Filtering by Subject: Geochemistry

Global mercury records from natural archives reveal ecosystem responses to changing atmospheric deposition

Qinqin Chen, Qingru Wu, Yuying Cui, et al.

Published: 2024-05-15
Subjects: Atmospheric Sciences, Environmental Sciences, Geochemistry, Geography, Physical and Environmental Geography

Global ecosystems face mercury contamination, yet long-term data is scarce, hindering understanding of ecosystem responses to atmospheric Hg input changes and policy evaluation. To address this gap, this study compiled a global mercury accumulation flux database using 221 cores from peat, lake, ice, and marine deposits. From 1700 to 2012, global averaged fluxes in peat, lake, ice, and marine [...]

Carbonate clumped isotope values compromised by nitrate-derived NO2 interferent

Jens Fiebig, Miguel Bernecker, Niels Meijer, et al.

Published: 2024-04-30
Subjects: Earth Sciences, Geochemistry

∆47 based clumped isotope thermometry has enabled reconstruction of Earth’s surface temperatures independent of the source of oxygen within the carbonate. It has been postulated that carbonate samples can contain contaminants that cause isobaric interferences, compromising measured ∆47 values and reconstructed temperatures. The exact nature of contaminants and isobaric interferents, however, [...]

High–precision determination of carbon stable isotope in silicate glasses by secondary ion mass spectrometry: Evaluation of international standards

Hyun Joo Lee, Yves Moussallam, Estelle Rose-Koga, et al.

Published: 2024-04-24
Subjects: Analytical Chemistry, Geochemistry

Secondary ion mass spectrometry (SIMS) has been used for isotope analysis of volatile components dissolved in silicate melts for decades. However, carbon in situ stable isotope analysis in natural silicate glasses has remained particularly challenging, with the few published attempts yielding high uncertainties. In this context, we characterized 31 reference silicate glasses of basaltic and [...]

Limited long-term cooling effects of flood basalt emplacements

Jack Longman, Benjamin Mills, Andrew Merdith

Published: 2024-04-22
Subjects: Biogeochemistry, Earth Sciences, Geochemistry, Geology, Volcanology

The emplacement of large igneous provinces (LIPs) is known to have been a driver of climate change in Earth’s past, particularly during the breakup of Pangaea. However, the balance between climate warming through CO2 emission and climate cooling through increased weathering is poorly understood. To better understand the role of LIP emplacement on long-term climate change, we utilize a coupled [...]

Systematic Review of the Geothermal Potential in Colombia: Implications as an Alternative Energy Source

Juan Camilo Mejía-Fragoso, Cristina Dapeña

Published: 2024-04-16
Subjects: Earth Sciences, Geochemistry, Geology, Geophysics and Seismology, Physical Sciences and Mathematics

Through literature review and information processing, the current state of geothermal energy in Colombia, its limitations, possible future uses, environmental impact and the current legal framework were described and analyzed. Approximations were made regarding the sustainability of geothermal energy in the country and its implications. Some of the projects, studies, and research that have been [...]

Wastewaters co-produced with shale gas drive slight regional salinization of groundwater

Samuel Shaheen, Tao Wen, Zhong Zheng, et al.

Published: 2024-04-04
Subjects: Geochemistry, Oil, Gas, and Energy, Water Resource Management

While unconventional oil and gas development (UOGD) is changing the world economy, processes that are used during UOGD such as high-volume hydraulic fracturing (“fracking”) have been linked with water contamination. Water quality risks include leaks of gas and salty fluids (brines) that are co-produced at wellpads. Identifying the cause of contamination is difficult, however, because UOG wells [...]

Grüneisen parameter formalism in the study of the Earth's core formation: a sensitivity study

Vincent Clesi, Renaud Deguen

Published: 2024-03-20
Subjects: Condensed Matter Physics, Earth Sciences, Geochemistry, Geology, Mineral Physics, Other Earth Sciences, Planetary Geophysics and Seismology, Planetary Mineral Physics, Planetary Sciences

The Grüneisen parameter is an important parameter for the thermal state and evolution of the core, but its uncertainties and their implications are sometimes overlooked . Several formalisms using different parameters values have been used in different studies, making comparison between studies difficult. In this paper, we use previously published datasets to test the sensitivity of modeling the [...]

Coral Ba/Ca reflected the past earthquake and tsunami on Kikai Island in 1911

Saori Ito, Tsuyoshi Watanabe

Published: 2024-03-18
Subjects: Geochemistry

Natural disasters like earthquakes and tsunamis significantly affect coral reefs and marine ecosystems. The Ryukyu Islands, including Kikai Island and the surrounding coral reefs, face the potential risk of experiencing a significant earthquake with Mw > 8. While historical records offer insights into past tsunami occurrences, there is scarce observation or quantitative data on the impacts of [...]

