Major oxide geochemical compositions of glass shards from disseminated tephra...

All iron calculated as FeO. Probe conditions: accelerating voltage 20kV, beam current 15nA, 10 second count times全铁以氧化亚铁（FeO）形式计算。探针测试条件：加速电压20kV，束流15nA，计数时间为10秒。