alluvialadj.冲积的；淤积的n.冲积土；淤积土alluvial plain冲积平原,沉积平原alluvial shoal冲积性浅滩alluvial ridge冲积脊alluvial soils冲积土alluvial fract冲积区alluvial epoch冲积世alluvial coast冲积海岸alluvial talus冲积山麓堆积alluvial placer冲积砂矿床alluvial values沉积矿回收值