Answer | Crossword Clue |
---|---|
silurian | the Silurian Period or System of rocks |
carboniferous | The Carboniferous period or the system of rocks deposited during it |
tertiaries | The Tertiary period or the system of rocks deposited during it |
triassic | The Triassic period or the system of rocks deposited during it |
paleocene | The Paleocene epoch or the system of rocks deposited during it |
oligocene | The Oligocene epoch or the system of rocks deposited during it |
paleozoic | The Paleozoic era or the system of rocks deposited during it |