1
|
Li C, Fan M, Wang X, Li X, Zhao G, Liu G, Zhao J. Effects of nitrogen fertilizers on the bacterial community diversity and the weathering of purple mudstone in Southwest China. Front Microbiol 2023; 14:1164826. [PMID: 37455726 PMCID: PMC10341161 DOI: 10.3389/fmicb.2023.1164826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Accepted: 06/05/2023] [Indexed: 07/18/2023] Open
Abstract
Introduction Rock weathering is crucial in the development of soil. Yet the role of bacteria in the fine particle-forming process of purple mudstone is not fully understood, especially under nitrogen fertilization. Methods In this study, the particles (0.25 mm to 1 mm) of purple mudstone from Penglai Group (J3p) were selected as the test material. Two nitrogen fertilizers, i.e., urea (U) and ammonium bicarbonate (AB), and four application levels (0, 280, 560, and 840 N kg∙ha-1) with 18 replications were designed in an incubation experiment. The weathering indices and bacterial community structure of the purple mudstone particles were investigated after 120 days of incubation. Results The results showed that the weathering indices of purple mudstone particles in the AB treatment were higher than that in the U treatment at the same fertilization levels and a reducing trend was observed with increasing nitrogen fertilizer levels under the same nitrogen fertilizer application types. The diversities of the bacterial community were extremely significantly altered by nitrogen fertilizer application (p < 0.01). The effect of the nitrogen fertilizer application level on the beta diversity of the bacterial community (R2 = 0.34) was greater than that of the nitrogen fertilizer application type (R2 = 0.20). Through stepwise regression analysis, the positive effects of nitrification of Nitrobacter (Nitrolancea) (R2 = 0.36), the Phosphorous-dissolving bacteria (Massilia) (R2 = 0.12), and N-NO3- (R2 = 0.35) on the weathering indices of J3p purple mudstone particles could be observed. Structural equation modelling indicated that nitrogen fertilizer application level affects the abundance of the dominant species at the genus level (Nitrolancea and Massilia), and key environmental factor (N-NO3-), which in turn accelerated the weathering indices (59%). Discussion and Conclusion Our findings imply that the enhancements of nitrification of Nitrobacter (Nitrolancea) and of phosphorus solubilization of Phosphorous-dissolving bacteria (Massilia) by nitrogen fertilization are the key factors affecting the weathering indices of J3p purple mudstone particles.
Collapse
Affiliation(s)
- Chunpei Li
- College of Resources and Environment, Yunnan Agricultural University, Kunming, China
| | - Maopan Fan
- College of Resources and Environment, Yunnan Agricultural University, Kunming, China
| | - Xuan Wang
- Key Laboratory of Mountain Surface Processes and Ecological Regulation, Chinese Academy of Sciences, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, and Ministry of Water Conservancy, Chengdu, China
- University of the Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, China
| | - Xue Li
- College of Resources and Environment, Yunnan Agricultural University, Kunming, China
| | - Guang Zhao
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China
| | - Gangcai Liu
- Key Laboratory of Mountain Surface Processes and Ecological Regulation, Chinese Academy of Sciences, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, and Ministry of Water Conservancy, Chengdu, China
| | - Jixia Zhao
- College of Resources and Environment, Yunnan Agricultural University, Kunming, China
| |
Collapse
|
2
|
Global ocean redox changes before and during the Toarcian Oceanic Anoxic Event. Nat Commun 2023; 14:815. [PMID: 36781894 PMCID: PMC9925726 DOI: 10.1038/s41467-023-36516-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2022] [Accepted: 02/03/2023] [Indexed: 02/15/2023] Open
Abstract
Mesozoic oceanic anoxic events are recognized as widespread deposits of marine organic-rich mudrocks temporally associated with mass extinctions and large igneous province emplacement. The Toarcian Oceanic Anoxic Event is one example during which expanded ocean anoxia is hypothesized in response to environmental perturbations associated with emplacement of the Karoo-Ferrar igneous province. However, the global extent of total seafloor anoxia and the relative extent of euxinic (anoxic and sulfide-rich) and non-euxinic anoxic conditions during the Toarcian Oceanic Anoxic Event are poorly constrained. Here we present estimates of the global total anoxic and euxinic seafloor areas before and during the Toarcian Oceanic Anoxic Event based on rhenium and molybdenum enrichments, respectively, in organic-rich mudrocks of the Fernie Formation (British Columbia, Canada). We find that mass balance models depict an expansion of up to ~7% total seafloor anoxia, which was dominated by euxinia, at the onset of the Toarcian Oceanic Anoxic Event, followed by a contraction before the end of the event. The global ocean redox trends revealed by the rhenium data mirrors the collapse and recovery patterns of global ammonite and foraminiferal biodiversity.
