Article
Geochemistry & Geophysics
Bin Zhao, Peng Yao, Thomas S. Bianchi, Xuchen Wang, Zhigang Yu
Summary: The organic carbon (OC) composition and age in river sedimentary systems are controlled by sediment dynamics and OC reactivities. The Huanghe (Yellow River) system has a higher proportion of pre-aged OC and continuous addition of young marine OC, while the Changjiang (Yangtze River) system experiences diagenetic aging and transport time-associated aging. The evolution pattern of OC in the Huanghe system is similar to small mountain river-active margins, while the Changjiang system is similar to other large river-passive margins.
Article
Geochemistry & Geophysics
Dong Feng, John W. Pohlman, Joern Peckmann, Yuedong Sun, Yu Hu, Harry H. Roberts, Duofu Chen
Summary: This study analyzed organic matter enclosed within seep carbonates from the Gulf of Mexico and the South China Sea to assess if sediment organic matter may be used as a proxy for methane seepage intensity. The research investigated carbon quantity, radiocarbon content, and stable carbon isotopic compositions, suggesting that seepage intensity and duration are the most important factors controlling the contribution of methane-derived carbon to the sedimentary column.
Article
Environmental Sciences
Blanca Ausin, Gina Bossert, Nicola Krake, Sarah Paradis, Negar Haghipour, Xavier Durrieu de Madron, Belen Alonso, Timothy Eglinton
Summary: This study investigates the origin and fate of organic matter in marine sediments in the Western Mediterranean Sea and adjacent Atlantic Ocean sector. The results reveal a southwest to northeast gradient in geographical and sedimentological features. Changes in primary productivity, river discharge, and canyons are identified as factors influencing the spatial distribution of organic carbon. Additionally, the study suggests the influence of lateral transport of allochthonous organic carbon and selective degradation of labile organic matter, as well as the protection of organic matter through association with mineral surfaces.
GLOBAL BIOGEOCHEMICAL CYCLES
(2023)
Article
Environmental Sciences
Lukasz Pawlik, Daniel Okupny, Pawel Kron, Piotr Cybul, Renata Stachowicz-Rybka, Agata Sady-Bugajska
Summary: Environmental changes during Holocene had a significant impact on all civilizations, highlighting the importance of reconstructing these changes. Researchers need to rely on proxy data, such as geochemical components and physical properties, to analyze climate and environmental conditions in the past. The study from southern Poland revealed different phases of organic material accumulation and sediment characteristics, reflecting the environmental evolution during the Holocene.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Anthropology
Rachel L. Lupien, James M. Russell, Avinash Subramanian, Rahab Kinyanjui, Emily J. Beverly, Kevin T. Uno, Peter de Menocal, Rene Dommain, Richard Potts
Summary: Assessing the importance of eastern African environmental variability on human evolution is crucial, however, records in this region are lacking. Over the past 1 million years, significant anatomical and cultural developments in Homo occurred alongside major global climatic changes. Results support the 'variability selection hypothesis' that increased environmental variability selected for adaptable traits, behaviors, and technology in our hominin ancestors.
JOURNAL OF HUMAN EVOLUTION
(2021)
Article
Chemistry, Multidisciplinary
Xue Chen, Xiao Jin, Xinjian Zhu, Ningning Zhong, Zhihuan Zhang
Summary: The organic-rich sediments of the Carboniferous in the Shibei Sag, Junggar Basin, China are potential source rocks for oil and gas exploration. The results show that these source rocks have good hydrocarbon generation potential and mainly produce natural gas. Various geochemical methods reveal that the organic matter in these rocks primarily comes from higher plants, such as coniferous trees, and they were likely deposited in a transitional environment under lacustrine-fluvial conditions.
