摘要
通过对海南岛西北部火山岩砖红壤铁质风化壳剖面样品进行主量元素含量检测及风化特征指数、迁移系数计算,揭示海南岛火山岩砖红壤铁质风化壳的主量元素分布、风化强度和迁移特征。结果表明:风化壳主量元素以Fe_(2)O_(3)、Al_(2)O_(3)、SiO_(2)为主,K、Na、Ca、Mg等易溶组分含量较低;Fe_(2)O_(3)、Al_(2)O_(3)富集,SiO_(2)淋失,符合热带地区风化特征。风化层的化学蚀变指数(CIA)高达95%以上,铁铝率(Fe_(2)O_(3)/Al_(2)O_(3))上升,莫耳比率(BA)较低,硅铁铝率(SiO_(2)/R_(2)O_(3))、BA下降。以Zr为参比元素,Fe_(2)O_(3)、Al_(2)O_(3)迁移系数大于1,最大可达4.039;Na_(2)O、K_(2)O、CaO、MgO、SiO_(2)迁移系数小于1,可低至-0.998。研究认为,海南岛西北部火山岩砖红壤铁质风化壳表现为典型的脱硅富铁,铁元素强烈富集,其他元素淋失明显,且铁、铝元素发生了的分异,是比较成熟的风化壳。
The distribution of major elements,weathering intensity and transfer characteristics of volcanic laterite ferric weathering crust in northwest Hainan Island were revealed by measuring the major element content and calculating the weathering characteristic index and transfer coefficient.The results showed that the major elements in the weathering crust were Fe_(2)O_(3),Al_(2)O_(3) and SiO_(2),while the contents of soluble components such as K,Na,Ca,and Mg were relatively low.In the weathered layer,Fe_(2)O_(3) and Al_(2)O_(3) were enriched and SiO_(2) was lost,which accorded with the weathering characteristics of tropical areas.The chemical alteration index(CIA)of the weathered layer reached more than 95%,Fe_(2)O_(3)/Al_(2)O_(3) increased,BA was lower,SiO_(2)/R_(2)O_(3) and BA decreased.Using Zr as the reference element,the transfer coefficients of Fe_(2)O_(3) and Al_(2)O_(3) were both greater than 1,with a maximum of 4.039;the transfer coefficients of Na_(2)O,K_(2)O,CaO,MgO and SiO_(2) were all less than 1,which could be as low as-0.998.The research indicated that the volcanic laterite ferric weathering crust in northwest Hainan Island exhibited typical desilication and iron enrichment,with strong enrichment of iron elements and significant leaching of other elements,and differentiation of iron and aluminum elements,which was relatively mature weathered crust.
作者
张家友
邢增富
曾广骅
岑锐
王成
ZHANG Jiayou;XING Zengfu;ZENG Guanghua;CEN Rui;WANG Cheng(Hainan Key Laboratory of Marine Geological Resources and Environment,Haikou Hainan 570206;Hainan Institute of Geological Survey,Haikou Hainan 570206)
出处
《现代农业科技》
2024年第2期98-102,106,共6页
Modern Agricultural Science and Technology
基金
中国地质调查局项目(1212011120313)
海南省自然资源和规划厅项目(HZ2015-588-B)。
关键词
火山岩砖红壤铁质风化壳
主量元素
风化强度
迁移特征
海南岛西北部
volcanic laterite ferric weathering crust
major element
weathering intensity
transfer characteristic
northwest Hainan Island
