Thrombolite

Modern thrombolites in Lake Clifton, Western Australia
Jurassic thrombolite formed around a tree trunk; Purbeck Formation, Isle of Portland, Dorset, England.
Fossil Thrombolites at Lake Walyungup

Thrombolites (from Ancient Greek θρόμβος thrómbos meaning "clot" and λῐ́θος líthos meaning "stone") are clotted accretionary structures formed in shallow water by the trapping, binding, and cementation of sedimentary grains by biofilms of microorganisms, especially cyanobacteria.[1]

  1. ^ Kennard, John M.; James, Noel P. (1986). "Thrombolites and Stromatolites: Two Distinct Types of Microbial Structures". PALAIOS. 1 (5): 492. doi:10.2307/3514631. JSTOR 3514631.