残积层 meaning in English

eluvial deposit
eluvium
residual overburden
residuum

Eluvial tantalite : eluvial tantalite is found in rubble consisting of fragments and pebbles of varied composition
残积层钽铁矿：残积层钽铁矿发现于由碎片和小鹅卵石成分的碎矿中。
The tantalite mineralisation at portee appears to be associated with quartz core zones , zones of k - metasomatism and with eluvial concentrations
钽铁矿的矿物性质是由石英核心带、 k长石同化矿带和残积层部分组合而成的。