arkose

/ahr-kohs/US // ˈɑr koʊs //UK // (ˈɑːkəʊs) //

阿卡索,阿克塞,阿卡索斯,阿库斯

Definitions

n.名词 noun

1
- : a granular sedimentary rock composed of quartz and feldspar or mica; a feldspathic sandstone.

Its heavy concentration of feldspar grains — known as arkose — means the rock is inevitably prone to chemical decay.
The lowest cretaceous rocks yet found are composed of an arkose, derived in large part from the original igneous mass.
At the base there is often an arkose, composed largely of fragments of serpentine and granite derived from the ancient floor.