As witnesses to the Tertiary volcanism of the area there are lava plains and isolated hills of basalt and phonolite.
22.
The main volcanics at Hoodoo Mountain are phonolite and comendic trachyte lavas and hyaloclastites, although some pyroclastic rocks also exist.
23.
Phonolite tuff was used as a source of flint for adze heads and such by prehistoric man from Hohentwiel and Hegau, Germany.
24.
The igneous material that forms the Tower is a phonolite columnar basalt, which are superficially similar, but with columns typically diameter .)
25.
The subvolcanic and intrusive rocks of the central Kaiserstuhl are plutonic equivalents of the erupted material ( essexite, carbonatite and coarse-granular phonolite ).
26.
The latter two are dark green minerals, which occur as original constituents of igneous rocks rich in sodium, such as nepheline-syenite and phonolite.
27.
This highly dissected volcanic edifice consists of a variety of rock types, including basanite, hawaiite, trachyte, rhyolite, phonolite and alkali olivine basalt.
28.
Rarely, economically mineralised phonolite-nepheline syenite alkaline complexes can be associated with rare earth mineralisation, uranium mineralisation and phosphates, such as at Phalaborwa, South Africa.
29.
Its geology consists of the formation known as the Old Volcanic Complex formed between 3 to 2 million years ago, it consists of basanite, tephrite and phonolite rocks.
30.
In those years he studied the phonolite of Lages, Santa Catarina ( 1933 ) described the rocks and geology of the former Federal District, covering the Rio de Janeiro.
