摘要
在六合霓辉正长斑岩中广泛发育的各类包体岩石中,新近发现了三类特殊包体。通过岩相学、岩石化学、电子探针和扫描电镜分析研究表明,纯方解石包晶(体)和含石英的黄玉伟晶岩包体是地幔流体在运移过程中发生去气作用的产物;黑色微晶富铁硅酸盐熔融包体是地幔流体伴随去气作用的分离产物,其主要矿物组成为石英、绿泥石和富铁的柱状和片状硅酸盐矿物,特征矿物有自然铁、磷灰石和锆石;据全岩化学成分和矿物组成特征及结晶状态分析,表明该包体岩石不是常规岩浆作用产物,尤其自然铁的存在进一步证明该微晶熔融包体是还原条件或缺氧环境下的地幔流体物质。通过对特殊包体岩石的研究,为该区不同岩性和地层中的多金属成矿提供了重要的深部过程地球化学背景。
Recently, 3 special xenoliths have been discovered in the aegirine syenite porphyry at Liuhe. Primary petrography, petroehemistry, electron microprobe and SFM studies showed that the pure calcite peritecticum （xenolith） and quartz-bearing topaz pegrnatite xenoliths resulted from degasification in the migration process of mantle fluids. And the black microerystalline iron-rich silicate-melting xenoliths, which are composed of major minerals （i. e., quartz, chlorite, ironrich columnar and sheet silicate） and characteristic minerals （i. e., native iron, apatite and azurite）,are the separation product of degasilication in the migration process of mantle fluids. According to the petroehemistry data, mineral compositions and the analysis of crystalline state, the microerystalline melting xenoliths are not the product of conventional magmatism. Especially, the existence of native iron further proves that the xenoliths were derived from mantle fluid material tmder reduction or anoxic conditions. The important deep-process geochemical backgrotmd of polymetallic metallization in multifarious rocks and strata is docttmented in terms of the study of these special xenoliths.
出处
《矿物学报》
CAS
CSCD
北大核心
2007年第3期249-254,共6页
Acta Mineralogica Sinica
基金
国家自然科学基金(批准号:40473027)
中国地质大学地质过程与矿产资源国家重点实验室开放课题基金项目(GPMR0509)
四川省矿物学
岩石学
矿床学重点学科建设项目
