Stromatolites
Conical stromatolites, associated with early photosynthetic microbes, also exhibit twisted and distorted patterns not solely due to phototaxis. Research reveals oxygen production by cyanobacteria in these formations results in such irregularities and trapped bubbles. The presence of similar fossilized bubbles in stromatolites dating back 2.7 billion years could serve as a marker for the evolution of oxygen-producing photosynthesis.
Tanja Bosak
Cerium anomalies in 2.74 billion-year-old stromatolites indicate fluctuating redox conditions due to oxygenic photosynthesis, supporting the concept of early “oxygen oases” predating the Great Oxidation Event.
Dylan T. Wilmeth
A detailed study reveals diverse and previously unknown microbial communities, including a wide range of archaea, within stromatolites from Western Australia, enriching our understanding of these ancient biosedimentary structures.
Brendan Burns
Carbon isotopic evidence from ancient stromatolites suggests oxygenic photosynthesis, enabled by Form I Rubisco, began around 2.9 billion years ago. Despite this, the late Archaean atmosphere remained anoxic, potentially due to Rubisco’s CO2 preference, impacting long-term atmospheric composition.
Euan Nisbet
Intensive study of Shark Bay’s stromatolites, the largest modern system, revealed unique structures formed predominantly by coccoid cyanobacteria, contradicting traditional views. Discoveries of microcrystalline carbonate within these stromatolites provide new insights into early Earth ecosystems.
R. Pamela Reid
Deep-water stromatolites in the Upper Devonian reef complexes of the northern Canning Basin indicate varied reef evolution conditions and flourished in areas with minimal sediment deposition, including during times of high productivity.
Annette George
Microbial precipitation of microcrystalline carbonate (micrite), previously overlooked, plays a key role in the formation of Shark Bay stromatolites, especially in the subtidal zone, adding a new layer of understanding to these ancient structures’ origins.
R. Pamela Reid
Newly discovered stromatolite forms in Western Australia’s Proterozoic Earaheedy Group suggest the potential for stromatolite-based biostratigraphy. However, a notable decrease in stromatolite diversity around 1.1 Ga needs further study.
Kathleen Grey
The branching and macrostructure of Neoproterozoic Acaciella australica stromatolites in Australia are majorly influenced by sediment and microbial contributions. Reduced sediment supply links to a shift towards microbial-controlled morphology and stromatolite branching.
Noah Planavsky
The 3.43 billion-year-old Strelley Pool Chert in Western Australia hosts ancient stromatolites, hinting at early Archaean life. Stromatolite abundance and diversity were influenced by environmental conditions, with higher occurrences in calm, shallow marine environments with low sedimentation rates and absence of high-temperature hydrothermal input. Evaporitic precipitation played a crucial non-biological role in stromatolite formation.
Abigail C. Allwood
High-resolution trace element analysis in Neoproterozoic Bitter Springs Formation stromatolites reveals they mainly formed from in-situ precipitation within microbial mats, not trapped sediment. This discovery aids the search for geochemical biosignatures and information about ancient water chemistry.
Peter. Southgate
High-resolution analysis differentiates stromatolites from sediment in Bitter Springs Formation. Stromatolites show elevated LREEs and in situ carbonate precipitation. Fine carbonate in stromatolites may preserve geochemical biosignatures.
Maree Corkeron
The 2.72 Ga Tumbiana Formation in Western Australia holds well-preserved stromatolites. It was deposited in fluvial and lacustrine environments of an inward-draining continental basin. Carbon isotope analysis suggests a higher contribution of phototrophic metabolism.
D.T. Flannery
This study unveils a 2.4-2.3 Ga dolomitic reef complex in Western Australia. It differs from a younger formation and showcases unique microbial structures. The Kazput Formation is significantly older than other Proterozoic reefs and suggests a link to the rise of atmospheric oxygen.
E. Barlow
Post End Permian Mass Extinction (EPME), stromatolite distribution surged globally. West Australian stromatolites in Northampton region found farther than expected, revealing alternating morphologies and environmental changes. Proposed revised model places them in intracontinental marine setting, challenging their presumed age and correlation with mass extinction.
Liam Olden
Fourteen microbial buildups are found along the Enorama Diapir in South Australia. They formed during the upper Cryogenian period and varied in size and stability. The buildups grew from stromatolite domes, with some reefs reaching 50 meters in height. The entire reef complex has been dolomitised by diapir-related solutions. The reefs developed during rising sea levels and were affected by diapir movement.
N.M. Lemon
Modern Shark Bay stromatolites grow slowly in a high-energy environment, with rates 250 times slower than Precambrian stromatolites. It takes up to 1000 years for subtidal columns to reach 350 mm in height. Early stromatolites at Shark Bay date back 1250-1000 years and are now stranded above high tide.
A. R. Chivas
Hamelin Pool reveals regional salinity and temperature trends, with decreasing energy moving southward. Wet winters have higher salinity, dry summers have lower salinity, suggesting groundwater influx affecting stromatolite growth. Insights inform stromatolite development understanding.