ACS EARTH AND SPACE CHEMISTRY
(2023)
Article
Geochemistry & Geophysics
Caroline R. Soderman, Oliver Shorttle, Simon Matthews, Helen M. Williams
Summary: The geochemistry of global mantle melts shows lithological and temperature heterogeneities from both upper and lower mantle. Non-traditional stable isotopes are suggested as new tools for understanding mantle heterogeneity. Some stable isotope systems can be used as tracers of mantle temperature and lithological heterogeneity, but are not predicted to be sensitive to mantle potential temperature variations with current analytical precision.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2022)
Article
Geosciences, Multidisciplinary
Paula Fernanda Chaves Soares, Rafael Cipriano da Silva, Eduardo Carvalho da Silva Neto, Marcos Gervasio Pereira, Carlos Roberto Pinheiro Junior, Luiz Carlos Ruiz Pessenda, Lucia Helena Cunha dos Anjos
Summary: This study evaluated the properties of Histosols in wetlands using isotopic and radiocarbon dating methods, revealing a mixture of algae and terrestrial organic matter deposited over the last 4000 years. The soils were formed by a combination of geogenic and pedogenic processes, indicating vertical accretion in lake environments.
Article
Environmental Sciences
Britta M. Voss, Timothy Eglinton, Bernhard Peucker-Ehrenbrink, Valier Galy, Susan Q. Lang, Cameron McIntyre, Robert G. M. Spencer, Ekaterina Bulygina, Zhaohui Aleck Wang, Katherine A. Guay
Summary: The sources of carbon in the Fraser River system vary spatially and temporally. Tributaries in the northern interior consistently contribute higher concentrations of dissolved organic carbon (DOC) to the main stem. The radiocarbon age of DOC exported from the Fraser River does not change significantly across seasons, indicating that there is modulation of heterogeneous chemical and isotopic signals during transit through the river basin. Dissolved inorganic carbon (DIC) concentrations are highest in the Rocky Mountain headwater region and in tributaries with high DOC concentrations, suggesting that DOC respiration plays a significant role in DIC in this basin. Overall, the cycling of DOC and DIC is closely linked in the river network, with active processing and transformation of carbon during transport.
Article
Geography, Physical
Rachel L. Lupien, James M. Russell, Chad L. Yost, John D. Kingston, Alan L. Deino, Jon Logan, Anna Schuh, Andrew S. Cohen
Summary: This study presents a new record of basin-scale vegetation change in the late Pliocene in the Baringo Basin of Kenya, showing a shift from C-3 forests to C-4 grasslands. This transition may have been driven by changes in basin geomorphology and a larger-scale drying and expansion of C-4 vegetation in East Africa. Variations in precipitation and lake level oscillations during the late Pliocene are found to be correlated with significant changes in vegetation resources in the Baringo Basin.
PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
(2021)
Article
Multidisciplinary Sciences
Timothy Eglinton, Valier V. Galy, Jordon D. Hemingway, Xiaojuan Feng, Hongyan Bao, Thomas M. Blattmann, Angela F. Dickens, Hannah Gies, Liviu Giosan, Negar Haghipour, Pengfei Hou, Maarten Lupker, Cameron P. McIntyre, Daniel B. Montlucon, Bernhard Peucker-Ehrenbrink, Camilo Ponton, Enno Schefuss, Melissa S. Schwab, Britta M. Voss, Lukas Wacker, Ying Wu, Meixun Zhao
Summary: Terrestrial vegetation and soils hold significantly more carbon than the atmosphere. Human activities impacting these reserves may exacerbate climate change uncertainties, particularly in extrapolating point-source observations to ecosystem-scale budgets. The turnover of organic carbon in river basins is influenced by mean annual temperature and precipitation, with implications for soil organic carbon vulnerability on a global scale. The scaling of riverine biospheric-carbon ages with soil OC turnover reveals the potential for constraints on carbon dynamics across broad spatial scales.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Environmental Sciences
Dong-Young Lee, Jung Hyun Kwak, Tae Hee Park, Hee Yoon Kang, Dongyoung Kim, Sungmin Hwang, Hyun Je Park
Summary: The geomorphology of coastal lagoons plays a crucial role in the hydrological balance and biogeochemical properties. This study found that seasonal variations in suspended particulate organic matter (POM) in different lagoon systems were influenced by environmental variability driven by hydrological dynamics. The differences in environmental conditions resulted in significant variations in POM composition between the two lagoon systems.
