Specific microaggregates and problematic microfossils as satellites of biochenogenic rocks

Pseudomorphs are formed along the envelopes of whole and destroyed cells as a result of a high rate of fossilization in microbial ecosystems. The destroyed cells may be mistaken for chemogenic formations of colloidal compounds, in particular, aqueous silicon dioxide. This paper focuses on microfacies, which are either mineralized biofilms or fragments of fossilized bacterial envelopes, as shown by electron microscopy and energy-dispersive spectrometry. In particular, we establish the biomineral origin of a number of mineral aggregates of specific appearance found in the samples studied: stromatolites and segregations.