Collapse
|
3
|
New age constraints on the Lower Jurassic Pliensbachian-Toarcian Boundary at Chacay Melehue (Neuquén Basin, Argentina). Sci Rep 2022; 12:4975. [PMID: 35322043 PMCID: PMC8942990 DOI: 10.1038/s41598-022-07886-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 02/25/2022] [Indexed: 12/02/2022] Open
Abstract
The Pliensbachian–Toarcian boundary interval is characterized by a ~ 3‰ negative carbon-isotope excursion (CIE) in organic and inorganic marine and terrestrial archives from sections in Europe, such as Peniche (Portugal) and Hawsker Bottoms, Yorkshire (UK). A new high-resolution organic-carbon isotope record, illustrating the same chemostratigraphic feature, is presented from the Southern Hemisphere Arroyo Chacay Melehue section, Chos Malal, Argentina, corroborating the global significance of this disturbance to the carbon cycle. The negative carbon-isotope excursion, mercury and organic-matter enrichment are accompanied by high-resolution ammonite and nannofossil biostratigraphy together with U–Pb CA-ID-TIMS geochronology derived from intercalated volcanic ash beds. A new age of ~ 183.73 + 0.35/− 0.50 Ma for the Pliensbachian–Toarcian boundary, and 182.77 + 0.11/− 0.15 for the tenuicostatum–serpentinum zonal boundary, is assigned based on high-precision U–Pb zircon geochronology and a Bayesian Markov chain Monte Carlo (MCMC) stratigraphic age model.
Collapse
|
4
|
Sinha S, Muscente AD, Schiffbauer JD, Williams M, Schweigert G, Martindale RC. Global controls on phosphatization of fossils during the toarcian oceanic anoxic event. Sci Rep 2021; 11:24087. [PMID: 34916533 PMCID: PMC8677819 DOI: 10.1038/s41598-021-03482-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 11/30/2021] [Indexed: 11/09/2022] Open
Abstract
Konservat-Lagerstätten-deposits with exceptionally preserved fossils-vary in abundance across geographic and stratigraphic space due to paleoenvironmental heterogeneity. While oceanic anoxic events (OAEs) may have promoted preservation of marine lagerstätten, the environmental controls on their taphonomy remain unclear. Here, we provide new data on the mineralization of fossils in three Lower Jurassic Lagerstätten-Strawberry Bank (UK), Ya Ha Tinda (Canada), and Posidonia Shale (Germany) -and test the hypothesis that they were preserved under similar conditions. Biostratigraphy indicates that all three Lagerstätten were deposited during the Toarcian OAE (TOAE), and scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) show that each deposit contains a variety of taxa preserved as phosphatized skeletons and tissues. Thus, despite their geographic and paleoenvironmental differences, all of these Lagerstätten were deposited in settings conducive to phosphatization, indicating that the TOAE fostered exceptional preservation in marine settings around the world. Phosphatization may have been fueled by phosphate delivery from climatically-driven sea level change and continental weathering, with anoxic basins acting as phosphorus traps.
