冀东司家营BIF型铁矿北矿区典型矿石矿物特征及其对成矿演化的约束

Mineralogical characteristics of typical ore from the BIF-type iron deposit at Sijiaying north mining district in eastern Hebei Province and their constraints on the metallogenic evolution

ES评分 0

DOI 10.20086/j.cnki.yskw.2025.3136
刊名
Acta Petrologica et Mineralogica
年,卷(期) 2025, 44(1)
作者
作者单位

1. 成都理工大学地球与行星科学学院, 四川 成都 610059;
2. 河北省地矿局第二地质大队, 河北 唐山 063000

摘要
冀东司家营BIF型铁矿床是我国最典型的条带状铁矿床之一,系统的矿石、矿物特征研究对BIF型铁矿床的成矿演化具有重要的指示意义。本文对该矿区多种典型铁矿石开展了详细的岩相学研究,结合矿物原位电子探针(EPMA)测试分析,共识别出5种磁铁矿类型,划分出原始沉积期、变质变形期、热液蚀变期以及表生氧化期4个成矿演化期次,并获得与之相关的磁铁矿、黑云母、绿泥石以及角闪石等矿物的化学定量分析结果。通过分析磁铁矿矿物化学特征,计算黑云母与绿泥石形成时的温度差异,结合化学特征指示的成矿环境变化,认为矿床早期为典型的沉积变质成因,后期遭受了变质、变形以及热液作用的影响和改造。综合地质特征、矿石矿物与脉石矿物的岩相学特征、主量元素分析等,我们认为抬升至地表后的氧化作用对矿床影响较小,Fe的富集可能与Mg、Mn和Ca等元素的迁移有关,变质变形期末-热液蚀变期为冀东司家营BIF铁矿床富铁矿形成最重要的时期。
Abstract
The BIF-type iron deposit at Sijiaying in eastern Hebei Province is considered one of the most representative banded iron deposits in China. A systematic investigation of ore and mineral characteristics holds significant implications for understanding the metallogenic evolution of BIF-type iron deposits. In this study, we conducted comprehensive petrographic observations on various typical iron ores from this mining area, and combined them with in situ electron probe (EPMA) testing and analysis, five distinct magnetite types were identified. Furthermore, we identified four stages of metallogenic evolution: the initial sedimentary stage, metamorphic deformation stage, hydrothermal alteration stage, and epigenetic oxidation stage. EPMA results were obtained for magnetite, biotite, chlorite, and hornblende. By analyzing the chemical characteristics of magnetite and calculating the different formation temperature of biotite and chlorite, and considering changes in the metallogenic environment indicated by their chemical characteristics, it indicated that a typical feature of sedimentary metamorphism is present in the early stage of the deposit and that it suffered from metamorphism, deformation, and hydrothermal effects in the later stage. Combined with geological features, petrographic characteristics of ore minerals and gangue minerals, major element analysis, and other studies, we considered that the oxidation after uplifting to the surface had less influence to the deposit; the enrichment of Fe may be related to the migration of elements such as Mg, Mn, and Ca. The end of the metamorphic deformation stage to the hydrothermal alteration stage is the most important stage for the formation of Fe-rich iron ore in the BIF-type iron deposit at Sijiaying in eastern Hebei Province.
关键词
冀东司家营;BIF型铁矿床;磁铁矿;矿物特征;成矿演化
KeyWord
Sijiaying in eastern Hebei Province; BIF-type iron deposit; magnetite; mineral characteristics; metallogenic evolution
基金项目
页码 68-86
  • 参考文献
  • 相关文献
  • 引用本文

李文韬,董国明*,丁枫,曹瑞明,杨立群,范宇航,刘佳,郑新. 冀东司家营BIF型铁矿北矿区典型矿石矿物特征及其对成矿演化的约束 [J]. 岩石矿物学杂志. 2025; 44; (1). 68 - 86.

  • 文献评论

相关学者

相关机构