Extreme 15N-enrichments in 2.72-Gyr-old sediments: evidence for a turning point in the nitrogen cycle.

abstract：:Biotic recovery after the Cretaceous-Palaeogene (K-Pg) impact is one unsolved question concerning this mass extinction event. To evaluate the incidence of the K-Pg event on biota, and the subsequent recovery, a recent environmental disaster has been analysed. Areas affected by the contamination disaster of Aználcollar...

journal_title：Geobiology

authors： Rodríguez-Tovar FJ,Martín-Peinado FJ

更新日期：2009-12-01 00:00:00

abstract：:The formation of carbonate concretions is a cementation process which passively infills the pore spaces within sediments. They record the original environments of deposition and diagenetic conditions of the host rocks. Little is known about the precise mechanisms responsible for the precipitation of carbonate concreti...

journal_title：Geobiology

authors： Wei H,Tang Z,Qiu Z,Yan D,Bai M

更新日期：2020-01-01 00:00:00

abstract：:Evaporitic deposits are a globally widespread habitat for micro-organisms. The microbe-mineral environment in weathered and remobilized gypsum from exposed mid-Ordovician marine evaporite beds in the polar desert of Devon Island, Nunavut, Canadian High Arctic was examined. The gypsum is characterized by internal green...

journal_title：Geobiology

authors： Cockell CS,Osinski GR,Banerjee NR,Howard KT,Gilmour I,Watson JS

更新日期：2010-09-01 00:00:00

abstract：:Ediacaran sediments record an unusual global carbon cycle perturbation that has been linked to widespread oceanic oxygenation, the Shuram negative C isotope excursion (NCIE). However, proxy-based estimates of global ocean redox conditions during this event have been limited largely due to proxy specificity (e.g., euxi...

journal_title：Geobiology

authors： Fan H,Nielsen SG,Owens JD,Auro M,Shu Y,Hardisty DS,Horner TJ,Bowman CN,Young SA,Wen H

更新日期：2020-05-01 00:00:00

abstract：:In modern microbial mats, hydrogen sulfide shows pronounced sulfur isotope (δ34 S) variability over small spatial scales (~50‰ over <4 mm), providing information about microbial sulfur cycling within different ecological niches in the mat. In the geological record, the location of pyrite formation, overprinting from m...

journal_title：Geobiology

authors： Gomes ML,Fike DA,Bergmann KD,Jones C,Knoll AH

更新日期：2018-01-01 00:00:00

abstract：:The paleoenvironmental setting in which the Ediacara Biota lived, died, and was preserved in the eponymous Ediacara Member of the Rawnsley Quartzite of South Australia is an issue of long-standing interest and recent debate. Over the past few decades, interpretations have ranged from deep marine to shallow marine to t...

journal_title：Geobiology

authors： Tarhan LG,Planavsky NJ,Wang X,Bellefroid EJ,Droser ML,Gehling JG

更新日期：2018-01-01 00:00:00

abstract：:We here show that nano-scale mapping of elements commonly utilized in biological cycles provides a promising new additional line of evidence when evaluating the extent of the contribution of biology to microbialites. Our case study comes from Lake Clifton in Western Australia, a unique environment where living domical...

journal_title：Geobiology

authors： Wacey D,Gleeson D,Kilburn MR

更新日期：2010-12-01 00:00:00

abstract：:The hydrocarbons preserved in an Archean rock were extracted, and their composition and distribution in consecutive slices from the outside to the inside of the rock were examined. The 2.7 Ga rock was collected from the Fortescue Group in the Pilbara region, Western Australia. The bitumen I (solvent-extracted rock) an...

journal_title：Geobiology

authors： Hoshino Y,Flannery DT,Walter MR,George SC

更新日期：2015-03-01 00:00:00

abstract：:Stromatolites are one of the oldest and most intriguing organosedimentary deposits. In contrast to stromatolites of the Precambrian to Early Ordovician, Phanerozoic equivalents occurred episodically under specific conditions. A group of previously undescribed stromatolites in composition occur in the Lower Triassic (O...

journal_title：Geobiology

authors： Ezaki Y,Liu JB,Adachi N

更新日期：2012-01-01 00:00:00

abstract：:The Strelley Pool Formation (SPF) is widely distributed in the East Pilbara Terrane (EPT) of the Pilbara Craton, Western Australia, and represents a Paleoarchean shallow-water to subaerial environment. It was deposited ~3.4 billion years ago and displays well-documented carbonate stromatolites. Diverse putative microf...

journal_title：Geobiology

authors： Sugitani K,Mimura K,Takeuchi M,Lepot K,Ito S,Javaux EJ

更新日期：2015-11-01 00:00:00

abstract：:Few topics in geobiology have been as extensively debated as the role of Earth's oxygenation in controlling when and why animals emerged and diversified. All currently described animals require oxygen for at least a portion of their life cycle. Therefore, the transition to an oxygenated planet was a prerequisite for t...