Collapse
Affiliation(s)
- Sinjini Sinha
- Department of Geological Sciences, The University of Texas at Austin, 2275 Speedway, Austin, TX, 78712, USA.
| | - A D Muscente
- Department of Geological Sciences, The University of Texas at Austin, 2275 Speedway, Austin, TX, 78712, USA.,Department of Geology, Cornell College, 600 First Street SW, Mount Vernon, Iowa, 52314, USA
| | - James D Schiffbauer
- Department of Geological Sciences, University of Missouri, 101 Geological Sciences Building, Columbia, MO, 65211, USA.,X-Ray Microanalysis Core Facility, University of Missouri, 1 Geological Sciences Building, Columbia, MO, 65211, USA
| | - Matt Williams
- Bath Royal Literary and Scientific Institution, 16-18 Queen Square, Bath, BA1 2HN, UK
| | - Günter Schweigert
- Staatliches Museum für Naturkunde, Rosenstein 1, 70191, Stuttgart, Germany
| | - Rowan C Martindale
- Department of Geological Sciences, The University of Texas at Austin, 2275 Speedway, Austin, TX, 78712, USA
| |
Collapse
|
5
|
Piazza V, Ullmann CV, Aberhan M. Ocean warming affected faunal dynamics of benthic invertebrate assemblages across the Toarcian Oceanic Anoxic Event in the Iberian Basin (Spain). PLoS One 2020; 15:e0242331. [PMID: 33296368 PMCID: PMC7725388 DOI: 10.1371/journal.pone.0242331] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 10/30/2020] [Indexed: 11/24/2022] Open
Abstract
The Toarcian Oceanic Anoxic Event (TOAE; Early Jurassic, ca. 182 Ma ago) represents one of the major environmental disturbances of the Mesozoic and is associated with global warming, widespread anoxia, and a severe perturbation of the global carbon cycle. Warming-related dysoxia-anoxia has long been considered the main cause of elevated marine extinction rates, although extinctions have been recorded also in environments without evidence for deoxygenation. We addressed the role of warming and disturbance of the carbon cycle in an oxygenated habitat in the Iberian Basin, Spain, by correlating high resolution quantitative faunal occurrences of early Toarcian benthic marine invertebrates with geochemical proxy data (δ18O and δ13C). We find that temperature, as derived from the δ18O record of shells, is significantly correlated with taxonomic and functional diversity and ecological composition, whereas we find no evidence to link carbon cycle variations to the faunal patterns. The local faunal assemblages before and after the TOAE are taxonomically and ecologically distinct. Most ecological change occurred at the onset of the TOAE, synchronous with an increase in water temperatures, and involved declines in multiple diversity metrics, abundance, and biomass. The TOAE interval experienced a complete turnover of brachiopods and a predominance of opportunistic species, which underscores the generality of this pattern recorded elsewhere in the western Tethys Ocean. Ecological instability during the TOAE is indicated by distinct fluctuations in diversity and in the relative abundance of individual modes of life. Local recovery to ecologically stable and diverse post-TOAE faunal assemblages occurred rapidly at the end of the TOAE, synchronous with decreasing water temperatures. Because oxygen-depleted conditions prevailed in many other regions during the TOAE, this study demonstrates that multiple mechanisms can be operating simultaneously with different relative contributions in different parts of the ocean.
Collapse
Affiliation(s)
- Veronica Piazza
- Museum für Naturkunde, Leibniz Institute for Evolution and Biodiversity Science, Berlin, Germany
| | - Clemens V. Ullmann
- University of Exeter, Camborne School of Mines, College of Engineering, Mathematics and Physical Sciences, Penryn, Cornwall, United Kingdom
| | - Martin Aberhan
- Museum für Naturkunde, Leibniz Institute for Evolution and Biodiversity Science, Berlin, Germany
| |
Collapse
|
6
|
Wang Y, Ossa Ossa F, Wille M, Schurr S, Saussele ME, Schmid-Röhl A, Schoenberg R. Evidence for local carbon-cycle perturbations superimposed on the Toarcian carbon isotope excursion. GEOBIOLOGY 2020; 18:682-709. [PMID: 32783292 DOI: 10.1111/gbi.12410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 07/09/2020] [Accepted: 07/20/2020] [Indexed: 06/11/2023]
Abstract
A Jurassic negative carbon isotope excursion (CIE), co-evolved with Toarcian Oceanic Anoxic Event (OAE) at ~183 Ma, is suggested to be linked to a global carbon-cycle perturbation and is well documented for Toarcian terrestrial fossil woods and marine sediments around the globe. A theoretically coupled δ13 Ccarb -δ13 Corg pattern due to such dubbed global carbon-cycle event from the negative CIE in Dotternhausen Toarcian stratigraphic profile (southwest Germany) is unexpectedly disturbed by two-step δ13 Ccarb -δ13 Corg decoupling in which the last step, upper in the stratigraphic order, is of higher magnitude. However, the trigger(s) for these sudden decoupling disturbances are still poorly constrained. Here, connecting new carbon and oxygen isotope data with documentary lipid biomarkers shows that the global carbon cycle during the Toarcian OAE was disturbed by enhanced green sulfur bacteria (GSB) metabolisms and early diagenesis at local scales. The first step δ13 Ccarb -δ13 Corg decoupling was induced in the initial stage of the GSB bloom. The second step of much larger δ13 Ccarb -δ13 Corg decoupling arising from a GSB prosperity was, however, exaggerated by early diagenesis through the respiration of sulfate-reducing bacteria (SRB). Paleo-geographically distinct localities of the Tethys region show contrasting decoupled δ13 Ccarb -δ13 Corg patterns, which implies that the second-order carbon-cycle perturbations have pervasively and independently impacted the global carbon event during the Toarcian OAE.
