Newly detected shock-induced high-pressure phases formed in amphibolite clasts of the suevite breccia (Ries impact crater, Germany): Liebermannite, kokchetavite, and other ultrahigh-pressure phases

Abstract Amphibolite clasts in the suevite of Ries impact crater contain shock-induced melt veins (SMVs) with high-pressure phases such as majoritic garnet, jadeitic clinopyroxene and others. In addition, heat conduction from hot SMVs into adjacent rock portions locally produced further high P – T pools. These melts were preferentially generated domains, where cross older (‘pre-Ries’) veinlets analcime or prehnite larger grains sericitized plagioclase. Melting chemically different local bulk systems (Na-, Ca-, Ca-Na- K-Na-rich) was facilitated by low solidus temperatures original secondary OH-bearing phases. From resulting melts, liebermannite, kokchetavite, jadeite, nonstoichiometric albitic grossular, vuagnatite, lawsonite + coesite, clinozoisite crystallized during pressure release. Vuagnatite is now proven to be a genuine phase. Its ubiquitous distance 20–35 μm shock suggests temperature sensitivity typical for an Na-rich jadeite appears instead assemblage SiO 2 . Liebermannite, dense polymorph K-feldspar identified Raman spectroscopy. After stishovite, liebermannite constitutes second known phase that contains silicon exclusively six-fold coordination. The KAlSi 3 O 8 -polymorph kokchetavite formed alkali-rich glasses. Pressure values range about 8–11 GPa ~ 800–1100 °C estimated chemical compositions occurring garnets (Si = 3.21–3.32 3.06–3.10 apfu), respectively, presence fine-grained aggregates coesite. Generally, neighboring areas are characterized sequence variable documenting strongly falling P–T conditions increasing vein. novel features enlighten dynamic event passage wave.