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Duan X, Shi Z. Sedimentary records of sea level fall during the end-Permian in the upper Yangtze region (southern China): Implications for the mass extinction. Heliyon 2024; 10:e31226. [PMID: 38799747 PMCID: PMC11126861 DOI: 10.1016/j.heliyon.2024.e31226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Revised: 05/10/2024] [Accepted: 05/13/2024] [Indexed: 05/29/2024] Open
Abstract
Sea level fall is considered one of the significant factors leading to the end-Permian mass extinction (EPME). We studied the relative sea level changes in the Beifengjing and Shangsi sections, and the results indicate that a sea level fall occurred in the Upper Yangtze region during the Permian-Triassic transition. Considering that there is no significant change in fossil abundance in the strata following the two sea level falls observed in the Beifengjing section, we conclude that the reduction in shallow marine habitat for sea level fall solely was insufficient to cause the mass extinction. However, sea level fall did exacerbate the input of terrestrial debris into the ocean, leading to the deterioration of the marine environment. We propose that the combined adverse effects of volcanic eruptions, sea level falls, and other events exceeded the threshold for biological survival, ultimately resulting in the catastrophic EPME.
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Affiliation(s)
- Xiong Duan
- School of Geographical Sciences, Sichuan Provincial Engineering Laboratory of Monitoring and Control for Soil Erosion in Dry Valley, China West Normal University, Nanchong, 637009, China
- State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Institute of Sedimentary Geology, Chengdu University of Technology, Chengdu, 610059, China
| | - Zhiqiang Shi
- State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Institute of Sedimentary Geology, Chengdu University of Technology, Chengdu, 610059, China
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2
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Algeo TJ, Shen J. Theory and classification of mass extinction causation. Natl Sci Rev 2024; 11:nwad237. [PMID: 38116094 PMCID: PMC10727847 DOI: 10.1093/nsr/nwad237] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 09/01/2023] [Accepted: 09/04/2023] [Indexed: 12/21/2023] Open
Abstract
Theory regarding the causation of mass extinctions is in need of systematization, which is the focus of this contribution. Every mass extinction has both an ultimate cause, i.e. the trigger that leads to various climato-environmental changes, and one or more proximate cause(s), i.e. the specific climato-environmental changes that result in elevated biotic mortality. With regard to ultimate causes, strong cases can be made that bolide (i.e. meteor) impacts, large igneous province (LIP) eruptions and bioevolutionary events have each triggered one or more of the Phanerozoic Big Five mass extinctions, and that tectono-oceanic changes have triggered some second-order extinction events. Apart from bolide impacts, other astronomical triggers (e.g. solar flares, gamma bursts and supernova explosions) remain entirely in the realm of speculation. With regard to proximate mechanisms, most extinctions are related to either carbon-release or carbon-burial processes, the former being associated with climatic warming, ocean acidification, reduced marine productivity and lower carbonate δ13C values, and the latter with climatic cooling, increased marine productivity and higher carbonate δ13C values. Environmental parameters such as marine redox conditions and terrestrial weathering intensity do not show consistent relationships with carbon-cycle changes. In this context, mass extinction causation can be usefully classified using a matrix of ultimate and proximate factors. Among the Big Five mass extinctions, the end-Cretaceous biocrisis is an example of a bolide-triggered carbon-release event, the end-Permian and end-Triassic biocrises are examples of LIP-triggered carbon-release events, and the Late Ordovician and Late Devonian biocrises are examples of bioevolution-triggered carbon-burial events. Whereas the bolide-impact and LIP-eruption mechanisms appear to invariably cause carbon release, bioevolutionary triggers can result in variable carbon-cycle changes, e.g. carbon burial during the Late Ordovician and Late Devonian events, carbon release associated with modern anthropogenic climate warming, and little to no carbon-cycle impact due to certain types of ecosystem change (e.g. the advent of the first predators around the end-Ediacaran; the appearance of Paleolithic human hunters in Australasia and the Americas). Broadly speaking, studies of mass extinction causation have suffered from insufficiently critical thinking-an impartial survey of the extant evidence shows that (i) hypotheses of a common ultimate cause (e.g. bolide impacts or LIP eruptions) for all Big Five mass extinctions are suspect given manifest differences in patterns of environmental and biotic change among them; (ii) the Late Ordovician and Late Devonian events were associated with carbon burial and long-term climatic cooling, i.e. changes that are inconsistent with a bolide-impact or LIP-eruption mechanism; and (iii) claims of periodicity in Phanerozoic mass extinctions depended critically on the now-disproven idea that they shared a common extrinsic trigger (i.e. bolide impacts).
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Affiliation(s)
- Thomas J Algeo
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences—Wuhan, Wuhan430074, China
- State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences—Wuhan, Wuhan430074, China
- Department of Geosciences, University of Cincinnati, Cincinnati, OH45221, USA
| | - Jun Shen
- State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences—Wuhan, Wuhan430074, China
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Sanchís J, Milačič R, Zuliani T, Vidmar J, Abad E, Farré M, Barceló D. Occurrence of C 60 and related fullerenes in the Sava River under different hydrologic conditions. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 643:1108-1116. [PMID: 30189528 DOI: 10.1016/j.scitotenv.2018.06.285] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Revised: 06/19/2018] [Accepted: 06/22/2018] [Indexed: 06/08/2023]
Abstract
The presence of nanomaterials in the environment has caught the attention of the scientific because of the uncertainties in their fate, mobility and potential toxic effects. However, few studies have determined experimentally their concentration levels in aquatic systems up to date, which complicates the development of an adequate risk assessment. In the present study, the occurrence of ten fullerenes has been assessed in the Sava River (Southeastern Europe): 27 freshwater samples and 12 sediment samples from 12 sampling points have been analysed during two sampling campaigns. C60 was the most ubiquitous fullerene, with concentrations of 8 pg/l-59 ng/l and 108-895 pg/gdw in water and sediments, respectively. Statistically significant differences existed between the levels in 2014 and 2015, which has been attributed to the extreme hydrologic conditions (severe floods and drought, respectively). C70 fullerene has been detected in most of the samples and the fullerene derivatives [6,6]-phenyl C61 butyric acid methyl ester and N‑methyl fulleropyrrolidine have been detected eventually, which highlights that nanotechnology research and development activities are responsible for emitting these emerging contaminants to the environment. The role of diverse potential anthropogenic sources (including oil refinery, general industrial activity, river navigation, urban emissions and nanotechnology) is discussed.
