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Uranium isotopes distinguish two geochemically distinct stages during the later Cambrian SPICE event

Published on Sep 1, 2014in Earth and Planetary Science Letters4.64
· DOI :10.1016/j.epsl.2014.05.043
Tais Wittchen Dahl14
Estimated H-index: 14
(Wild Center),
Richard A. Boyle9
Estimated H-index: 9
(University of Exeter)
+ 4 AuthorsMartin Bizzarro33
Estimated H-index: 33
(Wild Center)
Cite
Abstract
a b s t r a c t Anoxic marine zones were common in early Paleozoic oceans (542-400 Ma), and present a potential link to atmospheric pO2 via feedbacks linking global marine phosphorous recycling, primary production and organic carbon burial. Uranium (U ) isotopes in carbonate rocks track the extent of ocean anoxia, whereas carbon (C ) and sulfur (S) isotopes track the burial of organic carbon and pyrite sulfur (primary long-term sources of atmospheric oxygen). In combination, these proxies therefore reveal the comparative dynamics of ocean anoxia and oxygen liberation to the atmosphere over million-year time scales. Here we report high-precision uranium isotopic data in marine carbonates deposited during the Late Cambrian 'SPICE' event, at ca. 499 Ma, documenting a well-defined −0.18 negative δ 238 U excursion that occurs at the onset of the SPICE event's positive δ 13
  • References (84)
  • Citations (55)
Cite
References84
Newest
Published on Dec 1, 2013in Chemical Geology3.62
Stephen J. Romaniello13
Estimated H-index: 13
(ASU: Arizona State University),
Achim D. Herrmann13
Estimated H-index: 13
(LSU: Louisiana State University),
Ariel D. Anbar56
Estimated H-index: 56
(ASU: Arizona State University)
Abstract In order to validate the use of 238 U/ 235 U as a paleoredox proxy in carbonates, we examined the incorporation and early diagenetic evolution of U isotopes in shallow Bahamian carbonate sediments. Our sample set consists of a variety of primary precipitates that represent a range of carbonate producing organisms and components that were important in the past (scleractinian corals, calcareous green and red algae, ooids, and mollusks). In addition, four short push cores were taken in dif...
Published on May 1, 2013in Earth and Planetary Science Letters4.64
Camille A. Partin10
Estimated H-index: 10
(UM: University of Manitoba),
A. Bekker8
Estimated H-index: 8
(UM: University of Manitoba)
+ 10 AuthorsStefan V. Lalonde23
Estimated H-index: 23
(European Institute)
The atmosphere–ocean system experienced a progressive change from anoxic to more oxidizing conditions through time. This oxidation is traditionally envisaged to have occurred as two stepwise increases in atmospheric oxygen at the beginning and end of the Proterozoic Eon. Here, we present a study of the redox-sensitive element, uranium, in organic-rich shales to track the history of Earth's surface oxidation at an unprecedented temporal resolution. Fluctuations in the degree of uranium enrichment...
John R. Bargar51
Estimated H-index: 51
(SLAC National Accelerator Laboratory),
Kenneth H. Williams37
Estimated H-index: 37
(LBNL: Lawrence Berkeley National Laboratory)
+ 11 AuthorsSamuel M. Webb32
Estimated H-index: 32
(SLAC National Accelerator Laboratory)
Redox transitions of uranium [from U(VI) to U(IV)] in low-temperature sediments govern the mobility of uranium in the environment and the accumulation of uranium in ore bodies, and inform our understanding of Earth’s geochemical history. The molecular-scale mechanistic pathways of these transitions determine the U(IV) products formed, thus influencing uranium isotope fractionation, reoxidation, and transport in sediments. Studies that improve our understanding of these pathways have the potentia...
Published on Dec 1, 2012in Paleoceanography3.09
Fanny M Monteiro10
Estimated H-index: 10
(UoB: University of Bristol),
Richard D. Pancost60
Estimated H-index: 60
(UoB: University of Bristol)
+ 1 AuthorsYannick Donnadieu27
Estimated H-index: 27
(CNRS: Centre national de la recherche scientifique)
[1] The Cenomanian-Turonian oceanic anoxic event (OAE2) is characterized by large perturbations in the oxygen and sulfur cycles of the ocean, potentially resulting from changes in oxygen supply (via oxygen solubility and ocean circulation) and in marine productivity. We assess the relative impact of these mechanisms, comparing model experiments with a new compilation of observations for seafloor dysoxia/anoxia and photic zone euxinia. The model employed is an intermediate-complexity Earth system...
