| 11. | Most importantly, they sequentially replaced one another as dominant groups during the Phanerozoic.
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| 12. | Oldest to newest these are the Hadean, Archean, Proterozoic, and Phanerozoic.
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| 13. | Phanerozoic ironstones generally have a different genesis.
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| 14. | It is likely that the group has evolved minimally over the course of the Phanerozoic.
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| 15. | In the Sahara they are mostly covered by more recent sediments from the Phanerozoic Eon.
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| 16. | Pellets occur in Precambrian through Phanerozoic strata.
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| 17. | It marks the end of the Proterozoic Eon, and the beginning of the Phanerozoic Eon.
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| 18. | Prior to the Phanerozoic ( before 544 Ma ), it is believed that continental shelves.
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| 19. | Frenchman Mountain exposes a sequence of Phanerozoic strata equivalent to those found in the Grand Canyon.
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| 20. | These first appear after the boundary between the Proterozoic and Phanerozoic eons or Ediacaran and Cambrian periods.
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