11. Basement rocks consist of Ordovician clastic sediments consisting of phyllite with some sandstone interbedding.12. The break-up of Pangea resulted in the break-up of the Paleozoic metamorphic basement rock . 13. The basin is centered in Gladwin County where the Precambrian basement rocks are deep. 14. They are metamorphosed basement rocks from prior to the Miocene. 15. Other basement rocks are the sandstone-containing marine Devonian-Carboniferous Lila faults. 16. The Ravensthorpe region is underlain by basement rocks of the Albany-Fraser Orogen and Yilgarn Craton. 17. Lava from the western flank flowed over basement rocks and trachytes of the pre-explosive phase. 18. To the north of the N 065-striking fault the basement rocks consist of Plagioclase-bearing paragneisses. 19. The granitic basement rocks were of late Jurassic age. 20. The Patuxent is the basal unit of the Coastal Plain sedimentary formations and basement rocks .
