光谱学与光谱分析
光譜學與光譜分析
광보학여광보분석
SPECTROSCOPY AND SPECTRAL ANALYSIS
2015年
6期
1534-1538
,共5页
胡飘野%曾亮亮%杨志军%傅海福%刘思微%沈文杰%彭卓伦
鬍飄野%曾亮亮%楊誌軍%傅海福%劉思微%瀋文傑%彭卓倫
호표야%증량량%양지군%부해복%류사미%침문걸%팽탁륜
金刚石多晶%显微红外光谱%扬子克拉通西部%成因
金剛石多晶%顯微紅外光譜%颺子剋拉通西部%成因
금강석다정%현미홍외광보%양자극랍통서부%성인
Polycrystalline diamonds%Micro-FTIR%Western Yangtze Craton%Formation
扬子克拉通西部刻面状金刚石多晶的微区显微红外光谱研究结果表明,多晶以IaAB型为主,其中的氮含量变化较大,介于25.70~358.35μg?g -1之间,且同一多晶的不同晶粒中的氮含量有明显差异。金刚石中的“A氮心→B氮心”聚集转变不完全,且B%集中在40%左右,未见C氮心;多晶不是在金刚石的成核阶段所形成的,而是在各个金刚石晶粒形成后在地幔储藏期间聚集在一起的。其形成环境较华北克拉通东部的山东蒙阴刻面状金刚石多晶更为复杂;多晶极可能形成于地幔深部160~180 km的范围内,达到扬子克拉通的核部深度,接近于岩石圈底部,为地幔深源成因;多晶中的 s p2杂化C—H键的存在有利于片晶氮的形成,其浓度一般要高于 s p3杂化C— H键的浓度。
颺子剋拉通西部刻麵狀金剛石多晶的微區顯微紅外光譜研究結果錶明,多晶以IaAB型為主,其中的氮含量變化較大,介于25.70~358.35μg?g -1之間,且同一多晶的不同晶粒中的氮含量有明顯差異。金剛石中的“A氮心→B氮心”聚集轉變不完全,且B%集中在40%左右,未見C氮心;多晶不是在金剛石的成覈階段所形成的,而是在各箇金剛石晶粒形成後在地幔儲藏期間聚集在一起的。其形成環境較華北剋拉通東部的山東矇陰刻麵狀金剛石多晶更為複雜;多晶極可能形成于地幔深部160~180 km的範圍內,達到颺子剋拉通的覈部深度,接近于巖石圈底部,為地幔深源成因;多晶中的 s p2雜化C—H鍵的存在有利于片晶氮的形成,其濃度一般要高于 s p3雜化C— H鍵的濃度。
양자극랍통서부각면상금강석다정적미구현미홍외광보연구결과표명,다정이IaAB형위주,기중적담함량변화교대,개우25.70~358.35μg?g -1지간,차동일다정적불동정립중적담함량유명현차이。금강석중적“A담심→B담심”취집전변불완전,차B%집중재40%좌우,미견C담심;다정불시재금강석적성핵계단소형성적,이시재각개금강석정립형성후재지만저장기간취집재일기적。기형성배경교화북극랍통동부적산동몽음각면상금강석다정경위복잡;다정겁가능형성우지만심부160~180 km적범위내,체도양자극랍통적핵부심도,접근우암석권저부,위지만심원성인;다정중적 s p2잡화C—H건적존재유리우편정담적형성,기농도일반요고우 s p3잡화C— H건적농도。
The results of Micro‐FTIR spectra analysis of the euhedral faceted polycrystalline diamonds (EFPCDs) from the West‐ern Yangtze Craton show that the EFPCDs are mostly IaAB type ,the concentration of nitrogen varies greatly from 25.70~358.35 μg?g -1 .Different nitrogen content distributes in different diamond grains or position in same sample .The C Center was not found in the samples and the conversion from A center to B center is incomplete ,in the meanwhile ,B% value concentrated in 40% .Thus ,polycrystalline diamonds are not formed in the stage of nucleation but gathered together after formation of the indi‐vidual diamond grains during the residence time in the mantle .And its formation environment is more complex than the euhedral faceted polycrystalline diamonds from Mengyin kimberlite ,the Eastern of North China Craton .The diamonds extremely possibly originated in the deep mantle from 160 to 180 km ,reaching the depth of the core of the Yangtze Craton ,at the same time it is close to the bottom of the lithosphere .The C—H bond of sp2 hybridization are conducive to the formation of platelets in dia‐monds .Meanwhile ,its concentrations are generally higher than the C — H bond of sp3 hybridization in the samples .