FRONTIERS IN MARINE SCIENCE
(2022)
Article
Ecology
Franziska Slotta, Lukas Wacker, Frank Riedel, Karl-Uwe Heussner, Kai Hartmann, Gerhard Helle
Summary: The study established securely dated time series of annual wood increment growth and intra-ring stable isotopes for a baobab tree, examining their relationship to hydroclimate variability. It was found that the growth rings of the baobab tree exhibit annual character, with unique C-14 measurements providing precise dating. The study also revealed the influence of hydroclimate fluctuations on radial stem growth and the geochemistry of wood cellulose.
Article
Geosciences, Multidisciplinary
S. Wetterich, H. Meyer, M. Fritz, G. Mollenhauer, J. Rethemeyer, A. Kizyakov, L. Schirrmeister, T. Opel
Summary: Stable isotopes of wedge ice can help reconstruct past winter climate conditions. Records from Bol'shoy Lyakhovsky Island show that the LGM and MIS 3 had colder winter climates, while the moisture sources were similar during MIS 2.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Energy & Fuels
Qian Wang, Shifeng Dai, David French, Baruch Spiro, Ian Graham, Jingjing Liu
Summary: The thermal effects of a quartz intrusion during the Yanshanian Orogeny on coal mines in the Daqingshan Coalfield in Inner Mongolia have caused changes in coal quality and chemical characteristics. As the distance from the intrusion decreases, there is an increase in vitrinite reflectance values and a decrease in volatile matter content in the coal mines. The organic carbon isotopes in the coals also vary with the distance from the intrusion.
INTERNATIONAL JOURNAL OF COAL GEOLOGY
(2023)
Article
Geochemistry & Geophysics
Amber K. Hardison, Christopher K. Algar, Anne E. Giblin, Jeremy J. Rich
GEOCHIMICA ET COSMOCHIMICA ACTA
(2015)
Article
Multidisciplinary Sciences
N. D. McTigue, W. S. Gardner, K. H. Dunton, A. K. Hardison
NATURE COMMUNICATIONS
(2016)
Article
Environmental Sciences
Allan E. Jones, Ben R. Hodges, James W. McClelland, Amber K. Hardison, Kevan B. Moffett
WATER RESOURCES RESEARCH
(2017)
Article
Limnology
A. K. Hardison, I. C. Anderson, E. A. Canuel, C. R. Tobias, B. Veuger
LIMNOLOGY AND OCEANOGRAPHY
(2011)
Article
Multidisciplinary Sciences
Allan E. Jones, Amber K. Hardison, Ben R. Hodges, James W. McClelland, Kevan B. Moffett
Article
Environmental Sciences
C. J. Patrick, L. Yeager, A. R. Armitage, F. Carvallo, V. M. Congdon, K. H. Dunton, M. Fisher, A. K. Hardison, J. D. Hogan, J. Hosen, X. Hu, B. Kiel Reese, S. Kinard, J. S. Kominoski, X. Lin, Z. Liu, P. A. Montagna, S. C. Pennings, L. Walker, C. A. Weaver, M. Wetz
ESTUARIES AND COASTS
(2020)
Article
Environmental Sciences
Allan E. Jones, Amber K. Hardison, Ben R. Hodges, James W. McClelland, Kevan B. Moffett
WATER RESOURCES RESEARCH
(2020)
Article
Environmental Sciences
Xin Xu, Hengchen Wei, Grayson Barker, Kylie Holt, Spyder Julian, Tricia Light, Sierra Melton, Ana Salamanca, Kevan B. Moffett, James W. McClelland, Amber K. Hardison
Summary: This study quantified organic matter decomposition rates in surface sediment layers in two south Texas river channels, finding that oxygen consumption rates in TFZ sediments were primarily controlled by organic matter content and temperature. Additionally, sediment organic matter in TFZs was predominantly composed of algal biomass from in situ production.