Published on Nov 2, 2012in Science41.04
James N. Connelly33
Estimated H-index: 33
(Wild Center),
Martin Bizzarro33
Estimated H-index: 33
(Wild Center)
+ 3 AuthorsMarina A. Ivanova10
Estimated H-index: 10
Transient heating events that formed calcium-aluminum–rich inclusions (CAIs) and chondrules are fundamental processes in the evolution of the solar protoplanetary disk, but their chronology is not understood. Using U-corrected Pb-Pb dating, we determined absolute ages of individual CAIs and chondrules from primitive meteorites. CAIs define a brief formation interval corresponding to an age of 4567.30 ± 0.16 million years (My), whereas chondrule ages range from 4567.32 ± 0.42 to 4564.71 ± 0.30 My...
Published on Nov 1, 2012in Geochimica et Cosmochimica Acta4.26
M. Telus4
Estimated H-index: 4
(U of C: University of Chicago),
Nicolas Dauphas47
Estimated H-index: 47
(U of C: University of Chicago)
+ 5 AuthorsLee A. Groat21
Estimated H-index: 21
(UBC: University of British Columbia)
Abstract The causes of some stable isotopic variations in felsic rocks are not well understood. In particular, the origin of the heavy Fe isotopic compositions ( i.e. , high δ 56 Fe values, deviation in ‰ of the 56 Fe/ 54 Fe ratio relative to IRMM-014) of granites with SiO 2 > 70 wt.% compared with less silicic rocks is still debated. It has been interpreted to reflect isotopic fractionation during late stage aqueous fluid exsolution, magma differentiation, partial melting, or Soret (thermal) di...
Published on Jul 1, 2012in Geochimica et Cosmochimica Acta4.26
Jacquelyn W. Kitchen1
Estimated H-index: 1
(UIUC: University of Illinois at Urbana–Champaign),
Thomas Martin Johnson35
Estimated H-index: 35
(UIUC: University of Illinois at Urbana–Champaign)
+ 2 AuthorsAmanda Raddatz2
Estimated H-index: 2
(UIUC: University of Illinois at Urbana–Champaign)
Abstract Chromium stable isotope ratios are useful as indicators of Cr redox reactions and Cr sources in both modern and ancient geochemical systems. Correct interpretation of Cr isotope data requires a quantitative understanding of isotopic fractionation by various processes, the most important of which is reduction of Cr(VI) to Cr(III). We determined the magnitude of isotopic fractionation, for the 53 Cr/ 52 Cr ratio, induced by abiotic, dark reduction of Cr(VI) by aqueous Fe(II) and a few org...
Published on Jul 1, 2012in Geology5.01
Asfaw Zegeye9
Estimated H-index: 9
(Newcastle University),
Steeve Bonneville19
Estimated H-index: 19
(University of Leeds)
+ 9 AuthorsSulung Nomosatryo7
Estimated H-index: 7
(LIPI: Indonesian Institute of Sciences)
Iron-rich (ferruginous) conditions were a prevalent feature of the ocean throughout much of Earth’s history. The nature of elemental cycling in such settings is poorly understood, however, thus hampering reconstruction of paleoenvironmental conditions during key periods in Earth evolution. This is particularly true regarding controls on nutrient bioavailability, which is intimately linked to Earth’s oxygenation history. Elemental scavenging during precipitation of iron minerals exerts a major co...
Published on Mar 1, 2012in Paleoceanography3.09
Julien Plancq4
Estimated H-index: 4
('ENS Paris': École Normale Supérieure),
Vincent Grossi4
Estimated H-index: 4
('ENS Paris': École Normale Supérieure)
+ 2 AuthorsEmanuela Mattioli30
Estimated H-index: 30
('ENS Paris': École Normale Supérieure)
This study investigates ancient alkenone producers among the late Oligocene-early Miocene coccolithophores recorded at Deep Sea Drilling Project (DSDP) Site 516. Contrary to common assumptions, Reticulofenestra was not the most important alkenone producer throughout the studied time interval. The comparison between coccolith species-specific absolute abundances and alkenone contents in the same sedimentary samples shows that Cyclicargolithus abundances explain 40% of the total variance of alkeno...
