The 18-km-diameter El’gygytgyn crater is located on the Chukotka peninsula, northeastern Russia. It represents the only currently known impact structure formed in siliceous volcanics, including tuffs. The impact melt rocks and target rocks provide an excellent opportunity to study shock metamorphism of volcanic rocks. The shockinduced changes observed in porphyritic volcanic rocks from El’gygyt...

Abstract The Mesoproterozoic MARA terrane of western South America is a composite igneous-metamorphic complex that important for Paleozoic paleogeographic reconstructions and the relative positions Laurentia Gondwana. magmatic detrital records are consistent with Laurentian origin; however, metamorphic deformation lack sufficient detail to constrain correlation units within timing mechanisms ac...

INTRODUCTION The redox state of sillimanite zone (650–700°C, 5–6 kbar) metasediments of the Barrovian type area, Scotland, was investigated The chemical and mineralogical evolution of the crust using estimates of metamorphic oxygen fugacity (fO2 ), sulfur fugacity during orogenesis is critically dependent upon the redox (fS2 ), and fluid chemistry based on new determinations of mineral state of...

Ke y w o r d s : impact features, shock metamorphism, shock waves, minerals, crystal structure, defects, experimental study Apollo Luna Earth N um be r of c ra te rs ( > 1 km ) pe r km 2 0.04

U-Pb analyses of zircon from ten samples of augen gneisses, eight mafic and intermediate metaigneous rocks and six metasediments from some tectonic domains along the Calabria-Peloritani Terrane (Southern Italy) contribute to knowledge of peri-Gondwanan evolution from Late-Proterozoic to Paleozoic times. All samples were equilibrated under amphibolite to granulite facies metamorphism during the ...

a r t i c l e i n f o a b s t r a c t Abstract interpretation Program semantics Metamorphic malware detection Self-modifying programs Metamorphic code includes self-modifying semantics-preserving transformations to exploit code diversification. The impact of metamorphism is growing in security and code protection technologies, both for preventing malicious host attacks, e.g., in software divers...