What are the organo-mineral associations called 'nanoCLICs'?

Mineral associated organic matter significantly contributes to durable carbon sequestration in soils. Besides organic compounds adsorbed on mineral surfaces, organo-mineral associations in the form of coprecipitates are increasingly cited in the literature as a key mechanism of interaction between organic matter and soil minerals. Coprecipitates thus emerge as essential soil bodies in controlling carbon dynamics in soils. Their transitional structural/nature as well as their precise formation and maturation/transformation mechanisms remain poorly understood.Over the past 10 years, we have aimed to: (1) model the molecular structure of these coprecipitates (Basile-Doelsch, et al., 2015; Tamrat, et al., 2018; Tamrat, et al., 2019) (2) observe and characterize them down to the nanoscale (Jamoteau, et al., 2023; Jamoteau, et al., 2025a), (3) test their stability against mineralization by microorganisms (Jamoteau et al., 2025b), and (4) explain their formation mechanisms in soils in relation to microbial activity. Our work relied on both synthetic samples (laboratory coprecipitates) and natural andosols, and we employed complementary approaches combining physicochemistry, microfluidic systems, respirometry, electron microscopy (SEM, TEM), and spectroscopy (EXAFS, STXM, EDX, EELS) to characterize the nature, the structure and the dynamics of coprecipitates.This contribution will provide a synthesis of the studies conducted on these organo-mineral structures called "nanoCLICs" for nanosized coprecipitates of inorganic oligomers with organics (Tamrat, et al., 2019). We demonstrate that nanoCLICs could represent, within soil constituents, an ultimate boundary between biotic and abiotic components. NanoCLICs could thus play major roles in the biogeochemical dynamics that control soil functioning.Basile-Doelsch, I. et al. Environ. Sci. Technol. 49, 3997-3998, doi:https://doi.org/10.1021/acs.est.5b00650 (2015).Jamoteau, F. et al. Environmental Science & Technology 57 (49), 20615-20626, DOI: 10.1021/acs.est.3c06557 (2023)Jamoteau, F. et al. Environ. Sci. Technol. 57, 20615-20626, doi:10.1021/acs.est.3c06557 (2025a)Jamoteau, F. et al. SOIL, 11, 535–552, 2025, doi.org/10.5194/soil-11-535-2025 (2025b)Tamrat, W. Z. et al. Geochimica et Cosmochimica Acta 229, 53-64, doi:https://doi.org/10.1016/j.gca.2018.03.012 (2018).Tamrat, W. Z. et al. Geochimica et Cosmochimica Acta 260, 15-28, doi:https://doi.org/10.1016/j.gca.2019.05.043 (2019).