Suevite
Suevite is an impact breccia, a rock made of shattered target rock and fragments of glass and melt produced by a meteorite impact, welded in a fine matrix. It is named for Suevia, the Latin name of Swabia, after the Ries crater in Germany.
Suevite is an impact breccia, a rock made of shattered target rock and fragments of glass and melt produced by a meteorite impact, welded in a fine matrix. It is named for Suevia, the Latin name of Swabia, after the Ries crater in Germany.
🪨 Geology Guide Specimen: Open Impact Suevite Breccia in the CRV Science Rock & Mineral ID Guide to log the specimen, compare it with the other 6 subgroups of Metamorphic, and test your eye in LithoClade.
Shock Metamorphism: What Does an Impact Do to Rock?
A hypervelocity impact sends a shock wave through the target in milliseconds, at pressures far beyond those of any normal geological process. Quartz develops sets of microscopic planar fractures and can convert to the dense forms coesite and stishovite, which are diagnostic of impact.
Melt and Glass: What Are Flädle?
Suevite includes bombs and lenses of quenched impact melt. The twisted, flattened glass fragments in the Ries suevite are known as Flädle, from a German word for pancakes. The rest is a mixture of shattered crystalline and sedimentary fragments cemented in fine material.
Famous Craters: Where Is Suevite Found?
Suevite is described from the Nördlinger Ries crater in Germany, about 15 million years old, and from the Chicxulub crater of the end-Cretaceous extinction and others. At Sudbury in Canada the impact melt sheet cooled to form norite and related rocks. Compare ordinary volcanic breccia and sedimentary breccia.
Suevite at a Glance
| Property | Value |
|---|---|
| Type / variety | Shock-Metamorphosed Impact Melt Breccia |
| Composition | Shocked Target-Rock Clasts + Aerodynamic Glass Bombs (Flädle) + Coesite/Stishovite |
| Geology Guide group | Metamorphic Rocks (Foliated, Granoblastic & High-P) |
| Rock Classification | Hydrothermal & Fault Zone |
| Mohs hardness | Mohs 5–7 |
| Texture / habit | Polymict breccia containing contorted dark impact-melt glass lenses |
| Density | 2.25–2.55 g/cm³ |
| Lustre and cleavage | Light grey fragmental matrix with dark aerodynamic glass 'flädle' and shocked quartz |
| Geological setting | Hypervelocity meteorite/asteroid impact craters (e.g., Nördlinger Ries, Chicxulub, Sudbury) |
| Diagnostic feature (Geology Guide) | Crater breccia containing shattered crystalline bedrock clasts, planar-deformed quartz, and dark aerodynamic lenses of quenched rock melt ('flädle') forged in milliseconds by a hypervelocity asteroid strike. |
| Name origin | Suevia, the Latin name of Swabia |
| Diagnostic features | Shocked quartz and impact glass |
See Also
- Norite — a rock of the Sudbury impact melt sheet
- Volcanic Breccia — a breccia formed by volcanic processes
- Sedimentary Breccia — a breccia formed at the surface