Podiform chromitites are unique rock units of ophiolites and ophiolitic mélanges and represent invaluable repositories that reliably record the formation environment and evolution of their source and host rocks. However, there are relatively few podiform chromitites reported from Archean terranes. Here we document the major, minor, and trace element characteristics of podiform chromitites from the Archean Zunhua ophiolitic mélange in the North China Craton. The Zunhua ophiolitic mélange includes blocks of serpentinized peridotite (dunite and harzburgite), podiform chromitite, pyroxenite, amphibolite, metabasites (basalt and diabase), chert, and tectonic lenses of banded iron formation in a strongly sheared metapelitic matrix. The chromitites, host peridotites, and granitic dikes cutting the mélange all have ages between 2.6 and 2.5 Ga. Chondrite-normalized, whole-rock platinum group element (PGE) patterns of the Zunhua chromitites show a negative sloping PGE trend enriched in Ir and depleted in Pt, similar to typical Phanerozoic podiform chromitites. The geochemical characteristics of the calculated parental magma of the Zunhua chromitites closely resemble those of podiform chromitites in Phanerozoic ophiolites and ophiolitic mélanges but different from those of continental stratiform chromite deposits. The calculated major, minor, and trace element concentrations of the parental melt of Zunhua chromitites are similar to those of boninitic melts found in forearc settings. Geochemical characteristics and calculated parental melt composition of the chromites with the high Mg# values of their host peridotites suggest that the Zunhua podiform chromitites formed by magmatic processes including reactions between boninitic melt and harzburgite in a supra-subduction zone environment.

坡状铬铁矿是蛇绿岩和蛇绿岩混杂岩的独特岩石单元，代表了宝贵的储层，可以可靠地记录其形成环境及其源岩和基质岩的演化。但是，从太古宙地形中报道的豆荚状铬铁矿相对较少。在这里，我们记录了华北克拉通地区太古宙遵化蛇绿混杂岩中豆状铬铁​​矿的主要，次要和微量元素特征。遵化蛇绿岩混杂岩包括块状蛇纹石化橄榄岩（辉绿岩和哈兹伯格岩），坡铁状铬铁矿，辉石岩，闪石，变质岩，玄武岩（玄武岩和辉绿岩），石和在强烈剪切的变质岩质基质中形成带状铁的构造透镜。铬铁矿，宿主橄榄岩和花岗岩岩体切割混杂岩的年龄都在2.6至2.5 Ga之间。遵化铬铁矿的球粒陨石归一化全岩铂族元素（PGE）模式显示出负斜率的PGE趋势，其中富含Ir且贫化了Pt，与典型的生代半月形铬铁矿相似。计算出的遵化铬铁矿母体岩浆的地球化学特征与生代蛇绿岩和蛇绿岩中的裙状铬铁矿非常相似，但与大陆层状铬铁矿床不同。遵化铬铁矿母体熔体的计算的主要，次要和痕量元素浓度与前臂环境中发现的邦尼性熔体的浓度相似。