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Affiliation(s)
- Josep Sanchís
- Institute of Environmental Assessment and Water Research (IDAEA-CSIC), C/Jordi Girona, 18-26, 08034 Barcelona, Catalonia, Spain.
| | - Radmila Milačič
- Department of Environmental Sciences, Jožef Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia
| | - Tea Zuliani
- Department of Environmental Sciences, Jožef Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia
| | - Janja Vidmar
- Department of Environmental Sciences, Jožef Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia
| | - Esteban Abad
- Institute of Environmental Assessment and Water Research (IDAEA-CSIC), C/Jordi Girona, 18-26, 08034 Barcelona, Catalonia, Spain
| | - Marinella Farré
- Institute of Environmental Assessment and Water Research (IDAEA-CSIC), C/Jordi Girona, 18-26, 08034 Barcelona, Catalonia, Spain
| | - Damià Barceló
- Institute of Environmental Assessment and Water Research (IDAEA-CSIC), C/Jordi Girona, 18-26, 08034 Barcelona, Catalonia, Spain; Catalan Institute of Water Research (ICRA), C/Emili Grahit, 101, 17003 Girona, Catalonia, Spain
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4
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Kenny R. A geochemical view into continental palaeotemperatures of the end-Permian using oxygen and hydrogen isotope composition of secondary silica in chert rubble breccia: Kaibab Formation, Grand Canyon (USA). GEOCHEMICAL TRANSACTIONS 2018; 19:2. [PMID: 29340852 PMCID: PMC5770344 DOI: 10.1186/s12932-017-0047-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Accepted: 12/28/2017] [Indexed: 06/07/2023]
Abstract
The upper carbonate member of the Kaibab Formation in northern Arizona (USA) was subaerially exposed during the end Permian and contains fractured and zoned chert rubble lag deposits typical of karst topography. The karst chert rubble has secondary (authigenic) silica precipitates suitable for estimating continental weathering temperatures during the end Permian karst event. New oxygen and hydrogen isotope ratios of secondary silica precipitates in the residual rubble breccia: (1) yield continental palaeotemperature estimates between 17 and 22 °C; and, (2) indicate that meteoric water played a role in the crystallization history of the secondary silica. The continental palaeotemperatures presented herein are broadly consistent with a global mean temperature estimate of 18.2 °C for the latest Permian derived from published climate system models. Few data sets are presently available that allow even approximate quantitative estimates of regional continental palaeotemperatures. These data provide a basis for better understanding the end Permian palaeoclimate at a seasonally-tropical latitude along the western shoreline of Pangaea.
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Affiliation(s)
- Ray Kenny
- Geosciences Department, Fort Lewis College, Durango, CO, 81301, USA.
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Initial pulse of Siberian Traps sills as the trigger of the end-Permian mass extinction. Nat Commun 2017; 8:164. [PMID: 28761160 PMCID: PMC5537227 DOI: 10.1038/s41467-017-00083-9] [Citation(s) in RCA: 210] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Accepted: 05/31/2017] [Indexed: 11/19/2022] Open
Abstract
Mass extinction events are short-lived and characterized by catastrophic biosphere collapse and subsequent reorganization. Their abrupt nature necessitates a similarly short-lived trigger, and large igneous province magmatism is often implicated. However, large igneous provinces are long-lived compared to mass extinctions. Therefore, if large igneous provinces are an effective trigger, a subinterval of magmatism must be responsible for driving deleterious environmental effects. The onset of Earth’s most severe extinction, the end-Permian, coincided with an abrupt change in the emplacement style of the contemporaneous Siberian Traps large igneous province, from dominantly flood lavas to sill intrusions. Here we identify the initial emplacement pulse of laterally extensive sills as the critical deadly interval. Heat from these sills exposed untapped volatile-fertile sediments to contact metamorphism, likely liberating the massive greenhouse gas volumes needed to drive extinction. These observations suggest that large igneous provinces characterized by sill complexes are more likely to trigger catastrophic global environmental change than their flood basalt- and/or dike-dominated counterparts. Although the mass end-Permian extinction is linked to large igneous provinces, its trigger remains unclear. Here, the authors propose that the abrupt change from flood lavas to sills resulted in the heating of sediments and led to the release of large-scale greenhouse gases to drive the end-Permian extinction.
