Controls of eustasy and diagenesis on the 238U/235U of carbonates and evolution of the seawater (234U/238U) during the last 1.4 Myr

Tissot, F. L. H.; Chen, Cindy; Go, B. M.; Naziemiec, Magdalena; Healy, G.; Bekker, Andrey; Swart, Peter K.; Dauphas, N.

doi:10.1016/j.gca.2018.08.022

Cited by 80 publications

(102 citation statements)

References 128 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Romaniello et al () observed δ 238 U changes associated with dolomitization in a modern Bahamian tidal pond, as reflected in a strong correlation of δ 238 U with Mg/Ca ( R 2 = .96, p < .001). However, subsequent work by Chen et al () and Tissot et al (), who revisited the dolomitization question with a larger sample set from several cores through the Bahamian carbonate platform, shows no statistically significant differences between calcite and dolomite. There are now δ 238 U data from seven widely spaced carbonate sections spanning the Permian–Triassic boundary [the Dajiang (Lau et al, ), Guandao (Lau et al, ), Dawen (Brennecka et al, ), and Daxiakou (Elrick et al, ) sections in South China; the Taşkent section in Turkey (Lau et al, ); the Zal section in Iran (Zhang, Romaniello, et al, ); and the Kamura section in Japan (Zhang, Algeo, Romaniello, et al, )].…”

Section: Evidence For Primary Oceanographic Signalsmentioning

confidence: 93%

“…Modern carbonate sediments have a δ 238 U composition that is 0.2-0.4‰ higher than that of the contemporaneous seawater (0.27‰ by average; Chen et al, 2018;Romaniello et al, 2013;Tissot et al, 2018), which likely reflects incorporation of 238 Romaniello et al, 2013;Tissot et al, 2018). However, this process does not operate at greater burial depths as the mobility of U is severely restricted in anoxic porewaters, as shown by near-zero porewater U concentrations in deep Bahamian drillcores (Henderson, Slowey, & Haddad, 1999).…”

Section: Isotopic Offset Induced From Syndepositional Diagenesismentioning

confidence: 99%

“…Modern carbonate sediments have a δ 238 U composition that is 0.2–0.4‰ higher than that of the contemporaneous seawater (0.27‰ by average; Chen et al, ; Romaniello et al, ; Tissot et al, ), which likely reflects incorporation of 238 U‐enriched U(IV) from anoxic porewaters during early diagenesis or variation in porewater U‐speciation during carbonate recrystallization. Syndepositional diagenesis of carbonates occurs because shallow, relatively permeable carbonates can sequester dissolved U(VI) from the overlying oxic water via advective and diffusive transport.…”

Section: Evidence For Primary Oceanographic Signalsmentioning

confidence: 99%

“…Syndepositional diagenesis of carbonates occurs because shallow, relatively permeable carbonates can sequester dissolved U(VI) from the overlying oxic water via advective and diffusive transport. This semi‐open system behavior allows the exchange of U isotopes and can lead to slight 238 U enrichment in bulk carbonates (Chen et al, ; Romaniello et al, ; Tissot et al, ). However, this process does not operate at greater burial depths as the mobility of U is severely restricted in anoxic porewaters, as shown by near‐zero porewater U concentrations in deep Bahamian drillcores (Henderson, Slowey, & Haddad, ).…”

Section: Evidence For Primary Oceanographic Signalsmentioning

confidence: 99%

“…Thus, δ 238 U of U(VI) dissolved in seawater decreases as the global areal extent of bottom water anoxia increases (Brennecka et al, ). Marine carbonate sediments have been demonstrated to record the δ 238 U of seawater, subject to a 0.2‰–0.4‰ offset, which likely reflects incorporation of U(IV) into shallow sediments from anoxic porewaters (Chen et al, ; Romaniello, Herrmann, & Anbar, ; Tissot et al, ). Studies comparing the trends and absolute values of δ 238 U in coeval Permian–Triassic carbonate sediments from around the world have shown excellent agreement, demonstrating that carbonates may provide a robust record of variations in seawater δ 238 U (Brennecka et al, ; Elrick et al, ; Lau et al, ; Zhang, Algeo, Romaniello, et al, ; Zhang, Romaniello, et al, ).…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Global marine redox changes drove the rise and fall of the Ediacara biota

