Support is given to a two-stage model for the salinity of the cover of the
Siberian Platform. Cambrian and Devonian halmeic formations are recognized
in the section and traced laterally. Lower and Middle Paleozoic halmeic bas
ins were limited by intermediate zones providing a persistent regime of sal
t accumulation and supply of mother solutions From the vast seas covering t
he territory of the Patom-Vitim Upland and Upper Yana region. Parameters ar
e given, and paleostructural conditions of accumulation of these formations
are characterized. In some regions and districts of the Lena-Tunguska petr
oliferous province it has been observed that the industrial production of s
ubsalt reservoirs depends directly on the regional persistence and thicknes
s of the saliferous screen. The largest deposits occur in zones of thick te
rrigenous sequences overlapped by regional carbonate-saliferous confining b
eds. Hydrocarbon deposits have not been revealed in the Middle Paleozoic co
mplex yet, though oil, gas. and bitumen occurrences exist there and the geo
logostructural conditions (reservoirs, brachyanticlinal traps, etc.) are fa
vorable for hydrocarbon accumulation. Taking into account regular relations
hips in the Vendian-Cambrian complex, we suppose that the Devonian halmeic
formation is also appropriate For accumulation and preservation of hydrocar
bons in subsalt and intersalt reservoirs.
The recognized structural features of Paleozoic halmeic formations, regiona
l confining beds, permitted us to specify the earlier schemes of petroleum-
geological regionalization of the Siberian Platform. In the Vendian-Cambria
n complex, the main petroliferous belt is the Nepa-Botuobiyan and Baikit an
teclises separated by the Katanga Saddle. In addition, the Berezovo, Kempen
dyai, and Ygyatta troughs, Suntara uplift, and favorable structures of the
central regions of the Angara-Lena trough are estimated as highly promising
. The Devonian subsalt and intersalt reservoirs are of greatest practical i
nterest in the favorable zones of the West Vilyui potentially petroliferous
region. The Atyyakh, Uchugei, and Kedepchik structural stages are top-prio
rity objects For seismic prospecting and deep drilling there.