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Astefanei A, Núñez O, Galceran MT. Analysis of C60-fullerene derivatives and pristine fullerenes in environmental samples by ultrahigh performance liquid chromatography–atmospheric pressure photoionization-mass spectrometry. J Chromatogr A 2014; 1365:61-71. [DOI: 10.1016/j.chroma.2014.08.089] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Revised: 07/07/2014] [Accepted: 08/27/2014] [Indexed: 11/27/2022]
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Tanikawa T, Saito M, Guo JD, Nagase S, Minoura M. Synthesis, Structures, and Optical Properties of Heterasumanenes Containing Group 14 Elements and Their Related Compounds. European J Org Chem 2012. [DOI: 10.1002/ejoc.201201223] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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9
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Analysis and Fate of Organic Nanomaterials in Environmental Samples. ACTA ACUST UNITED AC 2012. [DOI: 10.1016/b978-0-444-56328-6.00004-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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10
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Shen SZ, Crowley JL, Wang Y, Bowring SA, Erwin DH, Sadler PM, Cao CQ, Rothman DH, Henderson CM, Ramezani J, Zhang H, Shen Y, Wang XD, Wang W, Mu L, Li WZ, Tang YG, Liu XL, Liu LJ, Zeng Y, Jiang YF, Jin YG. Calibrating the end-Permian mass extinction. Science 2011; 334:1367-72. [PMID: 22096103 DOI: 10.1126/science.1213454] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The end-Permian mass extinction was the most severe biodiversity crisis in Earth history. To better constrain the timing, and ultimately the causes of this event, we collected a suite of geochronologic, isotopic, and biostratigraphic data on several well-preserved sedimentary sections in South China. High-precision U-Pb dating reveals that the extinction peak occurred just before 252.28 ± 0.08 million years ago, after a decline of 2 per mil (‰) in δ(13)C over 90,000 years, and coincided with a δ(13)C excursion of -5‰ that is estimated to have lasted ≤20,000 years. The extinction interval was less than 200,000 years and synchronous in marine and terrestrial realms; associated charcoal-rich and soot-bearing layers indicate widespread wildfires on land. A massive release of thermogenic carbon dioxide and/or methane may have caused the catastrophic extinction.
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Affiliation(s)
- Shu-zhong Shen
- State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Nanjing 210008, China.
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11
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Sorkin A, Tay B, Su H. Three-Stage Transformation Pathway from Nanodiamonds to Fullerenes. J Phys Chem A 2011; 115:8327-34. [DOI: 10.1021/jp200449f] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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12
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Multiple S-isotopic evidence for episodic shoaling of anoxic water during Late Permian mass extinction. Nat Commun 2011; 2:210. [PMID: 21343928 PMCID: PMC3105335 DOI: 10.1038/ncomms1217] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2010] [Accepted: 01/26/2011] [Indexed: 12/04/2022] Open
Abstract
Global fossil data show that profound biodiversity loss preceded the final catastrophe that killed nearly 90% marine species on a global scale at the end of the Permian. Many hypotheses have been proposed to explain this extinction and yet still remain greatly debated. Here, we report analyses of all four sulphur isotopes (32S, 33S, 34S and 36S) for pyrites in sedimentary rocks from the Meishan section in South China. We observe a sulphur isotope signal (negative δ34S with negative Δ33S) that may have resulted from limitation of sulphate supply, which may be linked to a near shutdown of bioturbation during shoaling of anoxic water. These results indicate that episodic shoaling of anoxic water may have contributed to the profound biodiversity crisis before the final catastrophe. Our data suggest a prolonged deterioration of oceanic environments during the Late Permian mass extinction. A final catastrophe killed 90% of marine species at the end of the Permian period, but significant biodiversity loss preceded this event. In this study, sulphur isotope evidence suggests that incursion of anoxic water into shallow regions may have contributed to biodiversity loss.
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13
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Halling MD, Orendt AM, Strohmeier M, Solum MS, Tsefrikas VM, Hirao T, Scott LT, Pugmire RJ, Grant DM. Solid-state 13C NMR investigations of 4,7-dihydro-1H-tricyclopenta[def,jkl,pqr]triphenylene (sumanene) and indeno[1,2,3-cd]fluoranthene: Buckminsterfullerene moieties. Phys Chem Chem Phys 2010; 12:7934-41. [DOI: 10.1039/c001903h] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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14
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Paquay FS, Goderis S, Ravizza G, Vanhaeck F, Boyd M, Surovell TA, Holliday VT, Haynes CV, Claeys P. Absence of geochemical evidence for an impact event at the Bølling-Allerød/Younger Dryas transition. Proc Natl Acad Sci U S A 2009; 106:21505-10. [PMID: 20007789 PMCID: PMC2799824 DOI: 10.1073/pnas.0908874106] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2009] [Indexed: 11/18/2022] Open
Abstract
High concentrations of iridium have been reported in terrestrial sediments dated at 12.9 ka and are interpreted to support an extraterrestrial impact event as the cause of the observed extinction in the Rancholabrean fauna, changes in the Paleoindian cultures, and the onset of the Younger Dryas cooling [Firestone RB, et al. (2007) Proc Natl Acad Sci USA 104:16016-16021]. Here, we report platinum group element (PGE: Os, Ir, Ru, Rh, Pt, Pd), gold (Au) concentrations, and (187)Os/(188)Os ratios in time-equivalent terrestrial, lacustrine, and marine sections to seek robust evidence of an extraterrestrial contribution. First, our results do not reproduce the previously reported elevated Ir concentrations. Second, (187)Os/(188)Os isotopic ratios in the sediment layers investigated are similar to average crustal values, indicating the absence of a significant meteoritic Os contribution to these sediments. Third, no PGE anomalies distinct from crustal signatures are present in the marine record in either the Gulf of California (DSDP 480, Guaymas Basin) or the Cariaco Basin (ODP 1002C). Our data show no evidence of an extraterrestrial (ET)-PGE enrichment anomaly in any of the investigated depositional settings investigated across North America and in one section in Belgium. The lack of a clear ET-PGE signature in this sample suite is inconsistent with the impact of a large chondritic projectile at the Bølling-Allerød/Younger Dryas transition.
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Affiliation(s)
- François S Paquay
- Department of Geology and Geophysics, University of Hawaii at Manoa, Honolulu, HI 96822, USA.
