A Permian methane seep system as a paleoenvironmental analogue for the pre-metazoan carbonate platforms

ABSTRACT: Following the rise of metazoans, the beginning of bioclasticity and substrate competition, the saga of microbial mats was in a fluctuating decline in the end of the Neoproterozoic era. Increases in diversity during the Phanerozoic and punctual upturns in the microbial carbonate production occured after the events of global mass extinctions. Gradually along the Phanerozoic, the microbial colonies occupied isolated niches and grazers-free environments, characterized by physically and/or geochemically stressful conditions, such as those found in saline bays, alkaline lakes and hydrothermal or cold seep vents. Here we report one of the oldest occurrences of a vent camp coupled with cold seepage of methane in the geologic record, associated with well-preserved microbialites and elephant skin structures. During the seep activity, oxygen depletion and high salinity conditions are prohibitive for complex animal life, clearing the way to microbial colonies to flourish. Due to the co-occurrence of high adaptability and low competitiveness of microbial forms, they became highly specialized in stressful conditions. We argue that the sporadic microbial mat upturns in Earth’s history are not restricted to geological periods, following massive death of metazoan species; they also may occur in response to punctual paleoenvironmental conditions that enable microbial colonies to growth. Indeed, the Phanerozoic geological record is punctuated of these examples, in a kind of hide-and-seek game of Precambrian times.

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Patterns and Processes of Ancient Reef Crises

The Paleontological Society Papers ◽

10.1017/s1089332600002412 ◽

2011 ◽

Vol 17 ◽

pp. 1-14 ◽

Cited By ~ 1

Author(s):

Wolfgang Kiessling

Keyword(s):

Mass Extinctions ◽

Production Rates ◽

Short Term ◽

Carbonate Production ◽

Meteorite Impacts ◽

Comprehensive Database ◽

Extinction Rates ◽

High Volatility ◽

Patterns And Processes ◽

Geologic Record

Reef crises need to be separated from mass extinctions because they are manifested in reductions of reefal carbonate production rather than elevated extinction rates. The volume of preserved fossil reefs per unit time is perhaps the best accessible metric to assess reefal carbonate production rates in the geologic record. Although this metric is prone to biases introduced by weathering, burial, and sampling, it offers the possibility to analyze general connections between reef crises and mass extinctions. The biases can be partially corrected by looking at short-term variations and by utilizing independent proxies of sampling. Using a comprehensive database of ancient reefs and considering the generally high volatility in reefal carbonate production, we can identify five significant metazoan reef crises in the post-Cambrian Phanerozoic, only three of which correspond to traditional mass extinctions. Ancient reefs crises appear to be due to episodes of rapid CO2release and warming, rather than cooling or meteorite impacts.

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"Hypothesis for the role of toxin-producing algae in Phanerozoic mass extinctions based on evidence from the geologic record and modern environments" (Reply)

Environmental Geosciences ◽

10.1306/eg.03231010018 ◽

2011 ◽

Vol 18 (1) ◽

pp. 58-60 ◽

Cited By ~ 1

Author(s):

James W. Castle ◽

John H. Rodgers

Keyword(s):

Mass Extinctions ◽

Geologic Record

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Hydrodynamic influences on sedimentology and geomorphology of nearshore parts of carbonate ramps: Holocene, NE Yucatán Shelf, Mexico

Journal of Sedimentary Research ◽

10.2110/jsr.2020.103 ◽

2021 ◽

Vol 91 (10) ◽

pp. 1040-1066

Author(s):

Thomas C. Neal ◽

Christian M. Appendini ◽

Eugene C. Rankey

Keyword(s):

