Polymict Impact Breccia | 209 grams | Lockne Impact Structure, Sweden

This is a must have 209 gram polymict impact breccia from the Lockne Crater located approximately 21 km south of the city of Östersund in northern Sweden.  It is amazingly light considering its mass of 132x63x23 mm.  Although not a meteorite, impactites are directly linked to them and their impacts and are probably going to be one of the rarest collection items you'll ever own. Impactite is a slag-like glassy object found on the surface of the earth, formed from rock melted by the impact of a meteorite.

The term impactite encompasses shock-metamorphosed target rocks, melts or suevites and mixtures of the two, as well as sedimentary rocks with significant impact-derived components and shocked mineral grains, tektites, anomalous geochemical signatures, etc.

Lockne is a 7.5km-wide impact structure that formed circa 455 Ma when an L-chondritic asteroid impacted mixed sedimentary and crystalline target rocks that were under a shallow epicontinental sea (500m deep) at the time. The feature and its surrounding impactite deposits were covered by Caledonian thrust nappes that also partly folded them.

Erosion has breached much of the overthrust rocks to show the impact site. Impactites include the Loftarstone (graywacke-like arenite with carbonate grains), Lockne Breccia (polymictic but mostly limestone clasts), Resurge deposits, Ynntjämen Breccia (monomictic, matrix-supported with calcareous-argillaceous matrix) and the Tandsbyn Breccia (monomictic crystalline ejecta).  This crater has been suggested to be a doublet with the nearby smaller Målingen Crater, 16 km apart.

This gorgeous large slice displays very well.  It would be a beautiful addition to any new or existing collection. Comes with a Canagem Collection specimen card.