Disentangling palaeoecological and outcrop controls on <scp>MISS</scp> occurrence in c. 1 Ga fluvio‐lacustrine facies of the Diabaig Formation, Scotland

ABSTRACT The c. 1 Ga Diabaig Formation of north‐west Scotland preserves diverse lacustrine and fluvial facies and abundant microbial and non‐microbial surficial sedimentary features. 172.6 m of section was logged across seven localities to assess the distribution of microbially induced sedimentary structures (MISS) relative to lithofacies, substrate type and outcrop exposure. MISS‐like surficial textures are common in low‐energy lacustrine mudstones and intermittently observed in fluvial margin deposits, but rare or absent in high‐energy facies. Distinctive surface morphologies, including stellate boss‐like features, are locally developed and suggest variability in substrate–surface interactions. Observed MISS distributions reflect the combined influence of local sedimentological conditions conducive to mat development, preservation of true substrates and limits imposed by outcrop exposure and recognition, resulting in strong spatial heterogeneity. MISS occurrences in the Diabaig Formation thus provide palaeoenvironmental insights beyond those archived by lithofacies alone, when considered in their sedimentological and preservational context, but their apparent abundance and variety should not be interpreted as straightforward facies indicators when considered in isolation.