In situ S‐isotope compositions of sulfate and sulfide from the 3.2 Ga Moodies Group, South Africa: A record of oxidative sulfur cycling

Sulfate minerals are rare in the Archean rock record and largely restricted to the occurrence of barite (BaSO4). The origin of this barite remains controversially debated. The mass‐independent fractionation of sulfur isotopes in these and other Archean sedimentary rocks suggests that photolysis of volcanic aerosols in an oxygen‐poor atmosphere played an important role in their formation. Here, we report on the multiple sulfur isotopic composition of sedimentary anhydrite in the ca. 3.22 Ga Moodies Group of the Barberton Greenstone Belt, southern Africa. Anhydrite occurs, together with barite and pyrite, in regionally traceable beds that formed in fluvial settings. Variable abundances of barite versus anhydrite reflect changes in sulfate enrichment by evaporitic concentration across orders of magnitude in an arid, nearshore terrestrial environment, periodically replenished by influxes of seawater. The multiple S‐isotope compositions of anhydrite and pyrite are consistent with microbial sulfate reduction. S‐isotope signatures in barite suggest an additional oxidative sulfate source probably derived from continental weathering of sulfide possibly enhanced by microbial sulfur oxidation. Although depositional environments of Moodies sulfate minerals differ strongly from marine barite deposits, their sulfur isotopic composition is similar and most likely reflects a primary isotopic signature. The data indicate that a constant input of small portions of oxidized sulfur from the continents into the ocean may have contributed to the observed long‐term increase in Δ33Ssulfate values through the Paleoarchean.Centre National de la Recherche ScientifiqueDeutsche ForschungsgemeinschaftH2020 European Research Counci

Multiple Sulfur Isotope Records of the 3.22 Ga Moodies Group, Barberton Greenstone Belt

Co-auteur étrangerInternational audienceThe Moodies Group, the uppermost unit in the Barberton Greenstone Belt (BGB) in SouthAfrica, is a ~3.7-km-thick coarse clastic succession accumulated on terrestrial-to-shallow marinesettings at around 3.22 Ga. The multiple sulfur isotopic composition of pyrite of Moodies intervalswas newly obtained to examine the influence of these depositional settings on the sulfur isotope record.Conglomerate and sandstone rocks were collected from three synclines north of the Inyoka Fault of thecentral BGB, namely, the Eureka, Dycedale, and Saddleback synclines. The sulfur isotopic compositionof pyrite was analyzed by Secondary Ion Mass Spectrometry (SIMS) for 6 samples from the threesynclines and by Isotope Ratio Mass Spectrometry (IR-MS) for 17 samples from a stratigraphic sectionin the Saddleback Syncline. The present results show a signal of mass-independent fractionation ofsulfur isotopes (S-MIF), although t-tests statistically demonstrated that the Moodies S-MIF signals(mostly 0% < D33S < +0.5%) are significantly small compared to the signal of the older Paleoarchean(3.6–3.2 Ga) records. These peculiar signatures might be related to initial deposition of detrital pyriteof juvenile origin from the surrounding intrusive (tonalite–trondhjemite–granodiorite; TTG) andfelsic volcanic rocks, and/or to secondary addition of hydrothermal sulfur during late metasomatism.Moreover, fast accumulation (~0.1–1 mm/year) of the Moodies sediments might have led to a reducedaccumulation of sulfur derived from an atmospheric source during their deposition. As a result, thesulfur isotopic composition of the sediments may have become susceptible to the secondary additionof metasomatic sulfur on a mass balance point of view. The sulfur isotopic composition of Moodiespyrite is similar to the composition of sulfides from nearby gold mines. It suggests that, after theMoodies deposition, metasomatic pyrite formation commonly occurred north of the Inyoka Fault inthe central BGB at 3.1–3.0 Ga

Reassessing evidence of Moon–Earth dynamics from tidal bundles at 3.2 Ga (Moodies Group, Barberton Greenstone Belt, South Africa)