Collapse
Affiliation(s)
- Yunfeng Wang
- Department of Geosciences, University of Tuebingen, Tuebingen, Germany
| | - Frantz Ossa Ossa
- Department of Geosciences, University of Tuebingen, Tuebingen, Germany
- Department of Geology, University of Johannesburg, Johannesburg, South Africa
| | - Martin Wille
- Institute of Geological Sciences, University of Bern, Bern, Switzerland
| | - Simon Schurr
- Institute of Geology and Paleontology, University of Muenster, Muenster, Germany
| | | | - Annette Schmid-Röhl
- Fossil Museum and Werkforum, Holcim (Süddeutschland) GmbH, Dotternhausen, Germany
| | - Ronny Schoenberg
- Department of Geosciences, University of Tuebingen, Tuebingen, Germany
- Department of Geology, University of Johannesburg, Johannesburg, South Africa
| |
Collapse
|
7
|
Warm afterglow from the Toarcian Oceanic Anoxic Event drives the success of deep-adapted brachiopods. Sci Rep 2020; 10:6549. [PMID: 32300235 PMCID: PMC7162941 DOI: 10.1038/s41598-020-63487-6] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Accepted: 03/25/2020] [Indexed: 11/25/2022] Open
Abstract
Many aspects of the supposed hyperthermal Toarcian Oceanic Anoxic Event (T-OAE, Early Jurassic, c. 182 Ma) are well understood but a lack of robust palaeotemperature data severely limits reconstruction of the processes that drove the T-OAE and associated environmental and biotic changes. New oxygen isotope data from calcite shells of the benthic fauna suggest that bottom water temperatures in the western Tethys were elevated by c. 3.5 °C through the entire T-OAE. Modelling supports the idea that widespread marine anoxia was induced by a greenhouse-driven weathering pulse, and is compatible with the OAE duration being extended by limitation of the global silicate weathering flux. In the western Tethys Ocean, the later part of the T-OAE is characterized by abundant occurrences of the brachiopod Soaresirhynchia, which exhibits characteristics of slow-growing, deep sea brachiopods. The unlikely success of Soaresirhynchia in a hyperthermal event is attributed here to low metabolic rate, which put it at an advantage over other species from shallow epicontinental environments with higher metabolic demand.
