scholarly journals Microbial mat-induced sedimentary structures in siliciclastic sediments: Examples from the 1.6 Ga Chorhat Sandstone, Vindhyan Supergroup, M.P., India

2006 ◽  
Vol 115 (1) ◽  
pp. 49-60 ◽  
Author(s):  
Subir Sarkar ◽  
Santanu Banerjee ◽  
Pradip Samanta ◽  
Silambuchelvan Jeevankumar
Keyword(s):  
Microbial Mat ◽  
Vindhyan Supergroup ◽  
Sedimentary Structures ◽  
Siliciclastic Sediments

Tubey or not tubey: Death beds of Ediacaran macrofossils or microbially induced sedimentary structures?

Geology ◽  
2019 ◽  
Vol 47 (10) ◽  
pp. 909-913
Author(s):  
Lyle L. Nelson ◽  
Emily F. Smith
Keyword(s):  
Environmental Conditions ◽  
Trace Fossils ◽  
Microbial Mat ◽  
Sedimentary Structures ◽  
Bedding Planes ◽  
Stratigraphic Interval

Abstract Within the upper Ediacaran Esmeralda Member of the Deep Spring Formation in southeastern California, USA, an ∼3 m stratigraphic interval contains multiple clastic bedding surfaces with enigmatic, three-dimensionally preserved corrugated tubes (<60 cm in length and 6 cm in width). When viewed as fragments and in situ on bedding planes, these resemble larger versions of annulated, tubular soft-bodied macrofossils that are common in late Ediacaran biotic assemblages regionally and globally. Despite superficial similarities to casts and molds of body fossils preserved in correlative strata, we suggest these tubes are instead previously undescribed organosedimentary structures that developed through differential compaction of rippled heterolithic interbeds bound by pyritized microbial mat layers. These distinctive structures formed within peritidal settings in the latest Ediacaran Period as the result of specific ecological and environmental conditions marked by flourishing microbial mat communities and dysoxic sediments. This interpretation may inform the biogenicity of other structures previously reported as macroscopic body or trace fossils.

scholarly journals Neoproterozoic microbially-induced sedimentary structures (MISS) from Ediacaran Podillya Basin, Ukraine: mineralogical particularity and paleoenvironmental application

2019 ◽  
Vol 28 (3) ◽  
pp. 554-561
Author(s):  
Y. Soldatenko ◽  
A. El Albani ◽  
C. Fontaine ◽  
V. A. Nesterovsky ◽  
M. V. Ruzina
Keyword(s):  
Sedimentary Basin ◽  
Microbiological Activity ◽  
Sedimentary Structures ◽  
Diagenetic Processes ◽  
Coastal Marine ◽  
Bacterial Mats ◽  
The Difference ◽  
Biological Films ◽  
Host Rocks ◽  
Siliciclastic Sediments

The Neoproterozoic Podillya sedimentary Basin is well known to the imprints of the Ediacaran soft-bodied fauna which were previously described by many ukrainian and foreign authors. At this period, fossil-rich siliciclastic sediments recognized as traces of early metazoans also contain evidence of significant microbiological activity. In these ediacaran sediments, many structures can be interpreted as microbially induced sedimentary structures (MISS). Their morphologies have a great similarity with modern structures observed in relation with micro-organism activity. These specific structure and surfaces and their mineral composition are the criteria used to study the bacterial structures from the ukrainian Neoproterozoic sedimentary basin. Our results demonstrate microorganisms were organized in bacterial mats whose activity was recorded in the difference of mineralogy between biological films and host rocks. On outcrop, the different type of MISS are often associated with lenticular beddings, ripples and hummocky cross structures indicative of coastal-marine conditions close to the littoral zone of the basin at    this epoch. If MISS are important in the issue of paleogeographic reconstructions, they also give precious informations about early diagenetic processes, syn- and post-sedimentation. By mineralogical approach we show that during the time of development of MISS structures and the burial that followed the diagenetic processes have remained moderate. Finally, the close coexistence with ediacarian fossils suggest that such bacterial mats could be at the origin of the fossilization process of soft-bodies of enigmatic Ediacaran biota of Mohyliv-Podylska Group and their preservation until today.

Quantification of microbial mat response to physical disruption in siliciclastic sediments

2019 ◽  
Vol 230 ◽  
pp. 106434 ◽  
Author(s):  
Jerónimo Pan ◽  
Vanesa L. Perillo ◽  
Diana G. Cuadrado
Keyword(s):  
Microbial Mat ◽  
Siliciclastic Sediments

Suspected microbial mat-related crack-like sedimentary structures in the Palaeoproterozoic Magaliesberg Formation sandstones, South Africa

2005 ◽  
Vol 138 (3-4) ◽  
pp. 274-296 ◽  
Author(s):  
M PARIZOT ◽  
P ERIKSSON ◽  
T AIFA ◽  
S SARKAR ◽  
S BANERJEE ◽  
...  
Keyword(s):  
South Africa ◽  
Microbial Mat ◽  
Sedimentary Structures

scholarly journals Biological and geological characterization of modern biofilms and microbial mats and comparison with similar lithified structures in Colombian Cretaceous formations

2018 ◽  
Vol 22 (3) ◽  
pp. 159-168
Author(s):  
Daniela Osorio-Rodriguez ◽  
Carlos Alberto Sanchez-Quiñónez
Keyword(s):  
Microbial Mats ◽  
Extreme Environments ◽  
Microbial Mat ◽  
Mature Stage ◽  
Saline Environment ◽  
Symbiotic Relationships ◽  
Sedimentary Structures ◽  
Calcareous Rock ◽  
Siliciclastic Rock

Microorganisms may play an important role in the aggregation of sediments and the formation of sedimentary structures. Biofilms are microbial aggregates that, in a mature stage, can develop into microbial mats, fibrillar networks that irreversibly bind filaments of cyanobacteria and sediments, inside which it has been identified a stratification with functional groups of microorganisms that coexist, generate symbiotic relationships and potentially modify the characteristics of sediments and sedimentary rocks, particularly in extreme environments. In this work, filamentous cyanobacteria from biofilms of a lacustrine environment with intervals of flooding/desiccation and a saline environment, and a microbial mat from the Agua Caliente Thermal, El Rosal, Cundinamarca, are identified. In the biofilms, most cyanobacteria were found to belong to the Orden Oscillatoriales, while in the microbial mat cyanobacteria of the order Orden Nostocales were also recognized. Two rock samples isolated from the thermal which genesis was possibly influenced by the activity of cyanobacteria are described and classified. One of them, named R-1, is a calcareous rock inside which it was possible to differentiate biolaminations and an apparent dominance of biomineralization processes. This sample was both classified as a travertine and a microbial framestone with stromatolitic and thrombolytic texture. The second one, called R-2, is a siliciclastic rock classified as a mudstone and a microbial boundstone. Finally, a comparison between the sedimentary structures identified in those rocks with similar structures in the formations La Luna, Paja and Tetuán and the microbially-induced sedimentary structures (MISS) described in the literature is performed. Based on morphological resemblance, fibrillar networks identified locally in those formations are interpreted as possible biolaminations originated from the activity of cyanobacteria.

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