Geoscience Reference
In-Depth Information
Fig. 3.55
Fallen speleothem
covered with thick flowstone
in Shepran Cave
The data from the performed dating of deformed
stalagmites in Yamata Cave are evidence of the acti-
vation of the Dobrostan fault about 300,000 years BP
accompanied by a catastrophic effect on the sediments
in the cave. The same phase of the seismotectonic
activity can explained the deformations in Shepran
Cave as well. The active geodynamic behavior of the
fault during the Quaternary is confirmed by geomor-
phological studies in the past (Vaptsarov et al.
1986
).
The paleoseimological trench studies performed by
the Department of Seismotectonics of the Geological
Institute of Bulgarian Academy of Sciences in the last
decade on the Popovitsa fault near Plovdiv that gen-
erated the catastrophic Popovitsa earthquake
(M = 7.1, 18.04.1928), found traces of three paleo-
earthquakes with similar magnitudes to the 1928
event (Yaneva et al.
2004
). The excavated trenches
are 31-35 km NE from the studied caves.
3.3.2.4 Snezhanka Cave
Snezhanka is a show cave located on the left slope of
the Novomahlenska River, about 5 km southwest of
the town of Peshtera in Plovdiv District, Western
Rhodopes Mountains.
The cave is developed in highly karstified Prote-
rozoic marble from the Dobrostan Marble Formation
and consists of one gallery formed along two basic
systems of fractures directed southeast/northwest and
south/north. From a morphological point of view, the
cave can be divided into six chambers. The studied
stalagmites are situated in the biggest one—the Great
Hall (60 9 40 9 12 m).
The length of Snezanka Cave is 230 m, the den-
ivelation is 18 m, and the total surface area of the
cave is 3,150 m
2
(Fig.
3.57
) The deposits are pre-
sented by detritus (breakdown with a maximum block
size of 5.5 9 2.8 m), thin clay sediments, and a
variety of different speleothems. The morphological
Fig. 3.56
Rose-diagram of the directions of 46 fallen and
deformed speleothems in Shepran Cave