Cited By55
Newest
Published on 2019in Scientific Reports4.01
Tais Wittchen Dahl14
Estimated H-index: 14
(China University of Geosciences),
Marie-Louise Siggaard-Andersen14
Estimated H-index: 14
(UCPH: University of Copenhagen)
+ 6 AuthorsArne T. Nielsen14
Estimated H-index: 14
(UCPH: University of Copenhagen)
Oxygen is a prerequisite for all large and motile animals. It is a puzzling paradox that fossils of benthic animals are often found in black shales with geochemical evidence for deposition in marine environments with anoxic and sulfidic bottom waters. It is debated whether the geochemical proxies are unreliable, affected by diagenesis, or whether the fossils are transported from afar or perhaps were not benthic. Here, we improved the stratigraphic resolution of marine anoxia records 100–1000 fol...
Tais Wittchen Dahl14
Estimated H-index: 14
,
James N. Connelly33
Estimated H-index: 33
+ 5 AuthorsMartin Bizzarro33
Estimated H-index: 33
The proliferation of large, motile animals 540 to 520 Ma has been linked to both rising and declining O2 levels on Earth. To explore this conundrum, we reconstruct the global extent of seafloor oxygenation at approximately submillion-year resolution based on uranium isotope compositions of 187 marine carbonates samples from China, Siberia, and Morocco, and simulate O2 levels in the atmosphere and surface oceans using a mass balance model constrained by carbon, sulfur, and strontium isotopes in t...
Kimberly V. Lau6
Estimated H-index: 6
,
Stephen J. Romaniello13
Estimated H-index: 13
,
Feifei Zhang6
Estimated H-index: 6
Published on Jun 1, 2019in Earth-Science Reviews9.53
Thomas J. Algeo28
Estimated H-index: 28
(UC: University of Cincinnati),
Arnaud Brayard7
Estimated H-index: 7
(CNRS: Centre national de la recherche scientifique),
Sylvain Richoz11
Estimated H-index: 11
(University of Graz)
Published on Aug 1, 2019in Palaeogeography, Palaeoclimatology, Palaeoecology2.62
Rebecca L. Freeman6
Estimated H-index: 6
(UK: University of Kentucky),
Benjamin F. Dattilo12
Estimated H-index: 12
(IPFW: Indiana University – Purdue University Fort Wayne),
Carlton E. Brett44
Estimated H-index: 44
(UC: University of Cincinnati)
Abstract Carbonate fluorapatite-filled millimeter-scale microsteinkerns are a key element of the “Small Shelly Fossil” (SSF) fauna generally associated with the late Proterozoic–Cambrian. The purported disappearance of these fossils and this style of phosphatic preservation during the Cambrian Stage 2 “Botomian extinction” has been linked to changes in ocean chemistry and/or changes to the physical environment due to the evolution of metazoans, as well to the changing role of metazoans in the ma...
Published on Oct 1, 2018in Earth-Science Reviews9.53
Feifei Zhang1
Estimated H-index: 1
(Yale University),
Thomas J. Algeo28
Estimated H-index: 28
(UC: University of Cincinnati)
+ 5 AuthorsAriel D. Anbar56
Estimated H-index: 56
Abstract The Smithian-Spathian boundary (SSB) was an interval characterized by a major global carbon cycle perturbation, climatic cooling from a middle/late Smithian boundary hyperthermal condition, and a major setback in the recovery of marine necto-pelagic faunas from the end-Permian mass extinction. Although the SSB has been linked to changes in oceanic redox conditions, key aspects of this redox variation (e.g., duration, extent, and triggering mechanisms) and its relationship to coeval clim...
Published on Aug 1, 2019in Palaeogeography, Palaeoclimatology, Palaeoecology2.62
Justin E. Mackey (University of Pittsburgh), Brian W. Stewart22
Estimated H-index: 22
(University of Pittsburgh)
Abstract This study reports data from the Upper Cambrian Conasauga Group and overlying Copper Ridge Formation of the Central Appalachian region, eastern U.S.A. Geochemical, isotopic and petrographic analysis of core material was carried out to constrain the extent of marine anoxia and to characterize sediment fluxes on the carbonate platform and continental shelf of Laurentia contemporaneous with the Steptoean Positive Carbon Isotope Excursion (SPICE), a Late Cambrian global marine anoxic event....
Published on Feb 6, 2019in Geobiology4.10
Matthew A. LeRoy (VT: Virginia Tech), Benjamin C. Gill22
Estimated H-index: 22
(VT: Virginia Tech)
View next paperGlobal enhancement of ocean anoxia during Oceanic Anoxic Event 2: A quantitative approach using U isotopes