16 Water Resources from Apuseni Mountains …
537
For Some¸ sul Cald reservoir the dam was built on a lithology given by crystalline
shale of Gil˘ au, where the basic rock is represented by cracked amphibolites. There
are breached fractures, and at depths of over 15 m, the cracks are closed by diaclase
of calcite and quartz [38].
The reservoir cuvette extends on the basin generated by the confluence of the
Some¸ sul Cald River with the Agârbiciu Valley. The gorge petrography on the reservoir site is dominated by the sericitoaceous quartz shale and the sericito-chlorite
shale. Towards the upstream end of the reservoir, Some¸ sul Cald valley cuts an
orthoamfibolite intercalation [63].
In the case of Gil˘ au reservoir, the dam was located into a narrowing point of
Some¸ sul Mic valley at the exit of the mountainous area, determined by the presence
of a 140–200 m thick andesitic body of vein form. This andesite with amphibols
and biotite has a grayish- sometimes reddish colour, being heavily cracked and easily disaggregated near the surface. On the altered scattered rock, the rock has the
appearance of gravel sand, almost entirely lacking in cohesion, but where hard, consistent, less altered areas appear. At a depth of 3–5 m, the eruptive body consists of
compact, unaltered gray-green andesite [38]. The reservoir cuvetteation is situated
in an erosion basin contoured by the confluence of Some¸ sul Cald with Somes , ul Rece
creek.
Midlle Somes , basin is dominated by the main ridge of the Mese¸ s Mountains,
situated in the north-eastern extremity of the Apuseni area. Their southern part draws
tributaries of low importance belonging to Cri¸ sul Repede (Poicu valley), while their
northern part is associated with the Almas , and Agrij rivers, tributaries of the Somes , ,
in its middle sector.
The Mese¸ s Mountains, like the Plopis , Mountains, have a crystalline foundation,
covered by neogene sedimentary deposits, with maximum altitudes not exceeding
1000 m.
Barc˘ au basin is morphologically dominated by the Plopis , ( ¸
Ses) Mountains, which
appear as a horst with a smooth appearance, with peaks that have altitudes around
750 m.
*
All these geological and morphological components create very diverse conditions
for the existence and circulation of water resource, with somewhat lesser possibilities
of underground storage, due to the low permeability (Fig. 16.7) but with very good
water drainage conditions at the ground (Fig. 16.8).
16.2.2.1 Rocks’ Permeability
As mentioned at the beginning of this study in the Apuseni, although we encounter
the most extensive endoreal areas at the national level, surface drainage values are
quite important.
Except the predominantly karstic areas, the hydrographic network density values
range from 0.8 to 1.2 km/km
2 , with local convergence zones, sometimes exceeding
1.8 km/km
2 (Câmpeni and Brad Depression).
537
For Some¸ sul Cald reservoir the dam was built on a lithology given by crystalline
shale of Gil˘ au, where the basic rock is represented by cracked amphibolites. There
are breached fractures, and at depths of over 15 m, the cracks are closed by diaclase
of calcite and quartz [38].
The reservoir cuvette extends on the basin generated by the confluence of the
Some¸ sul Cald River with the Agârbiciu Valley. The gorge petrography on the reservoir site is dominated by the sericitoaceous quartz shale and the sericito-chlorite
shale. Towards the upstream end of the reservoir, Some¸ sul Cald valley cuts an
orthoamfibolite intercalation [63].
In the case of Gil˘ au reservoir, the dam was located into a narrowing point of
Some¸ sul Mic valley at the exit of the mountainous area, determined by the presence
of a 140–200 m thick andesitic body of vein form. This andesite with amphibols
and biotite has a grayish- sometimes reddish colour, being heavily cracked and easily disaggregated near the surface. On the altered scattered rock, the rock has the
appearance of gravel sand, almost entirely lacking in cohesion, but where hard, consistent, less altered areas appear. At a depth of 3–5 m, the eruptive body consists of
compact, unaltered gray-green andesite [38]. The reservoir cuvetteation is situated
in an erosion basin contoured by the confluence of Some¸ sul Cald with Somes , ul Rece
creek.
Midlle Somes , basin is dominated by the main ridge of the Mese¸ s Mountains,
situated in the north-eastern extremity of the Apuseni area. Their southern part draws
tributaries of low importance belonging to Cri¸ sul Repede (Poicu valley), while their
northern part is associated with the Almas , and Agrij rivers, tributaries of the Somes , ,
in its middle sector.
The Mese¸ s Mountains, like the Plopis , Mountains, have a crystalline foundation,
covered by neogene sedimentary deposits, with maximum altitudes not exceeding
1000 m.
Barc˘ au basin is morphologically dominated by the Plopis , ( ¸
Ses) Mountains, which
appear as a horst with a smooth appearance, with peaks that have altitudes around
750 m.
*
All these geological and morphological components create very diverse conditions
for the existence and circulation of water resource, with somewhat lesser possibilities
of underground storage, due to the low permeability (Fig. 16.7) but with very good
water drainage conditions at the ground (Fig. 16.8).
16.2.2.1 Rocks’ Permeability
As mentioned at the beginning of this study in the Apuseni, although we encounter
the most extensive endoreal areas at the national level, surface drainage values are
quite important.
Except the predominantly karstic areas, the hydrographic network density values
range from 0.8 to 1.2 km/km
2 , with local convergence zones, sometimes exceeding
1.8 km/km
2 (Câmpeni and Brad Depression).