Quadrupole collectivity in the neutron-rich sulfur isotopes 
S38,40,42,44

The Longquanzhan deposit is one of the largest gold deposits in the Yi-Shu fault zone (central section of the Tan-Lu fault zone) in Shandong Province, China. It is an altered-rock type gold deposit in which ore bodies mainly occur at the contact zone between the overlying Cretaceous rocks and the underlying Neoarchean gneissic monzogranite. Shi et al. reported that this deposit formed at 96 ± 2 Ma using pyrite Rb–Sr dating method and represents a new gold mineralization event in the Shandong Province in 2014. In this paper, we present new He–Ar–S isotopic compositions to further decipher the sources of fluids responsible for the Longquanzhan gold mineralization. The results show that the δ34S values of pyrites vary between 0.9‰ and 4.4‰ with an average of 2.3‰. Inclusion-trapped fluids in ore sulfides have 3He/4He and 40Ar/36Ar ratios of 0.14–0.78 Ra and 482–1811, respectively. These isotopic data indicate that the ore fluids are derived from a magmatic source, which is dominated by crustal components with minor mantle contribution. Air-saturated water may be also involved in the hydrothermal system during the magmatic fluids ascending or at the shallow deposit site. We suggest that the crust-mantle mixing signature of the Longquanzhan gold deposit is genetically related to the Late Cretaceous lithospheric thinning along the Tan-Lu fault zone, which triggers constantly uplifting of the asthenosphere surface and persistent ascending of the isotherm plane to form the gold mineralization-related crustal level magma sources. This genetic model can be applied, to some extent, to explain the ore genesis of other deposits near or within the Tan-Lu fault belt.

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Gut microbiome is affected by inter-sexual and inter-seasonal variation in diet for thick-billed murres (Uria lomvia)

Scientific Reports ◽

10.1038/s41598-020-80557-x ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Esteban Góngora ◽

Kyle H. Elliott ◽

Lyle Whyte

Keyword(s):

Gut Microbiome ◽

Sulfur Isotopes ◽

Trophic Position ◽

Isotope Analysis ◽

16S Rrna Gene Sequencing ◽

Rrna Gene ◽

Uria Lomvia ◽

Fecal Microbiome ◽

Prey Specialization ◽

Rrna Gene Sequencing

AbstractThe role of the gut microbiome is increasingly being recognized by health scientists and veterinarians, yet its role in wild animals remains understudied. Variations in the gut microbiome could be the result of differential diets among individuals, such as variation between sexes, across seasons, or across reproductive stages. We evaluated the hypothesis that diet alters the avian gut microbiome using stable isotope analysis (SIA) and 16S rRNA gene sequencing. We present the first description of the thick-billed murre (Uria lomvia) fecal microbiome. The murre microbiome was dominated by bacteria from the genus Catellicoccus, ubiquitous in the guts of many seabirds. Microbiome variation was explained by murre diet in terms of proportion of littoral carbon, trophic position, and sulfur isotopes, especially for the classes Actinobacteria, Bacilli, Bacteroidia, Clostridia, Alphaproteobacteria, and Gammaproteobacteria. We also observed differences in the abundance of bacterial genera such as Catellicoccus and Cetobacterium between sexes and reproductive stages. These results are in accordance with behavioural observations of changes in diet between sexes and across the reproductive season. We concluded that the observed variation in the gut microbiome may be caused by individual prey specialization and may also be reinforced by sexual and reproductive stage differences in diet.

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Evolution of a Deep Fluid in a Surficial Environment Using Stable Carbon and Sulfur Isotopes: Case of the Transitional Zone of the Edwards Aquifer in South Central Texas

Water Air & Soil Pollution ◽

10.1007/s11270-021-05159-3 ◽

2021 ◽

Vol 232 (5) ◽

Author(s):

Pride T. Abongwa ◽

Walter Den

Keyword(s):

Sulfur Isotopes ◽

Transitional Zone ◽

Stable Carbon ◽

Edwards Aquifer ◽

South Central ◽

Central Texas ◽

Deep Fluid

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Assessing the utility of sulfur isotope values for understanding mercury concentrations in water and biota from high Arctic lakes

Arctic Science ◽

10.1139/as-2018-0022 ◽

2019 ◽

Vol 5 (2) ◽

pp. 90-106 ◽

Cited By ~ 1

Author(s):

Gretchen L. Lescord ◽

Meredith G. Clayden ◽

Karen A. Kidd ◽

Jane L. Kirk ◽

Xiaowa Wang ◽

...

Keyword(s):

Food Webs ◽

Total Mercury ◽

Nitrogen Isotopes ◽

Sulfur Isotopes ◽

High Arctic ◽

Arctic Lakes ◽

Carbon And Nitrogen ◽

Resolute Bay ◽

Aquatic Food ◽

Globally Stable

Methylmercury (MeHg) biomagnifies through aquatic food webs resulting in elevated concentrations in fish globally. Stable carbon and nitrogen isotopes are frequently used to determine dietary sources of MeHg and to model its biomagnification. However, given the strong links between MeHg and sulfur cycling, we investigated whether sulfur isotopes (δ34S) would improve our understanding of MeHg concentrations ([MeHg]) in Arctic lacustrine food webs. Delta34S values and total mercury (THg) or MeHg were measured in water, sediments, and biota from six lakes near Resolute Bay, NU, Canada. In two lakes impacted by historical eutrophication, aqueous sulfate δ34S was ∼8‰ more positive than sedimentary δ34S, suggestive of bacterial sulfate reduction in the sediment. In addition, aqueous δ34S showed a significant positive relationship with aqueous [MeHg] across lakes. Within taxa across lakes, [THg] in Arctic char muscle and [MeHg] in their main prey, chironomids, were positively related to their δ34S values across lakes, but inconsistent relationships were found across entire food webs among lakes. Across lakes, nitrogen isotopes were better predictors of biotic [THg] and [MeHg] than δ34S within this dataset. Our results suggest some linkages between Hg and S biogeochemistry in high Arctic lakes, which is an important consideration given anticipated climate-mediated changes in nutrient cycling.

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