Numerical Models ◽

Remote Sensing Data ◽

Field Measurements ◽

High Energy ◽

Tidal Range ◽

Carbonate Platforms ◽

Trade Winds ◽

Tidal Forces ◽

Carbonate Ramps ◽

Geologic Record

ABSTRACT Although carbonate ramps are ubiquitous in the geologic record, the impacts of oceanographic processes on their facies patterns are less well constrained than with other carbonate geomorphic forms such as isolated carbonate platforms. To better understand the role of physical and chemical oceanographic forces on geomorphic and sedimentologic variability of ramps, this study examines in-situ field measurements, remote-sensing data, and hydrodynamic modeling of the nearshore inner ramp of the modern northeastern Yucatán Shelf, Mexico. The results reveal how sediment production and accumulation are influenced by the complex interactions of the physical, chemical, and biological processes on the ramp. Upwelled, cool, nutrient-rich waters are transported westward across the ramp and concentrated along the shoreline by cold fronts (Nortes), westerly regional currents, and longshore currents. This influx supports a mix of both heterozoan and photozoan fauna and flora in the nearshore realm. Geomorphically, the nearshore parts of this ramp system in the study area include lagoon, barrier island, and shoreface environments, influenced by the mixed-energy (wave and tidal) setting. Persistent trade winds, episodic tropical depressions, and winter storms generate waves that propagate onto the shoreface. Extensive shore-parallel sand bodies (beach ridges and subaqueous dune fields) of the high-energy, wave-dominated upper shoreface and foreshore are composed of fine to coarse skeletal sand, lack mud, and include highly abraded, broken and bored grains. The large shallow lagoon is mixed-energy: wave-dominated near the inlet, it transitions to tide-dominated in the more protected central and eastern regions. Lagoon sediment consists of Halimeda-rich muddy gravel and sand. Hydrodynamic forces are especially strong where bathymetry focuses water flow, as occurs along a promontory and at the lagoon inlet, and can form subaqueous dunes. Explicit comparison among numerical models of conceptual shorefaces in which variables are altered and isolated systematically demonstrates the influences of the winds, waves, tides, and currents on hydrodynamics across a broad spectrum of settings (e.g., increased tidal range, differing wind and wave conditions). Results quantify how sediment transport patterns are determined by wave height and direction relative to the shoreface, but tidal forces locally control geomorphic and sedimentologic character. Similarly, the physical oceanographic processes acting throughout the year (e.g., daily tides, episodic winter Nortes, and persistent easterly winds and waves) have more impact on geomorphology and sedimentology of comparable nearshore systems than intense, but infrequent, hurricanes. Overall, this study provides perspectives on how upwelling, nutrient levels, and hydrodynamics influence the varied sedimentologic and geomorphic character of the nearshore areas of this high-energy carbonate ramp system. These results also provide for more accurate and realistic conceptual models of the depositional variability for a spectrum of modern and ancient ramp systems.

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Triassic metasediments in the internal Dinarides (Kopaonik area, southern Serbia): stratigraphy, paleogeographic and tectonic significance

Geologica Carpathica ◽

10.2478/v10096-010-0003-6 ◽

2010 ◽

Vol 61 (2) ◽

pp. 89-109 ◽

Cited By ~ 27

Author(s):

Senecio Schefer ◽

Daniel Egli ◽

Sigrid Missoni ◽

Daniel Bernoulli ◽

Bernhard Fügenschuh ◽

...

Keyword(s):

Shallow Water ◽

Lower Triassic ◽

Turbidity Currents ◽

Distal Margin ◽

Carbonate Platforms ◽

Carbonate Production ◽

Tectonic Significance ◽

Internal Dinarides ◽

Water Carbonate ◽

Shallow Water Carbonate

Triassic metasediments in the internal Dinarides (Kopaonik area, southern Serbia): stratigraphy, paleogeographic and tectonic significanceStrongly deformed and metamorphosed sediments in the Studenica Valley and Kopaonik area in southern Serbia expose the easternmost occurrences of Triassic sediments in the Dinarides. In these areas, Upper Paleozoic terrigenous sediments are overlain by Lower Triassic siliciclastics and limestones and by Anisian shallow-water carbonates. A pronounced facies change to hemipelagic and distal turbiditic, cherty metalimestones (Kopaonik Formation) testifies a Late Anisian drowning of the former shallow-water carbonate shelf. Sedimentation of the Kopaonik Formation was contemporaneous with shallow-water carbonate production on nearby carbonate platforms that were the source areas of diluted turbidity currents reaching the depositional area of this formation. The Kopaonik Formation was dated by conodont faunas as Late Anisian to Norian and possibly extends into the Early Jurassic. It is therefore considered an equivalent of the grey Hallstatt facies of the Eastern Alps, the Western Carpathians, and the Albanides-Hellenides. The coeval carbonate platforms were generally situated in more proximal areas of the Adriatic margin, whereas the distal margin was dominated by hemipelagic/pelagic and distal turbiditic sedimentation, facing the evolving Neotethys Ocean to the east. A similar arrangement of Triassic facies belts can be recognized all along the evolving Meliata-Maliac-Vardar branch of Neotethys, which is in line with a ‘one-ocean-hypothesis’ for the Dinarides: all the ophiolites presently located southwest of the Drina-Ivanjica and Kopaonik thrust sheets are derived from an area to the east, and the Drina-Ivanjica and Kopaonik units emerge in tectonic windows from below this ophiolite nappe. On the base of the Triassic facies distribution we see neither argument for an independent Dinaridic Ocean nor evidence for isolated terranes or blocks.

