Trace sulfate in mid-Proterozoic carbonates and the sulfur isotope record of biospheric evolution

Gellatly, Anne M.; Lyons, Timothy W.

doi:10.1016/j.gca.2005.01.019

Cited by 101 publications

(73 citation statements)

References 105 publications

(214 reference statements)

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“…In fact, the scarcity of steroids and 2-methylhopanoids in samples with most abundant biomarkers for phototrophic sulfur bacteria is also consistent with the highly euxinic conditions they require. The extent to which this scenario reflects global versus local conditions awaits further elucidation, but it is consistent with geochemical proxies for oceanic redox conditions, observed globally (e.g., Logan et al 1995;Arnold et al 2003;Shen et al 2003;Gellatly and Lyons 2005).…”

Section: Proterozoic Molecular Biomarkerssupporting

confidence: 67%

Molecular biogeochemistry of modern and ancient marine microbes

Waldbauer¹

2010

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Biological activity has shaped the surface of the earth in numerous ways, but life's most pervasive and persistent global impact has been the secular oxidation of the surface environment. Through primary production -the biochemical reduction of carbon dioxide to synthesize biomass -large amounts of oxidants such as molecular oxygen, sulfate and ferric iron have accumulated in the ocean, atmosphere and crust, fundamentally altering the chemical environment of the earth's surface. This thesis addresses aspects of the role of marine microorganisms in driving this process. In the first section of the thesis, biomarkers (hydrocarbon molecular fossils) are used to investigate the early history of microbial diversity and biogeochemistry. Molecular fossils from the Transvaal Supergroup, South Africa, document the presence in the oceans of a diverse microbiota, including eukaryotes, as well as oxygenic photosynthesis and aerobic biochemistry, by ca. 2.7Ga. Experimental study of the oxygen requirements of steroid biosynthesis suggests that sterane biomarkers in late Archean rocks are consistent with the persistence of microaerobic surface ocean environments long before the initial oxygenation of the atmosphere. In the second part, using Prochlorococcus (a marine cyanobacterium that is the most abundant primary producer on earth today) as a model system, we explored how microbes use the limited nutrient resources available in the marine environment to make the protein catalysts that enable primary production. Quantification of the Prochlorococcus proteome over the diel cell-division cycle reveals that protein abundances are distinct from transcript-level dynamics, and that small temporal shifts in enzyme levels can redirect metabolic fluxes. This thesis illustrates how molecular techniques can contribute to a systems-level understanding of biogeochemical processes, which will aid in reconstructing the past of, and predicting future change in, earth surface environments. ACKNOWLEDGMENTSI have incurred many debts of gratitude and appreciation over the course of this work. None are greater than those to my advisors, Penny Chisholm and Roger Summons, who allowed and enabled me to pursue such a wide range of scientific interests and offered their help and advice every step of the way. I have been very lucky to have had the chance to learn so much during my Ph.D., and none of that would have been possible without their guidance and support.I have also had the great fortune to know and work with all the members of the Chisholm and Summons labs, who have made this an enjoyable and rewarding place to be. I am especially grateful to Laura Sherman for her skill and dedication in analyzing biomarkers in the late Archean cores -it was truly getting blood from a stone. I was lucky to collaborate with Sébastien Rodrigue, whose expertise and collegiality made the diel experiment even more fruitful than I could have hoped. IntroductionThe coevolution of life and earth surface environments is central to the history and functionin...

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Section: Proterozoic Molecular Biomarkerssupporting

confidence: 67%

Molecular biogeochemistry of modern and ancient marine microbes

Waldbauer¹

2010

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“…Evidence for low sulfate concentrations-on the order of <5% to 15% of the present-day value of 28-29 mM for the mid-Proterozoic-is seen in the abundance of 34 S-enriched pyrite deposited during this interval (Shen et al, 2002(Shen et al, , 2003; this report) and in the rapid and large-magnitude S isotope variability observed stratigraphically in many Proterozoic sulfi de-and sulfate-bearing sedimentary sequences (Luepke and Lyons, 2001;Hurtgen et al, 2002Hurtgen et al, , 2004Kah et al, 2004;Gellatly and Lyons, 2005). During the Phanerozoic, by contrast, δ 34 S fl uctuations of similar magnitude are described by Claypool et al (1980) for time periods of 10 7 to 10 8 years.…”

Section: Sulfur Geochemical Records Of Precambrian Oceanatmosphere Comentioning

confidence: 60%

“…sulfate (CAS) (Fig. 5) (Hurtgen et al, 2002(Hurtgen et al, , 2004Kah et al, 2004;Gellatly and Lyons, 2005). In contrast to earlier arguments for local controls on the patterns observed in the Belt basin (Lyons et al, 2000;Luepke and Lyons, 2001), the spatially and temporally widespread nature of this style of isotopic variability now suggests a global control.…”

Section: Implications Stratigraphic Isotope Trendsmentioning

confidence: 78%

Proterozoic sedimentary exhalative (SEDEX) deposits and links to evolving global ocean chemistry

