Formation pathways of ooids

Resolve whether ooid formation in shallow marine and lacustrine environments is governed predominantly by abiotic physicochemical processes or by microbial activity, and delineate the conditions and mechanisms associated with each pathway.

Background

Ooids are coated carbonate grains with concentric laminae that form in agitated waters. Historically, both abiotic precipitation and microbial mediation have been proposed to explain their textures and lamination.

The review emphasizes that, despite decades of investigation, the formation mechanism remains contested, making ooids a key test case for disentangling abiotic versus biotic controls on carbonate microfabrics.