How life affects mineral formation: a reappraisal of concepts and terminology

Numerous biological factors have been proposed to influence the formation of minerals under Earth-surface conditions, but the underlying concepts are often confused due to inconsistent terminology. The current systematics has largely developed historically, yet remains unclear because several terms have contrasting definitions or are not self-explanatory. Over time, the variety of processes proposed to explain biological effects on mineral formation has expanded, but the mechanisms often remain far from fully resolved and sometimes lack a proof of concept.

Here, a systematic framework of terms is proposed, requiring only slight modifications of the established terminology, primarily by removing some of the non-self-explanatory connotations. For example, the term ‘biologically influenced’ mineral formation better should represent a general ‘influence’ rather than a specific mechanism. In turn, ‘biologically induced’ should be used in its original meaning as ‘driven by supersaturation’. New terms such as ‘biologically nucleated’ and ‘biologically mediated’ precipitation would more precisely describe the specific mechanisms where organisms or biogenic organic substances act as a nucleation substrate or as a catalyst facilitating mineral growth from already supersaturated solution.

The proposed scheme would necessitate minimal intervention into existing terminology and at the same time become more user friendly for broad application in sedimentology and biogeosciences. Establishing a coherent and canonical terminology will not only improve clarity but also provide a common ground for future research on how biological and abiotic factors influence mineral formation under Earth-surface conditions.