| In the south of the island there are sills and dykes of felsite, quartz-porphyry, rhyolite, trachyte and pitchstone. |
| Not a single specimen of its trachyte has ever been deposited in a European museum. |
| Upon this rests a pumiceous breccia and conglomerate, with angular masses of trachyte, and some quartz pebbles. |
| They are chiefly leucite and nepheline rocks, such as leucitite, leucitophyre and nephelinite, but basalt and trachyte also occur. |
| South of the city of Isparta pyroclastic rocks are interbedded with rhyolite, trachyte, phonolite and lamproite flows. |
| The trachyte which once formed the summit of this mountain is now spread in fragments over the plain of Riobamba. |
