acidic lava

acidic lava

[ə′sid·ik ′lä·və]
(geology)
Extruded felsic igneous magma which is rich in silica (SiO2 content exceeds 65).
References in periodicals archive ?
Extensive basic and acidic lavas cap the Karoo Supergroup and their extrusion preceded the fragmentation of Gondwanaland, which began around 200 million years ago and lasted until the proto-Atlantic was formed about 120 million years ago.