Publications by authors named "Lee R Kump"

20 Publications

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Prolonged Late Permian-Early Triassic hyperthermal: failure of climate regulation?

Authors:
Lee R Kump

Philos Trans A Math Phys Eng Sci 2018 Oct;376(2130)

Department of Geosciences, Pennsylvania State University, University Park, PA 16802, USA

The extreme warmth associated with the mass extinction at the Permian-Triassic boundary was likely produced by a rapid build-up of carbon dioxide in the atmosphere from the eruption and emplacement of the Siberian Traps. In comparison to another hyperthermal event, the Palaeocene-Eocene Thermal Maximum, the Permian-Triassic event, while leaving a similar carbon isotope record, likely had larger amounts of CO emitted and did not follow the expected time scale of climate recovery. The quantities and rates of CO emission likely exhausted the capacity of the long-term climate regulator associated with silicate weathering. Failure was enhanced by slow rock uplift and high continentality associated with the supercontinental phase of global tectonics at the time of the Siberian Traps eruption.This article is part of a discussion meeting issue 'Hyperthermals: rapid and extreme global warming in our geological past'.
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http://dx.doi.org/10.1098/rsta.2017.0078DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6127386PMC
October 2018

Late inception of a resiliently oxygenated upper ocean.

Science 2018 07 31;361(6398):174-177. Epub 2018 May 31.

Department of Earth Sciences, Syracuse University, Syracuse, NY, USA.

Rising oceanic and atmospheric oxygen levels through time have been crucial to enhanced habitability of surface Earth environments. Few redox proxies can track secular variations in dissolved oxygen concentrations around threshold levels for metazoan survival in the upper ocean. We present an extensive compilation of iodine-to-calcium ratios (I/Ca) in marine carbonates. Our record supports a major rise in the partial pressure of oxygen in the atmosphere at ~400 million years (Ma) ago and reveals a step change in the oxygenation of the upper ocean to relatively sustainable near-modern conditions at ~200 Ma ago. An Earth system model demonstrates that a shift in organic matter remineralization to greater depths, which may have been due to increasing size and biomineralization of eukaryotic plankton, likely drove the I/Ca signals at ~200 Ma ago.
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http://dx.doi.org/10.1126/science.aar5372DOI Listing
July 2018

A probabilistic assessment of the rapidity of PETM onset.

Nat Commun 2017 08 25;8(1):353. Epub 2017 Aug 25.

Department of Earth Sciences, University of California, Riverside, Riverside, CA, 92506, USA.

Knowledge of the onset duration of the Paleocene-Eocene Thermal Maximum-the largest known greenhouse-gas-driven global warming event of the Cenozoic-is central to drawing inferences for future climate change. Single-foraminifera measurements of the associated carbon isotope excursion from Maud Rise (South Atlantic Ocean) are controversial, as they seem to indicate geologically instantaneous carbon release and anomalously long ocean mixing. Here, we fundamentally reinterpret this record and extract the likely PETM onset duration. First, we employ an Earth system model to illustrate how the response of ocean circulation to warming does not support the interpretation of instantaneous carbon release. Instead, we use a novel sediment-mixing model to show how changes in the relative population sizes of calcareous plankton, combined with sediment mixing, can explain the observations. Furthermore, for any plausible PETM onset duration and sampling methodology, we place a probability on not sampling an intermediate, syn-excursion isotopic value. Assuming mixed-layer carbonate production continued at Maud Rise, we deduce the PETM onset was likely <5 kyr.Single-foraminifera measurements of the PETM carbon isotope excursion from Maud Rise have been interpreted as indicating geologically instantaneous carbon release. Here, the authors explain these records using an Earth system model and a sediment-mixing model and extract the likely PETM onset duration.
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http://dx.doi.org/10.1038/s41467-017-00292-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5572461PMC
August 2017

Marine anoxia and delayed Earth system recovery after the end-Permian extinction.

Proc Natl Acad Sci U S A 2016 Mar 16;113(9):2360-5. Epub 2016 Feb 16.

