11. These consist of alkali-feldspar porphyritic quartz-trachyte and trachyte. 12. These consist of alkali-feldspar porphyritic quartz-trachyte and trachyte . 13. Later activity produced trachyte and phonolite plugs and lava flows. 14. Volcanic equivalents would be dacite, trachyte and trachydacite. 15. Rock types include trachyandesite, trachyte , syenite and amphibole-biotite granite. 16. These include nephelinite, basanite and peralkaline phonolite, trachyte and comendite lavas. 17. Pumice and trachyte eruptions at Puu Waawaa may be a sign of this change. 18. It occurs in sills as well as in the volcanic rocks andesite and trachyte . 19. The mountain is basically a column of trachyte . 20. On the village s outskirts is an old quarry where trachyte was once mined.
