Discussion of REE distribution patterns of carbonatites and alkalic rocks

Analytical data on REE, Sr, Ba, and Na of carbonatites, their calcite separates, and associated alkalic rocks from Fen/Norway, Alnö/Sweden and Kaiserstuhl/Germany are discussed. The REE distribution patterns of carbonatites suggest sympathetic behaviour with those of their associated alkalic rocks. This could be interpreted as the result of liquid/liquid separation. The typically steep patterns may be the result of Ca-metasomatism of alkaline-earth rich, but alkali-poor liquids with olivine-rich, alkali bearing, subcrustal rocks. Additionally, during this process incompatible elements could become concentrated in the carbonate rich liquid.