Reconstructing Mollisol Formation Processes Through Quantified Pedoturbation

Abstract

Mollisols are highly fertile soils and function as significant carbon reservoirs. However, determining their ages and formation processes is challenging due to extensive pedoturbation, which undermines conventional dating methods. Here, we employed luminescence, a light‐sensitive property of minerals widely used in geological dating, to investigate and quantify soil mixing. We analyzed over 2,400 luminescence ages of individual K‐feldspar grains from a Mollisol profile in Northeast China, and for the first time, we were able to determine the intensity of pedoturbation in the Mollisol profile over the past 50,000 years. The results showed that the current pedoturbation can penetrate to a depth of approximately 80 cm, with the intensity decreasing with depth. By identifying a significant intensification in historical pedoturbation, we inferred that the paleoenvironment might be suitable for the formation of Mollisols 16,400 years before present.