Past orbital parameters of the Moon are difficult to reconstruct from geological records because relevant data sets of tidal strata are scarce or incomplete. The sole Archean data point is from the Moodies Group (ca 3.22 Ga) of the Barberton Greenstone Belt, South Africa. From the time-series analysis of tidal bundles from a well-exposed subaqueous sand wave of this unit, Eriksson and Simpson (Geology, 28, 831) suggested that the Moon’s anomalistic month at 3.2 Ga was closer to 20 days than the present 27.5 days. This is in apparent accordance with models of orbital mechanics which place the Archean Moon in a closer orbit with a shorter period, resulting in stronger tidal action. Although this study’s detailed geological mapping and section measuring of the site confirmed that the sandstone bed in question is likely a migrating dune, the presence of angular mud clasts, channel-margin slumps, laterally aggrading channel fills and bidirectional paleocurrents in overlying and underlying beds suggests that this bedform was likely located in a nearshore channel near lower-intertidal flats and subtidal estuarine bars; it thus carries risk of incomplete preservation. Repeated measurements of foreset thicknesses along the published traverse, measured perpendicular to bedding, failed to show consistent spectral peaks. Larger data sets acquired along traverses measured parallel to bedding along the 20.5 m wide exposure are affected by minor faulting, uneven outcrop weathering, changing illumination, weather, observer bias and show a low reproducibility. The most robust measurements herein confirm the periodicity peak of approximately 14 in the original data of Eriksson and Simpson (Geology, 28, 831). Because laminae may have been eroded, the measurements may represent a lower bound of about 28 lunar days per synodic month. This estimate agrees well with Earth–Moon dynamic models which consider the conservation of angular momentum and place the Archaean Moon in a lower orbit around a faster-spinning Earth

Reassessing evidence of Moon–Earth dynamics from tidal bundles at 3.2 Ga (Moodies Group, Barberton Greenstone Belt, South Africa)

Past orbital parameters of the Moon are difficult to reconstruct from geological records because relevant data sets of tidal strata are scarce or incomplete. The sole Archean data point is from the Moodies Group (ca 3.22 Ga) of the Barberton Greenstone Belt, South Africa. From the time-series analysis of tidal bundles from a well-exposed subaqueous sand wave of this unit, Eriksson and Simpson (Geology, 28, 831) suggested that the Moon’s anomalistic month at 3.2 Ga was closer to 20 days than the present 27.5 days. This is in apparent accordance with models of orbital mechanics which place the Archean Moon in a closer orbit with a shorter period, resulting in stronger tidal action. Although this study’s detailed geological mapping and section measuring of the site confirmed that the sandstone bed in question is likely a migrating dune, the presence of angular mud clasts, channel-margin slumps, laterally aggrading channel fills and bidirectional paleocurrents in overlying and underlying beds suggests that this bedform was likely located in a nearshore channel near lower-intertidal flats and subtidal estuarine bars; it thus carries risk of incomplete preservation. Repeated measurements of foreset thicknesses along the published traverse, measured perpendicular to bedding, failed to show consistent spectral peaks. Larger data sets acquired along traverses measured parallel to bedding along the 20.5 m wide exposure are affected by minor faulting, uneven outcrop weathering, changing illumination, weather, observer bias and show a low reproducibility. The most robust measurements herein confirm the periodicity peak of approximately 14 in the original data of Eriksson and Simpson (Geology, 28, 831). Because laminae may have been eroded, the measurements may represent a lower bound of about 28 lunar days per synodic month. This estimate agrees well with Earth–Moon dynamic models which consider the conservation of angular momentum and place the Archaean Moon in a lower orbit around a faster-spinning Earth

Global injury morbidity and mortality from 1990 to 2017 : results from the Global Burden of Disease Study 2017