et al. 2019

View full text Add to dashboard Cite

The role of O2 in the evolution of early animals, as represented by some members of the Ediacara biota, has been heavily debated because current geochemical evidence paints a conflicting picture regarding global marine O2 levels during key intervals of the rise and fall of the Ediacara biota. Fossil evidence indicates that the diversification the Ediacara biota occurred during or shortly after the Ediacaran Shuram negative C‐isotope Excursion (SE), which is often interpreted to reflect ocean oxygenation. However, there is conflicting evidence regarding ocean oxygen levels during the SE and the middle Ediacaran Period. To help resolve this debate, we examined U isotope variations (δ238U) in three carbonate sections from South China, Siberia, and USA that record the SE. The δ238U data from all three sections are in excellent agreement and reveal the largest positive shift in δ238U ever reported in the geologic record (from ~ −0.74‰ to ~ −0.26‰). Quantitative modeling of these data suggests that the global ocean switched from a largely anoxic state (26%–100% of the seafloor overlain by anoxic waters) to near‐modern levels of ocean oxygenation during the SE. This episode of ocean oxygenation is broadly coincident with the rise of the Ediacara biota. Following this initial radiation, the Ediacara biota persisted until the terminal Ediacaran period, when recently published U isotope data indicate a return to more widespread ocean anoxia. Taken together, it appears that global marine redox changes drove the rise and fall of the Ediacara biota.

show abstract

Section: Evidence For Primary Oceanographic Signalsmentioning

confidence: 93%

Section: Isotopic Offset Induced From Syndepositional Diagenesismentioning

confidence: 99%

Section: Evidence For Primary Oceanographic Signalsmentioning

confidence: 99%

Section: Evidence For Primary Oceanographic Signalsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Global marine redox changes drove the rise and fall of the Ediacara biota

et al. 2019

View full text Add to dashboard Cite

show abstract

Assessing the Effect of Large Igneous Provinces on Global Oceanic Redox Conditions Using Non‐traditional Metal Isotopes (Molybdenum, Uranium, Thallium)

Kendall

Andersen

Owens

2021

Large Igneous Provinces

View full text Add to dashboard Cite

During the past two decades, the isotope ratios of numerous redox-sensitive metals in sedimentary archives (particularly organic-rich mudrocks, carbonates, and iron formations) have emerged as valuable tools for constraining changes in global oceanic redox conditions. The long modern ocean residence times of Mo (~440 kyr; Miller et al., 2011), U (~450 kyr; Dunk et al., 2002), and Tl (~20 kyr;Nielsen et al., 2017) relative to ocean mixing times (~1-2 kyr; Sarmiento & Gruber, 2006), together with the distinctive isotope fractionations observed for metal removal into diverse marine sinks, means that the isotopic composition of these metals can serve as global oceanic redox tracers. Redox-sensitive metal isotopes have become an attractive tool with which to place constraints on the magnitude of oceanic anoxia associated with the emplacement of LIPs. The overarching approach is to use sedimentary rocks (organic-rich mudrocks for Mo, U, and Tl; carbonates for U) to infer the isotopic composition of coeval global seawater before, during, and after LIP emplacement, and employ isotopic mass

show abstract

Marine Anoxia and Ocean Acidification During the End‐Permian Extinction

Cui

Zhang

Wang

et al. 2021

Large Igneous Provinces

View full text Add to dashboard Cite

The largest mass extinction event in the Phanerozoic, known as the end-Permian mass extinction (or EPME, ca. 252 Ma) is coincident with the main eruption phase of Siberian Traps volcanism (ca. 252 to 250 Ma), a large igneous province (LIP). This LIP is estimated to have a volume larger than 2 × 10 6 km 3 and to have released both mantle carbon dioxide (CO 2 ) through extrusions and thermogenic methane (CH 4 ) and carbon dioxide (CO 2 ) through intru sions. The climatic consequences of these greenhouse gases is detrimental to both marine and terrestrial life and may have delayed the recovery of ecosystems after the extinction. Quantitatively, the amount of CO 2 released can be estimated using global carbon (C) cycle model or plant and soil-based proxies with varying time resolution. In light of the recent advances in geochemical proxies of ocean anoxia and acidification, we review the latest uranium isotopes (δ 238 U) and calcium isotope (δ 44/40 Ca) records and Earth system modeling results to summarize the environ mental response to the forcing of increased atmospheric CO 2 concentrations. The extent of increase in oceanic anoxic area can be estimated by δ 238 U, and the δ 44/40 Ca records may be used to evaluate ocean acidification. This evidence suggests that excessive nutrient load in the ocean (decreased strength of meridional overturning circula tion) and ocean acidification in poorly buffered seawater (potentially triggered by the Siberian Traps LIP) worked together to create the most severe biological crisis and delayed recovery of life in the Earth's history.

show abstract

Controls of eustasy and diagenesis on the 238U/235U of carbonates and evolution of the seawater (234U/238U) during the last 1.4 Myr

Cited by 80 publications

References 128 publications

Global marine redox changes drove the rise and fall of the Ediacara biota

Global marine redox changes drove the rise and fall of the Ediacara biota

Assessing the Effect of Large Igneous Provinces on Global Oceanic Redox Conditions Using Non‐traditional Metal Isotopes (Molybdenum, Uranium, Thallium)

Marine Anoxia and Ocean Acidification During the End‐Permian Extinction

Contact Info

Product

Resources

About