侯广顺, 张艳林, 姜江,等.河南鹤壁地区地幔捕虏体中铁质小球特征及其成因探讨[J].河南理工大学学报（自然科学版）,2023,42(2):49-54.

HOU G S, ZHANG Y L, JIANG J,et al.Characters and genesis discussion on ferric small-balls in mantle xenoliths from Hebi kimberlite[J].Journal of Henan Polytechnic University(Natural Science) ,2023,42(2):49-54.

河南鹤壁地区地幔捕虏体中铁质小球特征及其成因探讨

侯广顺1,2, 张艳林1, 姜江1, 闫鑫洁1, 齐永安1, 向世红2, 李英杰3

1.河南理工大学 资源环境学院，河南 焦作  454000；2.河南省有色金属地质勘查总院，河南 郑州  450052；3.河南理工大学 化学化工学院，河南 焦作  454000

摘要:为探究地幔捕虏体中铁质小球特征和成因，以河南鹤壁地区蒋家顶金伯利岩携带的橄榄岩捕虏体中铁质小球为研究对象，对小球进行体式显微镜照相、扫描电镜表面形态照相和化学成分能谱分析。结果表明：小球呈圆球形，直径0.5~1 mm，部分小球带有乳状突起；小球成分以铁质为主，根据Fe质量分数大致可分为低Fe小球和高Fe小球两组；随着小球中Fe质量分数升高，Al，Si，Ca，Ti等亲石元素质量分数逐渐减少，O质量分数随Fe质量分数变化关系不明显；低Fe小球中Mg质量分数随Fe质量分数升高逐渐增加，高铁小球中Mg质量分数随Fe质量分数升高逐渐减少；根据铁质小球来源、形态和成分特征，推测小球为捕虏体中辉石绝热减压少量熔融的产物。小球记录了地幔捕虏体随金伯利岩侵位至近地表发生的减压熔融→快速冷凝的短暂地质过程，对研究地幔非平衡熔融和初始岩浆的化学成分等基础地质问题具有重要意义。

关键词:鹤壁地区;金伯利岩;地幔捕虏体;铁质小球;减压熔融

doi:10.16186/j.cnki.1673-9787.2020120094

基金项目:国家自然科学基金资助项目（41773024，21507145）；河南省科技厅2017年科技攻关项目（172102210331）

收稿日期:2020/12/28

修回日期:2021/04/12

出版日期:2023/03/25

Characters and genesis discussion on ferric small-balls in mantle xenoliths from Hebi kimberlite

HOU Guangshun1,2, ZHANG Yanlin1, JIANG Jiang1, YAN Xinjie1, QI Yongan1, XIANG Shihong2, LI Yingjie3

1.Institute of Resources & Environment，Henan Polytechnic University，Jiaozuo  454000，Henan，China；2.General Institute of Non-ferrous Metals Geological Exploration，Zhengzhou  450052，Henan，China；3.College of Chemistry and Chemical Engineering，Henan Polytechnic University，Jiaozuo  454000，Henan，China

Abstract:In order to study the character and genesis of iron-rich small-balls in mantle xenoliths，the small-balls found in the peridotite xenoliths from Jiangjiading kimberlite in Heibi region was studied.The small-balls’ stereomicroscope photos，scanning electron microscope surface morphology photos，and the chemical compositions energy spectrum analysis were taken.The results showed that，these small-balls were sphere in shape with diameter sizes of 0.5 mm to 1 mm，and some small balls had milky bulge.The composition of the small balls was mainly iron.According to the iron content，they could be roughly classified into two groups： low iron content group and high iron content group.With the increase of iron content in different samples，the lithosphere elements Al，Si，Ca，and Ti content were accordingly decreased.The O content was independent on the Fe content.In the low iron content group，the Mg content was positive correlation with that of Fe； While in the high iron content group，their correlation became negative.According to the source，shape and chemical characters of the small-balls，it was inferred that the small-balls were formed by partial of melt of pyroxene in mantle xenolith through thermal isolation and decompression forms when erupting to surface.These small-balls recorded this rapid and transient geological process.This was significant for us to understand the mantle partial non-equilibrium melt process and the primary magma composition.

Key words:Hebi region;kimberlite;mantle xenolith;ferric small-ball;decompression melting

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