Correction:Background Past research in population health trends has shown that injuries form a substantial burden of population health loss. Regular updates to injury burden assessments are critical. We report Global Burden of Disease (GBD) 2017 Study estimates on morbidity and mortality for all injuries. Methods We reviewed results for injuries from the GBD 2017 study. GBD 2017 measured injury-specific mortality and years of life lost (YLLs) using the Cause of Death Ensemble model. To measure non-fatal injuries, GBD 2017 modelled injury-specific incidence and converted this to prevalence and years lived with disability (YLDs). YLLs and YLDs were summed to calculate disability-adjusted life years (DALYs). Findings In 1990, there were 4 260 493 (4 085 700 to 4 396 138) injury deaths, which increased to 4 484 722 (4 332 010 to 4 585 554) deaths in 2017, while age-standardised mortality decreased from 1079 (1073 to 1086) to 738 (730 to 745) per 100 000. In 1990, there were 354 064 302 (95% uncertainty interval: 338 174 876 to 371 610 802) new cases of injury globally, which increased to 520 710 288 (493 430 247 to 547 988 635) new cases in 2017. During this time, age-standardised incidence decreased non-significantly from 6824 (6534 to 7147) to 6763 (6412 to 7118) per 100 000. Between 1990 and 2017, age-standardised DALYs decreased from 4947 (4655 to 5233) per 100 000 to 3267 (3058 to 3505). Interpretation Injuries are an important cause of health loss globally, though mortality has declined between 1990 and 2017. Future research in injury burden should focus on prevention in high-burden populations, improving data collection and ensuring access to medical care.Peer reviewe

The global burden of adolescent and young adult cancer in 2019 : a systematic analysis for the Global Burden of Disease Study 2019

Background In estimating the global burden of cancer, adolescents and young adults with cancer are often overlooked, despite being a distinct subgroup with unique epidemiology, clinical care needs, and societal impact. Comprehensive estimates of the global cancer burden in adolescents and young adults (aged 15-39 years) are lacking. To address this gap, we analysed results from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019, with a focus on the outcome of disability-adjusted life-years (DALYs), to inform global cancer control measures in adolescents and young adults. Methods Using the GBD 2019 methodology, international mortality data were collected from vital registration systems, verbal autopsies, and population-based cancer registry inputs modelled with mortality-to-incidence ratios (MIRs). Incidence was computed with mortality estimates and corresponding MIRs. Prevalence estimates were calculated using modelled survival and multiplied by disability weights to obtain years lived with disability (YLDs). Years of life lost (YLLs) were calculated as age-specific cancer deaths multiplied by the standard life expectancy at the age of death. The main outcome was DALYs (the sum of YLLs and YLDs). Estimates were presented globally and by Socio-demographic Index (SDI) quintiles (countries ranked and divided into five equal SDI groups), and all estimates were presented with corresponding 95% uncertainty intervals (UIs). For this analysis, we used the age range of 15-39 years to define adolescents and young adults. Findings There were 1.19 million (95% UI 1.11-1.28) incident cancer cases and 396 000 (370 000-425 000) deaths due to cancer among people aged 15-39 years worldwide in 2019. The highest age-standardised incidence rates occurred in high SDI (59.6 [54.5-65.7] per 100 000 person-years) and high-middle SDI countries (53.2 [48.8-57.9] per 100 000 person-years), while the highest age-standardised mortality rates were in low-middle SDI (14.2 [12.9-15.6] per 100 000 person-years) and middle SDI (13.6 [12.6-14.8] per 100 000 person-years) countries. In 2019, adolescent and young adult cancers contributed 23.5 million (21.9-25.2) DALYs to the global burden of disease, of which 2.7% (1.9-3.6) came from YLDs and 97.3% (96.4-98.1) from YLLs. Cancer was the fourth leading cause of death and tenth leading cause of DALYs in adolescents and young adults globally. Interpretation Adolescent and young adult cancers contributed substantially to the overall adolescent and young adult disease burden globally in 2019. These results provide new insights into the distribution and magnitude of the adolescent and young adult cancer burden around the world. With notable differences observed across SDI settings, these estimates can inform global and country-level cancer control efforts. Copyright (C) 2021 The Author(s). Published by Elsevier Ltd.Peer reviewe

The global burden of cancer attributable to risk factors, 2010-19 : a systematic analysis for the Global Burden of Disease Study 2019

