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.

New lead isotope data on Cretaceous volcanic rocks of Mongolia: the sources and the origin of the magmatic melts

2021 ◽  
Author(s):  
Maksim Kuznetsov ◽  
Valery Savatenkov ◽  
Shpakovich Lidia ◽  
Kozlovskiy Alexander ◽  
Kudryashova Ekaterina
Keyword(s):  
Late Cretaceous ◽  
Lithospheric Mantle ◽  
Lead Isotope ◽  
Isotope Composition ◽  
Volcanic Rocks ◽  
Volcanic Area ◽  
Sr Isotope ◽  
Pb Isotope ◽  
Eastern Mongolia

<p>The Eastern Mongolia Volcanic Area (EMVA) and the Gobi-Altai Volcanic Area (GAVA) are large parts of the Late Mesozoic volcanic-plutonic belt which is located in northeast Asia. The main value of the EMVA and the GAVA was formed during the Cretaceous. Previous research devoted to Cretaceous volcanic rocks of both volcanic areas has focused mainly on its geochemical features of main and trace components, and Nd – Sr isotope composition (Bars et al., 2018; Dash et al., 2015; Sheldrick et al., 2018; Sheldrick et al., 2020). At the same time, the published data on the Pb isotope composition of volcanic rocks of the EMVA and the GAVA is too scarce (Sheldrick et al., 2018; Sheldrick et al., 2020). However, the Pb isotope characteristic can be a key to the understanding of parent melts sources of the EMVA and the GAVA rocks.  Therefore, the goal of the presented work is a more extensive study of the Pb isotope systematics of the Cretaceous volcanic complexes within the EMVA and the GAVA.</p><p>Obtained data on Pb isotope characteristics of the EMVA volcanic rocks demonstrate the role of the upper crust terrigenous component (UCC) in magma generation. The role of the UCC in the EMVA formation is consistent with the Nd – Sr isotope composition and elevated LILE contents in rock samples. In contrast to the EMVA the Pb isotope features of the same aged GAVA rocks (135 – 120 Ma) with the enriched Nd – Sr composition point to the role of the lower crust component in their formation. Thus, there is a difference between the sources of the coeval rocks of two volcanic areas reflecting the difference in the melts source composition between the two areas.</p><p>The Late Cretaceous rocks of the GAVA (about 90 Ma), as well as the Early Cretaceous rocks of the EMVA, lie nearby a field of lithospheric mantle xenoliths on the Pb isotope ratios diagram. In turn, the obtained Pb isotope data on the lherzolite xenoliths as well as that on paleooceanic complexes of Mongolia reveal the obvious difference of Pb isotope composition of the lithospheric mantle of the region from that of the Paleo-Asian ocean mantle. The observed difference can be explained by the metasomatic alteration of the suboceanic mantle during accretion and subduction processes before the EMVA and the GAVA formation. Thus, the conclusion about the key role of the metasomatized lithospheric mantle in the GAVA Late Cretaceous rocks formation can be made.</p><p>The study was supported by the RFBR (20-05-00401).</p><p>KEYWORDS: Eastern Mongolia, Gobi-Altai, Cretaceous volcanic rocks, lead isotope composition.</p>

Seasonal trends in the stable isotopic composition of snow and meltwater runoff in a subarctic catchment at Okstindan, Norway

2004 ◽  
Vol 35 (2) ◽  
pp. 119-137 ◽  
Author(s):  
S.D. Gurney ◽  
D.S.L. Lawrence
Keyword(s):  
Isotopic Composition ◽  
Mean Value ◽  
Mean Values ◽  
Stable Isotopic Composition ◽  
Meltwater Runoff ◽  
Stable Isotopic ◽  
The Mean ◽  
The Difference ◽  
Δ18o And Δd

Seasonal variations in the stable isotopic composition of snow and meltwater were investigated in a sub-arctic, mountainous, but non-glacial, catchment at Okstindan in northern Norway based on analyses of δ18O and δD. Samples were collected during four field periods (August 1998; April 1999; June 1999 and August 1999) at three sites lying on an altitudinal transect (740–970 m a.s.l.). Snowpack data display an increase in the mean values of δ18O (increasing from a mean value of −13.51 to −11.49‰ between April and August), as well as a decrease in variability through the melt period. Comparison with a regional meteoric water line indicates that the slope of the δ18O–δD line for the snowpacks decreases over the same period, dropping from 7.49 to approximately 6.2.This change points to the role of evaporation in snowpack ablation and is confirmed by the vertical profile of deuterium excess. Snowpack seepage data, although limited, also suggest reduced values of δD, as might be associated with local evaporation during meltwater generation. In general, meltwaters were depleted in δ18O relative to the source snowpack at the peak of the melt (June), but later in the year (August) the difference between the two was not statistically significant. The diurnal pattern of isotopic composition indicates that the most depleted meltwaters coincide with the peak in temperature and, hence, meltwater production.

