Geology Reference
In-Depth Information
t
Areas of strong faulting, diapirism, etc. (Geodekian, 1968;
Krishnan, 1964; Kuchapin, 1953; Tainsh, 1950).
Clear association is noted in the Viennese and Pannonian Basins
between oil and gas accumulations and ground water discharge areas
(Steinberg, Schrattenberg, Lozhice-Brodsk, and Godonin group of thermal
sources, Hungarian thermal zone, Banat, Dravy and other depressions).
They are connected with saline lakes (the Bakon High, Byukk area, Great
Hungarian plain, Small Hungarian depression, Pre-Dinar zone and North
Belgrade area), surface oil and gas shows and thermobaric anomalies
(Boldizhar, 1975; Varentsov, 1948; Gurevich, 1980; Dolenko, 1974; Kolesik,
1966; Boldizar, 1968).
The role of faults and geo-fluid-dynamic system drainage zones in the
formation and placement of hydrocarbon accumulations is best seen within
the South Caspian Depression, reviewed in detail below as the type model.
There on the Apsheron Peninsula, practically all oil and gas (gas-con-
densate) fields are associated with the areas of intense present-day dis-
charge. These areas are represented on the surface by:
t
Numerous deep-feed salt lakes (about 200 of them in an area
of 2,000 km
2
).
t
Ascending thermal sources.
t
Travertine sinters.
t
Calcite-filled fractures.
t
Oil and gas shows.
t
Mud volcanoes.
t
Necks.
t
Kir sheaths.
t
Asphalt lakes, etc.
A similar situation occurs in the other oil-gas areas of the basin. This
is indicated by a consistent spatial conjunction between the fields, areas
of mud volcano activity (the Lower Kura Depression, Djeiranchekmes
Depression, Kobystan) and zones of strong underwater fluid discharge
forming oil and gas shows at sea and underwater mud volcano erup-
tions (Apsheron and Baku Archipelagos, Apsheron-Balkhan Sill). Specific
examples of the association between fields and zones of surface ground
water discharge are listed in Table 7.2.
Along with the described surface discharge, subsurface ground water
drainage is common in the South Caspian region. It is represented by