Background Understanding the magnitude of cancer burden attributable to potentially modifiable risk factors is crucial for development of effective prevention and mitigation strategies. We analysed results from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 to inform cancer control planning efforts globally. Methods The GBD 2019 comparative risk assessment framework was used to estimate cancer burden attributable to behavioural, environmental and occupational, and metabolic risk factors. A total of 82 risk-outcome pairs were included on the basis of the World Cancer Research Fund criteria. Estimated cancer deaths and disability-adjusted life-years (DALYs) in 2019 and change in these measures between 2010 and 2019 are presented. Findings Globally, in 2019, the risk factors included in this analysis accounted for 4.45 million (95% uncertainty interval 4.01-4.94) deaths and 105 million (95.0-116) DALYs for both sexes combined, representing 44.4% (41.3-48.4) of all cancer deaths and 42.0% (39.1-45.6) of all DALYs. There were 2.88 million (2.60-3.18) risk-attributable cancer deaths in males (50.6% [47.8-54.1] of all male cancer deaths) and 1.58 million (1.36-1.84) risk-attributable cancer deaths in females (36.3% [32.5-41.3] of all female cancer deaths). The leading risk factors at the most detailed level globally for risk-attributable cancer deaths and DALYs in 2019 for both sexes combined were smoking, followed by alcohol use and high BMI. Risk-attributable cancer burden varied by world region and Socio-demographic Index (SDI), with smoking, unsafe sex, and alcohol use being the three leading risk factors for risk-attributable cancer DALYs in low SDI locations in 2019, whereas DALYs in high SDI locations mirrored the top three global risk factor rankings. From 2010 to 2019, global risk-attributable cancer deaths increased by 20.4% (12.6-28.4) and DALYs by 16.8% (8.8-25.0), with the greatest percentage increase in metabolic risks (34.7% [27.9-42.8] and 33.3% [25.8-42.0]). Interpretation The leading risk factors contributing to global cancer burden in 2019 were behavioural, whereas metabolic risk factors saw the largest increases between 2010 and 2019. Reducing exposure to these modifiable risk factors would decrease cancer mortality and DALY rates worldwide, and policies should be tailored appropriately to local cancer risk factor burden. Copyright (C) 2022 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license.Peer reviewe