Department of Geological Sciences, Stanford University, Stanford, CA 94305;

Delayed Earth system recovery following the end-Permian mass extinction is often attributed to severe ocean anoxia. However, the extent and duration of Early Triassic anoxia remains poorly constrained. Here we use paired records of uranium concentrations ([U]) and (238)U/(235)U isotopic compositions (δ(238)U) of Upper Permian-Upper Triassic marine limestones from China and Turkey to quantify variations in global seafloor redox conditions. We observe abrupt decreases in [U] and δ(238)U across the end-Permian extinction horizon, from ∼3 ppm and -0.15‰ to ∼0.3 ppm and -0.77‰, followed by a gradual return to preextinction values over the subsequent 5 million years. These trends imply a factor of 100 increase in the extent of seafloor anoxia and suggest the presence of a shallow oxygen minimum zone (OMZ) that inhibited the recovery of benthic animal diversity and marine ecosystem function. We hypothesize that in the Early Triassic oceans-characterized by prolonged shallow anoxia that may have impinged onto continental shelves-global biogeochemical cycles and marine ecosystem structure became more sensitive to variation in the position of the OMZ. Under this hypothesis, the Middle Triassic decline in bottom water anoxia, stabilization of biogeochemical cycles, and diversification of marine animals together reflect the development of a deeper and less extensive OMZ, which regulated Earth system recovery following the end-Permian catastrophe.
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http://dx.doi.org/10.1073/pnas.1515080113DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4780601PMC
March 2016

The rise of oxygen and siderite oxidation during the Lomagundi Event.

Proc Natl Acad Sci U S A 2015 May 11;112(21):6562-7. Epub 2015 May 11.

Department of Geosciences, The Pennsylvania State University, University Park, PA 16802.

The Paleoproterozoic Lomagundi Event is an interval of 130-250 million years, ca. 2.3-2.1 billion years ago, in which extraordinarily (13)C enriched (>10‰) limestones and dolostones occur globally. The high levels of organic carbon burial implied by the positive δ(13)C values suggest the production of vast quantities of O2 as well as an alkalinity imbalance demanding extremely low levels of weathering. The oxidation of sulfides has been proposed as a mechanism capable of ameliorating these imbalances: It is a potent sink for O2 as well as a source of acidity. However, sulfide oxidation consumes more O2 than it can supply CO2, leading to insurmountable imbalances in both carbon and oxygen. In contrast, the oxidation of siderite (FeCO3 proper, as well as other Fe(2+)-bearing carbonate minerals), produces 4 times more CO2 than it consumes O2 and is a common--although often overlooked--constituent of Archean and Early Proterozoic sedimentary successions. Here we propose that following the initial rise of O2 in the atmosphere, oxidation of siderite provided the necessary carbon for the continued oxidation of sulfides, burial of organic carbon, and, most importantly, accumulation of free O2. The duration and magnitude of the Lomagundi Event were determined by the size of the preexisting Archean siderite reservoir, which was consumed through oxidative weathering. Our proposal helps resolve a long-standing conundrum and advances our understanding of the geologic history of atmospheric O2.
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http://dx.doi.org/10.1073/pnas.1422319112DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4450422PMC
May 2015

Hypothesized link between Neoproterozoic greening of the land surface and the establishment of an oxygen-rich atmosphere.

Authors:
Lee R Kump

Proc Natl Acad Sci U S A 2014 Sep 15;111(39):14062-5. Epub 2014 Sep 15.

