M. Dubois discovered these remains in the island of Java in andesite tufa of Pliocene or at least early Pleistocene age.
Surface eruption of quartz-porphyry, rhyolite, and andesite.
They are found mostly as loose crystals in gravel, but are known also in igenous rocks like andesite and lamprophyre.
A later series of small diorite or andesite dikes cut the ore bodies.
The lavas and ashes ejected by these volcanoes consist of liparite, dacite, andesite and basalt.
The Ochils and other hills of middle Scotland largely consist of andesite.
An examination of the stones which fell at Fort de France showed them to be of a variety of lava called hornblende and andesite.
The rocks thus extruded are mainly composed of dark, heavy basic material, such as basalt and andesite.
In the main the lava is an andesite, and is very generally of a porphyritic structure.
The rock in which the Hungarian Opals occur is eruptive, and of the kind known as andesite.
A gray, fine-grained volcanic rock. Andesite consists mainly of sodium-rich plagioclase and one or more mafic minerals such as biotite, hornblende, or pyroxene. It often contains small, visible crystals (phenocrysts) of plagioclase. It is the fine-grained equivalent of diorite.