Abstract. 

"The Rare Earth Element (REE) systematics of the post-Marinoan cap dolostones reflect the marine redox conditions and chemistry in the immediate aftermath of the snowball Earth. Rare earth elements and yttrium (REY) compositions in the Doushantuo cap dolostones that directly overlie Nantuo glacial diamictites in south China are determined from the inner shelf to the slope. In general, shale-normalized REY patterns (REYSN) of the cap dolostones show significant fractionations that are characterized by light REE depletion, slight middle REE enrichment relative to the light and heavy REEs, positive Eu anomalies, and slightly super-chondritic Y/Ho ratios. [...]".

Source: Science Direct
Authors: Min Ren & Ruifan Li
DOI: https://doi.org/10.1016/j.sedgeo.2023.106343

Read the full article here.

Abstract. 

"Early animals experienced multiple-phase radiations and extinctions from the late Ediacaran to early Cambrian. Oxygen likely played an important role in these evolutionary events, but detailed marine redox evolution during this period remains highly debated. The emerging vanadium (V) isotope system can better capture short-term perturbations to global ocean redox conditions. In this study, we analyzed V isotope compositions [...]".

Source: Science Direct 
Authors: Wei Wei et al.
DOI: https://doi.org/10.1016/j.epsl.2022.117942

Read the full article here.

Abstract. 

"Accurate monitoring of the long-term trend of oxygen content at global scale requires a better knowledge of the regional oxygen variability at interannual to decadal time scale. Here, we combined the Argo dataset and repeated ship-based sections to investigate the drivers of the oxygen variability in the North Atlantic Ocean, a key region for the oxygen supply into the deep ocean. We focus on the Labrador Sea Water in the Irminger Sea over the period 1991–2018 and we show that the oxygen solubility explains less than a third of the oxygen variability. [...]".

Source: Nature
Authors: Charlène Feucher et al.
DOI: https://doi.org/10.1038/s43247-022-00570-y

Read the full article here.

Abstract.

"Oxygen in the ocean has essential ecological and climatic functions, and can be an important indicator of deep-ocean ventilation and carbon storage. Previous studies are divided on whether the subsurface North Atlantic, which today is well-oxygenated, had higher or lower oxygen levels during the Last Glacial Maximum (LGM). Crucially, the limited number of previous reconstructions precludes any conclusions regarding basin-wide patterns in past changes in oxygenation. [...]".

Source: Science Direct 
Authors: Yuxin Zhou & Jerry F. McManus
DOI: https://doi.org/10.1016/j.quascirev.2022.107914

Read the full article here.

Abstract. 

"The evolution of global ocean oxygenation during the early Cambrian remains highly controversial, making it difficult to evaluate how environmental triggers play a role in controlling the organic matter (OM) accumulation in black shales. In this study, an integrated approach, including total organic carbon (TOC) content, major and trace element geochemistry, and microscope images, was systematically conducted in a continuous core well that penetrated through the Lower Cambrian Yanjiahe (YJH)–Shuijingtuo (SJT, subdivided into SM Ⅰ, SM Ⅱ, SM Ⅲ, and SM Ⅳ members) successions (∼541-514Ma) at the Three Gorges area [...]".

Source: Science Direct 
Authors: Yu Zhang et al.
DOI: https://doi.org/10.1016/j.marpetgeo.2022.105958

Read the full article here.

Abstract. 

"Variations in ocean oxygen levels during Earth’s history have been linked to evolution and mass extinctions. Simulations now suggest that the configuration of the continents has a substantial impact on ocean oxygenation. [...]". 

Source: Nature
Authors: Katrin J. Meissner & Andreas Oschlies
DOI: https://doi.org/10.1038/d41586-022-02187-9

Read the full article here.

Abstract. 

"Modern anoxic marine sediments release phosphorus (P) to seawater, driving feedbacks at multiple timescales. On sub-Myr timescales, anoxic P regeneration amplifies ocean deoxygenation; on multi-Myr timescales, it stabilizes atmospheric O2. Some authors have extended this thinking to the Precambrian: by analogy, widespread ocean anoxia would imply extensive P regeneration from sediments. However, this neglects the role of sulfate in P regeneration. [...]".

Source: Geophysical Research Letters
Authors: Michael A. Kipp
DOI: https://doi.org/10.1029/2022GL099817

Read the full article here.

Abstract. 

"Marine ironstone is a Phanerozoic biochemical sedimentary rock that contains abundant primary iron. Although rare, ironstone is conspicuous in the Paleozoic sedimentary record. Its iron source remains contentious, with traditional models invoking a continentally derived source. Increasing sedimentologic evidence suggests that many Paleozoic ironstones formed along favourably oriented continental margins where coastal upwelling delivered ferruginous waters, with the postulated source of iron being deep-ocean hydrothermal fluids. [...]".

Source: Science Direct 
Authors: Edward J. Matheson et al.
DOI: https://doi.org/10.1016/j.epsl.2022.117715

Read the full article here.

Abstract. 

"The early evolutionary and much of the extinction history of marine animals is thought to be driven by changes in dissolved oxygen concentrations ([O2]) in the ocean. In turn, [O2] is widely assumed to be dominated by the geological history of atmospheric oxygen (pO2). Here, by contrast, we show by means of a series of Earth system model experiments how continental rearrangement during the Phanerozoic Eon drives profound variations in ocean oxygenation and induces a fundamental decoupling in time between upper-ocean and benthic [O2]. [...]". 

Source: Nature
Authors: Alexandre Pohl et al.
DOI: https://doi.org/10.1038/s41586-022-05018-z 

Read the full article here.

Abstract.

"This study addresses marine palaeoredox conditions of the mid-Neoproterozoic by analysing the Mo isotope, trace element, and U-Th-Pb isotope compositions of shallow water microbial carbonate, deep water pelagic carbonate, and shale from the Stone Knife Formation (SKF) in NW Canada. The U-Th-Pb isotope SKF systematics of reef microbialite carbonates, and the moderately expressed negative Ce anomalies are consistent with the presence of dissolved O2 in the surface waters. [...]".

Source: Science Direct 
Authors: Edel Mary O'Sullivan et al.
DOI: https://doi.org/10.1016/j.precamres.2022.106760

Read the full article here.