小秦岭西段稀土矿特征及找矿远景浅析

Analysis on the Characteristics and Prospecting of Rare Earth Ore in the Western Section of Xiaoqinling

小秦岭西段是重要的稀土元素成矿地段。受华阳川断裂、金堆城青岗坪断裂和太古代变质基底等因素的控制产出了区内碳酸岩型和伟晶岩型2类稀土矿化。碳酸岩型稀土矿含矿主岩为各类碳酸岩脉,以小河断裂为界,南北含矿碳酸岩在矿物组合上具有差别明显,含稀土矿物主要为磷钇矿、独居石和氟碳铈镧矿,稀土元素以轻稀土为主,但重稀土相对偏高,并具有以华阳川为中心向外围逐渐富集重稀土的特点。伟晶岩型稀土矿含矿主岩为含褐帘石伟晶岩,含稀土矿物为褐帘石,稀土元素以轻稀土为主。2类稀土矿化在形成时间上存在较大差异,碳酸岩型稀土矿化形成于印支期,伟晶岩型稀土矿化形成于古元古代晚期。区内已发现了众多的稀土矿床(点),成矿远景较好,特别是碳酸岩型稀土矿床(点)及碳酸岩脉带展布地段具有较大的找矿潜力。

The western section of Xiaoqinling is an important metallogenic area of REE.Controlled by Huayangchuan fault,Jinduicheng-Qingpinggang fault and Archean metamorphic basement,two types of rare earth mineralization such as carbonatite type and pegmatite type,are produced in this area.The main ore-bearing rock of carbonatite type is all kinds of carbonate dike,which is bounded by Xiaohe fault.There are obvious differences in the mineral assemblages between the north and the south ore-bearing carbonates.The rare earth minerals are mainly yttrium phosphate,monazite and bastnaesite.The rare earth elements are mainly light rare earth,the heavy rare earth relatively high,and gradually enriching around Huayangchuan.The main ore-bearing rock of rare earth ore in the pegmatite type is epidote-bearing pegmatite.The mineral-bearing rare earth is epidote.The rare earth elements are mainly light rare earth.The formation time of the two types of rare earth mineralization is quite different.Carbonatite type was formed in the Indosinian period,and pegmatite type was formed in the late Paleoproterozoic period.Many rare earth deposits(points)have been found in the area,with a good metallogenic prospect.the carbonate type rare earth deposits(points)and the carbonate vein belt especially has great potentiality.