Produced by eruption; as, eruptive rocks, such as the igneous or volcanic.

An eruptive rock.

igneous rock produced by eruption and solidified on or near the earth's surface; rhyolite or andesite or basalt; "volcanic rock includes the volcanic glass obsidian"

Attended with eruption or efflorescence, or producing it; as, an eruptive fever.

erupting or tending to erupt; "a geyser is an intermittently eruptive hot spring"

Solar activity levels with at least one radio event and several chromospheric events per day.

Breaking out or bursting forth.