1
|
Jin Z, Wang X, Wang H, Ye Y, Zhang S. Organic carbon cycling and black shale deposition: an Earth System Science perspective. Natl Sci Rev 2023; 10:nwad243. [PMID: 37900193 PMCID: PMC10612131 DOI: 10.1093/nsr/nwad243] [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: 05/24/2023] [Revised: 08/15/2023] [Accepted: 08/27/2023] [Indexed: 10/31/2023] Open
Abstract
Earth has a prolonged history characterized by substantial cycling of matter and energy between multiple spheres. The production of organic carbon can be traced back to as early as ∼4.0 Ga, but the frequency and scale of organic-rich shales have varied markedly over geological time. In this paper, we discuss the organic carbon cycle and the development of black shale from the perspective of Earth System Science. We propose that black shale depositions are the results of interactions among lithospheric evolution, orbital forcing, weathering, photosynthesis and degradation. Black shales can record Earth's oxygenation process, provide petroleum and metallic mineral resources and reveal information about the driver, direction and magnitude of climate change. Future research on black shales should be expanded to encompass a more extensive and more multidimensional perspective.
Collapse
Affiliation(s)
- Zhijun Jin
- Institute of Energy, Peking University, Beijing100871, China
| | - Xiaomei Wang
- Key Laboratory of Petroleum Geochemistry, Central Laboratory of Geological Sciences, Research Institute of Petroleum Exploration and Development, China National Petroleum Corporation, Beijing100083, China
| | - Huajian Wang
- Key Laboratory of Petroleum Geochemistry, Central Laboratory of Geological Sciences, Research Institute of Petroleum Exploration and Development, China National Petroleum Corporation, Beijing100083, China
| | - Yuntao Ye
- Key Laboratory of Petroleum Geochemistry, Central Laboratory of Geological Sciences, Research Institute of Petroleum Exploration and Development, China National Petroleum Corporation, Beijing100083, China
- Key Laboratory of Orogenic Belts and Crustal Evolution, Ministry of Education, School of Earth and Space Sciences, Peking University, Beijing100871, China
| | - Shuichang Zhang
- Key Laboratory of Petroleum Geochemistry, Central Laboratory of Geological Sciences, Research Institute of Petroleum Exploration and Development, China National Petroleum Corporation, Beijing100083, China
| |
Collapse
|
2
|
Huang H, Gao Y, Ma C, Jones MM, Zeeden C, Ibarra DE, Wu H, Wang C. Organic carbon burial is paced by a ~173-ka obliquity cycle in the middle to high latitudes. SCIENCE ADVANCES 2021; 7:7/28/eabf9489. [PMID: 34244143 PMCID: PMC8270492 DOI: 10.1126/sciadv.abf9489] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 05/26/2021] [Indexed: 06/13/2023]
Abstract
Earth's climate system is complex and inherently nonlinear, which can induce some extraneous cycles in paleoclimatic proxies at orbital time scales. The paleoenvironmental consequences of these extraneous cycles are debated owing to their complex origin. Here, we compile high-resolution datasets of total organic carbon (TOC) and stable carbon isotope (δ13Corg) datasets to investigate organic carbon burial processes in middle to high latitudes. Our results document a robust cyclicity of ~173 thousand years (ka) in both TOC and δ13Corg The ~173-ka obliquity-related forcing signal was amplified by internal climate feedbacks of the carbon cycle under different geographic and climate conditions, which control a series of sensitive climatic processes. In addition, our new and compiled records from multiple proxies confirm the presence of the obliquity amplitude modulation (AM) cycle during the Mesozoic and Cenozoic and indicate the usefulness of the ~173-ka cycle as geochronometer and for paleoclimatic interpretation.
Collapse
Affiliation(s)
- He Huang
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences (Beijing), Beijing 100083, China
- School of Earth Sciences and Resources, China University of Geosciences (Beijing), Beijing 100083, China
| | - Yuan Gao
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences (Beijing), Beijing 100083, China.
- School of Earth Sciences and Resources, China University of Geosciences (Beijing), Beijing 100083, China
| | - Chao Ma
- State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation and Institute of Sedimentary Geology, Chengdu University of Technology, Chengdu 610059, China
| | - Matthew M Jones
- Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI 48109, USA
| | - Christian Zeeden
- Leibniz Institute for Applied Geophysics, Stilleweg 2, 30655 Hannover, Germany
| | - Daniel E Ibarra
- Department of Earth and Planetary Science, University of California, Berkeley, Berkeley, CA 94720, USA
- Institute at Brown for Environment and Society and Department of Earth, Environmental and Planetary Sciences, Brown University, Providence, RI 02912, USA
| | - Huaichun Wu
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences (Beijing), Beijing 100083, China
- School of Ocean Sciences, China University of Geosciences (Beijing), Beijing 100083, China
| | - Chengshan Wang
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences (Beijing), Beijing 100083, China.
