Project 2/819 Proceeding of materials obtained from the parametric drill holes on the Peschanoozerskaya Structure (on Arctic islands). Area of work was the north-eastern part of the Kolguev Island (Barents Sea) in the side part of the positive Peschanoozerskaya Structure detected during seismic survey.
Reasons for drilling:
1. Comprehensive study of the geological-geophysical section of the shelf in the area of the Kolguev Island. Study of stratal waters.
2. Identification of the main regularities and features of the geological structure in the drill section.
3. According to the program of drilling on islands and coasts of Arctic seas for creating a network of geological reference points for reliable referencing of geophysical data.
Technical results:
The hole has penetrated the section up to 3507 m and stopped in Late Devonian deposits.
Scientific results:
1. A lithologic and stratigraphic sequence of sedimentary rocks (based on different fauna groups) from Late Devonian to Neogene-Quaternary deposits has been carried out in the studied geological section. Composition of rocks has been studied, rock complexes have been specificated and their geophysical characteristics have been given.
2. Thicknesses of the units are as followed: Late Devonian - 7 m, Carboniferous - 320 m, Permian 1088 m, Triassic - 1317 m, Jurassic - 260 m, Cretaceous - 368 m, Neogene-Quaternary - 96 m.
3. According to rock types the section can be divided to two series. The lower series 3133-3507 m corresponds to the middle series in Hole Kolguev-1-4 and chiefly consists of carbonaceous series accumulated from the Carboniferous to the Early Permian. The upper series 0-3133 m corresponds to the upper series in Hole Kolguev-1-4 and chiefly consists of terrigenous accumulated from the Early Permian to the Cenozoic. The two series form a platform mantle.
4. The series are heterogeneous; both of them can be subdivided. In the lower part of the lower series dolomites with interlayers of anhydrites, limestones and terrigenous mottled rocks occur. In the upper part limestones with interlayers of terrigenous and terrigenous-carbonaceous rocks prevail. The upper series is chiefly composed of terrigenous deposits. Its lower part (the Artinskian and Kungurian stages) is transitional with the significant role of carbonaceous rocks. The upper part comprises silty-sandy and silty-clayey deposits.
5. The hole Kolguev-3 has been drilled in the side part of the positive Peschanoozerskaya structure. That is why thickness of the Triassic deposits in this hole is less than in the hole Kolguev-1-4 drilled in the arch part of the structure.
6. Stratigraphic disconformities occur at the boundaries Devonian-Carboniferous, Early-Middle Carboniferous, Permian-Triassic, Triassic-Jurassic, and Mesozoic-Cenozoic.
7. Many petrophysical relations are similar to ones indicated earlier in the holes drilled on the Franz Joseph Land and on the continent.
8. The obtained data indicate belonging of the area to the Pechora tectonic depression
