摘要:塔里木克拉通北缘是我国重要的稀有—稀土金属成矿带,近年来稀有—稀土矿床勘查工作不断取得重大进展,相继勘查和发现了瓦吉里塔格、波孜果儿、依兰里克、阔格塔格、且干布拉克和上户等多个稀有—稀土矿床,使该地区成为我国重要的大型稀有—稀土矿床后备基地。这些稀有—稀土矿床普遍赋存于碱性岩或碱性碳酸岩中,规模多数达到大中型,品位较高。然而,对该区的稀有—稀土矿床的研究程度普遍很低,成矿环境和成矿规律认识不清,缺乏综合性的总体研究。文章在已有的研究成果基础上,结合笔者研究小组近3年的大量野外调研和室内的综合研究,综述了塔里木克拉通北缘主要稀有—稀土矿床的地质特征、分布规律和矿化类型。根据碱性岩形成的不同构造环境将与碱性岩有关的稀有—稀土矿床划分为3种构造类型,即活动陆缘型、板边型和板内型;根据矿化类型将该区矿床进一步划分为与超基性—碱性杂岩有关的稀土矿床、碱性正长岩型稀土—铌-钽-锆矿床、碱性花岗岩型稀土—铌-钽-锆矿床和碱性伟晶岩型稀土—铌-钽-锆矿床4个亚类。在对典型矿床研究的基础之上,初步讨论了研究区碱性岩有关的稀有—稀土矿床的成矿动力学背景、地球化学特征和成矿动力学过程,认为该碱性岩带形成于造山拉张性的构造环境。
关键词: 成矿集中区/
稀有-稀土矿床/
成矿动力学背景/
塔里木北缘
Abstract:Tarim periphery is an important concentration area of endogenous metal mineralization in China. The northern margin of Tarim is one of the important rare earth metallogenic belts in China. The exploration and discovery of several rare-earth deposits in Wajirtagh, Pozigoer, Yilanlik, Kuogataghi, Qieganbulak and Shanghu have made this region an important reserve base for large rare-earth deposits in Xinjiang. These newly discovered rare-earth deposits are commonly found in alkaline rocks or alkaline carbonate rocks, and most of them are large and medium-sized with high grade. On the whole, the research degree of rare-earth deposits in this area is generally very low. Based on the existing research results, this paper summarizes the geological characteristics, distribution rules and mineralization types of the main rare-earth deposits in the northern margin of Tarim Craton, combining with a large number of field investigations and laboratory studies in the last three years. According to the different tectonic environments formed by alkaline rocks, the rare-earth deposits related to alkaline rocks are divided into three tectonic types, namely active continental margin type, plate edge type and plate type. According to the mineralization types, the deposits in this area are further divided into four subclasses:rare earth deposits related to ultrabasic-alkaline complex, alkaline syenite type rare earth-Nb-Ta-Zr deposit, alkaline granite type rare earth-Nb-Ta-Zr deposit and alkaline pegmatite type? rare earth-Nb-Ta-Zr deposit. Based on the study of typical deposits, the metallogenic dynamic background, geochemical characteristics and metallogenic dynamic process of rare earth deposits related to alkaline rocks in the study area are preliminarily discussed, and it is believed that the alkaline belt occurred in the orogenic tensional tectonic environment.
Key words:Metallogenic concentration area/
Rare-earth deposits/
Background of metallogenic dynamics/
Northern margin of Tarim
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