Geoscience Reference
In-Depth Information
Fig. 3.12
Map and
longitudinal profile of Elata
Cave (after Beron et al.
2006
)
Angelova and Benderev (
2000
), Angelova et al.
(
1995
,
1999
, 2002), Benderev (
1989
, 1991), Benderev
et al. (
2006
), Kostov (
1997
), and others.
There are 19 cave regions in the Stara Planina
Mountains according to the scheme of Popov (1970).
Most of the deepest pot-holes in Bulgaria have been
established here (12 caves more than 200 m deep)
including the deepest Bulgarian cave Raichova Dupka
Cave (-387 m).
included in the list of the Bulgarian protected natural
phenomena since 1964.
Elata Cave is developed in gray Upper Jurassic
limestone of the Yavoretz Formation. The chrono-
stratigraphic range of the formation is Lower
Calovian—Lower Cimeridgean. Structurally, the cave
is formed along the line of a fault with SE-NW direc-
tion. The displacement of the Pleistocene and Holocene
deposits on the surface can be assumed as a result of the
Quaternary activity of the fault (Paskalev et al.
1992
).
As a result of two strong seismic events in Ponor
Mountain are established hydrological phenomena
related to the discharge of the Iskrets karst springs. The
springs are located 6.2 km SW of Elata Cave. During
the devastating earthquake in Vrancea, Romania of
March 4, 1977, the spring's discharge decreased from
5.5 to 0.5 m
3
/s. After 7.5 hours there occurred a sharp
increase of water levels up to 18 m
3
/s, accompanied by
intense water turbidity possibly connected to erosion
of sediments in aqueous karst galleries and break-
downs. About that time the massif detained about
13,500 m
3
of water. A similar phenomenon was
described after Svoge earthquake of March 9, 1980
(Petrov
1983
; Paskalev et al.
1992
).
The registered hydrological anomalies in the flow
of the Iskrets springs can be explained by collapses in
the
3.3.1.1 Elata Cave
The Elata Cave is situated in Ponor Mountain (mor-
phological unit ot West Stara Planina (Balkan) Mts.),
about 55 km north of Sofia and 1.5 km SW from the
village of Zimevitsa.
The cave begins with a vertical pit of 18.5 m,
followed by a large gallery of length 176 m. The total
denivelation of the cave is 64 m (Fig.
3.12
). The cave
deposits are presented by breakdowns and a number
of speleothems: stalagmites, stalactites, sinter lakes
(gurs), stalactones. Typical for Elata Cave are poplar-
like stalagmites of height up to 3 m (''Elata'' means
''The fir tree'' in Bulgarian). This pot-hole was dis-
covered in 1960 by the cavers P. Beron, V. Beshkov,
and T. Michev and surveyed in the following years by
members of the ''Akademic'' Caving Club (Sofia).
According to its attractive speleothems, the cave is
karstic
galleries.
The
catchment
area
of
the
