Inversed rift systems on the shelf of the Chukchi Sea (Arctic region)
Abstract
In recent years we received a lot of new seismic lines in Russian Arctic. We present new version of geological history of the Chukchi Sea based on interpreting of seismic data of the Pegtymelsky rift region.
Pegtymelsky rift is a unique place where we can see all tectonic events of Chukchi Sea. It is an inversed rift with several phases of rifting and deformation. In Pegtymelsky rift there were two phases of rifting: in Aptian-Albian and in Cenozoic. Between these phases there was a stage of inversion at the Cretaceous/Paleogenic boundary. Interpreting the seismic data (figure), we found out two main angular unconformities with age before 34 Ma and 20 Ma and, as a result, two main phases of deformation with the same age. Generally, we can say that inversion of the rift started 34 Ma and had finished 20 Ma. So in this region there was Oligocen-Miocen phase of deformation that is known in the Southern Chukchi basin. The younger tectonic deformations can be assumed after 20Ma. This idea is based on different thickness of upper stratigraphic units. We also created balanced section for this region and have got not very high β-factor. So, we can say that extension of the rift was moderate. The reported study was funded by RFBR according to the research project №18-05-70011. Figure. Interpretation of composite seismic profile for the Chukchi Sea. Location of the profile is shown on the map. A. Seismic profile for the Pegtymelsky inversed rift. B. Interpretation is performed with a technical procedure of flattening of seismic horizon. Flattening on the horizon 20 Ma.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.T33G0441P
- Keywords:
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- 8105 Continental margins: divergent;
- TECTONOPHYSICS;
- 8109 Continental tectonics: extensional;
- TECTONOPHYSICS;
- 8120 Dynamics of lithosphere and mantle: general;
- TECTONOPHYSICS;
- 8159 Rheology: crust and lithosphere;
- TECTONOPHYSICS