Amoeboid olivine aggregates (AOAs) from the Kainsaz CO3.2 chondrite were analyzed using transmission electron microscopy in order to gain a more complete understanding of thermal metamorphism on parent body and role fluids during metamorphic heating. The AOAs are dominated by strongly zoned, fine-grained, grains (Fa2-31) with heterogeneous Fe enrichments along grain boundaries, which interprete...

The Palaeoproterozoic Great Slave Lake shear zone (GSLsz) is a crustal-scale strike-slip structure, with total length of >1,000 km and width ~25 km, that separates the Archean Rae cratons. range metamorphic rocks now exposed at surface encompasses granulite facies mylonite through to lower-greenschist ultramylonite cataclasite, providing potential type example fault-zone structure in middle low...

Introduction: The age significance of isotope chronometers in basaltic shergottites is not agreed yet [1-3]. Bouvier et al. [3] argued that crystallization ages of shergottites were old (~4.1 Ga), and suggested that young ages of shergottites (i.e., ~180 Ma) represent reset by shock metamorphism. Baddeleyite (ZrO 2) is an important mineral for U-Pb dating of basaltic shergottites. By compressio...

The Puncoviscana Formation, largely cropping out in NW Argentina, is mainly composed of a pelite-greywacke turbidite sequence affected by incipient regional metamorphism and polyphase deformation. Metapelites, composed mainly of quartz, albite, dioctahedral mica and chlorite, were sampled in the Lules-Puncoviscana and Choromoro belts. Lattice-fringe images, selected area electron diffraction an...