa River.
2. Geological structure and natural fossils
The Fore-Balkans are part of the morphostructure of the Balkans, consisting of fold structures located
parallel to each other. The relief has been subjected to several uplifts, which have alternated with
periods of calm, when denudation flats, river gorges and the river network were formed. The structure
of the earth's crust is characterized by the presence of fold structures, complicated by longitudinal or
transverse faults. In its northern part, the Fore-Balkans represent a natural transition between the
plain structures of the Danube Plain and the fold structures of the Main Stara Planina Range.
Volcanogenic and sedimentary rocks predominate, and various types of intrusive rocks are revealed in
the Belogradchik area. Limestones, sandstones, dolomites, calcareous sandstones are well represented.
Thick alluvial deposits have formed along the river valleys and valley extensions. Among fossil fuels,
there is coal and natural gas, and among metallic minerals, there are gold-bearing sands. In general,
there are no industrial reserves of ore minerals in the Foreland. Among non-metallic minerals, the
rock salt deposit near the town of Omurtag in the eastern part of the Foreland is significant. The
deposits of limestone and sandstone are of economic importance. The Foreland is poor in fossil fuels
and ore minerals.
3. Relief and morphographic division
A) relief
The Pre-Balkan region is characterized by a hilly, low-mountainous, partly mountainous relief. The
average altitude is 364 m., the highest point is Vasilyov Peak (1490 m) in Vasilyov Mountain, in its
middle part. The lowest altitude is in the eastern part, with the hills and elevations located to the north
being lower, and those in the southern part - higher. There is an increase in altitude from north to
south. The land surface is characterized by the dominance of convex (positive) forms - mountains,
hills, elevations and plateaus. Concave (negative) forms of the land surface are also characteristic,
represented by basins such as the Sevlievo, Gerlov, Barzii-Botun depression and others. The river
valleys are very characteristic, they are developed longitudinally and transversely to the direction of
extension of the mountains, hills and elevations. In places, narrow, deep and long river gorges have
been formed in them. The significant participation of limestones has determined the wide
development of surface and underground karst forms in the western part of the Fore-Balkans. The
great cracking of the limestones and the circulation of the waters has led to the formation of a whole
complex of surface karst forms - kars, ravines, whirlpools, sinkholes, ravines and karst fields (e.g. the
Devetashka plateau), and their great power and the complex horizontal and vertical circulation have
created large and beautiful caves (Magurata, Saeva dupka, Gradenishka, Bacho Kiro, Dryanovska) with
typical rock formations - stalactites, stalagmites and draperies. The underground circulation of the
karst waters has led to the formation of numerous karst springs - Palilula, Kobiljak, Toplya, Glava
Panega, Dryanovski izvor. In the Lower Triassic conglomerates and sandstones, erosion has sculpted
2
