11. A lava lake formed temporarily between the bottom of the new Pariou and the borders of the tuff ring . 12. A smaller vent and small tuff ring , in diameter, are located on Moffitt Butte's southwestern flank. 13. Quarrying has removed the small scoria cone in the crater and some of the tuff ring on the northeast side. 14. A number of basaltic phreatomagmatic deposits, frequently associated with tuff rings , have a dispersal index of less than. 15. In contrast to tuff cones, the crater of a tuff ring generally has been excavated below the existing ground surface. 16. It is across and its drained and sediment-filled flat floor is below the rim of the surrounding tuff ring . 17. The maximum thickness of the pyroclastic debris comprising the rim of a typical tuff ring is generally thin, less than to thick. 18. An earlier explosive eruption, created the prominent tuff ring that is still clearly visible extending in an arc south of Sunderlands Road. 19. This is because the lava flow is " rootless " meaning that it begins outside of the tuff ring directly around the vent. 20. A small scoria cone reaching above sea level, with a shallow St John's Church built on the tuff ring crest.
