辽宁本溪贾家堡子地区BIF铁矿床地球化学特征

GEOCHEMISTRY OF JIAJIAPUZI BANDED IRON FORMATION IN BENXI CITY,LIAONING PROVINCE

利用主量元素和稀土元素相结合的地球化学方法,对本溪贾家堡子铁矿成矿物质来源和矿床成因进行了研究.结果表明:贾家堡子地区条带状铁矿(BIF)的化学成分主要为TFe2O3和SiO2,并且Al2O3和TiO2含量较低,这一特征与鞍本地区及山西五台山和冀东迁安地区条带状铁矿基本一致,指示该条带状铁矿是由极少碎屑物质加入的化学沉积岩.稀土元素呈现弱轻稀土亏损、重稀土富集的特征,具有明显的Eu正异常特征,表明该BIF的稀土元素来源于火山热液和海水的混合液.贾家堡子地区条带状铁矿床成因类型为Algoma型铁矿.

The ore-forming material source and genesis of Jiajiapuzi banded iron formation(BIF)in Benxi City are studied by the geochemical analysis of combining major and rare earth elements(REE).The results show that the main chemical compositions of Jiajiapuzi BIF are TFe2O3 and SiO2,with low content of Al2O3 and TiO2,which is basically the same characteristics as the BIFs in Anshan-Benxi area,Wutai Mountain in Shanxi Province and Qian’an area in eastern Hebei Province,indicating that the BIF is a kind of chemical sedimentary rock with a little clastic material.The REEs are characterized by weak deficiency of LREEs,enrichment of HREEs and obvious positive Eu anomaly,reflecting the REEs in BIF are from a mixture of volcanic hydrothermal fluid and seawater.The Jiajiapuzi BIF genetically belongs to Algoma-type.