山东省郗山稀土矿地质特征及找矿前景分析

Geological Characteristics and Prospecting Potentiality of Xishan Rare Earth Deposit in Shandong Province

郗山稀土矿为山东省唯一一处中型规模的稀土矿产地,是轻稀土矿床,目前矿山采矿许可证内(+20^-160m)的资源储量已所剩不多。为扩大矿床资源储量,延长矿山服务年限,2012年对矿床深部进行了勘查,在原矿体深部(-160^-500m)探求了稀土矿石量419.3万t,稀土氧化物总量19.3万t,平均品位(RE_2O_3)4.61%。取得了较好的找矿成果。郗山稀土矿床分布在郗山碱性杂岩体顶、底板附近,共圈定矿体25个,矿体形态可分为脉型及细脉—网脉带型两种。其中(12)号矿体为矿床范围内主矿体,占矿床估算储量的54%。矿体展布严格受构造控制,成矿为多期次。矿床成因与燕山早期的碱性花岗岩、霓辉正长岩及石英正长岩等组成的碱性杂岩体关系密切,为与碱性侵入体有关的中—低温热液稀土矿床。通过深部勘查,进一步了解了郗山稀土矿的成矿地质背景、矿床地质特征。通过分析矿床成因、找矿标志及找矿前景,为今后的郗山稀土矿深部和外围找矿指明了方向。

Xishan deposit is the only medium size rare earth deposit in Shandong province.At present,only few reserve which is permited in the mining license（＋20~160-m）has been left.In order to expand the deposit reserves and extend the mine service life,deep exploration of this deposit has been carried out in2012.In the deep of original ore body（160m ~ 500m）,4.193 million tons rare earth ore quantity and 193000 ttotal rare earth oxides have been found.Average grade of RE_2O_3 is 4.61%.Good ore-prospecting results have been gained.Xishan rare earth deposit distributed in the top and bottom of XiShan alkaline complex rocks.25 ore bodies have been circled.The ore deposit can be divided into vein type ore body and veinlet-net vein type.No.12 ore body is the main ore body in the scope of the deposit.It accounts for 54% of the estimated reserves.Distribution of ore bodies are strictly controlled by structures,and belong to metallogenic multiple times type.The origin of deposit has close relation with alkaline complex rock which are composed of alkaline granite,neon glow syenite and quartz-syenite in early Yanshan period.It is a low temperature hydrothermal rare earth deposit related to alkaline intrusive rocks.Through deep exploration of Xishan rare earth deposit,its metallogenic and geological background and geological characteristics have been further understood.Through analysis on the origin,prospecting marks and prospecting prospect,the exploration direction in the deep and surrounding areas in the future has been pointed out.