海南玄武岩发育红土与第四纪网纹红土地球化学和磁性特征的差异  

Comparison of Geochemical Characteristics between the Basaltic Red Clay and Quaternary Red Clay in Hainan

作　　者：张培枫 胡雪峰[1,2] 安柏年 兰国俊 赵景龙 陆思文 门殿英 张伟杰 严丽君[1,2] ZHANG Pei-feng, HU Xue-feng , AN Bo-nian, LAN Guo-jun, ZHAO Jing-long, LU Si-wen, MEN Dian-ying, ZHANG Wei-jie, YAN Li-jun(1. School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China; Institute for A gri-food Standards and Testing Technology, Shanghai Academy of Agricultural Science, Shanghai 201106, China)

机构地区：[1]上海大学环境与化学工程学院,上海200444 [2]上海市农业科学院农产品质量标准与检测技术研究所,上海201106

出　　处：《土壤通报》2018年第5期1009-1014,共6页Chinese Journal of Soil Science

基　　金：国家自然科学基金项目(41471174)资助

摘　　要：海南岛地处中国热带,第四纪火山十分活跃,玄武岩出露广泛。玄武岩发育红土和第四纪网纹红土,是海南岛两种重要的成土母质。在海南临高县选择3个典型玄武岩发育红土剖面(BRC剖面)和1个第四纪网纹红土剖面(QRC剖面),分析比较了两剖面元素地球化学和磁性特征。结果表明,玄武岩发育红土Fe_2O_3平均含量约是第四纪网纹红土的3倍,而SiO_2含量只有后者的1/2。玄武岩红土剖面底部次生铁结核铁显著富集,全铁和游离铁含量分别是同剖面母岩和红土的1.3和1.4倍。玄武岩发育红土铁含量高,磁性强,磁化率平均达1104.39×10^(-8) m^3 kg^(-1)。而第四纪网纹红土铁含量低,磁性弱,均质层磁化率平均为37.64×10^(-8)m^3kg^(-1);网纹层受地下水活动影响,磁化率平均仅为8.24×10^(-8) m^3 kg^(-1)。此外,玄武岩发育红土的Ti平均含量分别为23.24 g kg^(-1),显著高于第四纪网纹红土平均含量8.26 g kg^(-1)。Abstract：Hainan Island is located in tropical China and is also a volcanic zone during the Quaternary period, where basalts were commonly seen. The basaltic red clay （BRC） and Quaternary Red Clay （QRC） are important parent materials in Hainan Island. Three BRC profiles and one QRC profile were selected in Lingao Country, Hainan Island. Geochemical characteristics and magnetic susceptibility of these profiles were compared. The Fe203 content of BRC was three times that of QRC, and the SiO2 content of BRC was only a half of QRC. The Fe nodules were enriched significantly in the bottom of the BRC profile. The contents of total Fe and free Fe in the Fe nodules were 1.3 times and 1.4 times higher than those of the parent rocks and red clay in the same profile, respectively. The value of magnetic susceptibility of the BRC profile which enriched in Fe and presented strong magnetic signals, attained 1093.07 × 10-8m3kg-1 The QRC profile generally had the lower content of Fe and the weaker magnetic signals. The magnetic susceptibility of the uniform red clay was 37.64 × 10-8m3kg-1. And that of the reticulate red clay, however,was significantly weakened, only 8.24 × 10-8m3kg-1. In addition, the content of Ti in the BRC, with an average of 23.24 g kg-l, was significantly higher than that in the QRC, with an average of 8.26 g kg-l.

关 键 词：第四纪红土 玄武岩 磁化率 风化 

分 类 号：P595[天文地球—地球化学]