冀东太古宙富铁苦橄岩年代学和成因研究

富铁苦橄岩是一类罕见的富铁高镁岩浆岩，其形成通常与地幔柱活动有关，但其地幔源区性质、熔融条件和富铁机制尚没有得到准确限定。本立项拟以华北克拉通冀东地区新发现的太古宙富铁苦橄岩为研究对象，基于详细的野外填图，并利用岩石学、同位素年代学、岩石地球化学等研究手段，查明冀东太古宙富铁苦橄岩及相关岩性的岩石组合、空间分布、形成时代、成分特征，确定其地幔源区特征和形成机制；并与全球太古宙地幔来源岩浆岩进行对比，对太古宙地幔的成分特征和热状态进行进一步约束。本立项不仅有助于确定富铁苦橄岩这一特殊岩石类型的成因，而且对于揭示太古宙地幔柱活动及地幔的成分不均一性具有重要意义。

Ferropicrites are a rare iron-rich variety of highly magnesian igneous rocks, and their formation is typically associated with mantle plume activities; but the mantle source characteristics, melting conditions and iron-enrichment mechanisms of ferropicrites remain poorly constrained. This project will focus on the newly discovered Archean ferropicrites in Eastern Hebei, the North China Craton. Through comprehensive investigations of field mapping, petrology, isotope geochronology and geochemistry, this project will unveil rock assemblages, spatial distribution, formation ages and compositional features of the Archean ferropicrites and related lithologies in Eastern Hebei, and reveal their mantle source characteristics and formation mechanisms. By comparison with other Archean mantle-derived igneous rocks worldwide, this project will provide further constraints on the compositional characteristics and thermal state of Archean mantle. Not only can this project contribute to the study of ferropicrite petrogenesis, but also play an important role in understanding Archean mantle plume activities and mantle heterogeneity.