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PRESERVATION OF FOSSIL MICROBES AND BIOFILM IN CAVE POOL CARBONATES AND COMPARISON TO OTHER MICROBIAL CARBONATE ENVIRONMENTS

Palaios ◽

10.2110/palo.2015.033 ◽

2016 ◽

Vol 31 (4) ◽

pp. 177-189 ◽

Cited By ~ 3

Author(s):

LESLIE A. MELIM ◽

DIANA E. NORTHUP ◽

PENELOPE J. BOSTON ◽

MICHAEL N. SPILDE

Keyword(s):

Organic Material ◽

Elevated Temperatures ◽

Hot Spring ◽

Cold Seep ◽

Alternative Mode ◽

Photolytic Degradation ◽

Microbial Carbonate ◽

Edx Analyses ◽

Uniform Diameter

Abstract Fossil microbes are generally preserved by authigenic minerals, including silica, apatite, iron minerals, clays, and carbonates. An alternative mode of preservation by entombment in calcite, without replacement, has been identified in carbonate cave pool microbialites that were etched and examined in the scanning electron microscope (SEM). Features identified include filaments, threads, and films that show excess carbon in energy dispersive X-ray (EDX) analyses, suggesting preservation of organic matter. Filaments are single smooth or reticulated strands with curving string-like morphology, often hollow, and with a uniform diameter of 0.5 to 1.0 μm. Threads, in contrast, are variable thickness, from several microns down to 0.1 μm, always solid, and commonly branch. Films are thin (< 1 μm) drapes associated with threads. Filaments are interpreted as microbial filaments, while threads and films are interpreted as preserved extracellular polymeric substance (EPS). In addition, microbial filaments and EPS are only revealed via acid etching, suggesting preservation of organic material by entombment, not by replacement with calcite. To determine whether entombed microbes are a common feature of carbonate microbialites that form in different environmental settings, samples of hot spring travertine, caliche soil, and reef microbialite were examined. Whereas the travertine samples were barren, entombed EPS was found in the caliche soil and the reef microbialite; the latter also contained a few entombed filaments. In addition, entombed microbial material has been reported from carbonate cold seep deposits. Such findings indicate that entombment of microbes and EPS in carbonates is not restricted to cave settings, but is more widespread than previously reported. Possible causes for the lack of preservation in travertines include rapid degradation of microbial material either by sunlight due to photolytic degradation, aerobic microbial degradation, detritivore consumption, or elevated temperatures. Rapid carbonate precipitation is ruled out as, somewhat surprisingly, preservation is better in slower growing cave carbonates than in rapidly growing travertines. Potential long-term preservation of organic material entombed in carbonate has implications for the characterization of fossil microbial communities using molecular biomarkers and the search for life on other planets.

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Role of microorganisms in the production of lime mud and implications for interpretation of ancient micrite deposits

The Paleontological Society Special Publications ◽

10.1017/s247526220000808x ◽

1992 ◽

Vol 6 ◽

pp. 248-248

Author(s):

L.L. Robbins ◽

K. Yates

Keyword(s):

