Squaring The Circle, A Randall Carlson Podcast #071 Breaking: New Evidence & Studies For Younger Dryas Impact Hypothesis - Squaring The Circle: A Randall Carlson Podcast
Dec 6, 2025
John Arthur, research collaborator who reviews impact-crater literature and provides technical commentary. They explore new Chinese crater discoveries like Jinlin and Shuiyan. Short dives explain planar deformation features, polymict breccias, shatter cones, and microscopic glass evidence. The conversation highlights how these finds expand the catalog of terrestrial impacts and their timing relative to late Pleistocene and Holocene events.
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Shocked Quartz Reveals Impact History
- Planar deformation features (PDFs) in quartz are a diagnostic indicator of hypervelocity impacts and are not produced by volcanic processes.
- Randall Carlson and John Arthur explain PDFs as parallel microscopic striations formed by extreme shock compression, similar to shock from nuclear tests.
Shuiyan Crater Has Deep Breccia and Shocked Quartz
- The Shuiyan (Zhuyan) crater in China is a 1.8 km diameter impact structure filled with >100 m of lake sediment above ~188 m of fallback breccia.
- Researchers found polymict breccia with glass fragments and abundant PDFs in quartz at depths of 260–295 m.
Central Uplift Comes From Rebound and Rapid Cooling
- Large impact craters often show a central uplift formed by elastic rebound and rapid cooling of melted rock.
- Randall Carlson compares this uplift to the upward splash seen when an object hits a liquid, explaining central peaks in multi-ring craters.