The tectonized central peak of the Mjølnir Impact Crater, Barents Sea
| Autor: | Romain Corseri, Sverre Planke, Sébastien Gac, Jan Inge Faleide |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
010504 meteorology & atmospheric sciences
Deformation (mechanics) Geology 010502 geochemistry & geophysics 01 natural sciences Paleontology Tectonics Impact crater VDP::Mathematics and natural science: 400::Geosciences: 450::Sedimentology: 456 Infill Sedimentary rock Compression (geology) VDP::Matematikk og Naturvitenskap: 400::Geofag: 450::Sedimentologi: 456 0105 earth and related environmental sciences |
| ISSN: | 0191-8141 |
| Popis: | The Mjolnir structure, SW Barents Sea, is one of the best-preserved marine impact craters on Earth. After impact on the paleo-seafloor about 142 Ma ago, this crater experienced an atypical deformation of its central peak, which is now elevated ~435 m above the crater rims. Here, we investigate the effect of far-field tectonic stresses on the central peak uplift based on interpretation of new high-resolution P-Cable and conventional seismic reflection data. Nearby wells provided stratigraphic control on the interpreted horizons. The reconstruction of the crater sedimentary infill supports a subdued original central peak relief with a 5 km-wide, gentle mound ~15 m below the rim. Our interpretation shows that subvertical, outward-dipping, impact-induced faults were reactivated by uplifted segments of the central peak up to 500 m above the platform level during one or several contractional episodes. We postulate that post-Albian tectonic compressional events triggered the structural uplift of the Mjolnir central peak. Differential compaction, previously seen as the main deformation process, may have increased the original central peak height by only ~10 m. The mobilization of impact-shattered rocks by tectonic compression provides a new and robust explanation for the structural rise of Mjolnir's central peak. |
| Databáze: | OpenAIRE |
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