吉林东南部地幔活动与金的成矿作用

地幔活动是岩石圈构造活动的动力学基础，是上地壳发生地质作用——区域变质作用、成岩成矿作用——所需要的深源物质、能量乃至流体的主要来源形式.吉林省东南部地区的麻粒岩相区域变质作用、幔源岩浆的侵入-喷发活动以及深部构造活动等特征表明，该地区曾有太古宙末期和中生代两个地幔活动高峰期.夹皮沟大型金矿田的金矿成矿作用与地幔活动有密切的成因联系.成矿作用主期与地幔活动的高峰期相对应.稳定同位素研究显示成矿物质、成矿热液主要来源于地幔.地幔活动引起携带大量热流体和丰富的成矿元素的幔源物质上侵，并且在下地壳重熔过程中活化、萃取了围岩中成矿物质而形成成矿流体；伴随地幔活动形成的深大断裂构造、大型韧性剪切带不仅是成矿流体运移的通道，而且为成矿物质沉淀提供了有利空间.

MANTLE PLUME AND GOLD MINERALIZATION OF SOUTHEAST JILIN PROVINCE

The mantle activity means material exchanges between the mantle and the crust The mantle strongly acted in the last stage of Archaeozoic era and Mesozoic era in the southeast area of Jilin Province,where the mantle activities are displayed as regional metamorphism up to granulitic facies,mantle derived magmatic activities and deep structures The regional metamorphism facies in the area is distributed in ring,with a center of granulite facies to amphibolite facies and greenschist facies outwardly,caused by heat dome structure formed by mantle gush The mantle derived magma acted mainly in two stages around the dome structure,forming large scale TTG and ultrabasic basic intrusive rocks in the Fuping stage,and large scale basaltic extrusive rocks from late Indo Chinese to Yanshanian epoch Also,the deep structures such as gravitational anomalies,dome structure and isopleth of Moho demonstrate the characteristics of mantle activities The wall rocks of the large scale gold ore field in Jiapigou are metamorphic rocks of Archean and mantle derived granites The ore controlling structures are large scale shear zones and faults that accompanied heat dome structure The main Au mineralization stages occurred in 2452～2469 Ma and 180～90 Ma,corresponding to the peaks of mantle derived magmatic activities The compositions of inclusions in quartz from ore are rich in Na +,Mg +,SO -4 ,CO 2,CH 4,and C 2H 4 The f O 2 is low and f CO 2 is high The isotopic compositions of ore are δ 13 C=-4 83 and δ 32 S=-0 73, 87 Sr/ 86 Sr=0 703, ε Nd ( t )=8 4,illustrating that the ore forming materials come from the mantle The fluids for two main mineralization epochs come from the same source The isotopic compositions of ore fluid are homogeneous, showing that the volume of fluid source is large The fluids are rich in CO 2,CH 4 and C 2H 4,with high water/rocks value This fluid is the same as that from mantle So,the Au mineralization in Jiapigou large scale ore field is genetically asociated with mantle activities