- School of Earth Sciences and Resources, China University of Geosciences (Beijing), Beijing 100083, China
| |
Collapse
|
3
|
De Vleeschouwer D, Drury AJ, Vahlenkamp M, Rochholz F, Liebrand D, Pälike H. High-latitude biomes and rock weathering mediate climate-carbon cycle feedbacks on eccentricity timescales. Nat Commun 2020; 11:5013. [PMID: 33024102 PMCID: PMC7538577 DOI: 10.1038/s41467-020-18733-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Accepted: 09/09/2020] [Indexed: 11/29/2022] Open
Abstract
The International Ocean Discovery Programme (IODP) and its predecessors generated a treasure trove of Cenozoic climate and carbon cycle dynamics. Yet, it remains unclear how climate and carbon cycle interacted under changing geologic boundary conditions. Here, we present the carbon isotope (δ13C) megasplice, documenting deep-ocean δ13C evolution since 35 million years ago (Ma). We juxtapose the δ13C megasplice with its δ18O counterpart and determine their phase-difference on ~100-kyr eccentricity timescales. This analysis reveals that 2.4-Myr eccentricity cycles modulate the δ13C-δ18O phase relationship throughout the Oligo-Miocene (34-6 Ma), potentially through changes in continental weathering. At 6 Ma, a striking switch from in-phase to anti-phase behaviour occurs, signalling a reorganization of the climate-carbon cycle system. We hypothesize that this transition is consistent with Arctic cooling: Prior to 6 Ma, low-latitude continental carbon reservoirs expanded during astronomically-forced cool spells. After 6 Ma, however, continental carbon reservoirs contract rather than expand during cold periods due to competing effects between Arctic biomes (ice, tundra, taiga). We conclude that, on geologic timescales, System Earth experienced state-dependent modes of climate–carbon cycle interaction. Climate and carbon cycle interactions during major Earth system changes through the Cenozoic remain unclear. Here, the authors present a combined δ13C-δ18O megasplice for the last 35 Ma which allows them to identify three marked intervals of distinct climate–carbon cycle interactions.
Collapse
Affiliation(s)
- David De Vleeschouwer
- MARUM - Center for Marine and Environmental Sciences, University of Bremen, Klagenfurterstraße 2-4, 28359, Bremen, Germany.
| | - Anna Joy Drury
- MARUM - Center for Marine and Environmental Sciences, University of Bremen, Klagenfurterstraße 2-4, 28359, Bremen, Germany.,Department of Earth Sciences, University College London, Gower Street, London, WC1E 6BT, UK
| | - Maximilian Vahlenkamp
- MARUM - Center for Marine and Environmental Sciences, University of Bremen, Klagenfurterstraße 2-4, 28359, Bremen, Germany
| | - Fiona Rochholz
- MARUM - Center for Marine and Environmental Sciences, University of Bremen, Klagenfurterstraße 2-4, 28359, Bremen, Germany.,Research Group for Earth Observation, Pädagogische Hochschule Heidelberg, Czernyring 22/10-12, 69120, Heidelberg, Germany
| | - Diederik Liebrand
- MARUM - Center for Marine and Environmental Sciences, University of Bremen, Klagenfurterstraße 2-4, 28359, Bremen, Germany
| | - Heiko Pälike
- MARUM - Center for Marine and Environmental Sciences, University of Bremen, Klagenfurterstraße 2-4, 28359, Bremen, Germany
| |
Collapse
|
4
|
Impact of 10-Myr scale monsoon dynamics on Mesozoic climate and ecosystems. Sci Rep 2020; 10:11984. [PMID: 32704030 PMCID: PMC7378230 DOI: 10.1038/s41598-020-68542-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 06/15/2020] [Indexed: 12/02/2022] Open
Abstract
Earth’s orbital variations on timescales of 104–105 years, known as Milankovitch cycles, have played a critical role in pacing climate change and ecosystem dynamics, through glacial and/or monsoon dynamics. However, the climatic and biotic consequences of these cycles on much longer (~ 107 years) timescales remain unclear, due to a lack of long proxy records with precise age constraints. Here, we show ~ 10-Myr scale variations in early Mesozoic (250–180 Ma) records of lake-level, desert distribution, biogenic-silica burial flux, atmospheric CO2 levels (pCO2), and sea-surface-temperature (SST). Their phase relationships, coupled with carbon cycle modeling results, suggest that orbitally-paced summer monsoon dynamics modulates changes in terrestrial weatherability by ~ 20%, affecting changes in pCO2 of up to 500–1,000 ppmv and 3–7 °C SST. We also infer that these ~ 10-Myr scale climatic variations could have been causally linked to biotic turnover, size variations in dinosaur footprints, and tetrapod dispersal, potentially through spatio-temporal variations in resource availability and arid-hot climatic barriers at low-middle latitudes.
