ALBERT

Description: 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 arch 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 3730 m and stopped in Early Ordovician deposits. Scientific results: 1. A lithologic and stratigraphic sequence of sedimentary rocks (based on different fauna groups) from Early Ordovician 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: Ordovician 134 m, Devonian 479 m, Carboniferous 302 m, Permian 1052 m, Triassic 1053 m, Jurassic 247 m, Cretaceous 367 m, Neogene-Quaternary 96 m. 3. According to rock types the section can be divided to three series. The lower series 3117-3730 m chiefly terrigenous series accumulated from the Early Ordovician to the Late Devonian. The middle series 2702-3117 m chiefly carbonaceous series accumulated from the Carboniferous to the Early Permian. The upper series 0-2702 m chiefly terrigenous accumulated from the Early Permian to the Cenozoic. The middle and upper series form a platform mantle; the lower series is transitional between the platform mantle and the folded basement. 4. The series are heterogeneous; each of them can be subdivided. In the base of the lower series (3636-3730 m) Early Ordovician quartzitic sandstones occur. They are overlain by Early Ordovician iron-bearing siltstones occurring in the interval 3596-3636 m. In the lower part of the middle 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-1-4 has been drilled in the arch part of the positive Peschanoozerskaya structure. That is why thickness of the Triassic deposits in this hole is higher than in the hole Kolguev-3 drilled in the side part of the structure. 6. Angular and stratigraphic disconformity has been identified at the boundary of the Early Ordovician and Late Devonian. The Ordovician deposits have an angle of inclination of 40-50°. The overlain deposits lay almost horizontally. 7. Stratigraphic disconformities also occur at the boundaries Devonian-Carboniferous, Early-Middle Carboniferous, Permian-Triassic, Triassic-Jurassic, and Mesozoic-Cenozoic. 8. Many petrophysical relations are similar to ones indicated earlier in the holes drilled on the Franz Joseph Land and on the continent. 9. The obtained data indicate belonging of the area to the Pechora tectonic depression.

Description: 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.

Description: Area of drilling: Murmanskaya Area, southern part of the South Barents Deep, Barents Sea. Reasons for drilling: 1. Obtaining additional information on the geological section in the Murmanskaya Area as well as data for stratification of the section and its allocation with reflecting seismic horizons; 2. Study of properties, composition and lithologic-facial features of sedimentary rocks. Technical results: The hole has penetrated the section of 3445 m and stopped in Late Permian deposits. Scientific results: 1. Comprehensive lithologic and paleontological studies (foraminifera, palynology) of drill samples from the hole have allowed to reveal lithologic features and to carry out a detailed lithologic and stratigraphic sequence of sedimentary rocks from Permian to Early Cretaceous ones. 2. Thicknesses of the units are as followed: Permian - 100 m, Early Triassic - 562 m, Middle Triassic - 460 m, Late Triassic - 438 m, Early Jurassic - 329 m, Middle Jurassic (Aalenian-Bathonian) 316 m, Late Jurassic - 125 m (Callovian - 55 m, Oxfordian?-Early Tithonian - 42 m, Middle-Late Tithonian - 28 m), Early Cretaceous - 1019 m (Berriasian - 18 m, Valanginian-Hauterivian - 66 m, Barremian-Aptian - 141 m, Aptian - 303 m, Albian - 491 m). The question about presence or absence of Late Cretaceous and Paleogene deposits (mapped in the South Barents Deep) in the section remains undetermined. Presumably these deposits have low thickness and occur above the sampling interval. 3. Pre-Valanginian washout and weathering crust have been identified. Hiatuses are assumed in the post-Jurassic, post-Valanginian, and pre-Cenozoic time. 4. Clayey-silty sedimentary rocks dominate in the hole. Silty-sandy rocks dominate in the Early and Middle Jurassic. 5. Coals of the gas stage metamorphism occur in the Permian, Late Triassic, Middle Jurassic and Late Aptian deposits. 6. Sedimentation environment has been reconstructed. Upper Permian sediments accumulated in near-shore marine and lagoonal-marine conditions. Triassic to Early Jurassic sediments accumulated in lagoonal-continental and continental conditions. Middle Jurassic to Early Cretaceous sediments accumulated in a marine basin. The marine basin was mainly shallow. Its greatest deepening was in the Late Jurassic. 7. Sedimentation rate varied from 0.3 cm/kyr in the Late Jurassic to 10 cm/kyr in the Early Triassic. 8. Sedimentary rocks are lithified from ones affected by deep epigenesis to ones affected by early epigenesis. 9. Mineral composition of sedimentary rocks from the Murmansk area strongly differs from one of deposits in the Kolguev Island and the Timan-Pechora region.