The preserved sediment infill of an impression or mould made in the top of a bed of soft sediment (e.g. flute cast, load cast, tool cast, casts of footprints or trails).
科学参考收录了60776条科技类词条，基本涵盖了常见科技类参考文献及英语词汇的翻译，是科学学习和研究的有利工具。