ERICA P. SUOSAARI
P. perplexa and A. ashburtonia coexist in sedimentary sequences, with their distribution influenced by the sedimentary environment. P. perplexa thrived in shallow lagoons and intertidal zones, while A. ashburtonia occupied a supratidal setting. Taxonomic differences between pilbariform and asperiform stromatolites suggest evolutionary rather than environmental influences
Kathleen Grey, Alan M. Thorne
Viruses shape global cycling, ancient ecosystems, and stromatolite formation. High-throughput sequencing reveals members and metabolisms, but viral impact remains unclear. Understanding viral interactions is crucial for interpreting biosignatures and mineral processes.
Richard Allen White III
Microbial mats found in the Pilbara Craton provide evidence of early life on Earth. A new type of microbial mat facies, consisting of black cherts with carbonate bodies, organic material, and pyrite, has been discovered. The facies represents microbial mats formed in a shallow marine environment. The presence of photoautotrophs and microbial sulfate reduction supports the idea of life in the Strelley Pool Formation.
Dr Jan-Peter Duda
Gas production in Archean stromatolites reveals ancient microbial metabolisms. Fenestral textures suggest the presence of gases released by microbial mats. Oxygenic photosynthesis is the most likely metabolism to produce fenestrae before the Great Oxidation Event. Gas volumes were estimated and reactants were considered for each metabolism.
Dylan T. Wilmeth
Neoarchean stromatolites reveal diverse microbial communities before the GOE. Pyrite grains suggest biomass recycling and sulfate reduction. Sulfur isotopes indicate marine sulfate mixing with stratospheric aerosols, supporting increased volcanism and atmospheric changes. Redox transformation in Archean atmosphere triggered the GOE by transforming the sulfur cycle.
Wlady Altermann
Rising CO2 levels affect ocean pH and carbonate chemistry, but their impact on carbonate-depositing microbial communities is uncertain. We studied the effects of elevated CO2 on microbial mats that form organosedimentary structures. Despite six months of exposure, microbial diversity and carbonate precipitation remained largely unchanged, suggesting some ecosystems may be more resilient to environmental change.
Steven R. Ahrendt
Chloroflexi-rich hot spring mats in Japan produce stromatolite-like structures similar to those formed by Cyanobacteria. Despite different microbial communities, they share analogous morphologies, suggesting morphology is influenced by hydrology and cell characteristics rather than oxygenic photosynthesis.
Lewis M. Ward
Mathematical models challenge stromatolites’ biotic origin. We propose a biotic model: upward growth of biofilm (v) and mineral accretion (λ). Domical stromatolites form when v≤λ. Coniform structures form when v>>λ. Angular coniform structures, resembling oldest evidence of life, form when v>>λ.
M. T. Batchelor
This study investigates grain trapping in stromatolites. Cyanobacterial mats effectively trap fine grains, while algal mats trap medium and coarse grains. Detrital grains beyond a specific angle are a biosignature in ancient stromatolites. Cyanobacterial mats may not solely construct stromatolites with coarse grains, revealing insights into their evolution.
C. M. Frantz
The rise of oxygen on Earth 2.3 billion years ago was enabled by the evolution of oxygenic photosynthesis in Cyanobacteria. Recent genomic data suggests that oxygenic photosynthesis evolved around 2.0 billion years ago, close to the rise of atmospheric dioxygen, providing support for their co-evolution.
P. M. Shih
Acaryochloris is a unique phototrophic organism with dominance of chlorophyll d, enabling it to capture light energy over a wide spectrum. A new Acaryochloris strain, Acarychloris LARK001, was discovered in microbial layers beneath stromatolite mats in Shark Bay, Australia. It exhibits distinct pigment patterns and adaptations compared to the original A. marina species, making it a novel cyanobacterial strain in the Shark Bay ecosystem.
Michael S. Johnson
Socompa Lake’s stromatolite microbes: Proteobacteria, Bacteroidetes, Firmicutes dominate. Diverse carbon fixation and arsenic resistance pathways found. Unique microbial community for future research.
Daniel Kurth
Airborne microalgae and cyanobacteria, often overlooked in aerobiology, play a role in cloud formation and climate impact. Recent studies focus on their negative effects on human health and toxic compound production. This review discusses measurement results, knowledge gaps, and suggests future research directions in bioaerosols and their potential risks.
A.U. Lewandowska
A non-invasive setup measures photosynthetic electron transport in microorganisms, revealing species-specific responses to carbon limitation. Valuable for screening traits in significant species.
Priyanka Pradeep Patel
Cyanobacteria form dense microbial mats with diverse metabolic processes. Organic matter produced by cyanobacteria is degraded by chemo trophic microorganisms, resulting in steep gradients of sulphide and oxygen. The laminated structure of microbial mats is influenced by physicochemical gradients and sediment accretion
L. J. Stal
This study examined microbial communities in Shark Bay stromatolites, resembling ancient life evidence. The diverse communities included abundant proteobacteria and cyanobacteria. Unicellular cyanobacteria dominated the surface, while archaea and bacteria were found in the sub-surface. The findings contribute to understanding the microbial physiology and ecological roles in stromatolite formation.
Falicia Goh