Lyons¹,

Gellatly²,

McGoldrick³

et al. 2006

Evolution of Early Earth's Atmosphere, Hydrosphere, and Biosphere - Constraints From Ore Deposits

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Sedimentary exhalative (SEDEX) Zn-Pb-sulfi de mineralization fi rst occurred on a large scale during the late Paleoproterozoic. Metal sulfi des in most Proterozoic deposits have yielded broad ranges of predominantly positive δ 34 S values traditionally attributed to bacterial sulfate reduction. Heavy isotopic signatures are often ascribed to fractionation within closed or partly closed local reservoirs isolated from the global ocean by rifting before, during, and after the formation of Rodinia. Although such conditions likely played a central role, we argue here that the fi rst appearance of signifi cant SEDEX mineralization during the Proterozoic and the isotopic properties of those deposits are also strongly coupled to temporal evolution of the amount of sulfate in seawater.The ubiquity of 34 S-enriched sulfi de in ore bodies and shales and the widespread stratigraphic patterns of rapid δ 34 S variability expressed in both sulfate and sulfi de data are among the principal evidence for global seawater sulfate that was increasing during the Proterozoic but remained substantially lower than today. Because sulfate is produced mostly through weathering of the continents in the presence of oxygen, low Proterozoic concentrations imply that levels of atmospheric oxygen fell between the abundances of the Phanerozoic and the defi ciencies of the Archean, which are also indicated by the Precambrian sulfur isotope record. Given the limited availability of atmospheric oxygen, deep-water anoxia may have persisted well into the Proterozoic in the presence of a growing sulfate reservoir, which promoted prevalent euxinia. Collectively, these observations suggest that the mid-Proterozoic maximum in SEDEX mineralization and the absence of Archean deposits refl ect a critical threshold in the accumulation of oceanic sulfate and thus sulfi de within anoxic bottom waters and pore fl uids-conditions that favored both the production and preservation of sulfi de mineralization at or just below the seafl oor. Consistent with these evolving global conditions, the appearance of voluminous SEDEX mineralization ca. 1800 Ma coincides generally with the disappearance of banded iron formations-marking the transition from an early iron-dominated ocean to one more strongly infl uenced by sulfi de availability. 170 T.W. Lyons et al.

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“…Carbonates deposited during the final stage of the LE with δ 13 C ≤ 5‰ in the Mistassini Basin, Quebec, show lower CAS concentrations compared to those deposited during the peak of the excursion (with an average of 46 ppm; AE14 ppm, 1 SD). Similarly, Lomagundi CAS concentrations are higher than those typical of carbonates (primarily dolomites) deposited during the later Paleoproterozoic (30,31), Mesoproterozoic (30,31), and Neoproterozoic (32) at times when the seawater sulfate reservoir was significantly smaller than that of modern and Phanerozoic oceans (32). Lomagundi CAS concentrations are comparable to those of Paleozoic micritic carbonates (SI Text) (33).…”

Section: Methodsmentioning

confidence: 92%

Sulfur record of rising and falling marine oxygen and sulfate levels during the Lomagundi event

Planavsky

Bekker

Hofmann

et al. 2012

Proc. Natl. Acad. Sci. U.S.A.

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187

130

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Carbonates from approximately 2.3-2.1 billion years ago show markedly positive δ 13 C values commonly reaching and sometimes exceeding þ10‰. Traditional interpretation of these positive δ 13 C values favors greatly enhanced organic carbon burial on a global scale, although other researchers have invoked widespread methanogenesis within the sediments. To resolve between these competing models and, more generally, among the mechanisms behind Earth's most dramatic carbon isotope event, we obtained coupled stable isotope data for carbonate carbon and carbonate-associated sulfate (CAS). CAS from the Lomagundi interval shows a narrow range of δ 34 S values and concentrations much like those of Phanerozoic and modern marine carbonate rocks. The δ 34 S values are a close match to those of coeval sulfate evaporites and likely reflect seawater composition. These observations are inconsistent with the idea of diagenetic carbonate formation in the methanic zone. Toward the end of the carbon isotope excursion there is an increase in the δ 34 S values of CAS. We propose that these trends in C and S isotope values track the isotopic evolution of seawater sulfate and reflect an increase in pyrite burial and a crash in the marine sulfate reservoir during ocean deoxygenation in the waning stages of the positive carbon isotope excursion.Lomagundi excursion | Great Oxidation Event | Precambrian

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Trace sulfate in mid-Proterozoic carbonates and the sulfur isotope record of biospheric evolution

Cited by 101 publications

References 105 publications

Molecular biogeochemistry of modern and ancient marine microbes

Molecular biogeochemistry of modern and ancient marine microbes

Proterozoic sedimentary exhalative (SEDEX) deposits and links to evolving global ocean chemistry

Sulfur record of rising and falling marine oxygen and sulfate levels during the Lomagundi event

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