Archaische Paleoböden auf Erde und Mars

Paleosols are unique recorders of physical and chemical processes at the interface between rocks and the atmosphere, hydrosphere and biosphere. Their capacity to record atmospheric and hydrologic conditions allows them to serve as information archives on past environments. Archean paleosols are, due to deformation, metamorphism and limited outcrop, commonly difficult to recognize and characterize, though the number of findings has increased remarkably over recent decades. Well-preserved Paleoarchean terrestrial strata are currently known only from in the Pilbara Block, northwestern Australia and the Barberton Greenstone Belt (BGB), southern Africa. This study describes the widespread occurrence of early diagenetic to pedogenic nodules that formed in unconsolidated sandy sediments in fluvial and coastal settings of the ~3.22 Ga old Archean Moodies Group, BGB, South Africa. They appear stratiform, in places rock-forming, in several regionally traceable units composed of megaquartz pseudomorphs after gypsum, barite and calcite. Nodule growth was dominated by seasonal fluctuations of the groundwater level under evaporitic conditions. The nodules likely represent the oldest terrestrial evaporites known to date. Their formation and composition constrain the local occurrence of sulfate in the Archean atmo- and hydrosphere and its interaction with the emerging biosphere, the Archean weathering regime, local climate and vadose- zone hydrodynamics. The nodules are interbedded with mm-thick heavy mineral laminations, mainly composed of pyrite. Pyrite grains show rounded detrital cores corroded by pore fluids related to pedogenic nodule formation and secondary idiomorphic rims which grew under reducing conditions. The trace element concentrations (Ni and Co) and δ34S ratios of the rims are clearly different from those of the cores. While cores have low Co and Ni concentrations, rims show up to 5.5 wt.-% of these elements. In-situ sulfur isotope analyses of pyrite cores show δ34SVCDT values between +5‰ and -5‰ while the rims show δ34SVCDT values between -20‰ and -24.5‰, suggesting a biogenic fractionation of sulfur. The close spatial association and nearly contemporaneous formation of pedogenic sulfate and secondary pyrite is consistent with microbial sulfur processing in the paleosols. This indicates that Archean soil-forming processes involved not only physical and chemical but also biological modification of unconsolidated sediment. Microbial life was already pervasive in terrestrial environments more than 3.2 Ga ago. The ~3.3-3.2 Ga old Sheepbed Member of the Yellowknife Bay Formation in Gale crater on Mars contains a number of diagenetic features, amongst which nodules are considered to be of early diagenetic origin. The nodules show solid, hollow and filled morphologies similar to those of the approximately contemporaneous paleosols of the lower Moodies Group. They formed pedogenic to early diagenetic under similar conditions. Moodies nodules are therefore an excellent Earth analog for the formation of the Sheepbed nodules on Mars. The S-isotope data, documenting the involvement of biogenic processes in the formation of the Moodies nodules, strengthens the case for the possibility of extraterrestrial life on Mars. Although Martian pyrite grains and their S-isotopic composition cannot be analyzed using the technical instrumentation of Curiosity, their possible existence and isotopic composition should be of high scientific interest.Paleoböden sind hervorragend geeignet, um physikalische und chemische Prozesse an der Schnittstelle zwischen Gestein, Atmo-, Hydro- und Biosphäre zu dokumentieren; sie dienen als Informationsspeicher der Vergangenheit. Archaische Paleoböden sind aufgrund von Deformation, Metamorphose und limitierter Aufschlüsse schwer zu erkennen und zu charakterisieren. Gut erhaltene palaeoarchaische, terrigene Abfolgen sind derzeit lediglich aus dem Pilbara Block, Nordwest-Australien, und dem Barberton Greenstone Belt (BGB) im südlichen Afrika bekannt. Diese Arbeit beschreibt kartierbare, frühdiagenetische bis pedogene Konkretionen, die sich in Sanden fluviatiler Küstenebenen der ~3.22 Ga alten Moodies-Gruppe des BGB in Südafrika bildeten. Sie treten stratiform, teilweise gesteinsbildend auf und bestehen aus Megaquarz-Pseudomorphosen nach Gips, Baryt und Kalzit. Verwitterung von Feldspäten und tuffigem Material lieferte alkalische Kationen wie Ca2+ und Ba2+ während Karbonat wahrscheinlich durch Silikatverwitterung mafischer Vulkanite im Kontakt zur CO2-reichen Atmosphäre entstand. Das Konkretionswachstum war dominiert von saisonalen Fluktuationen des Grundwasserspiegels unter evaporitischen Bedingungen. Die Konkretionen repräsentieren die ältesten bisher bekannten terrestrischen Evaporite. Ihre Entstehung und Zusammensetzung belegen das lokale Auftreten von Sulfat in der archaischen Atmo- und Hydrosphäre, ihre Wechselwirkung mit der entstehenden Biosphäre, dem Verwitterungsregime, dem lokalen Klima und der Hydrodynamik der vadosen Zone. Die Konkretionen sind mit mm- dünnen, überwiegend aus Pyrit bestehenden Schwerminerallaminae wechselgelagert. Diese Pyrite zeigen gerundete, durch Porenwässer korrodierte, detritische Kerne, und idiomorphe Anwachssäume, welche unter reduzierenden Bedingungen entstanden. Die Spurenelement-Gehalte (Ni und Co) und δ34S Verhältnisse der Säume unterscheiden sich deutlich von denen der Kerne. Während die Kerne niedrige Co- und Ni-Gehalte zeigen, enthalten die Säume bis zu 5,5 Gew.-% dieser Elemente. In-situ Schwefelisotopen- Analysen der Kerne zeigt δ34SVCDT Werte zwischen +5‰ und -5‰, während die Säume Werte zwischen -20‰ und -24.5‰ aufweisen und damit auf biogene Fraktionierung des Schwefels hindeuten. Die räumliche Nähe und fast zeitgleiche Entstehung pedogener Sulfate und sekundären Pyrits deutet auf mikrobielle Schwefel-verarbeitung in den Paläoböden hin, und zeigt, dass bodenbildende Prozesse im Archaikum nicht nur physikalische und chemische, sondern auch biogene Veränderungen umfassten. Mikrobielles Leben war in den terrestrischen Ablagerungsräumen vor 3.2 Ga bereits fest verankert. Die ~3.3-3.2 Ga alte Sheepbed-Lage der Yellowknife Bay Formation (Gale Crater, Mars) enthält mehrere diagenetische Ausbildungen, unter denen die Sheepbed Nodules als frühdiagenetisch gelten. Die Nodules haben (ähnlich zu den Konkretionen der Moodies Gruppe) drei morphologisch unterschiedliche Ausprägungen: massiv, hohl und hohl, aber gefüllt. In beiden Orten entstanden sie pedogen bis frühdiagenetisch unter ähnlichen Bedingungen. Die Moodies-Konkretionen sind deshalb ein exzellentes Erd-Analog für die Sheepbed Nodules auf dem Mars. Frühdiagenetischer Pyrit, der mit diesen Nodules, assoziiert sein könnten, ist mit der instrumentellen Ausstattung von Curiosity nicht belegbar. Seine Isotopie wäre analog zur Moodies-Gruppe, von hohem wissenschaftlichen Interesse

