THE NEPSKY-1 IMPACT CRATER AND ITS FILL DEPOSITS ON THE BASEMENT ROOF OF THE SIBERIAN PLATFORM
In the Earth studies, discoveries and investigations of impact craters buried beneath thick sediments are sporadic so far and may still remain inefficient, unless geophysical surveys of the areas of interest are initiated. Such studies can provide useful data to develop the knowledge about cosmic ev...
Saved in:
| Main Authors: | , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Russian Academy of Sciences, Siberian Branch, Institute of the Earth's crust
2020-12-01
|
| Series: | Геодинамика и тектонофизика |
| Subjects: | |
| Online Access: | https://www.gt-crust.ru/jour/article/view/1120 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1849771369919676416 |
|---|---|
| author | M. I. Gyokche A. V. Plyusnin |
| author_facet | M. I. Gyokche A. V. Plyusnin |
| author_sort | M. I. Gyokche |
| collection | DOAJ |
| description | In the Earth studies, discoveries and investigations of impact craters buried beneath thick sediments are sporadic so far and may still remain inefficient, unless geophysical surveys of the areas of interest are initiated. Such studies can provide useful data to develop the knowledge about cosmic events of the past geological eras, as well as contribute to industrial development of the areas. It is known that an impact crater is filled with layered deposits that create specific sequences and are generally thicker that deposits outside the crater. We have investigated a Precambrian crater located in the southern part of the Nepa-Botuoba anteclise of the Siberian platform. This impact crater called Nepsky-1 was discovered by seismic surveys using the common depth point method (CDPM). In our study, we used the geological and geophysical deep-drilling data of three wells, including gamma-ray and neutron logs and lithological core descriptions. With reference to the concepts of regional geological conditions, we reconstructed the conditions of sedimentation in the study area based on a comprehensive analysis of the structural and textural features of the rocks, and logging and seismic survey data. By processing and interpretation of the CDPM 3D seismic survey data, we obtained the structural images and cross-sections of the impact crater and analysed the thickness of its fill deposits. The Nepsky-1 crater is a bowl-shaped structure with a rim composed of allogenic breccia. In the area around the crater, fault systems are detected. Based on the core sample analysis, we identified the lithological members of the crater and its rim and described them in detail. Active compensation with lacustrine-delta sediments took place in the Nepa period of the late Vendian. By the end of the Tira time, the crater was completely leveled up. In our study, we obtained the first data on the structure of the crater section of the Vendian deposits. Sedimentation in the study area was controlled by the sea level changes. The main terrigenous productive horizons are confined to sandstones that accumulated during the sea level low stand, and found at the bottoms of the lower and upper Nepa subsuites, as well as at the bottoms of the lower and upper Tira subsuites. It is established that the study area was tectonically active in the late Tira time. As a result, the sediments filling the crater were removed to subaerial conditions, and the edges of the allogenic breccia rim were partially destroyed and formed granite breccia outgrowths observed in the rim’s cross-section. We conclude that in the Nepa and Tira times, tectonic vertical movements initiated relatively fast weathering and transportation of the terrigenous material from the adjacent hills into the sedimentation basin. The Nepsky-1 crater gives evidence of meteorite bombing of the Siberian paleocontinent in Precambrian. Finding similar crater structures can be reasonably expected in the study region. Considering the increased thicknesses of crater fill deposits, buried craters are promising potential for discovering oil-source and overlying seal rocks, which is important for petroleum industry. |
| format | Article |
| id | doaj-art-89f320e0b77a42428d1c009dcc153cc1 |
| institution | DOAJ |
| issn | 2078-502X |
| language | English |
| publishDate | 2020-12-01 |
| publisher | Russian Academy of Sciences, Siberian Branch, Institute of the Earth's crust |
| record_format | Article |
| series | Геодинамика и тектонофизика |
