Grey Monazite Paleoplacers in Lower Cretaceous Continental Formations in the Mons Basin, Belgium

Abstract : Grey monazite, a MREE-rich and Th-poor phosphate has previously been described in Lower Paleozoic bedrock and stream sediments in Belgium. Here we investigate potential paleoplacers of this monazite in Lower Cretaceous formations in the Mons Basin. Heavy minerals extracted from gravel and sand samples collected in three sites were analyzed using microscopy, cathodoluminescence (CL) and Electron Probe Micro-Analyzer (EPMA). The preliminary results are encouraging, with up to 1 kg/T monazite and potentially large reserves. This should promote further exploration based on a systematic sampling program and a better understanding of the geological processes leading to secondary concentration of grey monazite.