Pobiti Kamani Natural Monument

Description

Pobiti Kamani ("upright stones" - fossil forest) are calcareous columns formed by natural forces. They exist at an astonishing scale. The Monument is comprised of smaller and bigger stone groups distributed in 8 km long belt with South - North direction in the region of Varna, along the northern Bulgarian Black Sea coast. The stone columns vary in size - up to 10 m height and up to 2, rarely 6 m diameter. Some of them are solid, when others are hollow. . The calcareous material is pale grey sandstone with carbonate content. Some of the columns have been eroded by wind and water into fantastic forms. The desert like environment surrounding the columns possesses specific flora and fauna.

Justification of Outstanding Universal Value

From a geological point of view the Pobiti Kamani is a unique phenomenon with global significance. They reflect both a fossilization and size that are unique in the World. In addition the biodiversity in the territory surrounding the "stones" increases its value. The surrounding environment contains significant habitat in Bulgaria for 4 globally threatened, 2 threatened and 8 protected plant species. The total number of vertebrate and invertebrate species with conservation value amounts to 52 separate species. The territory protects 2 priority habitats included in the Habitats Directive 92/43/ЕЕС.

Criteria:

(vii) The columns are remarkable sedimentary structures developed at an imposing scale - the columns are formed in five levels/layers one over the other with total height of 40-45 m. The columns form 18 groups dispersed in an area of 70 km². All levels are exposed for observation only in the quarry near the village of Beloslav. The enormous stone columns are a unique natural phenomenon, which has no parallels in the World. Individually and as assemblages, the stones astonish with their size and number, and together with the semi-desert environment around them create characteristic landscape of exceptional natural beauty.

(viii) Pobiti Kamani are situated in the region of the Varna depression, in the eastern part of the Moesian Platform. To the east, the Platform is connected to the continental shelf of the Black Sea basin where active methane gas seeps exist. In the area of Pobiti Kamani several lithostratigraphic units from the Eocene period are observed. The Pobiti Kamani itself are Lower Eocene Dikilitash Formations.

One of the groups of Pobiti Kkamani formations in the quarry of Beloslav exposes the extraordinary dimensions of the columns.  Only in the quarry the bases of the columns can be observed as well as their various characteristics and morphology. There are also marvelous exhibits of columns in an embryonic stage, complex columns as well as laminated stromatolites, oncoids and trace fossils in the columns.

There are dozens of theories about the genesis of the stone columns near Varna. The newest hypothesis proves that these structures are formed around natural methane gas seeps.

Seeps of methane gas are well known in many places in the World. . They exist where the methane bearing fluids pass through sediments and reach the Earth's surface or sea floor.

The Dikilitash formation represents an ancient methane seep system. Methane-bearing fluids flowed along fault structures in shallow sea sands, influencing the digenetic processes that occurred there. The methane was oxidized by the methanotrophic bacteria near the surface and calcium carbonate was precipitated, cementing the particles around gas channel. Lithification of the sediments created typical ring-like cores and the columns grew in height at the same time. These formations are a byproduct of this process and are exposed after changes to the sea level and other geological processes.

When comparing the size, mineralogy, petrographic fabric and diagenesis of the structures of the Pobiti Kamani seep system with those of other systems, no clear analogue can be found.

Statements of authenticity and/or integrity

The Pobiti Kamani as proposed in the World Heritage tentative list includes the territory of the Protected Area "Pobiti kamani", which covers total area of 253,3 ha and all the groups of stone columns.

There is no buffer zone defined. For effective protection of the area, a buffer zone should be delineated. It should cover the territory around the protected area and the 18 groupings of fossil columns. The Management Scheme for the territory developed in 2000 may serve as a basis for the creation of a buffer zone. The Management Scheme provides for establishment of a territory named Pobiti Kamani Complex with an area of 2965,2 ha, including 246,3 ha area of the stone groups.

Comparison with other similar properties

Natural structures similar to the Pobiti Kamani exist only in Australia. These are stromatolites, rock-like structures built by microbes (single-celled cyanobacteria). They are found in the Shark Bay, the extreme western coast of Australia. The Shark Bay site is included in the UNESCO's World Heritage List.

The other such structures are the Pinnacles - limestone formations contained within Nambung National Park, Western Australia.

The Australian stromatolites and the pinnacles resemble the Pobiti Kamani stone columns mainly in their shape, but otherwise the differences are many and significant. This confirms the uniqueness of the Varna columns and their extraordinary scientific and aesthetic value.