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

scholarly journals Assessing Snow Phenology and Its Environmental Driving Factors in Northeast China

2022 ◽  
Vol 14 (2) ◽  
pp. 262
Author(s):  
Hui Guo ◽  
Xiaoyan Wang ◽  
Zecheng Guo ◽  
Siyong Chen
Keyword(s):  
Snow Cover ◽  
Northeast China ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Water Cycle ◽  
Water Source ◽  
Driving Factors ◽  
Change Rate ◽  
Mean Temperature ◽  
Forested Areas

Snow cover is an important water source and even an Essential Climate Variable (ECV) as defined by the World Meteorological Organization (WMO). Assessing snow phenology and its driving factors in Northeast China will help with comprehensively understanding the role of snow cover in regional water cycle and climate change. This study presents spatiotemporal variations in snow phenology and the relative importance of potential drivers, including climate, geography, and the normalized difference vegetation index (NDVI), based on the MODIS snow products across Northeast China from 2001 to 2018. The results indicated that the snow cover days (SCD), snow cover onset dates (SCOD) and snow cover end dates (SCED) all showed obvious latitudinal distribution characteristics. As the latitude gradually increases, SCD becomes longer, SCOD advances and SCED delays. Overall, there is a growing tendency in SCD and a delayed trend in SCED across time. The variations in snow phenology were driven by mean temperature, followed by latitude, while precipitation, aspect and slope all had little effect on the SCD, SCOD and SCED. With decreasing temperature, the SCD and SCED showed upward trends. The mean temperature has negatively correlation with SCD and SCED and positively correlation with SCOD. With increasing latitude, the change rate of the SCD, SCOD and SCED in the whole Northeast China were 10.20 d/degree, −3.82 d/degree and 5.41 d/degree, respectively, and the change rate of snow phenology in forested areas was lower than that in nonforested areas. At the same latitude, the snow phenology for different underlying surfaces varied greatly. The correlations between the snow phenology and NDVI were mainly positive, but weak correlations accounted for a large proportion.

scholarly journals Occurrence and Removal Characteristics of Phthalate Esters from Typical Water Sources in Northeast China

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Yu Liu ◽  
Zhonglin Chen ◽  
Jimin Shen
Keyword(s):  
Drinking Water ◽  
Northeast China ◽  
Phthalate Esters ◽  
Drinking Water Treatment ◽  
Water Source ◽  
Mean Value ◽  
Source Control ◽  
Water Ingestion ◽  
Treatment Processes ◽  
Harbin City

The presence of phthalate esters (PAEs) in the environment has gained a considerable attention due to their potential impacts on public health. This study reports the first data on the occurrence of 15 PAEs in the water near the Mopanshan Reservoir—the new and important water source of Harbin city in Northeast China. As drinking water is a major source for human exposure to PAEs, the fate of target PAEs in the two waterworks (Mopanshan Waterworks and Seven Waterworks) was also analyzed. The results demonstrated that the total concentrations of 15 PAEs in the water near the Mopanshan Reservoir were relatively moderate, ranging from 355.8 to 9226.5 ng/L, with the mean value of 2943.1 ng/L. DBP and DEHP dominated the PAE concentrations, which ranged from 52.5 to 4498.2 ng/L and 128.9 to 6570.9 ng/L, respectively. The occurrence and concentrations of these compounds were heavily spatially dependent. Meanwhile, the results on the waterworks samples suggested no significant differences in PAE levels with the input of the raw waters. Without effective and stable removal of PAEs after the conventional drinking water treatment in the waterworks (25.8% to 76.5%), the risks posed by PAEs through drinking water ingestion were still existing, which should be paid special attention to the source control in the Mopanshan Reservoir and some advanced treatment processes for drinking water supplies.

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