扬子地块东段大陆岩石圈地幔的氧逸度  

The Redox State of Subcontinental Lithospheric Mantle Beneath Eastern Yangtze Block

作　　者：支霞臣[1,2] 李彬贤[1,2] 陈道公[1,2] 苏永军[1,2] 

机构地区：[1]中国科学技术大学地球和空间科学系,第三世界科学院中国科大地球科学和天文学高级研究中心 [2]中国科学技术大学地球和空间科学系

出　　处：《岩石矿物学杂志》1996年第2期146-152,共7页Acta Petrologica et Mineralogica

基　　金：国家自然科学基金

摘　　要：由尖晶石相橄榄岩包体中的矿物化学成分，采用新近校准的ＦＦＭ地质氧逸度计和地质温－压计，计算包体的平衡氧逸度，Δｌｏｇ（ｆＯ２）ＦＭＱ＝－３．３２－０．１２，它反映了扬子地块东段大陆岩石圈地幔的氧化还原状态。两种氧逸度计计算结果相差在０．５ｌｏｇｆＯ２单位内。Chemical compositions of the coexistent mineral phases (olivine, spinel, clinopyroxene andorthopyroxene) in the spinel lherzolite and harzburgite xenoliths from Fanshan and Panshishan,Jiangsu Province, were determined by the electron and proton microprobe. The equilibriumoxygen fugacities were calculated by two oxygen geobarometers calibrated by Ballhaus et al.(1991 )and Bryndzia and Wood(1990) respectively. The difference between the two results islower than 0. 5 log (fO2)FMQ unit. The oxygen fugacities of the spinel peridotite zone in subcontinental lithospheric mantle beneath Eastern Yangtze Block are Δlog(fO2)FMQ =-2. 0- 0. 5, the typical values for subcontinental lithospheric mantle worldwide. The acctirate Fe3+ /Fe2+ ratio of spinel is a key factor for the calculation of oxygen fugacity.

关 键 词：氧逸度 大陆 岩石圈 地幔 扬子地块 

分 类 号：P544.1[天文地球—构造地质学] P593[天文地球—地质学]