Polyhalite microfabrics in an Alpine evaporite melange: Hallstatt, Eastern Alps.

ABSTRACT: In the Hallstatt salt mine (Austria), polyhalite rocks occur in 0.5-1 m thick and several metre long tectonic lenses within the protocataclasite to protomylonite matrix of the Alpine Haselgebirge Fm.. Thin section analysis of Hallstatt polyhalites reveals various fabric types similar to metamorphic rocks of crust-forming minerals, e.g. quartz and feldspar. Polyhalite microfabrics from Hallstatt include: (1) polyhalite mylonites, (2) metamorphic reaction fabrics, (3) vein-filling, fibrous polyhalite and (4) cavity-filling polyhalite. The polyhalite mylonites contain a wide range of shear fabrics commonly known in mylonitic quartzo-feldspathic shear zones within the ductile crust and developed from a more coarse-grained precursor rock. The mylonites are partly overprinted by recrystallised,

SUBMITTER: Schorn A 

PROVIDER: S-EPMC4689184 | biostudies-literature | 2013 Jan

REPOSITORIES: biostudies-literature