Geology Reference
In-Depth Information
in the Christianitos Creek and San Clemente fields in the southern part of
the basin. Total salinity of the waters is 126.3
−
133.0 mg.-equiv. (36.1
−
38.0
g/l) with the secondary salinity factor 13.7
14.2%-equiv.
Ground waters from the
Middle Miocene
complex (Topanga Fm.) were
obtained in the Wilmington, Inglewood, Sunset Beach and Puente Hills
fields and belong with the chlorine-calcium type. Total salinity is 108.5
−
−
120 mg.-equiv. (31
12.5%-equiv.
he
Upper Miocene
complex (Puente Fm.) includes chlorine-calcium
ground waters with salinity of 92.8
−
34.3 g/l), secondary salinity factor, 8.9
−
−
99.6 mg.-equiv. (26.5
−
28.5 g/l)
and secondary salinity factor, 2.1
9.2%-equiv. (Torrance, Wilmington,
Inglewood, Dominguez, Long Beach, Sid Beach, Huntington Beach, Santa
Fe Springs, Brea Olinda and Montebello fields).
he
Lower Pliocene
complex (Repetto Fm.) is saturated mostly with
hydrocarbonate-sodium waters. However, in the most productive fault-
blocks of some fields (usually most fractured crestal zones of a local
structure) sporadic presence is recorded of the chlorine-calcium and “tran-
sitional” chlorine-magnesium and sulphate-sodium varieties (Long Beach,
Seal Beach, Huntington Beach and Santa Fe Springs fields).
Alkaline waters of the hydrochemical background (distant beyond-
the-contour areas of accumulations and nonproductive fault-blocks) have
total salinity 52.5
−
−
61.4 mg.-equiv. (15
−
17.5 g/l) at primary alkalinity factor
27.2
12.0 mg.-equiv. A clear correla-
tion is recorded between salinity and primary alkalinity factor values (as
salinity grows the primary alkalinity declines).
Chlorine-calcium waters in their ion-salt composition and salinity are
almost identical with waters from the Miocene series. They are found in
combination with specific conditions of their localization and manifes-
tation, which suggests their injection into the Pliocene section from the
underlying sediments.
An intermediate position between background and hard ground water
varieties occupy alkaline waters produced from productive fault-blocks in
most fields of the region (Torrance, Wilmington, Seal Beach, Dominguez,
Rosekrantz and West Coyote). They have high total salinity of 82.6
−
37.1%-equiv. Total alkalinity is 9.6
−
−
96.7
mg.-equiv. (23.6
−
27.6 g/l) and an extremely low primary alkalinity factor
of 2.1
15.2%-equiv.
The waters in the
Upper Pliocene
complex (Pico Fm.) are mostly of the
hydrocarbonate-sodium type with salinity 40.4
−
−
24.4 g/l). The primary alkalinity factor ranges between 6.4 and 46.2%-
equiv. In some most productive areas and fault-blocks, are sporadically
present higher salinity (89.5
−
85.4 mg.-equiv. (11.5
27.5 g/l) “tran-
sitional” chlorine-calcium, chlorine-magnesium and sulphate-sodium
−
96.2 mg.-equiv. or 25.7
−
