tephra sequences

• 火山灰层

tephra sequences的用法和样例：

例句

1. New information on the response of vegetation to air-fall volcanic ash is provided by analysis of phytoliths from sediments containing major tephra beds.
   含火山灰层沉积的植硅体分析为了解植被对从空中下降的火山灰的反应提供新的信息。