Distinction between Natural and Anthropogenic Contaminants of Atmospheric Precipitates from Northeastern Kansas Based on Their Elemental Contents and Strontium Isotopic Signatures

AbstractEarth’s crust contains a substantial proportion of global biomass, hosting microbial life up to several kilometers depth. Yet, knowledge of the evolution and extent of life in this environment remains elusive and patchy. Here we present isotopic, molecular and morphological signatures for deep ancient life in vein mineral specimens from mines distributed across the Precambrian Fennoscandian shield. Stable carbon isotopic signatures of calcite indicate microbial methanogenesis. In addition, sulfur isotope variability in pyrite, supported by stable carbon isotopic signatures of methyl-branched fatty acids, suggest subsequent bacterial sulfate reduction. Carbonate geochronology constrains the timing of these processes to the Cenozoic. We suggest that signatures of an ancient deep biosphere and long-term microbial activity are present throughout this shield. We suggest that microbes may have been active in the continental igneous crust over geological timescales, and that subsurface investigations may be valuable in the search for extra-terrestrial life.

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Ontogenetic shift in the trophic role of the invasive killer shrimp Dikerogammarus villosus: a stable isotope study

Biological Invasions ◽

10.1007/s10530-021-02472-0 ◽

2021 ◽

Author(s):

Francesco Mancini ◽

Raffaele De Giorgi ◽

Alessandro Ludovisi ◽

Salvatrice Vizzini ◽

Giorgio Mancinelli

Keyword(s):

Dietary Habits ◽

Trophic Position ◽

Ecological Impact ◽

Central Italy ◽

Local Conditions ◽

Dikerogammarus Villosus ◽

Isotopic Signatures ◽

Depth Analysis ◽

Stable Isotope Study ◽

The Impact

AbstractThe introduction of the amphipod Dikerogammarus villosus in European fresh waters is to date recognized as a threat to the integrity of invaded communities. Predation by D. villosus on native benthic invertebrates is assumed as the key determinant of its ecological impact, yet available information describe the species as a primary consumer as well as a carnivore depending on local conditions. Here, we assessed the trophic position (TP) of D. villosus in Lake Trasimeno, a recently invaded lentic system in central Italy, using the CN isotopic signatures of individuals captured in winter spanning two orders of magnitude in body size. TP estimations were compared with those characterizing the native amphipod Echinogammarus veneris and other representative invertebrate predators. On average, D. villosus showed a trophic position higher than E. veneris, and comparable with that of odonate nymphs. An in-depth analysis revealed that large-sized individuals had a trophic position of 3.07, higher than odonates and close to that of the hirudinean predator Erpobdella octoculata, while small-sized specimens had a trophic position of 2.57, similar to that of E. veneris (2.41). These findings indicate that size-related ontogenetic shifts in dietary habits may per se vary the nature of the interaction between Dikerogammarus villosus and native invertebrates from competition to predation. Information collated from published isotopic studies corroborated the generality of our results. We conclude that intra-specific trophic flexibility may potentially amplify and make more multifaceted the impact of the species on other invertebrate species in invaded food webs.

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Noble gas isotopic signatures of sulfides in carbonatites of the Vuoriyarvi alkaline-ultrabasic complex (Kola Region, NW Russia)

Arabian Journal of Geosciences ◽

10.1007/s12517-021-07884-9 ◽

2021 ◽

Vol 14 (17) ◽

Author(s):

Evgeniy Kozlov ◽

Vladimir Skiba ◽

Ekaterina Fomina ◽

Mikhail Sidorov

Keyword(s):

Noble Gas ◽

Isotopic Signatures ◽

Kola Region

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Temperature affects carbon and nitrogen stable isotopic signatures of aquatic plants

Aquatic Sciences ◽

10.1007/s00027-021-00794-8 ◽

2021 ◽

Vol 83 (2) ◽

Author(s):

Peiyu Zhang ◽

Xianghong Kong ◽

Elisabeth S. Bakker ◽

Jun Xu ◽

Min Zhang

Keyword(s):

Aquatic Plants ◽

Isotopic Signatures ◽

Carbon And Nitrogen ◽

Stable Isotopic

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Radiogenic Pb Enrichment of Mississippi Valley-Type Metallic Ore Deposits, Southern Ozarks: Constraints Based on Geochemical Studies of Source Rocks and Their Diagenetic History

Geosciences ◽

10.3390/geosciences11040172 ◽

2021 ◽

Vol 11 (4) ◽

pp. 172

Author(s):

Jonathan Chick ◽

Sydney E. McKim ◽

Adriana Potra ◽

Walter L. Manger ◽

John R. Samuelsen

Keyword(s):

