CCSD岩芯中部分石英脉的氦、氩同位素初步研究  

Preliminary study of He, Ar isotope compositions of quartz veins in CCSD main hole.

作　　者：陈振宇[1] 王登红[1] 徐珏[1] 陈毓川[2] 李晓峰[1] 

机构地区：[1]中国地质科学院矿产资源研究所,北京100037 [2]中国地质科学院,北京100037

出　　处：《岩石学报》2006年第7期1952-1956,共5页Acta Petrologica Sinica

基　　金：国家重点基础研究发展规划项目(2003CB716507);国土资源部科技专项项目(2002207)的资助

摘　　要：对中国大陆科学钻探(CCSD)1700m-2300m岩芯中部分超高压变质岩中的石英脉进行了氦、氩同位素组成的初步研究,结果显示石英脉的3He／4He比值为0．37×10-6-0．98×10-6,40Ar／36Ar为498-3260,4He／40Ar为0．17-2．12, 3He／36Ar为0．81×10-4-39．38×10-4。分析结果与前人对大别-苏鲁的榴辉岩全岩和单矿物的氦、氩同位素分析结果相一致,在He-Ar相关图解上均位于地壳和地幔氦、氩同位素组成的过渡部位,表明石英脉的成矿流体中不仅有壳源稀有气体,还有幔源稀有气体。石英脉是榴辉岩的早期退变质脉,它不仅可以继承围岩超高压变质岩的氢氧稳定同位素特征,还可以继承并保存围岩的稀有气体同位素特征。Preliminary study of He, Ar isotope compositions of quartz veins in UHP rocks from Chinese Continental Scientific Drilling （CCSD） main hole （1700-2300m）. 3He/4He of quartz veins were 0. 37 10^-6 -0.98 10^-6, ^40Ar/^36Ar were 498- 3260, ^4He/^40Ar were 0. 17 -2. 12, and ^3He/^36Ar were 0. 81 × 10^-4 - 39. 38 × 10^-4. These results were consistent with those obtain from bulk and separated minerals of eclogites from Dabie-Sulu UHP terrane in previous studies, and were all fall into the mixing part of the crust and the mantle in the He-Ar diagrams, indicating that the mineralize fluid of quartz veins contains not only crust-like He, but also mantle-like He. Quartz veins were early stage retrograde metamorphic veins of eclogites, they can inherited and preserved not only the stable isotope compositions, but also noble gas isotope from UHP country rocks.

关 键 词：石英脉 CCSD He、Ar同位素 地幔流体 

分 类 号：P597.3[天文地球—地球化学]