Character, analysis, and preservation of biogenicity in terrestrial siliceous stromatolites from geothermal settings

Abstract

Siliceous stromatolites embody important records of past biological activity. The biogenic–mineralogical laminated structures form within a range of geothermal settings and physicochemical, hydrodynamic, and biological regimes. Silica provides an excellent medium for cellular preservation, due to its capacity to permineralize or encase microbial cells with an X-ray amorphous cement (Francis et al., 1978). As such, it has rendered some of the best microfossils in the geologic record.In particular, the Early Devonian, hot spring-related Rhynie and Windyfield cherts (Scotland) contain exceptionally clear and comprehensive examples of fossilized early terrestrial plant, animal (arthropod), and microbial life, including detailed preservation of internal structures, in addition to paleoenvironmental information (Trewin, 1994; Fayers and Trewin, 2004).