Nitrogen isotope constraints on the early Ediacaran ocean redox structure

Wang, Xinqiang; Jiang, Ganqing; Shi, Xiaoying; Peng, Yongbo; Morales, Deborah C.

doi:10.1016/j.gca.2018.08.034

Cited by 60 publications

(26 citation statements)

References 117 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Others have argued primary production was instead phosphorus-limited, either due to the scavenging of phosphate from riverine inputs and/or directly from the water column by abundant Fe 2+ ions [98][99][100][101], or due to organic phosphate remineralization being limited by electron acceptors in the absence of O2 [102]. Both sets of proposals are consistent with observations that post-Neoproterozoic oceans saw significant increases in the levels of both phosphate [101,103] and molybdenum [94,104], as well as isotopic shifts of sedimentary nitrogen that suggest the onset of a stable oceanic nitrate pool [105][106][107][108][109][110][111]. Such negative feedbacks (Fig.…”

supporting

confidence: 80%

See 1 more Smart Citation

Evolution of cellular metabolism and the rise of a globally productive biosphere

Braakman

2019

Preprint

View full text Add to dashboard Cite

The metabolic processes of cells and chemical processes in the environment are fundamentally intertwined and have evolved in concert over billions of years. Here I argue that intrinsic properties of cellular metabolism imposed central constraints on the historical trajectories of biopsheric productivity and atmospheric oxygenation. Photosynthesis depends on iron, but iron is highly insoluble under the aerobic conditions produced by oxygenic photosynthesis. These counteracting constraints led to two major stages of Earth oxygenation. Cyanobacterial photosynthesis drove a major biospheric expansion near the Archean-Proterozoic boundary but subsequently remained largely restricted to continental boundaries and shallow aquatic environments, where weathering inputs made iron more accessible. The anoxic deep open ocean was rich in free iron during the Proterozoic, but this iron remained effectively inaccessible since a photosynthetic expansion would have quenched its own supply. Near the Proterozoic-Phanerozoic boundary, bioenergetic innovations allowed eukaryotic photosynthesis to expand into the deep open oceans and onto the continents, where nutrients are inherently harder to come by. Key insights into the ecological rise of eukaryotic photosynthesis emerge from analyses of marine Synechococcus and Prochlorococcus, abundant marine picocyanobacteria whose ancestors colonized the oceans in the Neoproterozoic. The reconstructed evolution of Prochlorococcus reveals a sequence of innovations that ultimately produced a form of photosynthesis more like that of green plant cells than other cyanobacteria. Innovations increased the energy flux of cells, thereby enhancing their ability to acquire sparse nutrients, and as by-product also increased the production of organic carbon waste. Some of these organic waste products in turn had the ability to chelate iron and make it bioavailable, thereby indirectly pushing the oceans through a transition from an anoxic state rich in free iron to an oxygenated state with organic carbon-bound iron. The periods of Earth history around cyanobacteria- and eukaryote-driven biospheric expansions share several other parallels. Both epochs have also been linked to major carbon cycle perturbations and global glaciations, as well as changes in the nature of mantle convection and plate tectonics. This suggests the dynamics of life and Earth are intimately intertwined across many levels and that general principles governed Neoarchean and Neoproterozoic transitions in these coupled dynamics.

show abstract

supporting

confidence: 80%

“…Fe 3+ -DOC toward modern ocean values in the Neoproterozoic, indicating the onset of a stable oceanic nitrate pool [105][106][107][108][109][110][111]. Convergent biogeochemical evolution in the oceans and on the continents There are a wide range of parallels between the rise of marine picocyanobacteria and the rise of land plants.…”

Section: Fe 3+mentioning

confidence: 99%

Evolution of cellular metabolism and the rise of a globally productive biosphere

Braakman

2019

Preprint

View full text Add to dashboard Cite

show abstract

“…Denitrification and anammox preferentially release light 14 N to the atmosphere, rendering the residual nitrate pool in the ocean enriched in heavy 15 N, which, in most cases, would be quantitatively assimilated by photosynthetic organisms. These two processes are responsible for the positive δ 15 N values in modern seawater and sediments (Sigman et al, 2009; Tesdal et al, 2013) and have been widely used to interpret positive δ 15 N values in the geological record (Ader et al, 2014; Algeo et al, 2014; Garvin et al, 2009; Godfrey & Falkowski, 2009; Kipp et al, 2018; Koehler et al, 2017; Luo et al, 2018; Stüeken, 2013; Wang et al, 2013; Wang, Jiang, et al, 2018; Wang, Ling, et al, 2018; Zerkle et al, 2017). It is thus reasonable to infer that they also took effect during the deposition of the Gaoyuzhuang Member III.…”

Section: Discussionmentioning

confidence: 99%

Coupled Nitrate and Phosphate Availability Facilitated the Expansion of Eukaryotic Life at Circa 1.56 Ga

