zone de captage

CONT: Dans le cas des croûtes calcaires uranifères qui contiennent normalement des vanadates, ou des croûtes phosphatées, l'uranium s'est probablement accumulé dans de grandes zones de captage à partir d'une source distincte de celle du vanadium et du phosphate.

CONT: In the case of uranium-bearing calcrete, which normally contains vanadates, or phoscrete, the uranium probably is derived in large catchment areas from a separate source from that for the vanadium and phosphate.
OBS: Influence of catchment basin area on the sediment geochemistry appears to be minimal. There are weak, yet statistically significant,correlations of catchment area with loss on ignition, manganese, fluoride, iron, chromium and vanadium.