Morphological and isotopic changes of heterocystous cyanobacteria in response to N2 partial pressure.

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：: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 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：: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：: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 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：: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：:Nitrogen forms an integral part of the main building blocks of life, including DNA, RNA, and proteins. N2 is the dominant gas in Earth's atmosphere, and nitrogen is stored in all of Earth's geological reservoirs, including the crust, the mantle, and the core. As such, nitrogen geochemistry is fundamental to the evolut...

journal_title：Geobiology

authors： Zerkle AL,Mikhail S

更新日期：2017-05-01 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：: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 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：: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 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：:Although nitrogen is a key element in organic molecules such as nucleic acids and proteins, the timing of the emergence of its modern biogeochemical cycle is poorly known. Recent studies on the antiquity of the nitrogen cycle and its interaction with free oxygen suggests the establishment of a complete aerobic N bioge...

journal_title：Geobiology

authors： Thomazo C,Ader M,Philippot P

更新日期：2011-03-01 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：: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：: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：: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：: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：: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：:Reworked and fluidized fine-grained deposits in energetic settings are a major modern-day feature of river deltas and estuaries. Similar environments were probably settings for microbial evolution on the early Earth. These sedimentary systems act as efficient biogeochemical reactors with high bacterial phylogenetic di...

journal_title：Geobiology

authors： Aller JY,Aller RC,Kemp PF,Chistoserdov AY,Madrid VM

更新日期：2010-06-01 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：: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：:Metal sulfide minerals, including mercury sulfides (HgS), are widespread in hydrothermal vent systems where sulfur-oxidizing microbes are prevalent. Questions remain as to the impact of mineral composition and structure on sulfur-oxidizing microbial populations at deep-sea hydrothermal vents, including the possible ro...

journal_title：Geobiology

authors： Wang CH,Gulmann LK,Zhang T,Farfan GA,Hansel CM,Sievert SM

更新日期：2020-09-01 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：: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：: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 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：: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