| spelling | doaj-art-89f320e0b77a42428d1c009dcc153cc12025-08-20T03:02:39ZengRussian Academy of Sciences, Siberian Branch, Institute of the Earth's crustГеодинамика и тектонофизика2078-502X2020-12-0111471072110.5800/GT-2020-11-4-0502500THE NEPSKY-1 IMPACT CRATER AND ITS FILL DEPOSITS ON THE BASEMENT ROOF OF THE SIBERIAN PLATFORMM. I. Gyokche0A. V. Plyusnin1Irkutsk Oil Company LLCIrkutsk Oil Company LLCIn the Earth studies, discoveries and investigations of impact craters buried beneath thick sediments are sporadic so far and may still remain inefficient, unless geophysical surveys of the areas of interest are initiated. Such studies can provide useful data to develop the knowledge about cosmic events of the past geological eras, as well as contribute to industrial development of the areas. It is known that an impact crater is filled with layered deposits that create specific sequences and are generally thicker that deposits outside the crater. We have investigated a Precambrian crater located in the southern part of the Nepa-Botuoba anteclise of the Siberian platform. This impact crater called Nepsky-1 was discovered by seismic surveys using the common depth point method (CDPM). In our study, we used the geological and geophysical deep-drilling data of three wells, including gamma-ray and neutron logs and lithological core descriptions. With reference to the concepts of regional geological conditions, we reconstructed the conditions of sedimentation in the study area based on a comprehensive analysis of the structural and textural features of the rocks, and logging and seismic survey data. By processing and interpretation of the CDPM 3D seismic survey data, we obtained the structural images and cross-sections of the impact crater and analysed the thickness of its fill deposits. The Nepsky-1 crater is a bowl-shaped structure with a rim composed of allogenic breccia. In the area around the crater, fault systems are detected. Based on the core sample analysis, we identified the lithological members of the crater and its rim and described them in detail. Active compensation with lacustrine-delta sediments took place in the Nepa period of the late Vendian. By the end of the Tira time, the crater was completely leveled up. In our study, we obtained the first data on the structure of the crater section of the Vendian deposits. Sedimentation in the study area was controlled by the sea level changes. The main terrigenous productive horizons are confined to sandstones that accumulated during the sea level low stand, and found at the bottoms of the lower and upper Nepa subsuites, as well as at the bottoms of the lower and upper Tira subsuites. It is established that the study area was tectonically active in the late Tira time. As a result, the sediments filling the crater were removed to subaerial conditions, and the edges of the allogenic breccia rim were partially destroyed and formed granite breccia outgrowths observed in the rim’s cross-section. We conclude that in the Nepa and Tira times, tectonic vertical movements initiated relatively fast weathering and transportation of the terrigenous material from the adjacent hills into the sedimentation basin. The Nepsky-1 crater gives evidence of meteorite bombing of the Siberian paleocontinent in Precambrian. Finding similar crater structures can be reasonably expected in the study region. Considering the increased thicknesses of crater fill deposits, buried craters are promising potential for discovering oil-source and overlying seal rocks, which is important for petroleum industry.https://www.gt-crust.ru/jour/article/view/1120impact structurecratercrystalline basementseismic datacdpm 3dlithologylake deltanepa suitetira suitevendiansedimentary covernepa-botuoba anteclisesiberian platform |
| spellingShingle | M. I. Gyokche A. V. Plyusnin THE NEPSKY-1 IMPACT CRATER AND ITS FILL DEPOSITS ON THE BASEMENT ROOF OF THE SIBERIAN PLATFORM Геодинамика и тектонофизика impact structure crater crystalline basement seismic data cdpm 3d lithology lake delta nepa suite tira suite vendian sedimentary cover nepa-botuoba anteclise siberian platform |
| title | THE NEPSKY-1 IMPACT CRATER AND ITS FILL DEPOSITS ON THE BASEMENT ROOF OF THE SIBERIAN PLATFORM |
| title_full | THE NEPSKY-1 IMPACT CRATER AND ITS FILL DEPOSITS ON THE BASEMENT ROOF OF THE SIBERIAN PLATFORM |
| title_fullStr | THE NEPSKY-1 IMPACT CRATER AND ITS FILL DEPOSITS ON THE BASEMENT ROOF OF THE SIBERIAN PLATFORM |
| title_full_unstemmed | THE NEPSKY-1 IMPACT CRATER AND ITS FILL DEPOSITS ON THE BASEMENT ROOF OF THE SIBERIAN PLATFORM |
| title_short | THE NEPSKY-1 IMPACT CRATER AND ITS FILL DEPOSITS ON THE BASEMENT ROOF OF THE SIBERIAN PLATFORM |
| title_sort | nepsky 1 impact crater and its fill deposits on the basement roof of the siberian platform |
| topic | impact structure crater crystalline basement seismic data cdpm 3d lithology lake delta nepa suite tira suite vendian sedimentary cover nepa-botuoba anteclise siberian platform |
| url | https://www.gt-crust.ru/jour/article/view/1120 |
| work_keys_str_mv | AT migyokche thenepsky1impactcrateranditsfilldepositsonthebasementroofofthesiberianplatform AT avplyusnin thenepsky1impactcrateranditsfilldepositsonthebasementroofofthesiberianplatform AT migyokche nepsky1impactcrateranditsfilldepositsonthebasementroofofthesiberianplatform AT avplyusnin nepsky1impactcrateranditsfilldepositsonthebasementroofofthesiberianplatform |