informal chronostratigraphic unit非正式: unofficial; informal年代: the 1970s地层: stratum; layer; serati; geos ...单位: unit年代地层单位: chronolithologic unit; chronolithologicunit; chronostratigraphic unit; chronostratigraphicunit下载手机词典可随时随地查词查翻译关注微信公众号：chachacidian，回复:非正式年代地层单位，即可在微信中查询翻译