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15
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Cao C, Zheng Q. Geological event sequences of the Permian-Triassic transition recorded in the microfacies in Meishan section. ACTA ACUST UNITED AC 2009. [DOI: 10.1007/s11430-009-0113-0] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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16
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Bohme DK. Buckminsterfullerene cations: new dimensions in gas-phase ion chemistry. MASS SPECTROMETRY REVIEWS 2009; 28:672-693. [PMID: 19266570 DOI: 10.1002/mas.20227] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The author provides a brief overview, and shares the extraordinary excitement, of the years of unprecedented discoveries in ion chemistry that followed the first production of fullerene powder in 1990. Various charge states of the buckminsterfullerene C60n+ cation became available by conventional electron-impact ionization of the vapor of this powder and so for mass-spectrometric measurements of ion reactivity. The emphasis here will be on fullerene-ion research performed in the author's own laboratory at York University using electron ionization flow-tube mass spectrometry techniques.
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Affiliation(s)
- Diethard K Bohme
- Department of Chemistry, Centre for Research in Mass Spectrometry, York University, Toronto, Ontario, Canada M3J 1P3.
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17
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Hofmann T, von der Kammer F. Estimating the relevance of engineered carbonaceous nanoparticle facilitated transport of hydrophobic organic contaminants in porous media. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2009; 157:1117-1126. [PMID: 19064308 DOI: 10.1016/j.envpol.2008.10.022] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2008] [Revised: 10/13/2008] [Accepted: 10/27/2008] [Indexed: 05/27/2023]
Abstract
Naturally occurring nanoparticles (NP) enhance the transport of hydrophobic organic contaminants (HOCs) in porous media. In addition, the debate on the environmental impact of engineered nanoparticles (ENP) has become increasingly important. HOC bind strongly to carbonaceous ENP. Thus, carbonaceous ENP may also act as carriers for contaminant transport and might be important when compared to existing transport processes. ENP bound transport is strongly linked to the sorption behavior, and other carbonaceous ENP-specific properties. In our analysis the HOC-ENP sorption mechanism, as well as ENP size and ENP residence time, was of major importance. Our results show that depending on ENP size, sorption kinetics and residence time in the system, the ENP bound transport can be estimated either as (1) negligible, (2) enhancing contaminant transport, or (3) should be assessed by reactive transport modeling. One major challenge to this field is the current lack of data for HOC-ENP desorption kinetics.
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Affiliation(s)
- Thilo Hofmann
- Department of Environmental Geosciences, University of Vienna, Vienna, Austria.
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Abstract
The presence of helium in carbon systems, such as diamonds and fullerenes is of interest for planetary sciences, geophysics, astrophysics, and evolution biology. Such systems typically involve a large number of atoms and require a fast method for assessing the interaction potential and forces. We developed a tight-binding approach, based on density functional calculations, which includes a many-body potential term. This latter term is essential for consolidating the density functional results of helium in bulky diamond and Helium passing through a benzene ring which is important for helium-fullerene applications. The method is simple to apply and exhibits good transferability properties.
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Affiliation(s)
- Rebecca Granot
- Institute of Chemistry and the Fritz Haber Center for Molecular Dynamics, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
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19
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Nowack B, Bucheli TD. Occurrence, behavior and effects of nanoparticles in the environment. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2007; 150:5-22. [PMID: 17658673 DOI: 10.1016/j.envpol.2007.06.006] [Citation(s) in RCA: 1069] [Impact Index Per Article: 62.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2007] [Accepted: 06/03/2007] [Indexed: 05/16/2023]
Abstract
The increasing use of engineered nanoparticles (NP) in industrial and household applications will very likely lead to the release of such materials into the environment. Assessing the risks of these NP in the environment requires an understanding of their mobility, reactivity, ecotoxicity and persistency. This review presents an overview of the classes of NP relevant to the environment and summarizes their formation, emission, occurrence and fate in the environment. The engineered NP are thereby compared to natural products such as soot and organic colloids. To date only few quantitative analytical techniques for measuring NP in natural systems are available, which results in a serious lack of information about their occurrence in the environment. Results from ecotoxicological studies show that certain NP have effects on organisms under environmental conditions, though mostly at elevated concentrations. The next step towards an assessment of the risks of NP in the environment should therefore be to estimate the exposure to the different NP. It is also important to notice that most NP in technical applications are functionalized and therefore studies using pristine NP may not be relevant for assessing the behavior of the NP actually used.
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Affiliation(s)
- Bernd Nowack
- Technology and Society Laboratory, Empa - Materials Science and Technology, Lerchenfeldstrasse 5, CH-9014 St. Gallen, Switzerland.
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Irle S, Zheng G, Wang Z, Morokuma K. The C60 Formation Puzzle “Solved”: QM/MD Simulations Reveal the Shrinking Hot Giant Road of the Dynamic Fullerene Self-Assembly Mechanism. J Phys Chem B 2006; 110:14531-45. [PMID: 16869552 DOI: 10.1021/jp061173z] [Citation(s) in RCA: 215] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The dynamic self-assembly mechanism of fullerene molecules is an irreversible process emerging naturally under the nonequilibrium conditions of hot carbon vapor and is a consequence of the interplay between the dynamics and chemistry of polyyne chains, pi-conjugation and corresponding stabilization, and the dynamics of hot giant fullerene cages. In this feature article we briefly present an overview of experimental findings and past attempts to explain fullerene formation and show in detail how our recent quantum chemical molecular dynamics simulations of the dynamics of carbon vapor far from thermodynamic equilibrium have assisted in the discovery of the combined size-up/size-down "shrinking hot giant" road that leads to the formation of buckminsterfullerene C60, C70, and larger fullerenes. This formation mechanism is the first reported case of order created out of chaos where a distinct covalent bond network of an entire molecule is spontaneously self-assembled to a highly symmetric structure and fully explains the fullerene formation process consistently with all available experimental observations a priori. Experimental evidence suggests that it applies universally to all fullerene formation processes irrespective of the carbon source.
