The Dnieper-Donets rift is separated from the Ukrainian Shield on the south by the Pripyat-Manych deep border fault and from the Voronezh regional high on the north by the Baranovich-Astrakhan deep border fault. On the surface of the basement these are fault zones 30-40 km wide. Each zone is bounded in most places by two faults, between which is a zone that consists of a system of horsts and grabens. These have been called "paired faults". Each of the faults of the pairs coincides with a gravity gradient.
Maximum thicknesses of volcanic rocks are found where transverse deep structures (highs) intersect the zones of the deep border faults. For example, in the Baranovich-Astrakhan zone, Middle Devonian effusives occur at the junction of this zone with the Novomirgorod-Shorsov transverse deep structure. Thick effusives are found also at the junction with the Brusilov-Kholmech, Kremenetsa, and Tikich-Gomel deep structures.
Six salt-bearing macro-rhythms are recognized in the Baranovich-Astrakhan fault zone. Each begins with carbonate rock and ends with salt.
In contrast to the Baranovich-Astrakhan fault, where the salt is in basins between faults, in the area of the Pripyat-Manych fault the salt is commonly present both in the depressions as well as on the longitudinal basement highs. This appears to be due to repeated reversal of movement along the faults of this zone. These sediments, however, pass into carbonate-clay analogs on the most raised parts of the basement and on some longi- tudinal highs. Six salt-bearing macro-rhythms are also recognized in this zone.
The Devonian salt played an important role in the process of formation of the oil and gas pools in the zones of the deep border faults. They formed the uplifts on which so many pools occur. Pools are also present in traps on the flanks of the salt domes. These pools are largely in Carboniferous sediments; however, in the Baranovich-Astrakhan zone they occur also in Permian, Triassic, and Jurassic rocks.
Taken from Ryabchun, Garvish, and Nedoshovenko, 1986;
digested in Petroleum Geology, Vol. 23, No. 7/8, one map of
basement relief. Copyright 2003 James Clarke. You are
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Some would find fault with the morning sky, if they ever got up
early enough. The fault finder will find faults even in Paradise.
- Henry David Thoreau