Reexamination of 2.5-Ga whiff' of oxygen interval points to anoxic ocean before GOE

Article Multidisciplinary Sciences

Reexamination of 2.5-Ga whiff of oxygen interval points to anoxic ocean before GOE

Sarah P. Slotznick et al.

Summary: Based on chemical datasets and mineral characteristics, it is suggested that oxygen levels in the environment were very low approximately 150 million years before the Great Oxygenation Event (GOE), and the presence of certain redox-sensitive elements actually developed during postdepositional events.

SCIENCE ADVANCES (2022)

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Review Astronomy & Astrophysics

Earth's First Redox Revolution

Chadlin M. Ostrander et al.

Summary: The rise of oxygen on Earth was a significant event in Earth's history, with evidence suggesting multiple oxygenation events before the Great Oxidation Event. Understanding the timing and tempo of this revolution is crucial for unraveling the drivers of Earth's evolution.

ANNUAL REVIEW OF EARTH AND PLANETARY SCIENCES, VOL 49, 2021 (2021)

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Article Biology

The Archean origin of oxygenic photosynthesis and extant cyanobacterial lineages

G. P. Fournier et al.

Summary: The coevolution of oxygenic phototrophs and the environment is recorded in modern organisms' genomes, geochemical signals, and Proterozoic microfossils. Various interpretations of the fossil record and incorporation of relative dating from horizontal gene transfers improve the precision of age estimates, supporting an Archean origin of crown-group Cyanobacteria and evolution of oxygenic photosynthesis centuries before the Great Oxygenation Event.

PROCEEDINGS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES (2021)

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Article Geology

Molybdenum isotope systematics of subduction-related magmas from the Zhongdian region: Assessing the Mo fractionation behavior in magmatic-hydrothermal processes

De-Xin Kong et al.

Summary: This study investigates the behavior of molybdenum isotopes in magmatic-hydrothermal systems in the southeastern Tibetan Plateau of China. The results show that the molybdenum isotopic compositions in the Pulang deposit differ from those in the Disuga and Lannitang areas, with pyrite having higher values than chalcopyrite and molybdenite. The presence of micron-scale molybdenite inclusions in chalcopyrite from the Pulang deposit may contribute to the comparable Mo isotope values between the two minerals.

ORE GEOLOGY REVIEWS (2021)

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Article Geochemistry & Geophysics

Molybdenum isotope fractionation at upper-crustal magmatic-hydrothermal conditions

Anne K. C. Kaufmann et al.

Summary: The study focuses on the comprehensive dataset documenting the late stage magmatic-hydrothermal evolution of Mo isotope systematics in miarolitic cavities and their host granite from the Torres del Paine laccolith in Chile. Mo isotopic compositions were measured for different types of samples, showing variability in delta 98MoSRM3134 values. The Mo isotopic signature of magmatic fluids and hydrothermal minerals coexisting in the sampled cavities exhibit significant isotopic differences, providing insights into the fractionation processes during magmatic-hydrothermal stages at elevated temperatures.

CHEMICAL GEOLOGY (2021)

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Article Multidisciplinary Sciences

Reconciling evidence of oxidative weathering and atmospheric anoxia on Archean Earth

Aleisha C. Johnson et al.

Summary: Evidence suggests the presence of oxygen production and accumulation on Earth's surface before the Great Oxidation Event, but quantifying early oxygen levels has proven challenging. By analyzing the distribution and isotopic composition of molybdenum in ancient sedimentary records, researchers have been able to calculate lower limits for atmospheric oxygen levels and production fluxes during the Archean era. The findings indicate that oxygen levels in the Archean were extremely low compared to a lifeless Earth system, highlighting the complexity of early atmospheric oxygen dynamics.

SCIENCE ADVANCES (2021)

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Article Multidisciplinary Sciences

Mercury abundance and isotopic composition indicate subaerial volcanism prior to the end-Archean whiff of oxygen

Jana Meixnerova et al.

Summary: Multiple transient episodes of oxygenation occurred in Earth's early atmosphere before the Great Oxidation Event 2.4 billion years ago. Research suggests that the whiff of O-2 was preceded by subaerial volcanism, leading to temporary accumulation of oxygen. These events were triggered by diminished volcanic O-2 sinks and enhanced nutrient supply to the ocean from weathering of volcanic rocks.

PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA (2021)

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Article Multidisciplinary Sciences

Timing the evolution of antioxidant enzymes in cyanobacteria

Joanne S. Boden et al.

Summary: Research shows that ancestral cyanobacteria had the ability to deal with oxidative stress as early as the Archaean, gradually evolving more cofactors. The evolutionary history of metalloenzymes reveals how early cyanobacteria managed reactive oxygen species.

NATURE COMMUNICATIONS (2021)

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Article Geochemistry & Geophysics