21. Related to Greywacke , it comprises fine to medium-grained lithic sandstone. 22. It favours rocky habitats, particularly greywacke screes. 23. On the northeast a patch of Ordovician Pittman Formation greywacke outcrops along Canberra Avenue. 24. A patch of Ordovician Pittman Formation greywacke outcrops in the south along Canberra Avenue. 25. There is a beach of greywacke shingle along the east side of the island. 26. The Wadi Hammamat was a notable source of granite, greywacke , and gold. 27. Almost all the land that broke the surface of the sea was Torlesse Greywacke . 28. Geologically the peninsula consists of Waitemata Sandstone on top of folded and uplifted greywacke . 29. These deposits were kilometers thick and compressed, folded and heated became hard greywacke . 30. Locally, the greywacke and arenite are cut by quartz veins and are mineralized.