Three-dimensional mineral dendrites reveal a non-classical crystallization pathway

Zhaoliang Hou, Dawid Woś, Cornelius Tschegg, et al.

Published: 2024-03-03
Subjects: Earth Sciences, Fluid Dynamics, Geochemistry, Mineral Physics, Physical Sciences and Mathematics, Physics

Manganese (Mn) dendrites are a common type of mineral dendrite that typically forms two-dimensional structures on rock surfaces. Three-dimensional (3D) Mn dendrites in rocks have rarely been reported, hence their growth implications have largely escaped attention. Here, we combine high-resolution X-ray and electron-based data with numerical modelling to give the first detailed description of [...]

Chemical interdiffusion between Na-tephritic and phonolitic melts at different T, H2O and fO2

Diego González-García, Florian Pohl, Felix Marxer, et al.

Published: 2024-02-21
Subjects: Geochemistry, Volcanology

The diffusive exchange of major elements in Na-series tephrite-phonolite diffusion couples with compositions relevant to Canary Islands magmatism were determined at 300 MPa and variable H2O concentrations (0.3 to 3.3 wt.%), temperature (1150 to 1300°C) and fO2 (NNO-1.5 to NNO+1.7). Composition-dependent effective binary diffusion coefficients (D) were determined from concentration-distance [...]

An aminostratigraphy for the Quaternary of the Swiss Plateau

Kirsty Penkman, Nigel Thew, Samantha Presslee, et al.

Published: 2024-02-08
Subjects: Analytical Chemistry, Earth Sciences, Geochemistry, Other Earth Sciences, Stratigraphy

Here we develop an amino acid chronology to help establish a dated sequence for the important Early Pleistocene Höhere and Tiefere Deckenschotter lithostratigraphic units, as well as other Quaternary deposits from the Swiss Plateau. Age discrimination is possible between the Quaternary sites from the Swiss Plateau in six different biominerals: Bithynia opercula, shell fragments from Fruticola, [...]

Subsurface microbial community structure shifts along the geological features of the Central American Volcanic Arc

Marco Basili, Timothy J. Rogers, Mayuko Nakagawa, et al.

Published: 2024-02-04
Subjects: Biodiversity, Biogeochemistry, Earth Sciences, Environmental Microbiology and Microbial Ecology Life Sciences, Geochemistry, Geology, Microbiology, Volcanology

Subduction of the Cocos and Nazca oceanic plates beneath the Caribbean plate drives the upward movement of deep fluids enriched in carbon, nitrogen, sulfur, and iron along the Central American Volcanic Arc (CAVA). These compounds fuel diverse subsurface microbial communities that in turn alter the distribution, redox state, and isotopic composition of these compounds. Microbial community [...]

Regional trends and petrologic factors inhibit global interpretations of zircon trace element compositions

Nick M. W. Roberts, Christopher Spencer, Stephen Puetz, et al.

Published: 2024-02-01
Subjects: Earth Sciences, Geochemistry

The trace element composition of zircon reveals information about the melt that they are derived from, as such, detrital zircon trace element compositions can be used to interrogate melt compositions, and thus the evolution of the continental crust in time and space. Here, we present a global database of detrital zircon compositions and use it to test whether average global trends for five common [...]

Freshwater plume-like condition near the north-eastern coastal Arabian Sea during early Miocene: Evidence from the stable isotope record in the growth bands of gastropods (Turritella sp.)

Yogaraj Banerjee, Prosenjit Ghosh

Published: 2024-01-30
Subjects: Climate, Earth Sciences, Geochemistry, Oceanography and Atmospheric Sciences and Meteorology

The Early Miocene witnessed major tectonic, palaeoceanographic and climatological reorganizations over the Asian realm. The Himalayan and Tibetan plateau upliftment influenced monsoon intensity during this age. Contemporary high-resolution tropical hydroclimate records are limited. Here, we present an early Miocene sub-annual stable isotope record from the growth bands of well-preserved [...]

River Floodplains, Organic Carbon, and Paleoclimate: How River Dynamics Impart Biases in the Biogeochemical Climate Record of Terrestrial Landscapes

Anjali M Fernandes, Michael T Hren, Virginia B. Smith, et al.

Published: 2024-01-28
Subjects: Earth Sciences, Geochemistry, Geomorphology, Hydrology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy

River floodplains can be both sources and sinks for organic carbon. In the sedimentary record, geochemical signatures of terrestrial water availability record climate and ecology along river corridors in deep time. However, paleoenvironmental reconstructions are often confounded by the complex dynamics of organic carbon residence, entrainment, and deposition in a fluvial system. As alluvial [...]


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