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Affiliation(s)
- Stephan Irle
- Cherry L. Emerson Center for Scientific Computation and Department of Chemistry, Emory University, Atlanta, Georgia 30322, USA.
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22
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Chen C. CiteSpace II: Detecting and visualizing emerging trends and transient patterns in scientific literature. ACTA ACUST UNITED AC 2006. [DOI: 10.1002/asi.20317] [Citation(s) in RCA: 2057] [Impact Index Per Article: 114.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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Jehlicka J, Frank O, Pokorný J, Rouzaud JN. Evaluation of Raman spectroscopy to detect fullerenes in geological materials. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2005; 61:2364-7. [PMID: 16029858 DOI: 10.1016/j.saa.2005.02.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2004] [Accepted: 02/04/2005] [Indexed: 05/03/2023]
Abstract
Fullerene C(60) was determined repeatedly from a few types of carbonaceous matter from geological environments. Detailed investigation of structural aspects of pure carbonaceous matrices as well as of their experimental mixtures with fullerene C(60) permits better understanding of the occurrence mode of fullerenes inside the network of natural samples. However, it appears that Raman microspectrometry is not competitive in the case of investigated current geological carbonaceous matrices with added fullerenes, when the concentration of fullerene C(60) is 100 ppm or lower. In such a situation, C(60) is highly dispersed and careful interpretation of the results of Raman microspectrometry does not permit us to obtain valuable quantitative structural data. Obtained sensitivity for detecting C(60) in investigated matrices was only 1%. Analytical reasons for these results are discussed.
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Affiliation(s)
- Jan Jehlicka
- Institute of Geochemistry, Mineralogy and Mineral Resources, Charles University, Albertov 6, 128 43 Prague 2, Czech Republic.
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Luo SN, Tschauner O, Tierney TE, Swift DC, Chipera SJ, Asimow PD. Novel crystalline carbon-cage structure synthesized from laser-driven shock wave loading of graphite. J Chem Phys 2005; 123:24703. [PMID: 16050762 DOI: 10.1063/1.1953562] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We report a novel crystalline carbon-cage structure synthesized from laser-driven shock wave loading of a graphite-copper mixture to about 14+/-2 GPa and 1000 +/- 200 K. Quite unexpectedly, it can be structurally related to an extremely compressed three-dimensional C60 polymer with random displacement of C atoms around average positions equivalent to those of distorted C60 cages. Thus, the present carbon-cage structure represents a structural crossing point between graphite interlayer bridging and C60 polymerization as the two ways of forming diamond from two-dimensional and molecular carbon.
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Affiliation(s)
- Sheng-Nian Luo
- P-24 Plasma Physics, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
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Ward PD, Botha J, Buick R, De Kock MO, Erwin DH, Garrison GH, Kirschvink JL, Smith R. Abrupt and gradual extinction among Late Permian land vertebrates in the Karoo basin, South Africa. Science 2005; 307:709-14. [PMID: 15661973 DOI: 10.1126/science.1107068] [Citation(s) in RCA: 247] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The Karoo basin of South Africa exposes a succession of Upper Permian to Lower Triassic terrestrial strata containing abundant terrestrial vertebrate fossils. Paleomagnetic/magnetostratigraphic and carbon-isotope data allow sections to be correlated across the basin. With this stratigraphy, the vertebrate fossil data show a gradual extinction in the Upper Permian punctuated by an enhanced extinction pulse at the Permian-Triassic boundary interval, particularly among the dicynodont therapsids, coinciding with negative carbon-isotope anomalies.
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Affiliation(s)
- Peter D Ward
- Department of Biology, University of Washington, Seattle, WA 98195, USA.
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Mundil R, Ludwig KR, Metcalfe I, Renne PR. Age and timing of the Permian mass extinctions: U/Pb dating of closed-system zircons. Science 2004; 305:1760-3. [PMID: 15375264 DOI: 10.1126/science.1101012] [Citation(s) in RCA: 466] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The age and timing of the Permian-Triassic mass extinction have been difficult to determine because zircon populations from the type sections are typically affected by pervasive lead loss and contamination by indistinguishable older xenocrysts. Zircons from nine ash beds within the Shangsi and Meishan sections (China), pretreated by annealing followed by partial attack with hydrofluoric acid, result in suites of consistent and concordant uranium/lead (U/Pb) ages, eliminating the effects of lead loss. The U/Pb age of the main pulse of the extinction is 252.6 +/- 0.2 million years, synchronous with the Siberian flood volcanism, and it occurred within the quoted uncertainty.
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Affiliation(s)
- Roland Mundil
- Berkeley Geochronology Center, 2455 Ridge Road, Berkeley, CA 94709, USA
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Becker L, Poreda RJ, Basu AR, Pope KO, Harrison TM, Nicholson C, Iasky R. Bedout: A Possible End-Permian Impact Crater Offshore of Northwestern Australia. Science 2004; 304:1469-76. [PMID: 15143216 DOI: 10.1126/science.1093925] [Citation(s) in RCA: 158] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The Bedout High, located on the northwestern continental margin of Australia, has emerged as a prime candidate for an end-Permian impact structure. Seismic imaging, gravity data, and the identification of melt rocks and impact breccias from drill cores located on top of Bedout are consistent with the presence of a buried impact crater. The impact breccias contain nearly pure silica glass (SiO2), fractured and shock-melted plagioclases, and spherulitic glass. The distribution of glass and shocked minerals over hundreds of meters of core material implies that a melt sheet is present. Available gravity and seismic data suggest that the Bedout High represents the central uplift of a crater similar in size to Chicxulub. A plagioclase separate from the Lagrange-1 exploration well has an Ar/Ar age of 250.1 +/- 4.5 million years. The location, size, and age of the Bedout crater can account for reported occurrences of impact debris in Permian-Triassic boundary sediments worldwide.