Collapse
|
8
|
Abstract
Cyclic variations in Earth’s orbit drive periodic changes in the ocean–atmosphere system at a time scale of tens to hundreds of thousands of years. The Mochras δ13CTOC record illustrates the continued impact of long-eccentricity (405-ky) orbital forcing on the carbon cycle over at least ∼18 My of Early Jurassic time and emphasizes orbital forcing as a driving mechanism behind medium-amplitude δ13C fluctuations superimposed on larger-scale trends that are driven by other variables such as tectonically determined paleogeography and eruption of large igneous provinces. The dataset provides a framework for distinguishing between internal Earth processes and solar-system dynamics as the driving mechanism for Early Jurassic δ13C fluctuations and provides an astronomical time scale for the Sinemurian Stage. Global perturbations to the Early Jurassic environment (∼201 to ∼174 Ma), notably during the Triassic–Jurassic transition and Toarcian Oceanic Anoxic Event, are well studied and largely associated with volcanogenic greenhouse gas emissions released by large igneous provinces. The long-term secular evolution, timing, and pacing of changes in the Early Jurassic carbon cycle that provide context for these events are thus far poorly understood due to a lack of continuous high-resolution δ13C data. Here we present a δ13CTOC record for the uppermost Rhaetian (Triassic) to Pliensbachian (Lower Jurassic), derived from a calcareous mudstone succession of the exceptionally expanded Llanbedr (Mochras Farm) borehole, Cardigan Bay Basin, Wales, United Kingdom. Combined with existing δ13CTOC data from the Toarcian, the compilation covers the entire Lower Jurassic. The dataset reproduces large-amplitude δ13CTOC excursions (>3‰) recognized elsewhere, at the Sinemurian–Pliensbachian transition and in the lower Toarcian serpentinum zone, as well as several previously identified medium-amplitude (∼0.5 to 2‰) shifts in the Hettangian to Pliensbachian interval. In addition, multiple hitherto undiscovered isotope shifts of comparable amplitude and stratigraphic extent are recorded, demonstrating that those similar features described earlier from stratigraphically more limited sections are nonunique in a long-term context. These shifts are identified as long-eccentricity (∼405-ky) orbital cycles. Orbital tuning of the δ13CTOC record provides the basis for an astrochronological duration estimate for the Pliensbachian and Sinemurian, giving implications for the duration of the Hettangian Stage. Overall the chemostratigraphy illustrates particular sensitivity of the marine carbon cycle to long-eccentricity orbital forcing.
Collapse
|
9
|
De Lena LF, Taylor D, Guex J, Bartolini A, Adatte T, van Acken D, Spangenberg JE, Samankassou E, Vennemann T, Schaltegger U. The driving mechanisms of the carbon cycle perturbations in the late Pliensbachian (Early Jurassic). Sci Rep 2019; 9:18430. [PMID: 31804521 PMCID: PMC6895128 DOI: 10.1038/s41598-019-54593-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Accepted: 11/18/2019] [Indexed: 11/09/2022] Open
Abstract
The Early Jurassic (late Pliensbachian to early Toarcian) was a period marked by extinctions, climate fluctuations, and oceanic anoxia. Although the causes of the early Toarcian Oceanic Anoxia Event (OAE) have been fairly well studied, the events that lead to the Toarcian OAE, i.e. the events in the late Pliensbachian, have not been well constrained. Scenarios of the driving mechanism of biotic and environmental changes of the late Pliensbachian have ranged from LIP volcanism (the Karoo-Ferrar LIP), ocean stagnation, and changing ocean circulation, to orbital forcing. The temporal relationship between the Karoo LIP and the late Pliensbachian (Kunae-Carlottense ammonite Zones) are investigated in an effort to evaluate a causal relationship. We present the first absolute timescale on the Kunae and Carlottense Zones based on precise high-precision U-Pb geochronology, and additional geochemical proxies, for a range of environmental proxies such as bulk organic carbon isotope compositions, Hg concentration, and Hg/TOC ratios, and Re-Os isotopes to further explore their causal relationship. The data presented here show that causality between the Karoo LIP and the late Pliensbachian events cannot be maintained.
Collapse
Affiliation(s)
- Luis F De Lena
- Department of Earth Sciences, University of Geneva, Geneva, Switzerland.
