A diagenetic control on the Early Triassic Smithian-Spathian carbon isotopic excursions recorded in the marine settings of the Thaynes Group (Utah, USA).

abstract：:We established Fe(III)-reducing co-cultures of two species of metal-reducing bacteria, the Gram-positive Desulfotomaculum reducens MI-1 and the Gram-negative Geobacter sulfurreducens PCA. Co-cultures were given pyruvate, a substrate that D. reducens can ferment and use as electron donor for Fe(III) reduction. G. sulfu...

journal_title：Geobiology

authors： Otwell AE,Callister SJ,Sherwood RW,Zhang S,Goldman AR,Smith RD,Richardson RE

更新日期：2018-09-01 00:00:00

abstract：:New experimental results of fluid-mineral reactions at hydrothermal conditions relevant to life demonstrate that key redox reactions involving iron, sulfur, and hydrogen remain at disequilibrium at 100 °C, even in a heterogeneous system and thus are energetically favorable for microbial metabolism. Predictions from ge...

journal_title：Geobiology

authors： Houghton JL,Seyfried WE Jr

更新日期：2010-12-01 00:00:00

abstract：:Permanently anoxic regions in the ocean are widespread and exhibit unique microbial metabolic activity exerting substantial influence on global elemental cycles and climate. Reconstructing microbial metabolic activity rates in these regions has been challenging, due to the technical difficulty of direct rate measureme...

journal_title：Geobiology

authors： Louca S,Astor YM,Doebeli M,Taylor GT,Scranton MI

更新日期：2019-11-01 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：:Earth's atmospheric composition has changed significantly over geologic time. Many redox active atmospheric constituents have left evidence of their presence, while inert constituents such as dinitrogen gas (N2 ) are more elusive. In this study, we examine two potential biological indicators of atmospheric N2 : the mo...

journal_title：Geobiology

authors： Silverman SN,Kopf SH,Bebout BM,Gordon R,Som SM

更新日期：2019-01-01 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：: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：: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 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：: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：: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：:Mixing of sediments by moving animals becomes apparent in the trace fossil record from about 550 million years ago (Ma), loosely overlapping with the tail end of the extreme carbonate carbon isotope δ13 Ccarbonate fluctuations that qualitatively distinguish the Proterozoic geochemical record from that of the Phanerozo...

journal_title：Geobiology

authors： Boyle RA,Dahl TW,Bjerrum CJ,Canfield DE

更新日期：2018-05-01 00:00:00

abstract：:The lower Cambrian grainy phosphorites of the northern Montagne Noire occur interbedded with grey to black, laminated to massive shales and limestones deposited along the edge of a continental shelf, associated with slope-related facies and unstable substrates. The concentration of phosphate took place by repeated alt...

journal_title：Geobiology

authors： Alvaro JJ,Clausen S

更新日期：2010-03-01 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：: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 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：: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：:The dissolution of elemental selenium [Se(0)] during chemical weathering is an important step in the global selenium cycle. While microorganisms have been shown to play a key role in selenium dissolution in soils, the mechanisms of microbial selenium solubilization are poorly understood. In this study, we isolated a B...

journal_title：Geobiology

authors： Goff J,Terry L,Mal J,Schilling K,Pallud C,Yee N

更新日期：2019-05-01 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：: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：:Microfossils belonging to the 1.88-billion-year-old 'Gunflint-biota' are preserved as carbonaceous and hematitic filaments and spheres that are believed to represent ancient chemolithoautotrophic Fe(II) oxidizing bacteria that grew above a chemocline where ferruginous seawater upwelled into shallow, oxygenated waters....

journal_title：Geobiology

authors： Shapiro RS,Konhauser KO

更新日期：2015-05-01 00:00:00

abstract：:Previous studies of the subsurface biosphere have deduced average cellular doubling times of hundreds to thousands of years based upon geochemical models. We have directly constrained the in situ average cellular protein turnover or doubling times for metabolically active micro-organisms based on cellular amino acid a...

journal_title：Geobiology

authors： Onstott TC,Magnabosco C,Aubrey AD,Burton AS,Dworkin JP,Elsila JE,Grunsfeld S,Cao BH,Hein JE,Glavin DP,Kieft TL,Silver BJ,Phelps TJ,van Heerden E,Opperman DJ,Bada JL

更新日期：2014-01-01 00:00:00

abstract：:The diagenetic mineral assemblages in petroleum reservoirs control the formation fluid pH and pCO(2). Anaerobic biodegradation of petroleum is controlled by the transfer of electrons from reduced organic species to inorganic, redox sensitive, aqueous and mineral species in many cases through intermediates such as H(2)...

journal_title：Geobiology

authors： Onstott TC,Hinton SM,Silver BJ,King HE Jr

更新日期：2010-01-01 00:00:00

abstract：:The ca. 1.9 Ga Beaverlodge Lake paleosol was studied using redox-sensitive Cr isotopes in order to determine the isotopic response to paleoweathering of a rhyodacite parent rock 500 million years after the Great Oxidation Event. Redox reactions occurring in modern weathering environments produce Cr(VI) that is enriche...

journal_title：Geobiology

authors： Toma J,Holmden C,Shakotko P,Pan Y,Ootes L

更新日期：2019-09-01 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：:In aquatic habitats, micro-organisms successfully adhere to and mediate particles, thus changing the erosive response of fine sediments to hydrodynamic forcing by secreting glue-like extracellular polymeric substances (EPS). Because sediment dynamics is vital for many ecological and economic aspects of watersheds and ...

journal_title：Geobiology

authors： Gerbersdorf SU,Wieprecht S

更新日期：2015-01-01 00:00:00

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：:Lipid biomarker assemblages preserved within the bitumen and kerogen phases of sedimentary rocks from the ca. 780-729 Ma Chuar and Visingsö Groups facilitate paleoenvironmental reconstructions and reveal fundamental aspects of emerging mid-Neoproterozoic marine communities. The Chuar and Visingsö Groups were deposited...

journal_title：Geobiology

authors： Zumberge JA,Rocher D,Love GD

更新日期：2020-05-01 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