Geology Reference
In-Depth Information
(26.5-39.9 g/l) chlorine-calcium waters with secondary
salinity factor 9.2-17.2%-equiv.
t
The vertical hydrochemical zoning in the region's sediment
cover is direct: down the stratigraphic section the ground
water salinity increases, the primary alkalinity factor in
hydrocarbonate-sodium waters consistently declines and sec-
ondary salinity factor in the chlorine-calcium medium grows.
t
In the Pliocene waterhead complexes the ground water dis-
tribution by salinity and ion-salt composition on the local
highs is nonuniform. In a number of fields in most pro-
ductive fault-blocks (zones) over strongly faulted crestal
areas is recorded sporadic presence of saline (20.1-28.1 g/l)
chlorine-calcium and “transitional” chlorine-magnesium,
sulphate-sodium and hydrocarbonate --sodium waters (the
secondary salinity and primary alkalinity factors 0-3%-
equiv.). This occurs against a total background of low salinity
and high alkalinity. The impression therefore is of decreas-
ing ground water salinity, hardness and increasing alkalinity
from the crests to the peripheral parts of structures.
t
Total salinity and secondary salinity factor values in hard
waters appearing among the alkaline medium regularly
declines up the Pliocene section.
t
Horizontally from central to peripheral parts of structures,
the water type and salinity in the Pliocene intervals occurs
by zones, through the areals of mandatory sequential distri-
bution of chlorine-calcium, “transitional”, chlorine-magne-
sium, sulphate-sodium and hydrocarbonate-sodium waters
that are replaced by high-alkalinity low-salinity waters of the
regional hydrochemical background.
t
In the Pliocene complexes the alkaline waters of the produc-
tive areas on local structures, compared to the background
waters, have 1.5-2 times higher salinity and strongly low-
ered primary alkalinity factor values.
t
In the Pliocene complexes the oil and gas-related hydro-
chemical anomalies of high-salinity hard and “transitional”
varieties against the general low-salinity hydrocarbonate-
sodium background waters are usually associated with
zones, areas (foci) of relatively unobstructed hydrodynamic
discharge; spatially, they correspond with maximum faulted
parts of local structures.