Wang

Shi

et al. 2020

JGR Biogeosciences

Self Cite

View full text Add to dashboard Cite

Recent geochemical and paleontological studies have revealed a significant ocean oxygenation episode and an evolutionary leap of eukaryotes at the onset of the Mesoproterozoic. However, the potential role of nitrogen availability and its interaction with other nutrients in these environmental and biological events have not been investigated. Here we present an integrated study of nitrogen isotopes (δ 15 N), organic carbon isotopes (δ 13 C org ), and major and trace element concentrations from Member III of the Gaoyuzhuang Formation in the central North China Craton where the earliest macroscopic multicellular eukaryotic fossils were reported. The enrichments of redox-sensitive elements (Mo, U, and V), coupled with Mo-U covariations, δ 13 C org , and I/(Ca + Mg), indicate that the Gaoyuzhuang Member III in the study area was deposited in largely suboxic-anoxic environments with ephemeral occurrences of euxinia. These data reinforce previous inferences of a strongly redox stratified ocean during the early Mesoproterozoic, but a pulsed oxygenation event may have resulted in deepening of the chemocline. The high δ 15 N values from the study section are interpreted as a result of aerobic N cycling and the presence of a fairly stable nitrate pool in the surface oxic layer, possibly due to the combined effects of oxygenation and low primary productivity. Increased availability of nitrate could have contributed to the expansion of eukaryotic life at this time. However, our data also suggest that nitrate alone was not the only trigger. Instead, this evolutionary leap was likely facilitated by multiple environmental factors, including a rise in O 2 levels and increasing supplies of phosphorus and other bio-essential trace elements.Plain Language Summary The oldest macroscopic eukaryotes (algae) first appeared in ancient oceans about 1.56 billion years ago. Before that, only simple and microscopic fossils have been discovered. The reason behind this evolutionary leap is, however, still puzzling scientists. Here we use multiple proxies to study the change of nutrient and oxygen levels during this critical period. Our results demonstrate the availability of the nutrient nitrogen (in form of nitrate) in the oxic surface ocean owing largely to restrictive consumption by organic carbon decomposition, providing favorable N substance for bio-utilization. Furthermore, we also found evidence for the joint increase of O 2 level, seawater phosphorus, and some bio-essential trace elements along with the occurrence of these earliest algae. Our study provides important clues for untangling the triggers of biological innovation at circa 1.56 Ga.

show abstract

“…Normal marine production is typical of a state of equilibrium among nitrate assimilation, N2 fixation and denitrification, achieving near modern oceanic values in the range of +2‰ to +9‰ (Cremonese et al, 2013;Kikumoto et al, 2014;Wang et al, 2017Wang et al, , 2018. The δ 15 N values from the Wangjiapeng section are mostly scattered from +3‰ to +9‰ (Figure 6), suggestive of typical modern oceanic values.…”

Section: Genesis Of En3mentioning

confidence: 92%

“…Carbon isotope stratigraphy combined with strontium and nitrogen isotopic stratigraphy, sequence stratigraphy and redox sensitive elements such as Fe and Mn has helped to clarify some problematic correlations of Ediacaran sedimentary successions and the origin of negative δ 13 Ccarb excursions as well as recover redox conditions of ancient seawater, although in some sections correlations have been difficult to establish due to spatially limited outcrops, poor constraints on bathymetry-dependent facies variations, and low sampling resolution (Yang et al, 1999;Sawaki et al, 2010;Jiang et al, 2007Jiang et al, , 2011Zhu et al, 2013;Cremonese et al, 2013;Kikumoto et al, 2014;An et al, 2015;Cui et al, 2015;Zhou et al, 2017;Wang et al, 2018). As a result, the origin and timing of both EN2 and EN3, and their chronological order with respect to Ediacaran glaciation, remains ambiguous, which has led to the proposal of two possible models for Ediacaran subdivisions and correlation (Xiao et al, 2016).…”

Section: Introductionmentioning

confidence: 99%

An integrated chemostratigraphic (δ13C-δ18O-87Sr/86Sr-δ15N) study of the Doushantuo Formation in western Hubei Province, South China

Zhang

Sano

Yahagi

et al. 2019

Precambrian Research

View full text Add to dashboard Cite

High-resolution isotopic analyses were conducted on core samples from the Ediacaran Doushantuo Formation at the Wangjiapeng section, western Hubei Province in South China, whereby two laterally traceable, negative δ 13 Ccarb excursions (EN1 and EN3) were recognized. The magnitude and duration of these excursions permit intra-basinal and inter-basinal correlation, which indicates that they probably represent a global change in seawater composition. The occurrence of decoupled δ 13 Ccar-δ 13 Corg with almost invariable δ 13 Corg values at Wangjiapeng, Zhongling, Yangjiaping sections is consistent with remineralization of a dissolved organic carbon (DOC) pool by means of sulfate reduction, as recorded in EN3. The synchronous presence of EN3, a shift to higher 87 Sr/ 86 Sr and decrease of Mn and Fe contents and δ 15 N values together points to a glacial influence whereby oxygenation and remineralization of reduced carbon produced 13 C-depleted DIC. Glaciations cause a decrease in sea level, which itself leads to increased continental shelf area to be exposed to surface weathering, and ultimately to enhanced delivery of radiogenic 87 Sr. The increase of 87 Sr/ 86 Sr ratios, sulfate and phosphate are consequences of surface runoff into oceanic environments and such perturbations induce biogeochemical changes.

show abstract

Nitrogen isotope constraints on the early Ediacaran ocean redox structure

Cited by 60 publications

References 117 publications

Evolution of cellular metabolism and the rise of a globally productive biosphere

Evolution of cellular metabolism and the rise of a globally productive biosphere

Coupled Nitrate and Phosphate Availability Facilitated the Expansion of Eukaryotic Life at Circa 1.56 Ga

An integrated chemostratigraphic (δ13C-δ18O-87Sr/86Sr-δ15N) study of the Doushantuo Formation in western Hubei Province, South China

Contact Info

Product

Resources

About