A unique rock formation in China holds clues that tectonic plates subducted, or went underneath other plates, during the Archean eon (4 billion to 2.5 billion years ago), just as they do nowadays, a ...
Three specimens have been studied of the rare kyanite eclogite nodules in kimberlite from the Roberts Victor mine, South Africa. All are essentially the same with the primary assemblage: kyanite, ...