1) Metamorphic rock
Found on
https://www.crosswordclues.com/clue/killas
Killas is a Cornish mining term for metamorphic rock strata of sedimentary origin which were altered by heat from the intruded granites in the English counties of Devon and Cornwall. The term is used in both counties. ==Origin== The deposition of the killas strata occurred during the Devonian and Carboniferous geological periods. The sediments are...
Found on
http://en.wikipedia.org/wiki/Killas
clay slate
Found on
http://phrontistery.info/k.html
No exact match found.
