Monazites are one of the most interesting groups of accessory mineral components of crystalline rocks due to the information on geochemical evolution of the crystallisation environment coded in their chemical compositions, in addition to comprising one of the most valuable objects for geochronology studies. This paper presents monazite-(Sm) and monazite-(Nd) from the Blue Beryl Dyke of the Julianna system of rare-element pegmatites at Piława Górna, Lower Silesia, Poland. These monazites are unique due to their unusually high Sm and Nd contents, reaching 33.22 wt.% Sm2O3 and 34.12 wt.% Nd2O3, respectively. We consider the most significant factors of the enrichment in Sm and Nd to be the occurrence of highly fractionated pegmatite-forming melts during the final stages of solidification and associated hydrothermal fluids that were strongly enriched in rare earth element REE–Cl and REE–F complexes. Local disequilibria allowed for the rapid growth of accessory phases under supercooling conditions associated with the scavenging of selected elements, leading to their local depletion, which was not balanced by diffusion processes. As a consequence, the depletion of light rare earth elements (LREE) led to the incorporation of available middle rare earth elements (MREE, Sm–Dy) in the case of Sm and Nd, which could occupy an acceptable structural position in minerals of the monazite group.

独居石是结晶岩石中最有趣的副矿物成分之一，因为其化学成分中包含了结晶环境的地球化学演化信息，此外，独居石也是地质年代学研究最有价值的对象之一。本文介绍了来自波兰下西里西亚 Piława Górna 稀有元素伟晶岩朱丽安娜系统的蓝色绿柱石岩脉的独居石（Sm）和独居石（Nd）。这些独居石因其异常高的 Sm 和 Nd 含量而独一无二，达到 33.22 wt.% Sm 2 O 3和 34.12 wt.% Nd 2 O 3， 分别。我们认为 Sm 和 Nd 富集的最重要因素是在凝固的最后阶段出现高度分馏的伟晶岩形成熔体以及强烈富集稀土元素 REE-Cl 和 REE-F 复合物的相关热液流体。 。局部不平衡使得副相在与选定元素的清除相关的过冷条件下快速生长，导致其局部耗尽，而扩散过程无法平衡。因此，轻稀土元素 (LREE) 的消耗导致在 Sm 和 Nd 的情况下掺入可用的中稀土元素 (MREE、Sm-Dy)，这可能在该地区矿物中占据可接受的结构位置。独居石族。