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Affiliation(s)
- L Becker
- Institute for Crustal Studies, Department of Geological Sciences, University of California, Santa Barbara, CA 93106, USA.
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Basu AR, Petaev MI, Poreda RJ, Jacobsen SB, Becker L. Chondritic Meteorite Fragments Associated with the Permian-Triassic Boundary in Antarctica. Science 2003; 302:1388-92. [PMID: 14631038 DOI: 10.1126/science.1090852] [Citation(s) in RCA: 100] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Multiple chondritic meteorite fragments have been found in two sedimentary rock samples from an end-Permian bed at Graphite Peak in Antarctica. The Ni/Fe, Co/Ni, and P/Fe ratios in metal grains; the Fe/Mg and Mn/Fe ratios in olivine and pyroxene; and the chemistry of Fe-, Ni-, P-, and S-bearing oxide in the meteorite fragments are typical of CM-type chondritic meteorites. In one sample, the meteoritic fragments are accompanied by more abundant discrete metal grains, which are also found in an end-Permian bed at Meishan, southern China. We discuss the implications of this finding for a suggested global impact event at the Permian-Triassic boundary.
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Affiliation(s)
- Asish R Basu
- Department of Earth and Environmental Sciences, University of Rochester, Rochester, NY 14627, USA.
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Harris J, Vis R. High-resolution transmission electron microscopy of carbon and nanocrystals in the Allende meteorite. Proc Math Phys Eng Sci 2003. [DOI: 10.1098/rspa.2003.1125] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- J.F Harris
- Department of Chemistry, University of Reading, Whiteknights, Reading RG6 6AD, UK
| | - R.D Vis
- Deceased. Department of Physics and Astronomy, Free University of Amsterdam, De Boelelaan 1081, 1081 HV, Amsterdam, Netherlands
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Velasco-Santos C, Martınez-Hernández A, Consultchi A, Rodrıguez R, Castaño V. Naturally produced carbon nanotubes. Chem Phys Lett 2003. [DOI: 10.1016/s0009-2614(03)00615-8] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Affiliation(s)
- Michael E. Lipschutz
- Department of Chemistry, Wetherill Laboratory, 560 Oval Drive, Purdue University, West Lafayette, Indiana 47907-2038, Department of Chemistry, Indiana State University, Terre Haute, Indiana 47809-5901, and Department of Earth and Environmental Sciences, The George Washington University, 2029 G Street N.W., Washington, D.C. 20006
| | - Stephen F. Wolf
- Department of Chemistry, Wetherill Laboratory, 560 Oval Drive, Purdue University, West Lafayette, Indiana 47907-2038, Department of Chemistry, Indiana State University, Terre Haute, Indiana 47809-5901, and Department of Earth and Environmental Sciences, The George Washington University, 2029 G Street N.W., Washington, D.C. 20006
| | - John M. Hanchar
- Department of Chemistry, Wetherill Laboratory, 560 Oval Drive, Purdue University, West Lafayette, Indiana 47907-2038, Department of Chemistry, Indiana State University, Terre Haute, Indiana 47809-5901, and Department of Earth and Environmental Sciences, The George Washington University, 2029 G Street N.W., Washington, D.C. 20006
| | - F. Bartow Culp
- Department of Chemistry, Wetherill Laboratory, 560 Oval Drive, Purdue University, West Lafayette, Indiana 47907-2038, Department of Chemistry, Indiana State University, Terre Haute, Indiana 47809-5901, and Department of Earth and Environmental Sciences, The George Washington University, 2029 G Street N.W., Washington, D.C. 20006
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Abstract
The recognition in 1980 of a signature of an extraterrestrial impact at the Cretaceous-Tertiary boundary and its apparent involvement with the mass extinction generated considerable enthusiasm for impacts at other mass extinctions. Numerous claims of impact evidence for the Permo-Triassic mass extinction (251.6 Ma), the largest of the Phanerozoic mass extinctions, have generally been rejected, found wanting, or been difficult to reproduce. Despite this lack of repeatable support, considerable available evidence is consistent with an impact, including the rapidity of extinction, coincident carbon shift, and evident correlation between terrestrial and marine extinctions. However attractive the hypothesis, the coincidence with the Siberian flood basalts and the complex nature of the carbon shift are in conflict with an impact. The most intriguing possibility is that the greatest mass extinction of the Phanerozoic left signals very similar to the end-Cretaceous mass extinction but was produced by entirely Earth-bound processes. If true, this would tell us far more about the nature of ecosystems and how they fail than would identification of another impact.
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Affiliation(s)
- Douglas H Erwin
- Department of Paleobiology, Smithsonian Institution, Washington, DC 20560, USA.
