Large Mg Fe isotope fractionation in volcanic rocks from Northeast China: The role of chemical weathering and magma compositional effect

2021 ◽  
pp. 120075
Author(s):  
Haiquan Wei ◽  
Heng-Ci Tian ◽  
Shu-Guang Li ◽  
Wei Yang ◽  
Bing-Yu Gao ◽  
...  
Keyword(s):  
Northeast China ◽  
Chemical Weathering ◽  
Isotope Fractionation ◽  
Volcanic Rocks ◽  
Compositional Effect

scholarly journals Water-source contributions to barrier lakes and water-rock interactions in the Wudalianchi volcanic area, Northeast China

2021 ◽  
Author(s):  
Junyu Zou ◽  
Zefeng Song ◽  
Duan Yamin
Keyword(s):  
Northeast China ◽  
Volcanic Rocks ◽  
Water Source ◽  
Volcanic Area ◽  
Mineral Springs ◽  
Source Contributions ◽  
Δ18o And Δd ◽  
Isotopic Mixing ◽  
Fractionation Equation

Abstract Wudalianchi is a typical continental Cenozoic volcanic group rich in potassic volcanic rocks (Northeast China). Five hydrologically connected barrier lakes (Lakes 5 to 1) and upwelling cold mineral springs occur, forming a complex lake-groundwater system. Clarifying the water-source contributions and the role of water-rock interactions in the hydrological cycling for barrier lakes remains a challenge from scientific and engineering perspectives. In this study, seasonal variations of multiple isotopes were analyzed. δ18O and δD data indicate that the Wudalianchi lakes were mainly fed by mineral springs. The values, however, were greatly influenced by precipitation (rain and snow) and varying evaporation intensities. In contrast, 87Sr/86Sr ratios varied little between seasons (0.70701–0.7079), suggesting similar water-rock interactions through time. Nonetheless, Sr isotopic mixing models suggested that shallow mineral springs generally contributed >50% of the water to lower reaches. In contrast, the upstream wetland contributed >50% to Lake 5 and decreased down-valley (10.3–53.6%). Calculations based on the δ18O and δD Rayleigh fractionation equation suggest that evaporation in upper reaches were higher than the lower reaches. The evaporation in July were generally higher than in October. This study demonstrates the homogenous water-rock interactions and the associated water mixing effects on the terrestrial volcanic area.

scholarly journals More than redox, biological organic ligands control iron isotope fractionation in the riparian wetland

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Elaheh Lotfi-Kalahroodi ◽  
Anne-Catherine Pierson-Wickmann ◽  
Olivier Rouxel ◽  
Rémi Marsac ◽  
Martine Bouhnik-Le Coz ◽  
...  
Keyword(s):  
Redox Reactions ◽  
Isotope Fractionation ◽  
Isotopic Fractionation ◽  
Isotopic Signature ◽  
Organic Ligands ◽  
Riparian Wetland ◽  
Fe Isotopes ◽  
Preferential Binding ◽  
Isotope Systematics

AbstractAlthough redox reactions are recognized to fractionate iron (Fe) isotopes, the dominant mechanisms controlling the Fe isotope fractionation and notably the role of organic matter (OM) are still debated. Here, we demonstrate how binding to organic ligands governs Fe isotope fractionation beyond that arising from redox reactions. The reductive biodissolution of soil Fe(III) enriched the solution in light Fe isotopes, whereas, with the extended reduction, the preferential binding of heavy Fe isotopes to large biological organic ligands enriched the solution in heavy Fe isotopes. Under oxic conditions, the aggregation/sedimentation of Fe(III) nano-oxides with OM resulted in an initial enrichment of the solution in light Fe isotopes. However, heavy Fe isotopes progressively dominate the solution composition in response to their binding with large biologically-derived organic ligands. Confronted with field data, these results demonstrate that Fe isotope systematics in wetlands are controlled by the OM flux, masking Fe isotope fractionation arising from redox reactions. This work sheds light on an overseen aspect of Fe isotopic fractionation and calls for a reevaluation of the parameters controlling the Fe isotopes fractionation to clarify the interpretation of the Fe isotopic signature.

Role of male genetic factors in recurrent pregnancy loss in Northeast China

2018 ◽  
Vol 224 ◽  
pp. 6-11 ◽  
Author(s):  
Rulin Dai ◽  
Yuan Pan ◽  
Yan Fu ◽  
Qian Liu ◽  
Weifeng Han ◽  
...  
Keyword(s):  
Northeast China ◽  
Pregnancy Loss ◽  
Genetic Factors ◽  
Recurrent Pregnancy Loss

Prediction of Structural Fractures in Olituoz Volcanic Rocks, Liaohe Field, Northeast China

2011 ◽  
Vol 37 ◽  
Author(s):  
Fangfeng Xiao ◽  
Guiting Hou ◽  
Zhongyi Ding ◽  
Yadong Zheng ◽  
Xianglin Qian
Keyword(s):  
Northeast China ◽  
Volcanic Rocks

scholarly journals Quantifying molecular oxygen isotope variations during a Heinrich stadial

2015 ◽  
Vol 11 (11) ◽  
pp. 1527-1551 ◽  
Author(s):  
C. Reutenauer ◽  
A. Landais ◽  
T. Blunier ◽  
C. Bréant ◽  
M. Kageyama ◽  
...  
Keyword(s):  
Isotope Fractionation ◽  
Water Cycle ◽  
Atmospheric Oxygen ◽  
Dominant Role ◽  
Climatic Conditions ◽  
Fractionation Factor ◽  
Last Glacial Period ◽  
Main Driver ◽  
The Last Glacial

Abstract. δ18O of atmospheric oxygen (δ18Oatm) undergoes millennial-scale variations during the last glacial period, and systematically increases during Heinrich stadials (HSs). Changes in δ18Oatm combine variations in biospheric and water cycle processes. The identification of the main driver of the millennial variability in δ18Oatm is thus not straightforward. Here, we quantify the response of δ18Oatm to such millennial events using a freshwater hosing simulation performed under glacial boundary conditions. Our global approach takes into account the latest estimates of isotope fractionation factor for respiratory and photosynthetic processes and make use of atmospheric water isotope and vegetation changes. Our modeling approach allows to reproduce the main observed features of a HS in terms of climatic conditions, vegetation distribution and δ18O of precipitation. We use it to decipher the relative importance of the different processes behind the observed changes in δ18Oatm. The results highlight the dominant role of hydrology on δ18Oatm and confirm that δ18Oatm can be seen as a global integrator of hydrological changes over vegetated areas.

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