journal_title：Geobiology

authors： Cole DB,Mills DB,Erwin DH,Sperling EA,Porter SM,Reinhard CT,Planavsky NJ

更新日期：2020-05-01 00:00:00

abstract：:The composition of the oceans and of its biota have influenced each other through Earth's history. Of all the biologically essential elements, nitrogen is the only one whose seawater concentration is clearly controlled biologically; this is presumably the main reason why the stoichiometry of nitrogen (defined as its m...

journal_title：Geobiology

authors： Morel FM

更新日期：2008-06-01 00:00:00

abstract：:The Atacama Desert is the driest non-polar desert on Earth, presenting precarious conditions for biological activity. In the arid coastal belt, life is restricted to areas with fog events that cause almost daily wet-dry cycles. In such an area, we discovered a hitherto unknown and unique ground covering biocenosis dom...

journal_title：Geobiology

authors： Jung P,Baumann K,Lehnert LW,Samolov E,Achilles S,Schermer M,Wraase LM,Eckhardt KU,Bader MY,Leinweber P,Karsten U,Bendix J,Büdel B

更新日期：2020-01-01 00:00:00

abstract：:The persistence of DNA from microorganisms exposed to various concentrations of SiO2 (ranging from 0 to 3000 p.p.m.) was monitored over time. The impact of silica mineralization or silicification on the longevity of 16S rRNA and 16 s rDNA genes from whole cells of Bacillus subtilis and Escherichia coli K12 was quantif...

journal_title：Geobiology

authors： Schelble RT,Hall JA,Nealson KH,Steele A

更新日期：2008-12-01 00:00:00

abstract：:In the aftermath of the end-Permian mass extinction, Early Triassic sediments record some of the largest Phanerozoic carbon isotopic excursions. Among them, a global Smithian-negative carbonate carbon isotope excursion has been identified, followed by an abrupt increase across the Smithian-Spathian boundary (SSB; ~250...

journal_title：Geobiology

authors： Thomazo C,Vennin E,Brayard A,Bour I,Mathieu O,Elmeknassi S,Olivier N,Escarguel G,Bylund KG,Jenks J,Stephen DA,Fara E

更新日期：2016-05-01 00:00:00

abstract：:The well-known debate on the nature and origin of intracellular inclusions (ICIs) in silicified microfossils from the early Neoproterozoic Bitter Springs Formation has recently been revived by reports of possible fossilized nuclei in phosphatized animal embryo-like fossils from the Ediacaran Doushantuo Formation of So...

journal_title：Geobiology

authors： Pang K,Tang Q,Schiffbauer JD,Yao J,Yuan X,Wan B,Chen L,Ou Z,Xiao S

更新日期：2013-11-01 00:00:00

abstract：:Through the use of scanning transmission electron microscopy (STEM) combined with other complementary techniques (SEM, cryo-TEM, HRTEM, and EELS), we have studied the interaction of microorganisms inhabiting deep anoxic waters of acidic pit lakes with dissolved aluminum, silica, sulfate, and ferrous iron. These elemen...

journal_title：Geobiology

authors： Sánchez-España J,Wang K,Falagán C,Yusta I,Burgos WD

更新日期：2018-01-01 00:00:00

abstract：:Microbial fossils and textures are commonly preserved in Ediacaran and early Cambrian coarse-grained siliciclastic sediments that were deposited in tidal and intertidal marine settings. In contrast, the fossilization of micro-organisms in similar marine environments of post-Cambrian age is less frequently reported. Th...

journal_title：Geobiology

authors： Newman SA,Klepac-Ceraj V,Mariotti G,Pruss SB,Watson N,Bosak T

更新日期：2017-07-01 00:00:00

abstract：:Organic biomarkers in marine sedimentary rocks hold important clues about the early history of Earth's surface environment. The chemical relicts of carotenoids from anoxygenic sulfur bacteria are of particular interest to geoscientists because of their potential to signal episodes of marine photic-zone euxinia such as...

journal_title：Geobiology

authors： Meyer KM,Macalady JL,Fulton JM,Kump LR,Schaperdoth I,Freeman KH

更新日期：2011-07-01 00:00:00

abstract：:Biogeochemical changes in marine sediments during coastal water hypoxia are well described, but less is known about underlying changes in microbial communities. Bacterial and archaeal communities in Louisiana continental shelf (LCS) hypoxic zone sediments were characterized by pyrosequencing 16S rRNA V4-region gene fr...

journal_title：Geobiology

authors： Devereux R,Mosher JJ,Vishnivetskaya TA,Brown SD,Beddick DL Jr,Yates DF,Palumbo AV

