communities in Mediterranean streams: conditions to a changing environment.
One of these, a travertine and microbial framestone, had stromatolitic
and thrombolitic textures.
Detrital grains probably occur between or among stromatolitic
Cascade tufa manifest well defined stromatolitic
lamination as evidence of periodic changes of physical factors, crystallization order and biological activity, due to different amount of organic material specially bacteria and cyanobacteria.
Microherms in the Smackover consist of concentrically laminated (stromatolitic
), clotted (thrombolitic), calcimicrobial, or structureless (leiolitic) carbonate, and texturally resemble associated oncoids (algal balls).
226 Large stromatolitic
formations uncovered at low tide in Shark Bay (Western Australia).
Beating these caveats in mind, data currently available indicate that stromatolitic
microbial ecosystems, evidently including cyanobacteria and other members of the bacterial domain, were extant [approximately]3500 Ma ago (4, 5); methanogenic archaeans by [approximately]2800 Ma ago (6, 7); and gram-negative sulfate-reducing bacteria as early as [approximately]2700 Ma ago (8) and possibly earlier (9).
This portrayal of the environment in which stromatolitic
communities flourished billions of years ago is a classic one.
biostrome of the Cambrian Fengshan Formation at the Xiaweidian section in the western suburb of Beijing, North China.
It is typically white to grey and light green, banded, and locally stromatolitic
, calcareous to dolomitic marble interbedded with pelite, fine-grained quartzite, minor conglomerate, and mica schist.
Microfacies, Carbon and Oxygen Isotopes of the Late Archaean Stromatolitic
Carbonate Platform of the Kaapvaal Craton, South Africa: Implications for Changes in Paleo-environment.