536
R. B˘ atina¸ s et al.
mountainous area. The situation of the leveling platforms should not, however, be
absolutized from the point of view of the height limits, because sometimes, due to the
increased tectonization, they are much lower (especially in the case of low altitude
levels) [46].
In the northern and eastern parts of the Gil˘ au—Muntele Mare area, the foundation
consisting of crystalline rocks sinks under the sedimentary (paleogenic) formations
of the border area. As a result, the smooth ridge landscape is replaced by scenery of
steep slopes that are aligned with the lower slopes towards Transylvanian Depression
[37].
Between the mentioned mountain ranges, the valleys were inserted; of these, the
hydrographic system of Some¸ sul Mic drains about two thirds of the entire complex
area. The valleys in this hydrographic system have high depths (300–400 m) and
accentuated longitudinal slope (25–30 m/km) resulting in a great hydropower potential, used by the built facilities from Fântânele, Tarni¸ ta, Some¸ sul Cald and Gil˘ au.
Along these valleys, there are very steep sectors with impressive gorges, such as
Some¸ sul Cald (its upper sector and the one at L˘ apu¸ ste¸ sti), Some¸ sul Rece, R˘ ac˘ at˘ au
and Iri¸ soara, etc.
On the geological-geomorphologic background a diversified landscape was composed made of [63]:
– high karst plateau (1400 m) particularly attractive for speoturism and hiking;
– smooth or slightly curved mountain ridges with scattered settlements among meadows and forest clusters;
– valleys with steep slopes well forrested, with small meadows occupied by sheepfolds or small settlements (Giurcu¸ ta de Sus, Smida, Ciurtuci etc.).
The crossing of the granite intrusions, turn the valleys into narrow corridors which
become favorable to the construction of dams, while depression zones formed by
erosion, at the confluence of the watercourses, provide the basins necessary for the
development of lacustrine cuvettes.
In the case of Fântânele reservoir, it is noted the contact of Muntele Mare granite
with the crystalline deposits of Gil˘ au mountains, both extended on large surfaces.
They are, in some places, penetrated by andesitic and dacite veins and apophyses
[49].
A gravity dam was built at the entrance of Some¸ sul Cald in the defile of Belis , ,
in the sector with hard rocks represented by granodiorites and granites, rocks that
caused the Some¸ sul Cald valley to make a double detour to the southeast and then
again to its initial direction [47, 56–58]. Besides, these rocks were also exploited in
the quarry for building the edifice on the left bank of the river, a few hundred meters
downstream of its location.
The double arch dam of Tarni¸ ta reservoir was located into a narrow sector of
Somes , ul Cald Valley. Here the slopes have a thin layer of deluvium and detritus
covering the crystalline shale from the foundation (amphibolites, quartz amphiboloclorite), whose cracks and fractures were naturally filled with quartz and carbonate.
The reservoir cuvette is formed on the same crystalline shale, covered by sands and
quaternary gravels [57].
R. B˘ atina¸ s et al.
mountainous area. The situation of the leveling platforms should not, however, be
absolutized from the point of view of the height limits, because sometimes, due to the
increased tectonization, they are much lower (especially in the case of low altitude
levels) [46].
In the northern and eastern parts of the Gil˘ au—Muntele Mare area, the foundation
consisting of crystalline rocks sinks under the sedimentary (paleogenic) formations
of the border area. As a result, the smooth ridge landscape is replaced by scenery of
steep slopes that are aligned with the lower slopes towards Transylvanian Depression
[37].
Between the mentioned mountain ranges, the valleys were inserted; of these, the
hydrographic system of Some¸ sul Mic drains about two thirds of the entire complex
area. The valleys in this hydrographic system have high depths (300–400 m) and
accentuated longitudinal slope (25–30 m/km) resulting in a great hydropower potential, used by the built facilities from Fântânele, Tarni¸ ta, Some¸ sul Cald and Gil˘ au.
Along these valleys, there are very steep sectors with impressive gorges, such as
Some¸ sul Cald (its upper sector and the one at L˘ apu¸ ste¸ sti), Some¸ sul Rece, R˘ ac˘ at˘ au
and Iri¸ soara, etc.
On the geological-geomorphologic background a diversified landscape was composed made of [63]:
– high karst plateau (1400 m) particularly attractive for speoturism and hiking;
– smooth or slightly curved mountain ridges with scattered settlements among meadows and forest clusters;
– valleys with steep slopes well forrested, with small meadows occupied by sheepfolds or small settlements (Giurcu¸ ta de Sus, Smida, Ciurtuci etc.).
The crossing of the granite intrusions, turn the valleys into narrow corridors which
become favorable to the construction of dams, while depression zones formed by
erosion, at the confluence of the watercourses, provide the basins necessary for the
development of lacustrine cuvettes.
In the case of Fântânele reservoir, it is noted the contact of Muntele Mare granite
with the crystalline deposits of Gil˘ au mountains, both extended on large surfaces.
They are, in some places, penetrated by andesitic and dacite veins and apophyses
[49].
A gravity dam was built at the entrance of Some¸ sul Cald in the defile of Belis , ,
in the sector with hard rocks represented by granodiorites and granites, rocks that
caused the Some¸ sul Cald valley to make a double detour to the southeast and then
again to its initial direction [47, 56–58]. Besides, these rocks were also exploited in
the quarry for building the edifice on the left bank of the river, a few hundred meters
downstream of its location.
The double arch dam of Tarni¸ ta reservoir was located into a narrow sector of
Somes , ul Cald Valley. Here the slopes have a thin layer of deluvium and detritus
covering the crystalline shale from the foundation (amphibolites, quartz amphiboloclorite), whose cracks and fractures were naturally filled with quartz and carbonate.
The reservoir cuvette is formed on the same crystalline shale, covered by sands and
quaternary gravels [57].