| | - David Taylor
- Department of Earth Sciences, University of Oregon, Portland, OR, USA.,Department of Earth Sciences, University of Oregon, Eugene, OR, USA
| | - Jean Guex
- Faculty of Geosciences and Environmental Sciences, University of Lausanne, Lausanne, Switzerland
| | - Annachiara Bartolini
- Center for Research on Palaeontology - Paris, UMR7207, MNHN, CNRS, SU, Paris, France
| | - Thierry Adatte
- Institute of Earth Sciences, University of Lausanne, Géopolis, Lausanne, Switzerland
| | - David van Acken
- Irish Centre for Research in Applied Geosciences (iCRAG), UCD School of Earth Sciences, University College Dublin, Dublin, Ireland
| | - Jorge E Spangenberg
- Institute of Earth Sciences, University of Lausanne, Géopolis, Lausanne, Switzerland
| | - Elias Samankassou
- Department of Earth Sciences, University of Geneva, Geneva, Switzerland
| | | | - Urs Schaltegger
- Department of Earth Sciences, University of Geneva, Geneva, Switzerland
| |
Collapse
|
10
|
van der Ploeg R, Selby D, Cramwinckel MJ, Li Y, Bohaty SM, Middelburg JJ, Sluijs A. Middle Eocene greenhouse warming facilitated by diminished weathering feedback. Nat Commun 2018; 9:2877. [PMID: 30038400 PMCID: PMC6056486 DOI: 10.1038/s41467-018-05104-9] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Accepted: 06/15/2018] [Indexed: 11/23/2022] Open
Abstract
The Middle Eocene Climatic Optimum (MECO) represents a ~500-kyr period of global warming ~40 million years ago and is associated with a rise in atmospheric CO2 concentrations, but the cause of this CO2 rise remains enigmatic. Here we show, based on osmium isotope ratios (187Os/188Os) of marine sediments and published records of the carbonate compensation depth (CCD), that the continental silicate weathering response to the inferred CO2 rise and warming was strongly diminished during the MECO-in contrast to expectations from the silicate weathering thermostat hypothesis. We surmise that global early and middle Eocene warmth gradually diminished the weatherability of continental rocks and hence the strength of the silicate weathering feedback, allowing for the prolonged accumulation of volcanic CO2 in the oceans and atmosphere during the MECO. These results are supported by carbon cycle modeling simulations, which highlight the fundamental importance of a variable weathering feedback strength in climate and carbon cycle interactions in Earth's history.
Collapse
Affiliation(s)
- Robin van der Ploeg
- Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Utrecht, 3584 CB, The Netherlands.
| | - David Selby
- Department of Earth Sciences, Durham University, Durham, DH1 3LE, UK
- State Key Laboratory of Geological Processes and Mineral Resources, School of Earth Resources, China University of Geosciences, Wuhan, 430074, Hubei, China
| | - Margot J Cramwinckel
- Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Utrecht, 3584 CB, The Netherlands
| | - Yang Li
- Department of Geology and Geophysics, Yale University, New Haven, Connecticut, 06511, USA
- State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, 10029, China
| | - Steven M Bohaty
- Ocean and Earth Science, National Oceanography Centre, University of Southampton Waterfront Campus, Southampton, SO14 3ZH, UK
| | - Jack J Middelburg
- Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Utrecht, 3584 CB, The Netherlands
| | - Appy Sluijs
- Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Utrecht, 3584 CB, The Netherlands
| |
Collapse
|
11
|
Thallium isotopes reveal protracted anoxia during the Toarcian (Early Jurassic) associated with volcanism, carbon burial, and mass extinction. Proc Natl Acad Sci U S A 2018; 115:6596-6601. [PMID: 29891692 DOI: 10.1073/pnas.1803478115] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
For this study, we generated thallium (Tl) isotope records from two anoxic basins to track the earliest changes in global bottom water oxygen contents over the Toarcian Oceanic Anoxic Event (T-OAE; ∼183 Ma) of the Early Jurassic. The T-OAE, like other Mesozoic OAEs, has been interpreted as an expansion of marine oxygen depletion based on indirect methods such as organic-rich facies, carbon isotope excursions, and biological turnover. Our Tl isotope data, however, reveal explicit evidence for earlier global marine deoxygenation of ocean water, some 600 ka before the classically defined T-OAE. This antecedent deoxygenation occurs at the Pliensbachian/Toarcian boundary and is coeval with the onset of initial large igneous province (LIP) volcanism and the initiation of a marine mass extinction. Thallium isotopes are also perturbed during the T-OAE interval, as defined by carbon isotopes, reflecting a second deoxygenation event that coincides with the acme of elevated marine mass extinctions and the main phase of LIP volcanism. This suggests that the duration of widespread anoxic bottom waters was at least 1 million years in duration and spanned early to middle Toarcian time. Thus, the Tl data reveal a more nuanced record of marine oxygen depletion and its links to biological change during a period of climatic warming in Earth's past and highlight the role of oxygen depletion on past biological evolution.
Collapse
|