Hematite-coated microfossils: primary ecological fingerprint or taphonomic oddity of the Paleoproterozoic?

abstract：:Although a variety of leaf characteristics appear to be induced by light environment during development, analysis of ontogenetic changes in living broad leaved trees has suggested that a number of other traits also lumped into the classic 'sun' versus 'shade' morphological distinctions, including leaf size, shape, and...

journal_title：Geobiology

authors： Boyce CK

更新日期：2009-03-01 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：: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：: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：: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：: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：:Alvinellid polychaete worms form multilayered organic tubes in the hottest and most rapidly growing areas of deep-sea hydrothermal vent chimneys. Over short periods of time, these tubes can become entirely mineralized within this environment. Documenting the nature of this process in terms of the stages of mineralizat...

journal_title：Geobiology

authors： Georgieva MN,Little CT,Ball AD,Glover AG

更新日期：2015-03-01 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：: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：: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：: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 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：: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：: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：: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：: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：: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：: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：: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 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 emplacement of subaqueous gravity-driven sediment flows imposes a significant physical and geochemical impact on underlying sediment and microbial communities. Although previous studies have established lasting mineralogical and biological signatures of turbidite deposition, the response of bacteria and archaea wi...

journal_title：Geobiology

authors： Harrison BK,Myrbo A,Flood BE,Bailey JV

更新日期：2018-03-01 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：: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：: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：: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：: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：: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：: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：: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 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