The preservation of δ 34 S SO 4 and δ 18 O SO 4 in carbonate-associated sulfate during marine diagenesis: A 25 Myr test case using marine sediments

A 25 million year record of the sulfur and oxygen isotope composition of marine carbonate-associated sulfate (CAS) was constructed from 55 nannofossil ooze samples at three different locations. We tested the impact of early marine diagenesis on CAS by comparing the CAS extractions to the sulfur and oxygen isotope composition of the associated pore fluid sulfate, to determine the degree of pore fluid incorporation during carbonate recrystallization. Neither the sulfur nor the oxygen isotope composition of CAS are completely overprinted by incorporation of pore fluid sulfate. We compare our record to the sulfur and oxygen isotope records of coeval barite. The sulfur isotope record is in agreement with the barite record within ±2h, except where very young (<2 Ma) sediments are in the presence of highly evolved pore fluid sulfate (δ 34 S = 70h). A simple recrystallization model is used to illustrate the sensitivity of CAS δ 34 S SO 4 to sedimentation rate, and to emphasize that careful sample selection, along with an analysis of early diagenetic environmental conditions is crucial when interpreting CAS sulfur isotopes. Oxygen isotopes in CAS are more complex and do not reproduce similar values to those of coeval barite. We conclude that oxygen isotopes in sulfate may remain a useful proxy but merit closer attention in the future

Abyssal origin for the early Holocene pulse of unradiogenic neodymium isotopes in Atlantic seawater

The neodymium isotopic composition of authigenic phases of deep-sea sediment cores can be interpreted as reflecting past changes in water-mass mixing proportions if end-member water-mass compositions are constrained through time. Here we present three new records spanning 2480 to 4360 m depth in the North Atlantic Ocean that show seawater Nd isotope values in the early to mid-Holocene that are more radiogenic than values from the abyssal northwest Atlantic. This finding indicates that that the end-member composition of North Atlantic Deep Water was more stable within its core than it was at abyssal depths. The spatial distribution of the unradiogenic neodymium isotope values observed in the North Atlantic suggests a bottom source, and therefore that they were unlikely to have been due to the production of intermediate-depth Labrador Sea Water. We infer that the unradiogenic authigenic Nd isotope values were most likely derived from a pulse of poorly chemically weathered detrital material that was deposited into the Labrador Sea following Laurentide ice sheet retreat in the early Holocene. This unradiogenic sediment released neodymium into the bottom waters, yielding an unradiogenic seawater signal that was advected southward at abyssal depths and attenuated as it vertically mixed upward in the water column to shallower depths. The southward dispersion of these unradiogenic seawater values traces deep-water advection. However, the exact values observed at the most abyssal sites cannot be interpreted as proportionate to the strength of deep-water production without improved constraints on end-member changes

Combination of searches for heavy spin-1 resonances using 139 fb−1 of proton-proton collision data at s = 13 TeV with the ATLAS detector

A combination of searches for new heavy spin-1 resonances decaying into different pairings of W, Z, or Higgs bosons, as well as directly into leptons or quarks, is presented. The data sample used corresponds to 139 fb−1 of proton-proton collisions at = 13 TeV collected during 2015–2018 with the ATLAS detector at the CERN Large Hadron Collider. Analyses selecting quark pairs (qq, bb, , and tb) or third-generation leptons (τν and ττ) are included in this kind of combination for the first time. A simplified model predicting a spin-1 heavy vector-boson triplet is used. Cross-section limits are set at the 95% confidence level and are compared with predictions for the benchmark model. These limits are also expressed in terms of constraints on couplings of the heavy vector-boson triplet to quarks, leptons, and the Higgs boson. The complementarity of the various analyses increases the sensitivity to new physics, and the resulting constraints are stronger than those from any individual analysis considered. The data exclude a heavy vector-boson triplet with mass below 5.8 TeV in a weakly coupled scenario, below 4.4 TeV in a strongly coupled scenario, and up to 1.5 TeV in the case of production via vector-boson fusion

