| Answer | Crossword Clue |
|---|---|
| erathem | the group of rock strata of a particular era |
| erathems | ERATHEM, the group of rock strata of a particular era |
| terranes | any rock formation or series of formations or the area in which a particular formation or group of rocks is predominant |
| terrane | any rock formation or series of formations or the area in which a particular formation or group of rocks is predominant |
| horizons | A layer of soil or rock, or a set of strata, with particular characteristics |
| supergroup | An exceptionally successful rock group, in particular one formed by musicians already famous from playing in other groups |
| supergroups | An exceptionally successful rock group, in particular one formed by musicians already famous from playing in other groups |