ESTUARIES AND COASTS
(2021)
Article
Biodiversity Conservation
Xianbiao Lin, Kaijun Lu, Amber K. Hardison, Zhanfei Liu, Xin Xu, Dengzhou Gao, Jun Gong, Wayne S. Gardner
Summary: The developed REOX/MIMS method provides a sensitive and precise approach for quantifying (NO3-)-N-15 concentrations in small water volumes. It was rapid, accurate, and cost-effective, making it a valuable tool for studying N transformation rates in isotope-enrichment experiments in various ecosystems.
ECOLOGICAL INDICATORS
(2021)
Article
Multidisciplinary Sciences
Christopher J. Patrick, John S. Kominoski, William H. McDowell, Benjamin Branoff, David Lagomasino, Miguel Leon, Enie Hensel, Marc J. S. Hensel, Bradley A. Strickland, T. Mitchell Aide, Anna Armitage, Marconi Campos-Cerqueira, Victoria M. Congdon, Todd A. Crowl, Donna J. Devlin, Sarah Douglas, Brad E. Erisman, Rusty A. Feagin, Simon J. Geist, Nathan S. Hall, Amber K. Hardison, Michael R. Heithaus, J. Aaron Hogan, J. Derek Hogan, Sean Kinard, Jeremy J. Kiszka, Teng-Chiu Lin, Kaijun Lu, Christopher J. Madden, Paul A. Montagna, Christine S. O'Connell, C. Edward Proffitt, Brandi Kiel Reese, Joseph W. Reustle, Kelly L. Robinson, Scott A. Rush, Rolando O. Santos, Astrid Schnetzer, Delbert L. Smee, Rachel S. Smith, Gregory Starr, Beth A. Stauffer, Lily M. Walker, Carolyn A. Weaver, Michael S. Wetz, Elizabeth R. Whitman, Sara S. Wilson, Jianhong Xue, Xiaoming Zou
Summary: This study analyzed ecosystem time series data in the Northern Hemisphere to understand the patterns of resistance and resilience in coastal ecosystems subjected to tropical cyclones. The results suggest that there is a trade-off between resistance and resilience, which may be a result of evolutionary adaptation. These findings are important for predicting the impact of climate change on coastal ecosystems.
Article
Environmental Sciences
Hengchen Wei, Xin Xu, Allan E. Jones, Amber K. Hardison, Kevan B. Moffett, James W. McClelland
Summary: This study sheds light on the role of tidal freshwater zones (TFZs) in modifying the timing and forms of nitrogen (N) inputs to estuaries. The research found that median concentrations of dissolved inorganic N (DIN) were lower in TFZs compared to upstream non-tidal river reaches, and exhibited spatial gradients. The forms of N also changed within TFZs, with DIN transforming into organic N. Comparisons of discharge and N flux in the Aransas River TFZ showed that tidal patterns influenced the timing of N export, with export exceeding input in winter and being relatively balanced in summer.
ESTUARIES AND COASTS
(2022)
Article
Oceanography
Amber K. Hardison, Nathan D. McTigue, Wayne S. Gardner, Kenneth H. Dunton
DEEP-SEA RESEARCH PART II-TOPICAL STUDIES IN OCEANOGRAPHY
(2017)
Article
Ecology
A. K. Hardison, E. A. Canuel, I. C. Anderson, C. R. Tobias, B. Veuger, M. N. Waters
Article
Environmental Sciences
Nicolas E. Reyna, Amber K. Hardison, Zhanfei Liu
FRONTIERS IN MARINE SCIENCE
(2017)