Geology Reference
In-Depth Information
east flank of the South Caspian Depression are published by Kolody and
Kudelsky (1972).
On the other hand, geologic features of the South Caspian Depression
do not facilitate a current development there of an active elision regime.
Two factors that determine the existence in the Mesozoic section of a stag-
nant hydrodynamic environment with a predominantly vertical discharge
of the Middle Jurassic-Valanginian hydrocarbonate-sodium water through
the system of tectonic unconformities (faults) are:
t
Wide development in the Mesozoic section of compact clays
incapable of releasing significant volumes of squeezed-out
waters and the phenomenon of tectonic (see Figure 5.4).
t
Lithological barrier in the direction of their possible flow
from the central depression toward its flank zones.
The latter is supported by the present-day hydrochemical zoning of
the Mesozoic deposits (see Chapter 2), by ascending springs of the depth-
generated ultra-alkaline waters, by AHFP manifestations spatially associ-
ated with faults and fracturing, by powerful eruptions of alkaline waters
from mud volcanoes, etc. (Akhundov, Mekhtiyev and Rachinsky, 1976;
Durmishyan, Muradian and Rachinsky, 1982).
The issues of ground water dynamics in the
Paleogene-Miocene
complex
were not paid attention to until recently because it was assumed that the
elision regime is developed in the complex in its deep zones and the infil-
tration regime in the exposed areas (Southwestern Kobystan, northwestern
part of the Apsheron Peninsula).
A peculiar litho-tectonic environment of the Paleogene-Miocene series
is caused by:
t
Lens-shaped structure.
t
Low permeability, thickness and substantial variability of
reservoir members.
t
Their replacement by clays down the regional dip.
t
Mostly clayey nature of the section.
t
Contact between heterochronous stratigraphic intervals
across the regional faults (Gidjaki-Suleyman, Sundi-Cheildag,
Adjiveli-Umbaki, Arzani-Klych, Nardaran-Adjiveli,
Suleyman-Umbaki, Cheildag-Ragim and others; Figure 5.5).
t
High-amplitude sequential subsidence of individual tec-
tonic blocks, etc.
