huǒ / chéng / suì / xiè / chén / jī / wù / jì / lù / le / gǔ / dài / huǒ / shān / bào / fā / de / lì / shǐ火成碎屑沉积物记录了古代火山爆发的历史。Pyroclastic deposits record the history of ancient volcanic eruptions.