Geology Reference
In-Depth Information
2.1 Intermontane Depressions
2.1.1
South Caspian Basin
2.1.1.1
Underground Water: Hydrogeochemical Description and
Patterns of Spatial Distribution
The Middle Jurassic-Valanginian, Hauterivian-Danian, Paleogene-
Miocene and Middle-Upper Pliocene water-head complexes are identified
in the basin's sediment cover. The identification is based on lithofacies,
hydrodynamic and hydrochemical indications.
The underground waters from the Mesozoic complexes were sub-
jected to detailed studies in some basins. They include the Caspian
region and North Kobystan over the southeastern plunge of the Caucasus
Major meganticlinorium (at the Kesh, Begimdagh-Tamchay, Gyadysu,
Yashma, West Agburun, Sovetadad, Geytapa, Kabandagh, Kurkachidagh,
Nasosnaya and some other prospects) and some structures in the Aladag-
Messerian (the Zirik and Suydji prospects) and Urundzhuk-Boyadagh
(the Urundzhuk, Tuzluchay, Boyadagh and Syrtlanli prospects) folded
areas adjacent to the Great Balkhan, Kubadagh and Kopet-Dagh folded
mountains (Table 2.1).
he
Middle Jurassic - Valanginian complex's
waters belong to the hydro-
carbonate-sodium type (Kesh, Begimdagh-Tegchay and Gyadysu pros-
pects). Their salinity ranges between 18.2 and 42.2 mg-equiv.
1
(5.2-12.1 g/l).
The chlorine content is 5.5 to 14.6 mg-equiv.; the sulphate-ion content is up
to 1.7 mg-equiv.; total alkalinity reaches 11.8 mg-equiv. Calcium and mag-
nesium are present in the amount of up to 0.1 to 0.4 mg-equiv., sodium and
potassium, 8.7 to 20.7 mg-equiv. The primary alkalinity factors are 12.4 to
58.4%-equiv.
he
Hauterivian-Danian
waters in the lower portion of the interval
are mostly of hydrocarbonate-sodium type and in the upper section they
include at a number of prospects sulphate-sodium, chlorine-magnesium
and chlorine-calcium varieties (Akhundov, Mekhtiyev and Rachinsky,
1976; Durmishyan
,
Muradyan and Rachinsky
,
1973). The salinity is
between 20.8 and 52.4 mg-equiv. (6.0-15.0 g/l) and its maximum val-
ues are recorded in alkaline waters. The chlorine content is 9.2-24.8 mg-
equiv.; the sulphate content does not exceed 2.1 mg-equiv.; the contents of
calcium and magnesium are respectively 0.1-2.3 and 0.1-1.3 mg-equiv.;
1
Here and thereafter the water component composition and salinity values are provided in
mg-equiv./100 g. The salinity and alkalinity factors are after Palmer (%-equiv.).
