The Dongjun deposit, located in the Hailaer Jurassic volcanic fault-depress basin, is a typical hydrothermal lead-zinc-silver deposit generated from volcanic rocks, which is characterized by significant hydrothermal alternation, apparent ore-controlling fault of metallogenic, many orebodies with small scale, etc. Volcanic rocks have high content of Alkali (K2 O＋ Na2 O= 5. 93％ ～8.26％), with the average value of Na2 O/K2O at 1.81, relatively rich in light rare earths ( LaN/YbN ＝ 16. 72 ～ 23.31 ), and with slightly Eu negative abnormality. Also, Large-ion lithophile elements (LILE) are richer than high field strength elements(HFSE), while Nb、Ta、Ti are relative drawdown, compared to LREE and LILE. The δ34S values of sulfide ores vary from +4.48‰ and +6.97％ and are typical of mantle S. In sulfide ores,the n(206Pb)/n(204Pb), n(207P1b)/ n(204Pb) and n(208Pb)/ n(204Pb) ratios vary in the ranges of 18. 3143～ 18. 4315, 15. 4934 ～ 15. 6265 and 37. 9810 ～ 38. 4236 respectively, showing that the U-Pb is richer, while Th-Ph is slightly less. Besides, in volcanic rocks, [n(87Sr) /n(86Sr)]i =0. 70506～0. 70512, [n(143Nd)/n (147Nd)]i＝0. 512521～0. 512602,εNa(t) values of 1.4～2.9. The geological and geochemical features of ore deposit indicate that the ore-forming matter is from magma system or the host rock, while the magma is mainly from the mantle rich in light rare earths, maybe mixed with a small amount of crustal materials.%东珺矿床位于海拉尔侏罗纪火山断陷盆地,具有热液蚀变明显、断裂构造控矿显著、矿体多且规模小等特征,为一产于火山岩中的典型热液型铅锌银矿床,火山岩含碱量较高(K2O+Na2O=5.93%～8.26%).Na2O/K2O平均为1.81,轻稀土相对富集(LaN/YbN=16.72～23.31),具轻微的负Eu异常,大离子亲石元素(LILE)相对高场强元素富集,Nb、Ta、Ti相对于LREE和LILE亏损.矿石硫化物δ34S介于+4.48%～+6.97‰,具幔源硫特征.矿石硫化物,n(206Pb)/n(204Pb)、n(207Pb)/m(204Pb)、n(204Pb)/n(204Pb)分别变化于18.3143～18.4315、15.4934～15.6265、37.9810～38.4236,显示铀铅富集,钍铅微弱亏损.火山岩[n(87Sr)/n(86Sr)]1=0.70506～0.70512,[n(143Nd)/n(147Nd)]1=0.512521～O.512602,ENd(t)值变化于1.4～2.9.矿床地质特征和地球化学特征指示,成矿物质来源于岩浆系统或赋矿围岩,岩浆主要来源于轻稀土富集地幔,可能有少量地壳物质的混染.
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