In total, the Belknap shield and its multiple vents were formed in less than 1,500 years, which was a comparable effusion rate to the Nash Crater scoria cone, the Sand Mountain Volcanic Field, and the Mount Bachelor chain. Eruption rates for Belknap were high, at per 1,000 years, similar to the buildup of rhyodacite before the climactic eruption at Mount Mazama. Within the last 15,000 years, Cascades volcanoes have erupted about of material excluding rear-arc volcanoes. Of this, about (21 percent) came from 63 distributed or peripheral cones, shields, or mafic and intermediate composition chains, with Belknap and Mount Bachelor contributing 71 percent of that material. Over the course of its eruptive history, Belknap erupted of material with several eruptive pulses.