Department of Geosciences, The Pennsylvania State University, University Park, PA 16802

Considerable geological, geochemical, paleontological, and isotopic evidence exists to support the hypothesis that the atmospheric oxygen level rose from an Archean baseline of essentially zero to modern values in two steps roughly 2.3 billion and 0.8-0.6 billion years ago (Ga). The first step in oxygen content, the Great Oxidation Event, was likely a threshold response to diminishing reductant input from Earth's interior. Here I provide an alternative to previous suggestions that the second step was the result of the establishment of the first terrestrial fungal-lichen ecosystems. The consumption of oxygen by aerobes respiring this new source of organic matter in soils would have necessitated an increase in the atmospheric oxygen content to compensate for the reduced delivery of oxygen to the weathering environment below the organic-rich upper soil layer. Support for this hypothesis comes from the observed spread toward more negative carbon isotope compositions in Neoproterozoic (1.0-0.542 Ga) and younger limestones altered under the influence of ground waters, and the positive correlation between the carbon isotope composition and oxygen content of modern ground waters in contact with limestones. Thus, the greening of the planet's land surfaces forced the atmospheric oxygen level to a new, higher equilibrium state.
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http://dx.doi.org/10.1073/pnas.1321496111DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4191777PMC
September 2014

Geochemistry. Carbon cycle makeover.

Science 2013 Feb;339(6119):533-4

Nordic Center for Earth Evolution, University of Southern Denmark, Odense, 5230 Denmark.

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http://dx.doi.org/10.1126/science.1231981DOI Listing
February 2013

Isotopic evidence for massive oxidation of organic matter following the great oxidation event.

Science 2011 Dec 1;334(6063):1694-6. Epub 2011 Dec 1.

Department of Geosciences, Pennsylvania State University, University Park, PA 16802, USA.

The stable isotope record of marine carbon indicates that the Proterozoic Eon began and ended with extreme fluctuations in the carbon cycle. In both the Paleoproterozoic [2500 to 1600 million years ago (Ma)] and Neoproterozoic (1000 to 542 Ma), extended intervals of anomalously high carbon isotope ratios (δ(13)C) indicate high rates of organic matter burial and release of oxygen to the atmosphere; in the Neoproterozoic, the high δ(13)C interval was punctuated by abrupt swings to low δ(13)C, indicating massive oxidation of organic matter. We report a Paleoproterozoic negative δ(13)C excursion that is similar in magnitude and apparent duration to the Neoproterozoic anomaly. This Shunga-Francevillian anomaly may reflect intense oxidative weathering of rocks as the result of the initial establishment of an oxygen-rich atmosphere.
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http://dx.doi.org/10.1126/science.1213999DOI Listing
December 2011

Aerobic bacterial pyrite oxidation and acid rock drainage during the Great Oxidation Event.

Nature 2011 Oct 19;478(7369):369-73. Epub 2011 Oct 19.

Department of Earth & Atmospheric Sciences, University of Alberta, Edmonton, Alberta T6G 2E3, Canada.

The enrichment of redox-sensitive trace metals in ancient marine sedimentary rocks has been used to determine the timing of the oxidation of the Earth's land surface. Chromium (Cr) is among the emerging proxies for tracking the effects of atmospheric oxygenation on continental weathering; this is because its supply to the oceans is dominated by terrestrial processes that can be recorded in the Cr isotope composition of Precambrian iron formations. However, the factors controlling past and present seawater Cr isotope composition are poorly understood. Here we provide an independent and complementary record of marine Cr supply, in the form of Cr concentrations and authigenic enrichment in iron-rich sedimentary rocks. Our data suggest that Cr was largely immobile on land until around 2.48 Gyr ago, but within the 160 Myr that followed--and synchronous with independent evidence for oxygenation associated with the Great Oxidation Event (see, for example, refs 4-6)--marked excursions in Cr content and Cr/Ti ratios indicate that Cr was solubilized at a scale unrivalled in history. As Cr isotope fractionations at that time were muted, Cr must have been mobilized predominantly in reduced, Cr(III), form. We demonstrate that only the oxidation of an abundant and previously stable crustal pyrite reservoir by aerobic-respiring, chemolithoautotrophic bacteria could have generated the degree of acidity required to solubilize Cr(III) from ultramafic source rocks and residual soils. This profound shift in weathering regimes beginning at 2.48 Gyr ago constitutes the earliest known geochemical evidence for acidophilic aerobes and the resulting acid rock drainage, and accounts for independent evidence of an increased supply of dissolved sulphate and sulphide-hosted trace elements to the oceans around that time. Our model adds to amassing evidence that the Archaean-Palaeoproterozoic boundary was marked by a substantial shift in terrestrial geochemistry and biology.
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http://dx.doi.org/10.1038/nature10511DOI Listing
October 2011

The last great global warming.

