Potential garnet reference materials for LA-ICPMS in-situ U-Pb isotope analysis

石榴石存在于各种岩浆岩、变质岩和交代岩中，具有广泛的压力-温度（P-T）稳定性场。由于这些特性，石榴石是地球科学各个研究领域的核心，包括地质年代学。传统的石榴石定年方法是利用Lu-Hf和/或Sm-Nd等时线，通过耗时而繁琐的同位素稀释技术。近年来，随着激光烧蚀等离子体质谱（LA-ICPMS）技术的发展，石榴石U-Pb测年技术以其快速的数据采集和处理、高的空间分辨率和相对较低的成本成为地质年代学领域的一项前沿技术。最近越来越多的研究暗示了这项技术的巨大潜力。然而，这一技术仍处于起步阶段，其推广的主要障碍之一是石榴石参考材料的有限可用性，这是必不可少的U-Pb分析技术，使用激光探针。在过去几年中，申请人及其合作者研究了几种宝石级石榴石，以测试它们是否适合成为U-Pb分析的参考材料。初步数据在三个研究地点产生了令人鼓舞的结果。该项目的目标是对这些地点的大量晶体进行完整的地球化学表征，然后将其确定为U-Pb测年的可靠参考材料。将通过LA-ICPMS和TIMS技术进行分析。

Garnet is present in diverse magmatic, metamorphic, and metasomatic rocks and has an extensive pressure-temperature (P-T) stability field. Due to these characteristics, garnet is central to various areas of research in geosciences, including geochronology. Traditionally, garnet has been dated by means of Lu-Hf and/or Sm-Nd isochrons through time-consuming and tedious isotope dilution techniques. Recent instrumental advances and technical developments in the field of laser-ablation ICPMS, have led to the appearance of U-Pb dating of garnet by LA-ICPMS as a state-of-the-art technique in the field of Geochronology, with rapid data acquisition and processing, high spatial resolution, and relatively low costs. The growing number of recent studies hints at the immense potential of this technique. However, this technique is still in its infancy and one of the major obstacles to its widespread is the limited availability of garnet reference materials, which are essential for U-Pb analytical techniques using laser probes. During the last years, the applicant and his collaborators have studied several gem-quality garnet to test their suitability to become a reference material for U-Pb analysis. Preliminary data has yielded encouraging results in three of the studied localities. The objective of the project is to perform a complete geochemical characterization of those localities over a larger number of crystals before establishing them as reliable reference material for U-Pb dating. The analyses will be done by LA-ICPMS and TIMS techniques.