trachyte

/trey-kahyt, trak-ahyt/US // ˈtreɪ kaɪt, ˈtræk aɪt //UK // (ˈtreɪkaɪt, ˈtræ-) //

梯田,梯形石,梯形砂岩,蔓生植物

Definitions

n.名词 noun

1
- : a fine-grained volcanic rock consisting essentially of alkali feldspar and one or more subordinate minerals, as hornblende or mica: the extrusive equivalent of syenite.

Trachyte (trachys, rough) is a pale or dark-gray rock, harsh and rough to the touch, in which felspar is the predominant mineral.
Or, again, I see no difficulty in a mass of trachyte being exposed by subsequent dislocations and bared or cleaned by rain.
The volcanic origin of the whole archipelago is proved by the principal rocks being of basalt, trachyte and lava.
Large areas are overlain with trachyte, basalt, obsidian, tuff and pumice.
Trachyte has been extruded in a state so viscid that it has formed steepsided domes like that of Sarcoui (Fig. 230).