I am studying weathered soil distributed around hornfels. No intermediate (partially weathered) stage is observed between hornfels and the soil. A candidate rock B is located ~200 m away, but based on strike/dip relations, B is structurally unlikely to be the parent.

However, the soil’s geochemistry appears closer to B than to hornfels:

• REE patterns: soil shows Ce–Eu anomalies comparable to B. Hornfels has weaker anomalies and is HREE-depleted, while the soil is HREE-enriched.
• δ¹³C: soil differs from B by