Element Covariation Reveals Diverse Core Differentiation Histories among Magmatic Iron Meteorites

Iron meteorites preserve key records of early planetary differentiation and core formation processes. However, the combined effects of metal–silicate separation, core crystallization, and subsequent impact modification have produced complex and variable geochemical signatures, complicating efforts to reconstruct their parent-body origins and evolutionary histories. To address this challenge, we compiled a comprehensive geochemical dataset of iron meteorites and developed a process-oriented statistical framework that characterizes iron meteorite geochemistry through element covariation patterns and compares their internal chemical structures across different meteorite groups. The results reveal distinct and internally consistent geochemical structures among major magmatic iron meteorite groups. IIAB and IIIAB irons show strong positive correlations among HSEs and systematic anticorrelations with Ni, consistent with well-developed metal crystallization trends and relatively continuous core differentiation histories. In contrast, IVA and IVB irons exhibit weaker coupling between HSEs and other elements, together with subdued or decoupled Ga–Ge behavior, suggesting more complex or non-equilibrium differentiation pathways. The IID group displays intermediate and less coherent correlation structures, indicating greater heterogeneity in internal processes or parent-body conditions. This process-oriented framework provides a quantitative basis for comparing the internal geochemical architectures of iron meteorite groups and offers new perspectives on the diversity of differentiation histories recorded by metallic planetary cores.