Authors:
Lee R Kump

Sci Am 2011 Jul;305(1):56-61

Pennsylvania State University, USA.

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http://dx.doi.org/10.1038/scientificamerican0711-56DOI Listing
July 2011

Pulse of atmospheric oxygen during the late Cambrian.

Proc Natl Acad Sci U S A 2011 Mar 22;108(10):3876-81. Epub 2011 Feb 22.

School of Earth Sciences, Ohio State University, Columbus, OH 43210, USA.

A rise in atmospheric O(2) has been linked to the Cambrian explosion of life. For the plankton and animal radiation that began some 40 million yr later and continued through much of the Ordovician (Great Ordovician Biodiversification Event), the search for an environmental trigger(s) has remained elusive. Here we present a carbon and sulfur isotope mass balance model for the latest Cambrian time interval spanning the globally recognized Steptoean Positive Carbon Isotope Excursion (SPICE) that indicates a major increase in atmospheric O(2). We estimate that this organic carbon and pyrite burial event added approximately 19 × 10(18) moles of O(2) to the atmosphere (i.e., equal to change from an initial starting point for O(2) between 10-18% to a peak of 20-28% O(2)) beginning at approximately 500 million years. We further report on new paired carbon isotope results from carbonate and organic matter through the SPICE in North America, Australia, and China that reveal an approximately 2‰ increase in biological fractionation, also consistent with a major increase in atmospheric O(2). The SPICE is followed by an increase in plankton diversity that may relate to changes in macro- and micronutrient abundances in increasingly oxic marine environments, representing a critical initial step in the trophic chain. Ecologically diverse plankton groups could provide new food sources for an animal biota expanding into progressively more ventilated marine habitats during the Ordovician, ultimately establishing complex ecosystems that are a hallmark of the Great Ordovician Biodiversification Event.
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http://dx.doi.org/10.1073/pnas.1011836108DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3053972PMC
March 2011

Geochemical evidence for widespread euxinia in the later Cambrian ocean.

Nature 2011 Jan;469(7328):80-3

Department of Earth Sciences, University of California, 900 University Avenue, Riverside, California 92521, USA.

Widespread anoxia in the ocean is frequently invoked as a primary driver of mass extinction as well as a long-term inhibitor of evolutionary radiation on early Earth. In recent biogeochemical studies it has been hypothesized that oxygen deficiency was widespread in subsurface water masses of later Cambrian oceans, possibly influencing evolutionary events during this time. Physical evidence of widespread anoxia in Cambrian oceans has remained elusive and thus its potential relationship to the palaeontological record remains largely unexplored. Here we present sulphur isotope records from six globally distributed stratigraphic sections of later Cambrian marine rocks (about 499 million years old). We find a positive sulphur isotope excursion in phase with the Steptoean Positive Carbon Isotope Excursion (SPICE), a large and rapid excursion in the marine carbon isotope record, which is thought to be indicative of a global carbon cycle perturbation. Numerical box modelling of the paired carbon sulphur isotope data indicates that these isotope shifts reflect transient increases in the burial of organic carbon and pyrite sulphur in sediments deposited under large-scale anoxic and sulphidic (euxinic) conditions. Independently, molybdenum abundances in a coeval black shale point convincingly to the transient spread of anoxia. These results identify the SPICE interval as the best characterized ocean anoxic event in the pre-Mesozoic ocean and an extreme example of oxygen deficiency in the later Cambrian ocean. Thus, a redox structure similar to those in Proterozoic oceans may have persisted or returned in the oceans of the early Phanerozoic eon. Indeed, the environmental challenges presented by widespread anoxia may have been a prevalent if not dominant influence on animal evolution in Cambrian oceans.
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http://dx.doi.org/10.1038/nature09700DOI Listing
January 2011

Geochemistry. Earth's second wind.

