alluvial mining

基本解釋

Placer mining: Oldest method of recovering gold from alluvial deposits.
砂礦古河床里的金砂礦床。
Mechanized placer mining, with special devices for washing and separating waste from valuable minerals, is used in productive alluvial deposits.
機械化砂礦開采用于含礦量豐富的砂礦床．利用專門設(shè)備來淘洗、分離廢物與有用礦物。
Gravel cemented geological body, called solid formation, has been found in the fluvial sediment of Quaternary system in the exploration and mining of alluvial gold deposit in recent years.
近年來在砂金礦床的勘探和開采中，發(fā)現(xiàn)在第四系河流沖積物中存在砂礫石膠結(jié)地質(zhì)體，被稱為膠結(jié)層。

He is one of many who have flocked to the Kangari hills in southern Sierra Leone to find small fortunes in the hard graft of alluvial gold mining.

De Beers is active in every category of industrial diamond mining: open-pit, underground, large-scale alluvial, coastal and deep sea.
FORBES: Anglo American Receives Final Regulatory Approval for De Beers Acquisition