山东微山稀土矿床成矿预测分析

微山稀土矿是鲁西地区已查明的一处中型稀土矿床,研究表明,目前的开采深度还处于岩体顶部的脉状矿体,成矿流体温度剖面初步揭示了高温区域随深度增加有明显收窄的趋势,经勘查工程验证,稀土矿脉深部厚度增大,数量增多,总体矿化强度增强。该文总结了微山稀土矿成矿要素和找矿标志,在成矿要素划分的基础上,增加放射性异常特征,建立了10个要素组成的预测要素表。依据地质成果,叠加放射性异常,编制了预测模型图,圈定出3个最小预测成矿靶区,编号分别为1~#,2~#,3~#。其中,1~#成矿预测区内有石英脉出露,推测为地下岩浆热液填充裂隙形成石英脉,存在伴生矿脉的可能;2~#成矿预测区包含2个放射性异常,南东侧为(12)号含稀土石英重晶石矿脉,推断该预测区浅部可能存在NW向延伸的隐伏矿脉;3~#成矿预测区包含4个放射异常区,异常区周边发育(15)(16)号含稀土矿脉,是最为有利的稀土矿找矿地段。验证已发现多个新矿脉,厚度在2.35～8.90m,稀土氧化物品位(TRE_2O_3)2.35%～6.40%,显示成矿预测区具有较好的稀土矿找矿潜力。

Metallogenic Predication Analysis on Rare Earth Deposit in Weishan Area in Shandong Province

Weishan rare earth deposit is Luxi area is an identified medium rare earth deposit. The present mining depth is still in the vein type orebody at the top of the rock mass. Oreforming fluid temperature profile preliminary reveals that the high temperature area has an significant narrowed trend with the increasing depth. It is verified that the thickness of rare earth vein increases, the numbers rise, and the overall intensity of mineralization strengthens in the deep part. In this paper, the metallogenic elements and prospecting criteria of Weishan rare earth deposit have been summarized. The characteristics of radioactive anomalies are added on the basis of the classification of metallogenic elements. Based on geological results and the superposition of radioactive anomalies, the predication model diagram has been made. On these basis, three minimum predicated metallogenic target areas have been delineated and numbered as 1#, 2# and 3# respectively. Among them, quartz veins are exposed in 1# metallogenic predication area, which is speculated to be the quartz veins formed by filling fractures of underground magmatic hydrothermal fluid, and there is the possibility of associated veins. There are two radioactive anomalies in 2# oreforming predication area. rare earth quartz barite vein is located in the southeast of the predication area. It is inferred that there may be hidden vein extending to the northwest in the shallow part of the predication area. There are 4 radioactive abnormal areas in 3# oreforming predication area. rareearth veinsdeveloped around the abnormal areas. It is the most favorable rare earth ore prospecting area. As verified by drilling test, a number of new veins have been found. The thickness ranges from 2.35m to 8.90m, and the grade of rare earth oxide (TRE2O3) ranges from 2.35% to 6.40%. It is indicated that the oreforming predication area has good ore prospecting potential.