更新日期：2015-09-01 00:00:00

abstract：:It has been argued that skeletal Mg/Ca ratio in echinoderms is mostly governed by Mg2+ and Ca2+ concentrations in the ambient seawater. Accordingly, well-preserved fossil echinoderms were used to reconstruct Phanerozoic seawater Mg2+ /Ca2+ ratio. However, Mg/Ca ratio in echinoderm skeleton can be affected by a number ...

journal_title：Geobiology

authors： Kołbuk D,Di Giglio S,M'Zoudi S,Dubois P,Stolarski J,Gorzelak P

更新日期：2020-11-01 00:00:00

abstract：:All life requires energy to drive metabolic reactions such as growth and cell maintenance; therefore, fluctuations in energy availability can alter microbial activity. There is a gap in our knowledge concerning how energy availability affects the growth of extreme chemolithoautotrophs. Toward this end, we investigated...

journal_title：Geobiology

authors： Hart C,Gorman-Lewis D

更新日期：2021-01-01 00:00:00

abstract：:Meromictic lakes with anoxic bottom waters often have active methane cycles whereby methane is generally produced biogenically under anoxic conditions and oxidized in oxic surface waters prior to reaching the atmosphere. Lakes that contain dissolved ferrous iron in their deep waters (i.e., ferruginous) are rare, but v...

journal_title：Geobiology

authors： Lambrecht N,Katsev S,Wittkop C,Hall SJ,Sheik CS,Picard A,Fakhraee M,Swanner ED

更新日期：2020-01-01 00:00:00

abstract：:Ooids from the Mesoarchaean Chobeni Formation, Pongola Supergroup, KwaZulu-Natal, South Africa are older than any ooids reported to date. They are made of dolomite and ankerite and show concentric, radial-concentric, micritic, and radial fabrics. Radial ooids are interpreted to have originated from high-Mg-calcite and...

journal_title：Geobiology

authors： Siahi M,Hofmann A,Master S,Mueller CW,Gerdes A

更新日期：2017-11-01 00:00:00

abstract：:Ocean acidification by atmospheric carbon dioxide has increased almost continuously since the last glacial maximum (LGM), 21,000 years ago. It is expected to impair tropical reef development, but effects on reefs at the present day and in the recent past have proved difficult to evaluate. We present evidence that acid...

journal_title：Geobiology

authors： Riding R,Liang L,Braga JC

更新日期：2014-09-01 00:00:00

abstract：:The later Cambrian Steptoean Positive Carbon Isotope Excursion (SPICE) event was an episode marked by pronounced changes to the global biogeochemical cycles of carbon and sulfur and significant extinctions on several paleocontinents including Laurentia (North America). While the exact cause(s) of these events remains ...

journal_title：Geobiology

authors： LeRoy MA,Gill BC

更新日期：2019-07-01 00:00:00

abstract：:The ability of micro-organisms to oxidize manganese (Mn) from Mn(II) to Mn(III/IV) oxides transcends boundaries of biological clade or domain. Many bacteria and fungi oxidize Mn(II) to Mn(III/IV) oxides directly through enzymatic activity or indirectly through the production of reactive oxygen species. Here, we determ...

journal_title：Geobiology

authors： Sutherland KM,Wankel SD,Hansel CM

更新日期：2018-07-01 00:00:00

abstract：:Subseafloor sulfate concentrations typically decrease with depth as this electron acceptor is consumed by respiring microorganisms. However, studies show that seawater can flow through hydraulically conductive basalt to deliver sulfate upwards into deeply buried overlying sediments. Our previous work on IODP Site C001...

journal_title：Geobiology

authors： Cox TL,Gan HM,Moreau JW

更新日期：2019-03-01 00:00:00

abstract：:The period 800-717 million years (Ma) ago, in the lead-up to the Sturtian Snowball glaciation, saw an increase in the diversity of eukaryotic microfossils. To afford an independent and complementary view of this evolutionary period, this study presents the distribution of eukaryotic biomarkers from three pre-Sturtian ...

journal_title：Geobiology

authors： Brocks JJ,Jarrett AJ,Sirantoine E,Kenig F,Moczydłowska M,Porter S,Hope J

更新日期：2016-03-01 00:00:00

abstract：:A combination of scanning transmission X-ray microscopy and X-ray magnetic circular dichroism was used to spatially resolve the distribution of different carbon and iron species associated with Shewanella oneidensis MR-1 cells. S. oneidensis MR-1 couples the reduction of Fe(III)-oxyhydroxides to the oxidation of organ...

journal_title：Geobiology

authors： Coker VS,Byrne JM,Telling ND,VAN DER Laan G,Lloyd JR,Hitchcock AP,Wang J,Pattrick RA

更新日期：2012-07-01 00:00:00