莱西塔埠头稀土矿氟碳铈矿Th-Pb定年及矿床成因

ThPb Dating and the Origin of Rare Earth Deposits and Bastnadite Deposit in Tabutou in Laixi City

摘要:

山东莱西市塔埠头稀土矿为一小型伟晶岩型稀土矿床，具有较好的找矿前景。该文通过对塔埠头稀土矿床地质特征、氟碳铈矿物的ThPb定年、成矿要素等的综合分析研究，确定了其成矿时代，建立了成矿模式，讨论了矿床成因。研究指出，塔埠头稀土矿床为小型伟晶岩型稀土矿床，主要稀土矿物氟碳铈矿包裹于长石中，2个样品获得的氟碳铈矿ThPb加权平均年龄为（128.5±2.0）Ma和（134.4±1.2）Ma。将塔埠头稀土矿成矿要素划分为4个必要要素、3个重要要素，认为在伟晶岩侵入到围岩的降温冷却过程中，形成了塔埠头中生代稀土热液成矿事件。

Abstract:

Tabutou rare earth deposit is located in the southwest of Laixi city. It is a small type of pegmatite rare earth deposit. The oreforming conditions in the area are very favorable and have good prospecting prospects. Through comprehensive analysis on geological characteristics of Tajutou rare earth deposit, the metallogenic epoch has been determined, the metallogenic model has been established, and the origin of the deposit has been discussed. It is pointed out that Tabutou rare earth deposit is a small pegmatite type rare earth deposit. The main rare earth mineral of bastnaesite is encapsulated in feldspar. The weighted average ages of ThPb of bastnaesite from two samples are (128.5+2.0) Ma and (134.4+1.2) Ma. The metallogenic elements of Tabutou rare earth deposit are divided into four essential elements and three important elements. It is considered that Mesozoic rare earth hydrothermal metallogenic event in Tabutou is formed during the cooling process of pegmatite intrusion into wall rocks.