Sulfur geochemistry across a terrestrial Permian–Triassic boundary section in the Karoo Basin, South Africa

Maruoka, Teruyuki; Koeberl, Christian; Hancox, P. John; Reimold, W. U.

doi:10.1016/s0012-821x(02)01087-7

Cited by 64 publications

(44 citation statements)

References 70 publications

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“…Sulfur isotopic compositions were determined for the barium sulfate precipitates and the pyritic and elemental sulfur using a helium gas continuous-flow isotope ratio mass spectrometer (CF-IR-MS; Isoprime-EA; Isoprime Ltd., UK) at the University of Tsukuba (see Maruoka et al 2003a). The samples were weighed in 3.3 mm × 5 mm tin capsules, and 200-300 μg of V 2 O 5 was added to each sample.…”

Section: Sampling Locations and Analytical Methodsmentioning

confidence: 99%

Sulfur isotopic characteristics of volcanic products from the September 2014 Mount Ontake eruption, Japan

Ikehata

Maruoka

2016

Earth Planet Sp

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which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. AbstractComponents and sulfur isotopic compositions of pyroclastic materials from the 2014 Mt. Ontake eruption were investigated. The volcanic ash samples were found to be composed of altered volcanic fragments, alunite, anhydrite, biotite, cristobalite, gypsum, ilmenite, kaolin minerals, native sulfur, orthopyroxene, plagioclase, potassium feldspar, pyrite, pyrophyllite, quartz, rutile, and smectite, and most of these minerals were likely derived from the acidic alteration zones of Mt. Ontake. The absence of juvenile material in the eruptive products indicates that the eruption was phreatic. The sulfur isotopic compositions of the water-leached sulfate, hydrochloric acid-leached sulfate, acetone-leached native sulfur, and pyrite of the samples indicate that these sulfur species were produced by disproportionation of magmatic SO 2 in the hydrothermal system at temperatures of 270-281 °C. This temperature range is consistent with that inferred from the hydrothermal mineral assemblage (e.g., pyrophyllite and rutile) in the 2014 pyroclastic materials (200-300 °C). Except for the sulfur isotopic compositions of anhydrite, which may have been altered by incorporation of sulfate minerals in a fumarolic area with lower sulfur isotopic values into the underground materials during the 1979 eruption, no significant differences in the mineral assemblages and sulfur isotopic compositions of the pyroclastic materials were identified between the products of the 2014 and 1979 Ontake phreatic eruptions, which suggests geochemical similarities in the underlying hydrothermal systems before the 2014 and 1979 eruptions.

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Section: Sampling Locations and Analytical Methodsmentioning

confidence: 99%

Sulfur isotopic characteristics of volcanic products from the September 2014 Mount Ontake eruption, Japan

Ikehata

Maruoka

2016

Earth Planet Sp

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“…This gas rapidly converts into H 2 SO 4 aerosols that could produce acid precipitation. Large-scale atmospheric acidification is generally attributed to extensive P-Tr volcanism in Siberia (3,52,53 Ar dating suggests that the main phase of volcanic activity was contemporaneous with the endPermian crisis (52,56). However, crisis scenarios that rely on adverse effects of acid precipitation suffer an obvious difficulty.…”

Section: Causation Of Global Environmental Mutagenesismentioning

confidence: 99%

Environmental mutagenesis during the end-Permian ecological crisis

Visscher

Looy

Collinson

et al. 2004

Proc. Natl. Acad. Sci. U.S.A.

219

171

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During the end-Permian ecological crisis, terrestrial ecosystems experienced preferential dieback of woody vegetation. Across the world, surviving herbaceous lycopsids played a pioneering role in repopulating deforested terrain. We document that the microspores of these lycopsids were regularly released in unseparated tetrads indicative of failure to complete the normal process of spore development. Although involvement of mutation has long been hinted at or proposed in theory, this finding provides concrete evidence for chronic environmental mutagenesis at the time of global ecological crisis. Prolonged exposure to enhanced UV radiation could account satisfactorily for a worldwide increase in land plant mutation. At the end of the Permian, a period of raised UV stress may have been the consequence of severe disruption of the stratospheric ozone balance by excessive emission of hydrothermal organohalogens in the vast area of Siberian Traps volcanism.

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“…Dickson and Coleman (2009) [28] pointed to the negative correlation of δ 13 C carb and δ 18 O carb values, where the isotopic signals were a result of meteoric alteration during subaerial exposure of the sections. While the meteoric-water diagenesis usually results in 18 O and 13 C depletions [29,30], such trends are also ubiquitous in modern diagenetically unaffected carbonates [31].…”

Section: Discussionmentioning

confidence: 99%

“…While the meteoric-water diagenesis usually results in 18 O and 13 C depletions [29,30], such trends are also ubiquitous in modern diagenetically unaffected carbonates [31].…”

Section: Discussionmentioning

confidence: 99%

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Sulfur, Strontium, Carbon, and Oxygen Isotopes of Calcium Sulfate Deposits in Late Carboniferous Rocks of the Loei-Wang Saphung (LWS) Area, Loei Province, Thailand

et al. 2018

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Sulfate deposits of the Loei-Wang Saphung (LWS) area, northeastern Thailand, intercalated with carbonate and silicic clastic rock were analyzed for S, O, C, and Sr to determine the depositional environment, as well as the age of formation. Sulfate samples yielded average values of δ 34 S of 14.6‰, while the 87 Sr/ 86 Sr ratio of gypsum was 0.708282 and that of anhydrite was 0.708288. The carbonate layers yielded average δ 18 O PDB , and δ 13 C values of −12.5‰ and −0.1‰, respectively. Our results revealed that the LWS evaporite deposits were originally formed from seawater, and the relatively negative value of δ 18 O was a result of meteoric alteration during subaerial exposure of the sections. Comparing these isotopic values with the nearby Nakon Sawan sulfate deposits, the Sr isotopes showed slightly higher values with very mild variations. These isotopic values suggest that the LWS deposits were not affected by subsequent hydrothermal alteration by younger igneous dikes in this area. Therefore, some of these isotope signatures are considered to be primary features of the deposit, despite the fact that the deposit underwent anchizone to epizone metamorphism. The S and Sr isotope values support the depositional age of the LWS sulfate deposit in the Middle to Late Carboniferous.

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Sulfur geochemistry across a terrestrial Permian–Triassic boundary section in the Karoo Basin, South Africa

Cited by 64 publications

References 70 publications

Sulfur isotopic characteristics of volcanic products from the September 2014 Mount Ontake eruption, Japan

Sulfur isotopic characteristics of volcanic products from the September 2014 Mount Ontake eruption, Japan

Environmental mutagenesis during the end-Permian ecological crisis

Sulfur, Strontium, Carbon, and Oxygen Isotopes of Calcium Sulfate Deposits in Late Carboniferous Rocks of the Loei-Wang Saphung (LWS) Area, Loei Province, Thailand

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