Collapse
|
5
|
Zeeden C, Obreht I, Veres D, Kaboth-Bahr S, Hošek J, Marković SB, Bösken J, Lehmkuhl F, Rolf C, Hambach U. Smoothed millennial-scale palaeoclimatic reference data as unconventional comparison targets: Application to European loess records. Sci Rep 2020; 10:5455. [PMID: 32214119 PMCID: PMC7096450 DOI: 10.1038/s41598-020-61528-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Accepted: 02/24/2020] [Indexed: 11/09/2022] Open
Abstract
Millennial-scale palaeoclimate variability has been documented in various terrestrial and marine palaeoclimate proxy records throughout the Northern Hemisphere for the last glacial cycle. Its clear expression and rapid shifts between different states of climate (Greenland Interstadials and Stadials) represents a correlation tool beyond the resolution of e.g. luminescence dating, especially relevant for terrestrial deposits. Usually, comparison of terrestrial proxy datasets and the Greenland ice cores indicates a complex expression of millennial-scale climate variability as recorded in terrestrial geoarchives including loess. Loess is the most widespread terrestrial geoarchive of the Quaternary and especially widespread over Eurasia. However, loess often records a smoothed representation of millennial-scale variability without all fidelity when compared to the Greenland data, this being a relevant limiting feature in integrating loess with other palaeoclimate records. To better understand the loess proxy-response to millennial-scale climate variability, we simulate a proxy signal smoothing by natural processes through application of low-pass filters of δ18O data from Greenland, a high-resolution palaeoclimate reference record, alongside speleothem isotope records from the Black Sea-Mediterranean region. We show that low-pass filters represent rather simple models for better constraining the expression of millennial-scale climate variability in low sedimentation environments, and in sediments where proxy-response signals are most likely affected by natural smoothing (by e.g. bioturbation). Interestingly, smoothed datasets from Greenland and the Black Sea-Mediterranean region are most similar in the last ~15 ka and between ~50-30 ka. Between ~30-15 ka, roughly corresponding to the Last Glacial Maximum and the deglaciation, the records show dissimilarities, challenging the construction of robust correlative time-scales in this age range. From our analysis it becomes apparent that patterns of palaeoclimate signals in loess-palaeosol sequences often might be better explained by smoothed Greenland reference data than the original high-resolution Greenland dataset, or other reference data. This opens the possibility to better assess the temporal resolution and palaeoclimate potential of loess-palaeosol sequences in recording supra-regional climate patterns, as well as to securely integrate loess with other chronologically better-resolved palaeoclimate records.
Collapse
Affiliation(s)
- Christian Zeeden
- LIAG, Leibniz Institute for Applied Geophysics, Hannover, Germany.
- IMCCE, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universités, UPMC Univ. Paris 06, Univ. Lille, Paris, France.
| | - Igor Obreht
- Organic Geochemistry Group, MARUM-Center for Marine Environmental Sciences and Department of Geosciences, University of Bremen, Bremen, Germany
| | - Daniel Veres
- Romanian Academy, Institute of Speleology, Cluj-Napoca, Romania
| | - Stefanie Kaboth-Bahr
- Institute of Earth Sciences, Ruprecht-Karls-Universität Heidelberg, Heidelberg, Germany
- Institut für Geowissenschaften, Universität Potsdam, Potsdam, Germany
| | - Jan Hošek
- Czech Geological Survey, Prague, Czech Republic
- Center for Theoretical Study, Charles University and the Academy of Sciences, Prague, Czech Republic
| | - Slobodan B Marković
- Chair of Physical Geography, Faculty of Sciences, University of Novi Sad, Novi Sad, Serbia
| | - Janina Bösken
- Department of Geography, RWTH Aachen University, Aachen, Germany
| | - Frank Lehmkuhl
- Department of Geography, RWTH Aachen University, Aachen, Germany
| | - Christian Rolf
- LIAG, Leibniz Institute for Applied Geophysics, Hannover, Germany
| | - Ulrich Hambach
- BayCEER & Chair of Geomorphology, University of Bayreuth, Bayreuth, Germany
| |
Collapse
|
6
|
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
|
7
|
A record of seafloor methane seepage across the last 150 million years. Sci Rep 2020; 10:2562. [PMID: 32054937 PMCID: PMC7018728 DOI: 10.1038/s41598-020-59431-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Accepted: 01/29/2020] [Indexed: 11/29/2022] Open
Abstract
Seafloor methane seepage is a significant source of carbon in the marine environment. The processes and temporal patterns of seafloor methane seepage over multi-million-year time scales are still poorly understood. The microbial oxidation of methane can store carbon in sediments through precipitation of carbonate minerals, thus providing a record of past methane emission. In this study, we compiled data on methane-derived carbonates to build a proxy time series of methane emission over the last 150 My and statistically compared it with the main hypothesised geological controllers of methane emission. We quantitatively demonstrate that variations in sea level and organic carbon burial are the dominant controls on methane leakage since the Early Cretaceous. Sea level controls methane seepage variations by imposing smooth trends on timescales in the order of tens of My. Organic carbon burial is affected by the same cyclicities, and instantaneously controls methane release because of the geologically rapid generation of biogenic methane. Both the identified fundamental (26–27 My) and higher (12 My) cyclicities relate to global phenomena. Temporal correlation analysis supports the evidence that modern expansion of hypoxic areas and its effect on organic carbon burial may lead to higher seawater methane concentrations over the coming centuries.