In situ S-isotope compositions of sulfate and sulfide from the 3.2 Ga Moodies Group, South Africa: A record of oxidative sulfur cycling

Sulfate minerals are rare in the Archean rock record and largely restricted to the occurrence of barite (BaSO4). The origin of this barite remains controversially debated. The mass-independent fractionation of sulfur isotopes in these and other Archean sedimentary rocks suggests that photolysis of volcanic aerosols in an oxygen-poor atmosphere played an important role in their formation. Here, we report on the multiple sulfur isotopic composition of sedimentary anhydrite in the ca. 3.22 Ga Moodies Group of the Barberton Greenstone Belt, southern Africa. Anhydrite occurs, together with barite and pyrite, in regionally traceable beds that formed in fluvial settings. Variable abundances of barite versus anhydrite reflect changes in sulfate enrichment by evaporitic concentration across orders of magnitude in an arid, nearshore terrestrial environment, periodically replenished by influxes of seawater. The multiple S-isotope compositions of anhydrite and pyrite are consistent with microbial sulfate reduction. S-isotope signatures in barite suggest an additional oxidative sulfate source probably derived from continental weathering of sulfide possibly enhanced by microbial sulfur oxidation. Although depositional environments of Moodies sulfate minerals differ strongly from marine barite deposits, their sulfur isotopic composition is similar and most likely reflects a primary isotopic signature. The data indicate that a constant input of small portions of oxidized sulfur from the continents into the ocean may have contributed to the observed long-term increase in Δ33Ssulfate values through the Paleoarchean

In situ S-isotope compositions of sulfate and sulfide from the 3.2 Ga Moodies Group, South Africa: A record of oxidative sulfur cycling

Sulfate minerals are rare in the Archean rock record and largely restricted to the occurrence of barite (BaSO4). The origin of this barite remains controversially debated. The mass-independent fractionation of sulfur isotopes in these and other Archean sedimentary rocks suggests that photolysis of volcanic aerosols in an oxygen-poor atmosphere played an important role in their formation. Here, we report on the multiple sulfur isotopic composition of sedimentary anhydrite in the ca. 3.22 Ga Moodies Group of the Barberton Greenstone Belt, southern Africa. Anhydrite occurs, together with barite and pyrite, in regionally traceable beds that formed in fluvial settings. Variable abundances of barite versus anhydrite reflect changes in sulfate enrichment by evaporitic concentration across orders of magnitude in an arid, nearshore terrestrial environment, periodically replenished by influxes of seawater. The multiple S-isotope compositions of anhydrite and pyrite are consistent with microbial sulfate reduction. S-isotope signatures in barite suggest an additional oxidative sulfate source probably derived from continental weathering of sulfide possibly enhanced by microbial sulfur oxidation. Although depositional environments of Moodies sulfate minerals differ strongly from marine barite deposits, their sulfur isotopic composition is similar and most likely reflects a primary isotopic signature. The data indicate that a constant input of small portions of oxidized sulfur from the continents into the ocean may have contributed to the observed long-term increase in Δ33Ssulfate values through the Paleoarchean