Combination of searches for heavy spin-1 resonances using 139 fb−1 of proton-proton collision data at √s = 13 TeV with the ATLAS detector

A combination of searches for new heavy spin-1 resonances decaying into different pairings of W, Z, or Higgs bosons, as well as directly into leptons or quarks, is presented. The data sample used corresponds to 139 fb−1 of proton-proton collisions at √s = 13 TeV collected during 2015–2018 with the ATLAS detector at the CERN Large Hadron Collider. Analyses selecting quark pairs (qq, bb, tt¯, and tb) or third-generation leptons (τν and ττ) are included in this kind of combination for the first time. A simplified model predicting a spin-1 heavy vector-boson triplet is used. Cross-section limits are set at the 95% confidence level and are compared with predictions for the benchmark model. These limits are also expressed in terms of constraints on couplings of the heavy vector-boson triplet to quarks, leptons, and the Higgs boson. The complementarity of the various analyses increases the sensitivity to new physics, and the resulting constraints are stronger than those from any individual analysis considered. The data exclude a heavy vector-boson triplet with mass below 5.8 TeV in a weakly coupled scenario, below 4.4 TeV in a strongly coupled scenario, and up to 1.5 TeV in the case of production via vector-boson fusion

Combination of searches for heavy spin-1 resonances using 139 fb−1 of proton-proton collision data at √s = 13 TeV with the ATLAS detector

A combination of searches for new heavy spin-1 resonances decaying into diferent pairings of W, Z, or Higgs bosons, as well as directly into leptons or quarks, is presented. The data sample used corresponds to 139 fb−1 of proton-proton collisions at √s = 13 TeV collected during 2015–2018 with the ATLAS detector at the CERN Large Hadron Collider. Analyses selecting quark pairs (qq, bb, tt¯, and tb) or third-generation leptons (τν and τ τ ) are included in this kind of combination for the frst time. A simplifed model predicting a spin-1 heavy vector-boson triplet is used. Cross-section limits are set at the 95% confdence level and are compared with predictions for the benchmark model. These limits are also expressed in terms of constraints on couplings of the heavy vector-boson triplet to quarks, leptons, and the Higgs boson. The complementarity of the various analyses increases the sensitivity to new physics, and the resulting constraints are stronger than those from any individual analysis considered. The data exclude a heavy vector-boson triplet with mass below 5.8 TeV in a weakly coupled scenario, below 4.4 TeV in a strongly coupled scenario, and up to 1.5 TeV in the case of production via vector-boson fusion

Sulfur and oxygen isotope tracing of sulfate driven anaerobic methane oxidation in estuarine sediments

We use multiple stable isotope measurements in two highly stratified estuaries located along the Mediterranean coast of Israel (the Yarqon and the Qishon) to explore the consumption of sulfate through the anaerobic oxidation of methane (sulfate-driven AOM). At both sites, pore fluid sulfate is rapidly consumed within the upper 15–20 cm. Although the pore fluid sulfate and dissolved inorganic carbon (DIC) concentration profiles change over a similar range with respect to depth, the sulfur and oxygen isotopes in the pore fluid sulfate and the carbon isotopes in the pore fluid DIC are fundamentally different. This pore fluid isotope geochemistry indicates that the microbial mechanism of sulfate reduction differs between the studied sites. We suggest that in the Yarqon estuary, sulfate is consumed entirely through AOM, whereas in the Qishon, both AOM and bacterial sulfate reduction through organic matter oxidation coexist. These results have implications for understanding the microbial mechanisms behind sulfate-driven AOM. Our data compilation from marine and marginal marine environments supports the conclusion that the intracellular pathways of sulfate reduction varies among environments with sulfate-driven AOM. The data can be used to elucidate new pathways in the cycling of methane and sulfate, and the findings are applicable to the broader marine environment