Collapse
|
8
|
Boulila S. Coupling between Grand cycles and Events in Earth's climate during the past 115 million years. Sci Rep 2019; 9:327. [PMID: 30674928 PMCID: PMC6344641 DOI: 10.1038/s41598-018-36509-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Accepted: 11/20/2018] [Indexed: 11/21/2022] Open
Abstract
Geological sediment archives document a rich periodic series of astronomically driven climate, but record also abrupt, severe climatic changes called events, the multi-Myr boundary conditions of which have generally been ascribed to acyclic processes from Earth’s interior dynamics. These events have rarely been considered together within extended time series for potential correlation with long-term (multi-million year, Myr) cycling. Here I show a coupling between events and multi-Myr cycles in a temperature and ice-volume climatic proxy of the geological past 115 Myr. I use Cenozoic through middle Cretaceous climatic variations, as recorded in benthic foraminifera δ18O, to highlight prominent ~9 and ~36 Myr cyclicities. These cyclicities were previously attributed either to astronomical or tectonic variations. In particular, I point out that most of the well-known events during the past 115 Myr geological interval occur during extremes in the ~9 and ~36 Myr cycling. One exception is the early Cenozoic hyperthermal events including the salient Paleocene-Eocene Thermal Maximum (~56 Ma), which do not match extremes in long-period cyclicities, but to inflection point of these cycles. Specific focus on climatic events, as inferred from δ18O proxy, suggest that some “events”, marked by gradual trends within the ~9 and ~36 Myr cycle extremes, would principally be paced by long-term cycling, while “events”, recorded as abrupt δ18O changes nearby cycle extremes, would be rather induced by acyclic processes. The connection between cyclic and acyclic processes, as triggers or feedbacks, is very likely. Such link between cycling and events in Earth’s past climate provides insight into celestial dynamics governing perturbations in Earth’s surface systems, but also the potential connection between external and Earth’s interior processes.
Collapse
Affiliation(s)
- Slah Boulila
- Sorbonne Université, CNRS, Institut des Sciences de la Terre Paris, ISTeP, F-75005, Paris, France. .,ASD/IMCCE, CNRS-UMR8028, Observatoire de Paris, PSL University, Sorbonne Université, 77 Avenue Denfert-Rochereau, 75014, Paris, France.
| |
Collapse
|
9
|
Timing and pacing of the Late Devonian mass extinction event regulated by eccentricity and obliquity. Nat Commun 2017; 8:2268. [PMID: 29273792 PMCID: PMC5741662 DOI: 10.1038/s41467-017-02407-1] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Accepted: 11/29/2017] [Indexed: 11/15/2022] Open
Abstract
The Late Devonian envelops one of Earth’s big five mass extinction events at the Frasnian–Famennian boundary (374 Ma). Environmental change across the extinction severely affected Devonian reef-builders, besides many other forms of marine life. Yet, cause-and-effect chains leading to the extinction remain poorly constrained as Late Devonian stratigraphy is poorly resolved, compared to younger cataclysmic intervals. In this study we present a global orbitally calibrated chronology across this momentous interval, applying cyclostratigraphic techniques. Our timescale stipulates that 600 kyr separate the lower and upper Kellwasser positive δ13C excursions. The latter excursion is paced by obliquity and is therein similar to Mesozoic intervals of environmental upheaval, like the Cretaceous Ocean-Anoxic-Event-2 (OAE-2). This obliquity signature implies coincidence with a minimum of the 2.4 Myr eccentricity cycle, during which obliquity prevails over precession, and highlights the decisive role of astronomically forced “Milankovitch” climate change in timing and pacing the Late Devonian mass extinction. Understanding of Late Devonian mass extinction mechanisms is poor due to imprecise stratigraphies. Here, using cyclostratigraphic techniques, the authors present a global orbitally-calibrated chronology and reveal the key role of astronomically-forced Milankovitch climate change.
