Formation conditions and REY enrichment of the 2060 Ma phosphorus mineralization at Schiel (South Africa): geochemical and geochronological constraints - Torsten Graupner; Reiner Klemd; Friedhelm Henjes-Kunst; Simon Goldmann; Helge Behnsen; Axel Gerdes; Reiner Dohrmann; Jay M. Barton; Rehan Opperman (Mineralium Deposita, 2018)