1. The Thirlstane Basalt is above at, an alkali-olivine basalt . 2. Their compositions range from alkali olivine basalt to basanitic. 3. At St Marys there were two volcanic eruptions of alkali-olivine basalt at. 4. From near Hobart there is olivine basalt from. 5. Once the alkali olivine basalt flows cooled, they formed well-developed columnar joints. 6. Mount Cameron West has olivine basalt from 15.5 and 14.4 Ma. 7. Most of the soil consisted of olivine basalt sands that did not come from the local rocks. 8. The Thumb consists of alkali olivine basalt along with other Quaternary volcanic plugs in the Omineca Mountains. 9. Olivine basalt , basanite and tholeiite have been found as well, with smaller amounts of trachyandesite.10. Hawaiite is the dominant rock type, but alkali olivine basalt and spinel lherzolite-bearing basanite is also present.