Authors:
Lee R Kump

Science 2010 Dec;330(6010):1490-1

Department of Geosciences, Pennsylvania State University, University Park, PA 16802, USA.

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http://dx.doi.org/10.1126/science.1199919DOI Listing
December 2010

Atmospheric science. Tipping pointedly colder.

Authors:
Lee R Kump

Science 2009 Feb;323(5918):1175-6

Department of Geosciences and Earth and Environmental Systems Institute, Pennsylvania State University, University Park, PA 16802, USA.

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http://dx.doi.org/10.1126/science.1170613DOI Listing
February 2009

Amplification of Cretaceous warmth by biological cloud feedbacks.

Science 2008 Apr;320(5873):195

Department of Geosciences and Earth System Science Center, Pennsylvania State University, University Park, PA 16802, USA.

The extreme warmth of particular intervals of geologic history cannot be simulated with climate models, which are constrained by the geologic proxy record to relatively modest increases in atmospheric carbon dioxide levels. Recent recognition that biological productivity controls the abundance of cloud condensation nuclei (CCN) in the unpolluted atmosphere provides a solution to this problem. Our climate simulations show that reduced biological productivity (low CCN abundance) provides a substantial amplification of CO2-induced warming by reducing cloud lifetimes and reflectivity. If the stress of elevated temperatures did indeed suppress marine and terrestrial ecosystems during these times, this long-standing climate enigma may be solved.
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http://dx.doi.org/10.1126/science.1153883DOI Listing
April 2008

The rise of atmospheric oxygen.

Authors:
Lee R Kump

Nature 2008 Jan;451(7176):277-8

Department of Geosciences, Pennsylvania State University, 535 Deike Building, University Park, Pennsylvania 16802, USA.

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http://dx.doi.org/10.1038/nature06587DOI Listing
January 2008

Increased subaerial volcanism and the rise of atmospheric oxygen 2.5 billion years ago.

Nature 2007 Aug;448(7157):1033-6

NASA Astrobiology Institute and Department of Geosciences, Pennsylvania State University, 535 Deike Building, University Park, Pennsylvania 16802, USA.

The hypothesis that the establishment of a permanently oxygenated atmosphere at the Archaean-Proterozoic transition (approximately 2.5 billion years ago) occurred when oxygen-producing cyanobacteria evolved is contradicted by biomarker evidence for their presence in rocks 200 million years older. To sustain vanishingly low oxygen levels despite near-modern rates of oxygen production from approximately 2.7-2.5 billion years ago thus requires that oxygen sinks must have been much larger than they are now. Here we propose that the rise of atmospheric oxygen occurred because the predominant sink for oxygen in the Archaean era-enhanced submarine volcanism-was abruptly and permanently diminished during the Archaean-Proterozoic transition. Observations are consistent with the corollary that subaerial volcanism only became widespread after a major tectonic episode of continental stabilization at the beginning of the Proterozoic. Submarine volcanoes are more reducing than subaerial volcanoes, so a shift from predominantly submarine to a mix of subaerial and submarine volcanism more similar to that observed today would have reduced the overall sink for oxygen and led to the rise of atmospheric oxygen.
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http://dx.doi.org/10.1038/nature06058DOI Listing
August 2007

Palaeoclimate: foreshadowing the glacial era.

Authors:
Lee R Kump

Nature 2005 Jul;436(7049):333-4

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http://dx.doi.org/10.1038/436333aDOI Listing
July 2005

Reducing uncertainty about carbon dioxide as a climate driver.

Authors:
Lee R Kump

Nature 2002 Sep;419(6903):188-90

Department of Geosciences and NASA Astrobiology Institute, The Pennsylvania State University, University Park, 16802, USA.

The lack of an adequate ancient analogue for future climates means that we ultimately must use and trust climate models, evaluated against modern observation and our best geologic records of warm and cold climates of the past. Armed with an elevated confidence in the models, we will then be able to make reliable predictions of the Earth's response to our risky experiment with the climate system.
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http://dx.doi.org/10.1038/nature01087DOI Listing
September 2002