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Poreda RJ, Becker L. Fullerenes and interplanetary dust at the Permian-Triassic boundary. ASTROBIOLOGY 2003; 3:75-90. [PMID: 12804366 DOI: 10.1089/153110703321632435] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
We recently presented new evidence that an impact occurred approximately 250 million years ago at the Permian-Triassic boundary (PTB), triggering the most severe mass extinction in the history of life on Earth. We used a new extraterrestrial tracer, fullerene, a third carbon carrier of noble gases besides diamond and graphite. By exploiting the unique properties of this molecule to trap noble gases inside of its caged structure (helium, neon, argon), the origin of the fullerenes can be determined. Here, we present new evidence for fullerenes with extraterrestrial noble gases in the PTB at Graphite Peak, Antarctica, similar to PTB fullerenes from Meishan, China and Sasayama, Japan. In addition, we isolated a (3)He-rich magnetic carrier phase in three fractions from the Graphite Peak section. The noble gases in this magnetic fraction were similar to zero-age deep-sea interplanetary dust particles (IDPs) and some magnetic grains isolated from the Cretaceous-Tertiary boundary. The helium and neon isotopic compositions for both the bulk Graphite Peak sediments and an isolated magnetic fraction from the bulk material are consistent with solar-type gases measured in zero-age deep-sea sediments and point to a common source, namely, the flux of IDPs to the Earth's surface. In this instance, the IDP noble gas signature for the bulk sediment can be uniquely decoupled from fullerene, demonstrating that two separate tracers are present (direct flux of IDPs for (3)He vs. giant impact for fullerene).
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Affiliation(s)
- Robert J Poreda
- Department of Earth and Environmental Sciences, University of Rochester, Rochester, New York, USA
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Alvarez W. Comparing the evidence relevant to impact and flood basalt at times of major mass extinctions. ASTROBIOLOGY 2003; 3:153-161. [PMID: 12804370 DOI: 10.1089/153110703321632480] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The five major mass extinctions identified in 1982 by Raup and Sepkoski have expanded to six, with the suggestion that the Permian-Triassic extinction was a double event. Is there a general explanation for great mass extinctions, or can they result from different triggers, or even from internal system instabilities? The two most-discussed candidates for a general extinction mechanism are impacts and flood-basalt eruptions. A compilation of evidence for impact at the times of mass extinctions shows that this cause is abundantly confirmed in the case of the Cretaceous-Tertiary extinction and the late Eocene, which is a time of minor and gradual extinction, but little or no evidence connects other major extinctions to impact. On the other hand, there is a remarkable time correlation between flood basalts and four major extinctions, but no other evidence that flood basalts cause mass extinctions. The evidence for an impact-extinction linkage is strikingly different from that for a connection between flood basalts and extinctions. Flood basalts cover larger areas than craters and their associated thick ejecta blankets, which are thus less likely to be found. Impacts distribute proxies globally at instantaneous time horizons, whereas flood-basalt events are extended in time, and no remote proxies have been recognized. Many global killing mechanisms have been proposed in the case of impacts, but few have been suggested for flood basalts. It is possible that flood basalts are triggered by impact, but it is not obvious how impacts could result from anything other than chance. The hypothesis that impacts are the general cause of mass extinctions has not received supporting evidence, but has not been falsified. The hypothesis that flood basalts are the general cause of mass extinctions is supported by evidence from timing, but is not susceptible to falsification. Other candidates for general extinction causes, especially sea-level changes and system instabilities, would require separate treatment. The question is still very much open.
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Affiliation(s)
- Walter Alvarez
- Department of Earth and Planetary Science, University of California, Berkeley 94720-4767, USA.
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White RV. Earth's biggest 'whodunnit': unravelling the clues in the case of the end-Permian mass extinction. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2002; 360:2963-2985. [PMID: 12626276 DOI: 10.1098/rsta.2002.1097] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The mass extinction that occurred at the end of the Permian period, 250 million years ago, was the most devastating loss of life that Earth has ever experienced. It is estimated that ca. 96% of marine species were wiped out and land plants, reptiles, amphibians and insects also suffered. The causes of this catastrophic event are currently a topic of intense debate. The geological record points to significant environmental disturbances, for example, global warming and stagnation of ocean water. A key issue is whether the Earth's feedback mechanisms can become unstable on their own, or whether some forcing is required to precipitate a catastrophe of this magnitude. A prime suspect for pushing Earth's systems into a critical condition is massive end-Permian Siberian volcanism, which would have pumped large quantities of carbon dioxide and toxic gases into the atmosphere. Recently, it has been postulated that Earth was also the victim of a bolide impact at this time. If further research substantiates this claim, it raises some intriguing questions. The Cretaceous-Tertiary mass extinction, 65 million years ago, was contemporaneous with both an impact and massive volcanism. Are both types of calamity necessary to drive Earth to the brink of faunal cataclysm? We do not presently have enough pieces of the jigsaw to solve the mystery of the end-Permian extinction, but the forensic work continues.
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Affiliation(s)
- Rosalind V White
- Department of Geology, University of Leicester, University Road, Leicester LE1 7RH, UK.
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Reichow MK, Saunders AD, White RV, Pringle MS, Al'Mukhamedov AI, Medvedev AI, Kirda NP. 40Ar/39Ar dates from the West Siberian Basin: Siberian flood basalt province doubled. Science 2002; 296:1846-9. [PMID: 12052954 DOI: 10.1126/science.1071671] [Citation(s) in RCA: 220] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Widespread basaltic volcanism occurred in the region of the West Siberian Basin in central Russia during Permo-Triassic times. New 40Ar/39Ar age determinations on plagioclase grains from deep boreholes in the basin reveal that the basalts were erupted 249.4 +/- 0.5 million years ago. This is synchronous with the bulk of the Siberian Traps, erupted further east on the Siberian Platform. The age and geochemical data confirm that the West Siberian Basin basalts are part of the Siberian Traps and at least double the confirmed area of the volcanic province as a whole. The larger area of volcanism strengthens the link between the volcanism and the end-Permian mass extinction.
