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A 20-km-diameter multi-ringed impact structure in the North Sea
Simon A Stewart1, Philip J Allen
1BP plc, Burnside Road, Dyce, Aberdeen AB21 7PB, UK. stewartsa1@bp.com
Nature
|August 2, 2002
Summary
A well-preserved 20 km wide impact structure with ten concentric rings was discovered in the North Sea. This finding challenges previous assumptions about the formation of such impact craters on terrestrial planets.
Area of Science:
- Geology
- Planetary Science
- Impact Cratering
Background:
- Terrestrial impact craters are often eroded and poorly preserved.
- Previous research suggested small-scale multi-ringed impact structures were unlikely on terrestrial planets.
Purpose of the Study:
- To describe a newly discovered multi-ringed impact structure in the North Sea.
- To analyze the formation and preservation of this impact structure.
Main Methods:
- Analysis of three-dimensional seismic reflection data.
- Mapping of concentric ring structures in Cretaceous chalk and Jurassic shales.
Main Results:
- Discovery of a 20 km diameter impact structure with at least ten concentric rings.
- The structure is well-preserved beneath Tertiary strata, dating it to 60-65 million years old.
- Concentric rings identified as fault-bounded graben structures, accommodating post-impact extension.
Conclusions:
- The formation of multi-ringed impact structures at this scale is possible, even on terrestrial planets.
- The ring structures likely formed through detachment on weak rock layers.
- This discovery provides new insights into impact cratering processes.
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