Linear Trend ◽

Ore Deposits ◽

Source Rocks ◽

Mississippi Valley ◽

Isotopic Signatures ◽

Boone Formation ◽

Tripolitic Chert ◽

Geochemical Studies ◽

Mississippi Valley Type ◽

Valley Type

Southern Ozark Mississippi Valley-type ores are enriched in radiogenic Pb, with isotopic signatures suggesting that metals were supplied by two end-member components. While the less radiogenic component appears to be derived from various shale and sandstone units, the source of the more radiogenic component has not yet been identified. Analyses of cherts from the Early Ordovician Cotter Dolomite and tripolitic chert from the Early Mississippian Boone Formation contain highly radiogenic Pb, with isotopic ratios comparable to those of ores. However, most samples have lower 208Pb/204Pb and 207Pb/204Pb for a given 206Pb/204Pb compared to ores. These relationships demonstrate that the enriched Pb isotopic values of the ore array cannot be related to the host and regional lithologies sampled, suggesting that the source of high ratios may lay further afield. The slope of the linear trend defined by the Pb isotope ratios of ores corresponds to an age of about 1.19 Ga. Therefore, an alternative for the linear array is the involvement of Precambrian basement in supplying ore Pb. Rare earth element patterns show that diagenetic processes involving the action of groundwater and hydrothermal fluids affected the sampled lithologies to various degrees, with Cotter Dolomite having experienced the highest degree of alteration.

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How Does Diet Influence Our Lives? Evaluating the Relationship between Isotopic Signatures and Mortality Patterns in Italian Roman Imperial and Medieval Periods

Molecules ◽

10.3390/molecules26133895 ◽

2021 ◽

Vol 26 (13) ◽

pp. 3895

Author(s):

Marica Baldoni ◽

Alessandra Nardi ◽

Flavio De Angelis ◽

Olga Rickards ◽

Cristina Martínez-Labarga

Keyword(s):

Middle Ages ◽

Dietary Habits ◽

Roman Period ◽

Survivorship Analysis ◽

Linear Effect ◽

Isotopic Signatures ◽

Carbon Isotopic ◽

Religious Aspects ◽

The Relationship ◽

Source Of Information

The present research investigates the relationship between dietary habits and mortality patterns in the Roman Imperial and Medieval periods. The reconstructions of population dynamics and subsistence strategies provide a fascinating source of information for understanding our history. This is particularly true given that the changes in social, economic, political, and religious aspects related to the transition from the Roman period to the Middle Ages have been widely discussed. We analyzed the isotopic and mortality patterns of 616 individuals from 18 archeological sites (the Medieval Latium sites of Colonna, Santa Severa, Allumiere, Cencelle, and 14 Medieval and Imperial funerary contexts from Rome) to compile a survivorship analysis. A semi-parametric approach was applied, suggesting variations in mortality patterns between sexes in the Roman period. Nitrogen isotopic signatures influenced mortality in both periods, showing a quadratic and a linear effect for Roman Imperial and Medieval populations, respectively. No influence of carbon isotopic signatures has been detected for Roman Imperial populations. Conversely, increased mortality risk for rising carbon isotopic values was observed in Medieval samples.

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The δ13C, δ18O and Δ47 records in biogenic, pedogenic and geogenic carbonate types from paleosol-loess sequence and their paleoenvironmental meaning

Quaternary Research ◽

10.1017/qua.2020.109 ◽

2021 ◽

pp. 1-17

Author(s):

Kazem Zamanian ◽

Alex R. Lechler ◽

Andrew J. Schauer ◽

Yakov Kuzyakov ◽

Katharine W. Huntington

Keyword(s):

Land Snail ◽

Isotopic Signature ◽

Sediment Layer ◽

Isotopic Signatures ◽

Pedogenic Carbonates ◽

Rhine Valley ◽

Clumped Isotope ◽

Time Specific ◽

Sediment Layers ◽

Paleoenvironmental Reconstructions

Abstract Paleoenvironmental reconstructions are commonly based on isotopic signatures of a variety of carbonate types, including rhizoliths and land-snail shells, present in paleosol-loess sequences. However, various carbonate types are formed through distinct biotic and abiotic processes over various periods, and therefore may record diverging environmental information in the same sedimentological layer. Here, we investigate the effects of carbonate type on δ13C, δ18O, and clumped isotope-derived paleotemperature [T(Δ47)] from the Quaternary Nussloch paleosol-loess sequence (Rhine Valley, SW Germany). δ13C, δ18O, and T(Δ47) values of co-occurring rhizoliths (-8.2‰ to -5.8‰, -6.1‰ to -5.9‰, 12–32°C, respectively), loess dolls (-7.0‰, -5.6‰, 23°C), land-snail shells (-8.1‰ to -3.2‰, -4.0‰ to -2.2‰, 12–38°C), earthworm biospheroliths (-11‰, -4.7‰, 8°C), and “bulk” carbonates (-1.9‰ to -0.5‰, -5.6‰ to -5.3‰, 78–120°C) from three sediment layers depend systematically on the carbonate type, admixture from geogenic carbonate, and the duration of formation periods. Based on these findings, we provide a comprehensive summary for the application of the three isotopic proxies of δ13C, δ18O, and Δ47 in biogenic and pedogenic carbonates present in the same sediment layer to reconstruct paleoenvironments (e.g., local vegetation, evaporative conditions, and temperature). We conclude that bulk carbonates in Nussloch loess should be excluded from paleoenvironmental reconstructions. Instead, pedogenic and biogenic carbonates should be used to provide context for interpreting the isotopic signature for detailed site- and time-specific paleoenvironmental information.

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