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Affiliation(s)
- Marc K Reichow
- Department of Geology, University of Leicester, Leicester LE1 7RH, UK
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Retallack GJ. Carbon dioxide and climate over the past 300 Myr. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2002; 360:659-673. [PMID: 12804298 DOI: 10.1098/rsta.2001.0960] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The link between atmospheric CO(2) levels and global warming is an axiom of current public policy, and is well supported by physicochemical experiments, by comparative planetary climatology and by geochemical modelling. Geological tests of this idea seek to compare proxies of past atmospheric CO(2) with other proxies of palaeotemperature. For at least the past 300 Myr, there is a remarkably high temporal correlation between peaks of atmospheric CO(2), revealed by study of stomatal indices of fossil leaves of Ginkgo, Lepidopteris, Tatarina and Rhachiphyllum, and palaeotemperature maxima, revealed by oxygen isotopic (delta(18)O) composition of marine biogenic carbonate. Large and growing databases on these proxy indicators support the idea that atmospheric CO(2) and temperature are coupled. In contrast, CO(2)-temperature uncoupling has been proposed from geological time-series of carbon isotopic composition of palaeosols and of marine phytoplankton compared with foraminifera, which fail to indicate high CO(2) at known times of high palaeotemperature. Failure of carbon isotopic palaeobarometers may be due to episodic release of CH(4), which has an unusually light isotopic value (down to -110 per thousand, and typically -60 per thousand delta(13)C) and which oxidizes rapidly (within 7-24 yr) to isotopically light CO(2). Past CO(2) highs (above 2000 ppmv) were not only times of catastrophic release of CH(4) from clathrates, but of asteroid and comet impacts, flood basalt eruptions and mass extinctions. The primary reason for iterative return to low CO(2) was carbon consumption by hydrolytic weathering and photosynthesis, perhaps stimulated by mountain uplift and changing patterns of oceanic thermohaline circulation. Sequestration of carbon was promoted in the long term by such evolutionary innovations as the lignin of forests and the sod of grasslands, which accelerated physicochemical weathering and delivery of nutrients to fuel oceanic productivity and carbon burial.
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Berner RA. Examination of hypotheses for the Permo-Triassic boundary extinction by carbon cycle modeling. Proc Natl Acad Sci U S A 2002; 99:4172-7. [PMID: 11917102 PMCID: PMC123621 DOI: 10.1073/pnas.032095199] [Citation(s) in RCA: 291] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/15/2002] [Indexed: 11/18/2022] Open
Abstract
The biological extinction that occurred at the Permian-Triassic boundary represents the most extensive loss of species of any known event of the past 550 million years. There have been a wide variety of explanations offered for this extinction. In the present paper, a number of the more popular recent hypotheses are evaluated in terms of predictions that they make, or that they imply, concerning the global carbon cycle. For this purpose, a mass balance model is used that calculates atmospheric CO2 and oceanic delta13C as a function of time. Hypotheses considered include: (i) the release of massive amounts of CO2 from the ocean to the atmosphere resulting in mass poisoning; (ii) the release of large amounts of CO2 from volcanic degassing; (iii) the release of methane stored in methane hydrates; (iv) the decomposition and oxidation of dead organisms to CO2 after sudden mass mortality; and (v) the long-term reorganization of the global carbon cycle. The modeling indicates that measured short-term changes in delta13C at the boundary are best explained by methane release with mass mortality and volcanic degassing contributing in secondary roles. None of the processes result in excessively high levels of atmospheric CO2 if they occurred on time scales of more than about 1,000 years. The idea of poisoning by high levels of atmospheric CO2 depends on the absence of subthermocline calcium carbonate deposition during the latest Permian. The most far-reaching effect was found to be reorganization of the carbon cycle with major sedimentary burial of organic matter shifting from the land to the sea, resulting in less burial overall, decreased atmospheric O2, and higher atmospheric CO2 for the entire Triassic Period.
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Affiliation(s)
- Robert A Berner
- Department of Geology and Geophysics, Yale University, New Haven, CT 06520-8109, USA.
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Affiliation(s)
- Robert T Rood
- Department of Astronomy, University of Virginia, Charlottesville, VA 22903, USA.
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Braun T, Osawa E, Detre C, Tóth I. On some analytical aspects of the determination of fullerenes in samples from the permian/triassic boundary layers. Chem Phys Lett 2001. [DOI: 10.1016/s0009-2614(01)01169-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Modesto S, Sues HD, Damiani R. A new Triassic procolophonoid reptile and its implications for procolophonoid survivorship during the Permo-Triassic extinction event. Proc Biol Sci 2001; 268:2047-52. [PMID: 11571052 PMCID: PMC1088847 DOI: 10.1098/rspb.2001.1766] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
A reptile specimen from the Lystrosaurus Assemblage Zone of the Beaufort Group, lowermost Triassic of South Africa, represents a new procolophonoid parareptile. Sauropareion anoplus gen. et sp. nov. is identified as the sister taxon of Procolophonidae in a phylogenetic analysis of procolophonoids. Stratigraphic calibration of the most parsimonious tree reveals that four of the six procolophonoid lineages originating in the Permian Period extended into the succeeding Triassic Period. This relatively high taxic survivorship (67%) across the Permo-Triassic boundary strongly suggests that procolophonoids were little if at all affected by the mass extinction event that punctuated the end of the Palaeozoic Era (ca. 251 million years ago).
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Affiliation(s)
- S Modesto
- Department of Palaeobiology, Royal Ontario Museum, 100 Queen's Park, Toronto, Ontario, Canada M5S 2C6.
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Affiliation(s)
- K A Farley
- Division of Geological and, Planetary Sciences, MS 170-25, California Institute of Technology, Pasadena, CA 91125, USA.
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Oops, they're doin’ it again…The Permian–Triassic Extinction. Trends Ecol Evol 2001. [DOI: 10.1016/s0169-5347(01)02238-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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