Collapse
|
10
|
Ikeda M, Tada R, Ozaki K. Astronomical pacing of the global silica cycle recorded in Mesozoic bedded cherts. Nat Commun 2017; 8:15532. [PMID: 28589958 PMCID: PMC5467233 DOI: 10.1038/ncomms15532] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2016] [Accepted: 04/05/2017] [Indexed: 11/08/2022] Open
Abstract
The global silica cycle is an important component of the long-term climate system, yet its controlling factors are largely uncertain due to poorly constrained proxy records. Here we present a ∼70 Myr-long record of early Mesozoic biogenic silica (BSi) flux from radiolarian chert in Japan. Average low-mid-latitude BSi burial flux in the superocean Panthalassa is ∼90% of that of the modern global ocean and relative amplitude varied by ∼20-50% over the 100 kyr to 30 Myr orbital cycles during the early Mesozoic. We hypothesize that BSi in chert was a major sink for oceanic dissolved silica (DSi), with fluctuations proportional to DSi input from chemical weathering on timescales longer than the residence time of DSi (<∼100 Kyr). Chemical weathering rates estimated by the GEOCARBSULFvolc model support these hypotheses, excluding the volcanism-driven oceanic anoxic events of the Early-Middle Triassic and Toarcian that exceed model limits. We propose that the Mega monsoon of the supercontinent Pangea nonlinearly amplified the orbitally paced chemical weathering that drove BSi burial during the early Mesozoic greenhouse world.
Collapse
Affiliation(s)
- Masayuki Ikeda
- Department of Geosciences, Graduate School of Science, Shizuoka University, 836 Ooya, Suruga-ku, Shizuoka 790-8577, Japan
- Lamont Doherty Earth Observatory, Columbia University, Columbia, New York 10964, USA
| | - Ryuji Tada
- Department of Earth and Planetary Science, Graduate School of Science, University of Tokyo, Tokyo 113-8654, Japan
| | - Kazumi Ozaki
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
- NASA Postdoctoral Program, Universities Space Research Association, Columbia, Maryland 21046, USA
| |
Collapse
|
11
|
Pieńkowski G, Hodbod M, Ullmann CV. Fungal decomposition of terrestrial organic matter accelerated Early Jurassic climate warming. Sci Rep 2016; 6:31930. [PMID: 27554210 PMCID: PMC4995404 DOI: 10.1038/srep31930] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Accepted: 07/26/2016] [Indexed: 12/04/2022] Open
Abstract
Soils - constituting the largest terrestrial carbon pool - are vulnerable to climatic warming. Currently existing uncertainties regarding carbon fluxes within terrestrial systems can be addressed by studies of past carbon cycle dynamics and related climate change recorded in sedimentary successions. Here we show an example from the Early Jurassic (early Toarcian, c. 183 mya) marginal-marine strata from Poland, tracking the hinterland response to climatic changes through a super-greenhouse event. In contrast to anoxia-related enhanced carbon storage in coeval open marine environments, Total Organic Carbon (TOC) concentrations in the Polish successions are substantially reduced during this event. Increasing temperature favoured fungal-mediated decomposition of plant litter - specifically of normally resistant woody tissues. The associated injection of oxidized organic matter into the atmosphere corresponds to abrupt changes in standing vegetation and may have contributed significantly to the amplified greenhouse climate on Earth. The characteristic Toarcian signature of multiple warm pulses coinciding with rapidly decreasing carbon isotope ratios may in part be the result of a radical reduction of the terrestrial carbon pool as a response to climate change.
Collapse
Affiliation(s)
- Grzegorz Pieńkowski
- Polish Geological Institute – National Research Institute, Rakowiecka 4, PL-00-975 Warszawa, Poland
| | - Marta Hodbod
- Polish Geological Institute – National Research Institute, Rakowiecka 4, PL-00-975 Warszawa, Poland
| | - Clemens V. Ullmann
- University of Exeter, Camborne School of Mines and Environment and Sustainability Institute, Penryn Campus, Penryn, Treliever Road, TE10 9FE, UK
| |
Collapse
|