The Keishöhe carbonatites of southwestern Namibia -- the post-magmatic role of silicate xenoliths on REE mobilisation. - Walter, Benjamin F.; Giebel, Johannes; Marlow, Alan G.; Siegfried, Pete R.; Marks, Michael; Markl, Gregor; Palmer, Martin; Kolb, Jochen (Communications of the Geological Survey of Namibia, 2022)