Throughout the Podravina region, NE Croatia, over one hundred locations with signs of iron production, dating to the late Antique period and the Middle Ages, have been discovered in the last 30 years. Recently, signs of various bog iron ore types and formations were discovered throughout the area. This study investigates the mineralogical and geochemical characteristics of local bog iron and roasted iron ores. Furthermore, statistical clustering of different geochemical components in the ores is presented, while the abundance and distribution of macro-, micro- and rare earth elements (REE) and how they correlate within the bog iron ores and roasted iron ores is considered. A total of 15 samples acquired from geological investigations and 13 samples found during archaeological excavations were analysed using geochemical and mineralogical methods. In bog iron ores, X-ray diffraction (XRD) confirmed goethite and quartz as the primary mineral phases, while roasted iron ores contained several Fe minerals and had variable quartz and clay mineral contents. Chemical analyses confirmed high Fe contents in both bog iron ores (up to 70.89 mass. %) and roasted iron ores (up to 84.97 mass. %), with a distinct differentiation of Fe and Si between the different bog iron ore types. Scanning electron microscopy with attached EDS detector (SEM-EDS) showed features of laminar Fe and Mn mineralization, confirming the theory that bog iron ore forms as seasonal precipitation from groundwater. Using the hierarchical clustering analysis, a geochemical correlation of the iron component in bog iron ores and roasted iron ores was compared to other major oxides, micro- and REEs. It was established that the iron component has very little influence on REE and microelements behaviour. Therefore, microelements and REEs were used as a tracer for establishing a geographical connection between the bog iron ores and roasted iron ores in the Podravina region.

在整个波德拉维纳地区，克罗地亚东北部，在过去30年中发现了一百多个带有铁矿生产迹象的地点，可追溯到古色古香的晚期和中世纪。最近，在整个地区发现了各种沼泽铁矿石类型和形成的迹象。这项研究调查了当地沼泽铁和烤铁矿石的矿物学和地球化学特征。此外，介绍了矿石中不同地球化学成分的统计聚类，同时考虑了大量，微量和稀土元素（REE）的含量和分布以及它们在生铁矿石和焙烧铁矿石中的相关性。使用地球化学和矿物学方法对从地质调查中获得的15个样品和在考古发掘过程中发现的13个样品进行了分析。在沼泽铁矿石中，X射线衍射（XRD）证实针铁矿和石英为主要矿物相，而焙烧铁矿石含有几种铁矿物，并且石英和粘土矿物含量可变。化学分析证实，在沼泽铁矿石（至多70.89质量％）和焙烧铁矿石（至多84.97质量％）中均具有高铁含量，不同类型的沼泽铁矿石之间铁和硅有明显区别。带有附加EDS检测器（SEM-EDS）的扫描电子显微镜显示出层状Fe和Mn矿化的特征，从而证实了沼泽铁矿石形成为地下水的季节性沉淀的理论。使用分层聚类分析，将沼泽铁矿石和焙烧铁矿石中铁成分的地球化学相关性与其他主要氧化物，微量元素和稀土元素进行了比较。已经确定，铁组分对稀土元素和微量元素的行为影响很小。因此，微量元素和稀土元素被用作示踪剂，以在波德拉维纳地区的沼泽铁矿石和焙烧铁矿石之间建立地理联系。