Calcium Carbonate ◽

Green Algae ◽

Close Association ◽

Carbonate Platforms ◽

Blue Green Algae ◽

Marine Deposits ◽

Lime Mud ◽

Transmission Electron ◽

Geologic Record

Geologists have long been plagued by the lack of evidence for the origin of ancient micrite deposits: any paleontological evidence is typically obscured or lacking altogether. The role of modern marine picoplankton gives insight into the origin of one mode of lime mud formation and may aid in the interpretation of ancient marine deposits.Whitings, patches of floating lime mud in supersaturated seawater on carbonate platforms, obtained from the Bahama Bank were analyzed utilizing biochemical techniques and Transmission Electron Microscopy. All Whitings indicated a close association between picoplankton cellular material and calcium carbonate crystals. Culture experiments indicated the presence of at least ten different picoplankton species in Whitings water. Two major genera found were the blue-green algae, Synechococcus and Synechocystis. Field and laboratory experimental data indicated that these cells and cellular organics play a major role in Whitings formation. The cells may undergo epicellular precipitation of calcium carbonate induced by photosynthesis. Environmental conditions necessary for this process have been delineated through field data and laboratory experiments.While picoplankton organics are rarely preserved over geologic time, the product of their life habit, namely lime mud, is preserved as micrite. Thick occurrences of micrite deposited in marine environments are widespread throughout the geologic record, ranging in age from Precambrian to Recent. Although rare, fossilized blue-green algae have been observed in Archean rocks and may be the only evidence that implicates these organisms in lime mud formation. The Whitings phenomenon serves as an excellent example in which a specific type of organism may be a prolific contributor to the rock record, and yet leaves no direct paleontological evidence of its involvement.

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Hypothesis for the role of toxin-producing algae in Phanerozoic mass extinctions based on evidence from the geologic record and modern environments

Environmental Geosciences ◽

10.1306/eg.08110808003 ◽

2009 ◽

Vol 16 (1) ◽

pp. 1-23 ◽

Cited By ~ 27

Author(s):

James W. Castle ◽

John H. Rodgers

Keyword(s):

Mass Extinctions ◽

Geologic Record

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A New Niche for Anoxygenic Phototrophs as Endoliths

Applied and Environmental Microbiology ◽

10.1128/aem.02055-17 ◽

2017 ◽

Vol 84 (4) ◽

Cited By ~ 3

Author(s):

Daniel Roush ◽

Estelle Couradeau ◽

Brandon Guida ◽

Susanne Neuer ◽

Ferran Garcia-Pichel

Keyword(s):

High Throughput Sequencing ◽

Microbial Mats ◽

Hot Springs ◽

Significant Proportion ◽

Anoxygenic Phototrophic Bacteria ◽

Major Type ◽

Carbonate Platforms ◽

Content Type ◽

Wide Range ◽

Isla De Mona

ABSTRACTAnoxygenic phototrophic bacteria (APBs) occur in a wide range of aquatic habitats, from hot springs to freshwater lakes and intertidal microbial mats. Here, we report the discovery of a novel niche for APBs: endoliths within marine littoral carbonates. In a study of 40 locations around Isla de Mona, Puerto Rico, and Menorca, Spain, 16S rRNA high-throughput sequencing of endolithic community DNA revealed the presence of abundant phylotypes potentially belonging to well-known APB clades. Anad hocphylogenetic classification of these sequences enabled us to refine the assignments more stringently. Even then, all locations contained such putative APBs, often reaching a significant proportion of all phototrophic sequences. In fact, in some 20% of samples, their contribution exceeded that of oxygenic phototrophs, previously regarded as the major type of endolithic microbe in carbonates. The communities contained representatives of APBs in theChloroflexales, various proteobacterial groups, andChlorobi. The most abundant phylotypes varied with geography: on Isla de Mona,RoseiflexusandChlorothrix-related phylotypes dominated, whereas those related toErythrobacterwere the most common in Menorca. The presence of active populations of APBs was corroborated through an analysis of photopigments: bacteriochlorophylls were detected in all samples, bacteriochlorophyllcandabeing most abundant. We discuss the potential metabolism and geomicrobial roles of endolithic APBs. Phylogenetic inference suggests that APBs may be playing a role as photoheterotrophs, adding biogeochemical complexity to our understanding of such communities. Given the global extent of coastal carbonate platforms, they likely represent a very large and unexplored habitat for APBs.IMPORTANCEEndolithic microbial communities from carbonates, which have been explored for over 2 centuries in predominantly naturalistic studies, were thought to be primarily composed of eukaryotic algae and cyanobacteria. Our report represents a paradigm shift in this regard, at least for the marine environment, demonstrating the presence of ubiquitous and abundant populations of APBs in this habitat. It raises questions about the role of these organisms in the geological dynamics of coastal carbonates, including coral reefs.

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