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.

doi:10.16186/j.cnki.1673-9787.2020120094

Received:2020/12/28

Revised:2021/04/12

Published: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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