rhyolite

/rahy-uh-lahyt/US // ˈraɪ əˌlaɪt //UK // (ˈraɪəˌlaɪt) //

流纹岩,流纹石,流沙岩,流云岩

Definitions

n.名词 noun

1
- : a fine-grained igneous rock rich in silica: the volcanic equivalent of granite.

This is shown in the glaciated rock-surfaces of the rim that are covered with layers of pumice and rhyolite.
Granite is an acidic rock corresponding to rhyolite in chemical composition.
The oldest volcanic rock appears to be rhyolite, which peers up in two small hills almost smothered beneath the lake deposits.
Basalt is less siliceous than granite and rhyolite, and contains much more iron, calcium, and magnesium.
Rhyolite and other forms of lava were last spread over the region.